[Phosphorus availability in cropland soils of China and related affecting factors].
Wang, Yong-Zhuang; Chen, Xin; Shi, Yi
2013-01-01
Soil phosphorus (P) availability directly determines cropland productivity. Based on the long-term fertilization experiments in different climatic zones of China, this paper summarized the P content, its availability, and the factors affecting the P transformation in China cropland soils. The total and available P contents in different types of China cropland soils were 0.31-1.72 g x kg(-1) and 0.1-228.8 mg x kg(-1), respectively. Soil parent material, soil physical and chemical prosperities, and fertilization practices were the main factors affecting the soil P availability. It was suggested that more attentions should be paid on the mixed application of organic manure and chemical fertilizers to improve the P availability of cropland soils and on the potential environmental impacts of this fertilization.
Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei
2016-04-15
To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability.
Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei
2016-01-01
To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability. PMID:27079657
Murrell, Ebony G; Cullen, Eileen M
2014-10-01
Few studies compare how different soil fertilization practices affect plant mineral content and insect performance in organic systems. This study examined: 1) The European corn borer, Ostrinia nubilalis (Hübner), larval response on corn (Zea mays L.) grown in field soils with different soil management histories; and 2) resilience of these plants to O. nubilalis herbivory. Treatments included: 1) standard organic--organically managed soil fertilized with dairy manure and 2 yr of alfalfa (Medicago sativa L.) in the rotation; 2) basic cation saturation ratio--organically managed soil fertilized with dairy manure and alfalfa nitrogen credits, plus addition of gypsum (CaSO4·2H2O) according to the soil balance hypothesis; and 3) conventional--conventionally managed soil fertilized with synthetic fertilizers. Corn plants were reared to maturity in a greenhouse, and then infested with 0-40 O. nubilalis larvae for 17 d. O. nubilalis exhibited negative competitive response to increasing larval densities. Mean development time was significantly faster for larvae consuming basic cation saturation ratio plants than those on standard organic plants, with intermediate development time on conventional plants. Neither total yield (number of kernels) nor proportion kernels damaged differed among soil fertility treatments. Soil nutrients differed significantly in S and in Ca:Mg and Ca:K ratios, but principal components analysis of plant tissue samples taken before O. nubilalis infestation showed that S, Fe, and Cu contributed most to differences in plant nutrient profiles among soil fertility treatments. Results demonstrate that different fertilization regimens can significantly affect insect performance within the context of organic systems, but the effects in this study were relatively minor compared with effects of intraspecific competition.
Strecker, Tanja; Barnard, Romain L.; Niklaus, Pascal A.; Scherer-Lorenzen, Michael; Weigelt, Alexandra; Scheu, Stefan; Eisenhauer, Nico
2015-01-01
Background Loss of biodiversity and increased nutrient inputs are two of the most crucial anthropogenic factors driving ecosystem change. Although both received considerable attention in previous studies, information on their interactive effects on ecosystem functioning is scarce. In particular, little is known on how soil biota and their functions are affected by combined changes in plant diversity and fertilization. Methodology/Principal Findings We investigated the effects of plant diversity, functional community composition, and fertilization on the biomass and respiration of soil microbial communities in a long-term biodiversity experiment in semi-natural grassland (Jena Experiment). Plant species richness enhanced microbial basal respiration and microbial biomass, but did not significantly affect microbial specific respiration. In contrast, the presence of legumes and fertilization significantly decreased microbial specific respiration, without altering microbial biomass. The effect of legumes was superimposed by fertilization as indicated by a significant interaction between the presence of legumes and fertilization. Further, changes in microbial stoichiometry (C-to-N ratio) and specific respiration suggest the presence of legumes to reduce N limitation of soil microorganisms and to modify microbial C use efficiency. Conclusions/Significance Our study highlights the role of plant species and functional group diversity as well as interactions between plant community composition and fertilizer application for soil microbial functions. Our results suggest soil microbial stoichiometry to be a powerful indicator of microbial functioning under N limited conditions. Although our results support the notion that plant diversity and fertilizer application independently affect microbial functioning, legume effects on microbial N limitation were superimposed by fertilization, indicating significant interactions between the functional composition of plant communities and nutrient inputs for soil processes. PMID:25938580
Soil management shapes ecosystem service provision and trade-offs in agricultural landscapes.
Tamburini, Giovanni; De Simone, Serena; Sigura, Maurizia; Boscutti, Francesco; Marini, Lorenzo
2016-08-31
Agroecosystems are principally managed to maximize food provisioning even if they receive a large array of supporting and regulating ecosystem services (ESs). Hence, comprehensive studies investigating the effects of local management and landscape composition on the provision of and trade-offs between multiple ESs are urgently needed. We explored the effects of conservation tillage, nitrogen fertilization and landscape composition on six ESs (crop production, disease control, soil fertility, water quality regulation, weed and pest control) in winter cereals. Conservation tillage enhanced soil fertility and pest control, decreased water quality regulation and weed control, without affecting crop production and disease control. Fertilization only influenced crop production by increasing grain yield. Landscape intensification reduced the provision of disease and pest control. We also found tillage and landscape composition to interactively affect water quality regulation and weed control. Under N fertilization, conventional tillage resulted in more trade-offs between ESs than conservation tillage. Our results demonstrate that soil management and landscape composition affect the provision of several ESs and that soil management potentially shapes the trade-offs between them. © 2016 The Author(s).
Zhang, Yu-Lan; Sun, Cai-Xia; Chen, Zhen-Hua; Li, Dong-Po; Liu, Xing-Bin; Chen, Li-Jun; Wu, Zhi-Jie; Du, Jian-Xiong
2010-05-01
The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year's fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree. After 26 years' fertilization, the infrared spectrum shapes with different treatments are similar, but the characteristic peak intensity is obviously different, which reflects the effects of different fertilization treatments on the structure and amounts of soil humus or functional groups. Compared with no fertilization, little molecule saccharides decreased and aryl-groups increased under application of inorganic fertilizer or combined application of organic and chemical fertilizer. The effect was greater in Treatment NPK and M+NPK than in Treatment M1 N and M2 N. Organic and NPK fertilizer increased the development of soil and increased soil quality to a certain extent. Results showed that organic fertilization increased aromatization degree of soil humus and humus fractions distinctly. The authors could estimate soil humus evolvement of different fertilization with infrared spectroscopy.
Effects of Long-term Fertilization on Potassium Fixation Capacity in Brown Soil
NASA Astrophysics Data System (ADS)
Li, Na; Guo, Chunlei; Wang, Yue; Gao, Tianyi; Yang, Jinfeng; Han, Xiaori
2018-01-01
This study concentrated on the research of features of fixation. The objective of this study was to provide theoretical foundation of rational application of potassium fertilizer along with improving fertilizer availability ratio. A 32 years long-term experiment was conducted to evaluate the effects of fertilizer application on potassium changes and the factors affecting K fixation on brown soil by simulation in laboratory. When the concentration of exogenous potassium was in range of 400∼4000 mg·kg-1, potassium fixation capacity increased along with the rise of concentration of exogenous potassium, whereas K fixation rate reduced; Compared with no-potassium fertilizer, application of potassium fertilizer and organic fertilizer reduced soil potassium fixation capacity. Potassium rate and fixation-release of potassium character in soil should be taken into comprehensive consideration for rational fertilization to maintain or improve soil fertility for increasing potassium fertilizers efficiency in agriculture.
[Influences of biochar and nitrogen fertilizer on soil nematode assemblage of upland red soil].
Lu, Yan-yan; Wang, Ming-wei; Chen, Xiao-vun; Liu, Man-qiang; Chen, Xiao-min; Cheng, Yan-hong; Huang, Qian-ru; Hu, Feng
2016-01-01
The use of biochar as soil remediation amendment has received more and more concerns, but little attention has been paid to its effect on soil fauna. Based on the field experiment in an upland red soil, we studied the influences of different application rates of biochar (0, 10, 20, 30, 40 t · hm⁻²) and nitrogen fertilizer (60, 90, 120 kg N · hm⁻²) on soil basic properties and nematode assemblages during drought and wet periods. Our results showed that the biochar amendment significantly affect soil moisture and pH regardless of drought or wet period. With the increasing of biochar application, soil pH significantly increased, while soil moisture increased first and then decreased. Soil microbial properties (microbial biomass C, microbial biomass N, microbial biomass C/N, basal respiration) were also significantly affected by the application of biochar and N fertilizer. Low doses of biochar could stimulate the microbial activity, while high doses depressed microbial activity. For example, averaged across different N application rates, biochar amendment at less than 30 t · hm⁻² could increase microbial activity in the drought and wet periods. Besides, the effects of biochar also depended on wet or drought period. When the biochar application rate higher than 30 t · hm⁻², the microbial biomass C was significantly higher in the drought period than the control, but no differences were observed in the wet period. On the contrary, microbial biomass N showed a reverse pattern. Dissolved organic matter and mineral N were affected by biochar and N fertilizer significantly in the drought period, however, in the wet period they were only affected by N fertilizer rather than biochar. There was significant interaction between biochar and N fertilizer on soil nematode abundance and nematode trophic composition independent of sampling period. Combined high doses of both biochar and N fertilization promoted soil nematode abundance. Moreover, the biochar amendment increased the proportion of fungivores especially in the drought period, suggesting the biochar was the preferred fungal energy channel in comparison to soil without biochar addition. In summary, complex patterns occurred not only due to the application rate of biochar as well as their interactions with N fertilization but also due to the drought and wet periods. It is, therefore, necessary to consider different ecological factors when evaluating the effects of biochar in future.
Feiziene, Dalia; Feiza, Virginijus; Slepetiene, Alvyra; Liaudanskiene, Inga; Kadziene, Grazina; Deveikyte, Irena; Vaideliene, Asta
2011-01-01
The importance of agricultural practices to greenhouse gas mitigation is examined worldwide. However, there is no consensus on soil organic carbon (SOC) content and CO emissions as affected by soil management practices and their relationships with soil texture. No-till (NT) agriculture often results in soil C gain, though, not always. Soil net CO exchange rate (NCER) and environmental factors (SOC, soil temperature [T], and water content [W]), as affected by soil type (loam and sandy loam), tillage (conventional, reduced, and NT), and fertilization, were quantified in long-term field experiments in Lithuania. Soil tillage and fertilization affected total CO flux (heterotrophic and autotrophic) through effect on soil SOC sequestration, water, and temperature regime. After 11 yr of different tillage and fertilization management, SOC content was 23% more in loam than in sandy loam. Long-term NT contributed to 7 to 27% more SOC sequestration on loam and to 29 to 33% more on sandy loam compared with reduced tillage (RT) or conventional tillage (CT). Soil water content in loam was 7% more than in sandy loam. Soil gravimetric water content, averaged across measurement dates and fertilization treatments, was significantly less in NT than CT and RT in both soils. Soil organic carbon content and water storage capacity of the loam and sandy loam soils exerted different influences on NCER. The NCER from the sandy loam soil was 13% greater than that from the loam. In addition, NCER was 4 to 9% less with NT than with CT and RT systems on both loam and sandy loam soils. Application of mineral NPK fertilizers promoted significantly greater NCER from loam but suppressed NCER by 15% from sandy loam. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Lekfeldt, Jonas Duus Stevens; Kjaergaard, Charlotte; Magid, Jakob
2017-07-01
Organic waste fertilizers have previously been observed to significantly affect soil organic carbon (SOC) content and soil structure. However, the effect of organic waste fertilizers on colloid dispersibility and leaching of colloids from topsoil has not yet been studied extensively. We investigated how the repeated application of different types of agricultural (liquid cattle slurry and solid cattle manure) and urban waste fertilizers (sewage sludge and composted organic household waste) affected soil physical properties, colloid dispersion from aggregates, tracer transport, and colloid leaching from intact soil cores. Total porosity was positively correlated with SOC content. Yearly applications of sewage sludge increased absolute microporosity (pores <30 μm) and decreased relative macroporosity (pores >30 μm) compared with the unfertilized control, whereas organic household waste compost fertilization increased both total porosity and the absolute porosity in all pore size classes (though not significant for 100-600 μm). Treatments receiving large amounts of organic fertilizers exhibited significantly lower levels of dispersible colloids compared with an unfertilized control and a treatment that had received moderate applications of cattle slurry. The content of water-dispersible colloids could not be explained by a single factor, but differences in SOC content, electrical conductivity, and sodium adsorption ratio were important factors. Moreover, we found that the fertilizer treatments did not significantly affect the solute transport properties of the topsoil. Finally, we found that the leaching of soil colloids was significantly decreased in treatments that had received large amounts of organic waste fertilizers, and we ascribe this primarily to treatment-induced differences in effluent electrical conductivity during leaching. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
NASA Astrophysics Data System (ADS)
Hobley, E.; Honermeier, B.; Don, A.; Gocke, M. I.; Amelung, W.; Kogel-Knabner, I.
2016-12-01
We investigated the effects of pre-crops with and without biological nitrogen fixation capacity (fava beans, clover mulch, fodder maize) and fertilization (no fertilizer, NPK fertilizer, PK fertilizer) on soil physico-chemical properties (bulk density, electrical conductivity, soil organic carbon (SOC) concentration and stocks, N concentration and stocks) and their depth distribution (down to 1 m) at a long-term field experiment set up in 1982 in Gießen, Germany. Fertilization had significant but small impacts on the soil chemical environment, most particularly the salt content of the soil, with PK fertilization increasing electrical conductivity throughout the soil profile. Similarly, fertilization resulted in a small reduction of soil pH throughout the entire soil profile. The soil was physically and chemically affected by the type of pre-crop. Plots with fava beans and maize had lower bulk densities in the subsoil than those with clover. Pre-crop type also significantly affected the depth distribution of both N and SOC. Specifically, clover pre-cropping led to an enrichment of N at the surface compared with fava beans and maize. SOC enrichment at the surface was also observed under clover, with the effect most pronounced under PK fertilization. Combined with the bulk density effects, this shift in N distribution resulted in significantly higher N stocks under clover than under fava beans. However, the total stocks of SOC were not affected by pre-crop or fertilizer regime. Our results indicate that humans influence C and N cycling and distribution in soils through the selection of pre-crops and that the influence of crop type is greater than that of fertilization regimes. Pre-cropping with clover, which is used as a mulch, leads to N enrichment in the topsoil, reducing the need for N fertilizer for the subsequent cereal crop. In contrast, the use of fava beans as a pre-crop does not lead to N enrichment. We believe this is due to the greater rooting depth of fava beans compared with clover, resulting in lower bulk density in the subsoil and associated lower stocks. Additionally, the harvest of fava beans removes N-rich biomass from the soil, lowering N-input. Lastly, the uptake of water at depth may facilitate subsoil N uptake, so that fava bean N is utilized by the cereal crop but does not lead to its enrichment in the subsoil.
Su, Jian-Qiang; Ding, Long-Jun; Xue, Kai; Yao, Huai-Ying; Quensen, John; Bai, Shi-Jie; Wei, Wen-Xue; Wu, Jin-Shui; Zhou, Jizhong; Tiedje, James M; Zhu, Yong-Guan
2015-01-01
The influence of long-term chemical fertilization on soil microbial communities has been one of the frontier topics of agricultural and environmental sciences and is critical for linking soil microbial flora with soil functions. In this study, 16S rRNA gene pyrosequencing and a functional gene array, geochip 4.0, were used to investigate the shifts in microbial composition and functional gene structure in paddy soils with different fertilization treatments over a 22-year period. These included a control without fertilizers; chemical nitrogen fertilizer (N); N and phosphate (NP); N and potassium (NK); and N, P and K (NPK). Based on 16S rRNA gene data, both species evenness and key genera were affected by P fertilization. Functional gene array-based analysis revealed that long-term fertilization significantly changed the overall microbial functional structures. Chemical fertilization significantly increased the diversity and abundance of most genes involved in C, N, P and S cycling, especially for the treatments NK and NPK. Significant correlations were found among functional gene structure and abundance, related soil enzymatic activities and rice yield, suggesting that a fertilizer-induced shift in the microbial community may accelerate the nutrient turnover in soil, which in turn influenced rice growth. The effect of N fertilization on soil microbial functional genes was mitigated by the addition of P fertilizer in this P-limited paddy soil, suggesting that balanced chemical fertilization is beneficial to the soil microbial community and its functions. © 2014 John Wiley & Sons Ltd.
Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang
2016-01-01
Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0–20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization. PMID:27492771
NASA Astrophysics Data System (ADS)
Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang
2016-08-01
Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0-20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization.
Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang
2016-08-05
Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0-20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization.
NASA Astrophysics Data System (ADS)
Xiao, Jian; He, Xinhua; Hao, Jialong; Zhou, Ying; Zheng, Lirong; Ran, Wei; Shen, Qirong; Yu, Guanghui
2016-06-01
Mineral binding is a major mechanism for soil carbon (C) stabilization. However, the submicron information about the in situ mechanisms of different fertilization practices affecting organo-mineral complexes and associated C preservation remains unclear. Here, we applied nano-scale secondary ion mass spectrometry (NanoSIMS), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure spectroscopy (XAFS) to examine differentiating effects of inorganic versus organic fertilization on interactions between highly reactive minerals and soil C preservation. To examine such interactions, soils and their extracted colloids were collected during a 24-year long-term fertilization period (1990-2014) (no fertilization, control; chemical nitrogen (N), phosphorus (P), and potassium (K) fertilization, NPK; and NPK plus swine manure fertilization, NPKM). The results for different fertilization conditions showed a ranked soil organic matter concentration with NPKM > NPK > control. Meanwhile, oxalate-extracted Al (Alo), Fe (Feo), short-range ordered Al (Alxps), Fe (Fexps), and dissolved organic carbon (DOC) ranked with NPKM > control > NPK, but the ratios of DOC / Alxps and DOC / Fexps ranked with NPKM > NPK > control. Compared with the NPK treatment, the NPKM treatment enhanced the C-binding loadings of Al and Fe minerals in soil colloids at the submicron scale. Furthermore, a greater concentration of highly reactive Al and Fe minerals was presented under NPKM than under NPK. Together, these submicron-scale findings suggest that both the reactive mineral species and their associations with C are differentially affected by 24-year long-term inorganic and organic fertilization.
The influence of nitrogen fertilization on the magnitude of rhizosphere effects
NASA Astrophysics Data System (ADS)
Zhu, B.; Panke-Buisse, K.; Kao-Kniffin, J.
2012-12-01
The labile carbon released from roots to the rhizosphere enhances soil microbial activity and nutrient availability, but factors that regulate such "rhizosphere effects" are poorly understood. Nitrogen fertilization may suppress rhizosphere effects by reducing plant carbon allocation belowground. Here we investigated the impact of nitrogen fertilization (+100 mg NH4NO3-N kg soil-1) on the magnitude of rhizosphere effects of two grass species (Bermuda grass Cynodon dactylon and smooth crabgrass Digitaria ischaemum) grown in a nutrient-poor soil for 80-100 days inside a growth chamber. Rhizosphere effects were estimated by the percentage difference between the planted soil (rhizosphere soil) and the unplanted soil (bulk soil) for several assays. We found that the rhizosphere soil of both plants had higher pH (+ 0.5~0.7 units), similar microbial biomass carbon, but lower microbial biomass nitrogen (- 27~37%) compared to the bulk soil. The rate of net N mineralization and the activity of three soil enzymes that degrade chitin (NAG), protein (LAP) and lignin (peroxidase) and produce mineral nitrogen were generally enhanced by the rhizosphere effects (up to 80%). Although nitrogen fertilization significantly increased plant biomass, it generally affected microbial biomass, activity and net N mineralization rate to a similar extent between rhizosphere soil and bulk soil, and thus did not significantly impact the magnitude of rhizosphere effects. Moreover, the community structure of soil bacteria (indicated by T-RFLP) showed remarkable divergence between the planted and unplanted soils, but not between the control and fertilized soils. Collectively, these results suggest that grass roots affects soil microbial activity and community structure, but short-term nitrogen fertilization may not significantly influence these rhizosphere effects.
Ingham, Steven C; Fanslau, Melody A; Engel, Rebecca A; Breuer, Jeffry R; Breuer, Jane E; Wright, Thomas H; Reith-Rozelle, Judith K; Zhu, Jun
2005-06-01
Fresh bovine manure was mechanically incorporated into loamy sand and silty clay loam Wisconsin soils in April 2004. At varying fertilization-to-planting intervals, radish, lettuce, and carrot seeds were planted; crops were harvested 90, 100, 110 or 111, and 120 days after manure application. As an indicator of potential contamination with fecal pathogens, levels of Escherichia coli in the manure-fertilized soil and presence of E. coli on harvested vegetables were monitored. From initial levels of 4.0 to 4.2 log CFU/g, E. coli levels in both manure-fertilized soils decreased by 2.4 to 2.5 log CFU/g during the first 7 weeks. However, E. coli was consistently detected from enriched soil samples through week 17, perhaps as a result of contamination by birds and other wildlife. In the higher clay silty clay loam soil, the fertilization-to-planting interval affected the prevalence of E. coli on lettuce but not on radishes and carrots. Root crop contamination was consistent across different fertilization-to-harvest intervals in silty clay loam, including the National Organic Program minimum fertilization-to-harvest interval of 120 days. However, lettuce contamination in silty clay loam was significantly (P < 0.10) affected by fertilization-to-harvest interval. Increasing the fertilization-to-planting interval in the lower clay loamy sand soil decreased the prevalence of E. coli on root crops. The fertilization-to-harvest interval had no clear effect on vegetable contamination in loamy sand. Overall, these results do not provide grounds for reducing the National Organic Program minimum fertilization-to-harvest interval from the current 120-day standard.
Xun, Weibing; Xu, Zhihui; Li, Wei; Ren, Yi; Huang, Ting; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu
2016-09-01
Natural ecosystems comprise the planet's wild plant and animal resources, but large tracts of land have been converted to agroecosystems to support the demand for agricultural products. This conversion limits the number of plant species and decreases the soil biological diversity. Here we used high-throughput 16S rRNA gene sequencing to evaluate the responses of soil bacterial communities in long-term converted and fertilized red soils (a type of Ferralic Cambisol). We observed that soil bacterial diversity was strongly affected by different types of fertilization management. Oligotrophic bacterial taxa demonstrated large relative abundances in chemically fertilized soil, whereas copiotrophic bacterial taxa were found in large relative abundances in organically fertilized and fallow management soils. Only organic-inorganic fertilization exhibited the same local taxonomic and phylogenetic diversity as that of a natural ecosystem. However, the independent use of organic or inorganic fertilizer reduced local taxonomic and phylogenetic diversity and caused biotic homogenization. This study demonstrated that the homogenization of bacterial communities caused by natural-to-agricultural ecosystem conversion can be mitigated by employing rational organic-inorganic fertilization management.
Response of Bacteria Community to Long-Term Inorganic Nitrogen Application in Mulberry Field Soil
Hu, Xingming; Deng, Wen; Li, Yong; Han, Guangming; Xiong, Chao
2016-01-01
The bacterial community and diversity in mulberry field soils with different application ages of inorganic nitrogen fertilizer (4Y, 4-year-old; 17Y, 17-year-old; 32Y, 32-year- old) were investigated using next-generation sequencing. The results demonstrated that the application ages of nitrogen fertilizer significantly altered soil bacterial community and diversity. Soil bacterial Shannon diversity index and Chao 1 index decreased with the consecutive application of nitrogen fertilizer, and the 4Y soil exhibited the highest bacterial relative abundance and diversity. Of 45 bacterial genera (relative abundance ratio of genera greater than 0.3%), 18 were significantly affected by the plant age, and seven belong to Acidobacteria. The relative abundances of Acidobacteria Gp 1, Gp4 and Gp6 in the 4Y soil were significantly lower than that of in the 17Y and 32Y soils. However, the relative abundance of Pseudononas sp. in the 4Y soil was significantly higher than that of in the 17Y and 32Y soils. Most microbial parameters were significantly affected by soil pH and organic matter content which were significantly changed by long-term application of inorganic nitrogen fertilizer. PMID:27977728
Response of Bacteria Community to Long-Term Inorganic Nitrogen Application in Mulberry Field Soil.
Yu, Cui; Hu, Xingming; Deng, Wen; Li, Yong; Han, Guangming; Xiong, Chao
2016-01-01
The bacterial community and diversity in mulberry field soils with different application ages of inorganic nitrogen fertilizer (4Y, 4-year-old; 17Y, 17-year-old; 32Y, 32-year- old) were investigated using next-generation sequencing. The results demonstrated that the application ages of nitrogen fertilizer significantly altered soil bacterial community and diversity. Soil bacterial Shannon diversity index and Chao 1 index decreased with the consecutive application of nitrogen fertilizer, and the 4Y soil exhibited the highest bacterial relative abundance and diversity. Of 45 bacterial genera (relative abundance ratio of genera greater than 0.3%), 18 were significantly affected by the plant age, and seven belong to Acidobacteria. The relative abundances of Acidobacteria Gp 1, Gp4 and Gp6 in the 4Y soil were significantly lower than that of in the 17Y and 32Y soils. However, the relative abundance of Pseudononas sp. in the 4Y soil was significantly higher than that of in the 17Y and 32Y soils. Most microbial parameters were significantly affected by soil pH and organic matter content which were significantly changed by long-term application of inorganic nitrogen fertilizer.
NASA Astrophysics Data System (ADS)
Li, D.; Nanseki, T.; Chomei, Y.; Yokota, S.
2017-07-01
Rice, a staple crop in Japan, is at risk of decreasing production and its yield highly depends on soil fertility. This study aimed to investigate determinants of rice yield, from the perspectives of fertilizer nitrogen and soil chemical properties. The data were sampled in 2014 and 2015 from 92 peat soil paddy fields on a large-scale farm located in the Kanto Region of Japan. The rice variety used was the most widely planted Koshihikari in Japan. Regression analysis indicated that fertilizer nitrogen significantly affected the yield, with a significant sustained effect to the subsequent year. Twelve soil chemical properties, including pH, cation exchange capacity, content of pyridine base elements, phosphoric acid, and silicic acid, were estimated. In addition to silicic acid, magnesia, in forms of its exchangeable content, saturation, and ratios to potassium and lime, positively affected the yield, while phosphoric acid negatively affected the yield. We assessed the soil chemical properties by soil quality index and principal component analysis. Positive effects were identified for both approaches, with the former performing better in explaining the rice yield. For soil quality index, the individual standardized soil properties and margins for improvement were indicated for each paddy field. Finally, multivariate regression on the principal components identified the most significant properties.
Daebeler, Anne; Abell, Guy C. J.; Bodelier, Paul L. E.; Bodrossy, Levente; Frampton, Dion M. F.; Hefting, Mariet M.; Laanbroek, Hendrikus J.
2012-01-01
The contribution of ammonia-oxidizing bacteria and archaea (AOB and AOA, respectively) to the net oxidation of ammonia varies greatly between terrestrial environments. To better understand, predict and possibly manage terrestrial nitrogen turnover, we need to develop a conceptual understanding of ammonia oxidation as a function of environmental conditions including the ecophysiology of associated organisms. We examined the discrete and combined effects of mineral nitrogen deposition and geothermal heating on ammonia-oxidizing communities by sampling soils from a long-term fertilization site along a temperature gradient in Icelandic grasslands. Microarray, clone library and quantitative PCR analyses of the ammonia monooxygenase subunit A (amoA) gene accompanied by physico-chemical measurements of the soil properties were conducted. In contrast to most other terrestrial environments, the ammonia-oxidizing communities consisted almost exclusively of archaea. Their bacterial counterparts proved to be undetectable by quantitative polymerase chain reaction suggesting AOB are only of minor relevance for ammonia oxidation in these soils. Our results show that fertilization and local, geothermal warming affected detectable ammonia-oxidizing communities, but not soil chemistry: only a subset of the detected AOA phylotypes was present in higher temperature soils and AOA abundance was increased in the fertilized soils, while soil physio-chemical properties remained unchanged. Differences in distribution and structure of AOA communities were best explained by soil pH and clay content irrespective of temperature or fertilizer treatment in these grassland soils, suggesting that these factors have a greater potential for ecological niche-differentiation of AOA in soil than temperature and N fertilization. PMID:23060870
Daebeler, Anne; Abell, Guy C J; Bodelier, Paul L E; Bodrossy, Levente; Frampton, Dion M F; Hefting, Mariet M; Laanbroek, Hendrikus J
2012-01-01
The contribution of ammonia-oxidizing bacteria and archaea (AOB and AOA, respectively) to the net oxidation of ammonia varies greatly between terrestrial environments. To better understand, predict and possibly manage terrestrial nitrogen turnover, we need to develop a conceptual understanding of ammonia oxidation as a function of environmental conditions including the ecophysiology of associated organisms. We examined the discrete and combined effects of mineral nitrogen deposition and geothermal heating on ammonia-oxidizing communities by sampling soils from a long-term fertilization site along a temperature gradient in Icelandic grasslands. Microarray, clone library and quantitative PCR analyses of the ammonia monooxygenase subunit A (amoA) gene accompanied by physico-chemical measurements of the soil properties were conducted. In contrast to most other terrestrial environments, the ammonia-oxidizing communities consisted almost exclusively of archaea. Their bacterial counterparts proved to be undetectable by quantitative polymerase chain reaction suggesting AOB are only of minor relevance for ammonia oxidation in these soils. Our results show that fertilization and local, geothermal warming affected detectable ammonia-oxidizing communities, but not soil chemistry: only a subset of the detected AOA phylotypes was present in higher temperature soils and AOA abundance was increased in the fertilized soils, while soil physio-chemical properties remained unchanged. Differences in distribution and structure of AOA communities were best explained by soil pH and clay content irrespective of temperature or fertilizer treatment in these grassland soils, suggesting that these factors have a greater potential for ecological niche-differentiation of AOA in soil than temperature and N fertilization.
USDA-ARS?s Scientific Manuscript database
Soil microorganisms have the potential to dramatically alter the nitrogen (N) availability in agricultural systems, and therefore affect the efficiency of fertilizer application. Data regarding the effects of cereal management systems on the soil microbiology functional to N cycling have yielded var...
Biochar for soil fertility and natural carbon sequestration
Rostad, C.E.; Rutherford, D.W.
2011-01-01
Biochar is charcoal (similar to chars generated by forest fires) that is made for incorporation into soils to increase soil fertility while providing natural carbon sequestration. The incorporation of biochar into soils can preserve and enrich soils and also slow the rate at which climate change is affecting our planet. Studies on biochar, such as those cited by this report, are applicable to both fire science and soil science.
Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu
2016-06-01
Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Li, Dongdong; Luo, Peiyu; Yang, Jinfeng
2017-12-01
This study aims to explore changes of long-term fertilization on spore density and colonization of AMF (Arbuscular mycorrhizal fungi) under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm,20-40cm,40-60cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen andphosphate fertilizer).Spores were isolated from soils by wet sieving and sucrose density gradient centrifugation; mycorrhizal colonization levels were determined by the gridline intersect. The spore density was highest in the topsoils (0-20 cm), and was decreased with increasing of soil depth in each treatment. The spores density of M2N1P treatment was significantly higher than that of other treatments in each soil layer. Application of inorganic fertilizer (especially inorganic with organic fertilizer) can greatly improve the level of colonization. Our results suggested that long-term fertilization significantly affects spore density and colonization of AMF, however, spore density is not related to colonization rate.
Effect of Fresh Poultry Litter and Compost on Soil Physical and Chemical Properties
NASA Technical Reports Server (NTRS)
Carr, Stacy; Tsegaye, Teferi; Coleman, Tommy
1998-01-01
Application of poultry litter and compost as a substitute for fertilizer not only uses unwanted waste and decreases expenditures for commercial fertilizer, it adds nutrients to soil for plant uptake. The properties of soil affected by poultry litter were analyzed to determine the positive and negative aspects of using this substitute fertilizer. This study focused on changes associated with saturated hydraulic conductivity, bulk density, nitrate concentrations, and pH after application of varying concentrations of poultry litter and compost. Soil samples from Tennessee Valley Substation in Alabama were analyzed in a laboratory at Alabama A&M University. As a result of the application of fresh poultry litter and compost, we found that the saturated hydraulic conductivity increased and the bulk density decreased, while the pH was generally not affected. Using poultry litter and compost as an alternative commercial fertilizers could be adapted by the farming community to protect the sustainability of our environment. Unwanted waste is used productively and soil is enriched for farming.
Sall, Saïdou Nourou; Ndour, Ndèye Yacine Badiane; Diédhiou-Sall, Siré; Dick, Richard; Chotte, Jean-Luc
2015-09-15
Soil degradation and salinization caused by inappropriate cultivation practices and high levels of saltwater intrusion are having an adverse effect on agriculture in Central Senegal. The residues of Piliostigma reticulatum, a local shrub that coexists with crops, were recently shown to increase particulate organic matter and improve soil quality and may be a promising means of alleviating the effects of salinization. This study compared the effects of inorganic fertilizer and P. reticulatum residues on microbial properties and the ability of soil to withstand salinity stress. We hypothesized that soils amended with P. reticulatum would be less affected by salinity stress than soils amended with inorganic fertilizer and control soil. Salinity stress was applied to soil from a field site that had been cultivated for 5 years under a millet/peanut crop rotation when microbial biomass, phospholipid fatty acid (PLFA) community profile, catabolic diversity, microbial activities were determined. Microbial biomass, nitrification potential and dehydrogenase activity were higher by 20%, 56% and 69% respectively in soil with the organic amendment. With salinity stress, the structure and activities of the microbial community were significantly affected. Although the biomass of actinobacteria community increased with salinity stress, there was a substantial reduction in microbial activity in all soils. The soil organically amended was, however, less affected by salinity stress than the control or inorganic fertilizer treatment. This suggests that amendment using P. reticulatum residues may improve the ability of soils to respond to saline conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.
[Effect of long-term fertilizing regime on soil microbial diversity and soil property].
Li, Chenhua; Zhang, Caixia; Tang, Lisong; Xiong, Zhengqin; Wang, Baozhan; Jia, Zhongjun; Li, Yan
2014-03-04
To evaluate the effect of long-term fertilization on soil microbial community and soil chemical and physical properties. Using a high-throughput pyrosequencing technique, we studied microbial community in the 0-300 cm soil samples covering a 20-year field-experiment with different fertilization applications including inorganic fertilizer alone (N 300 kg/hm2, P2O5 150 kg/hm2 and K2O 60 kg/hm2) and inorganic fertilizer combined with straw (same application rate of N and P fertilizer combined with 5.4 t straw). Actinobacteria and alpha-proteobacteria were the predominant groups in the topsoil (0-20 cm). As the soil depth increased, the relative abundance of actinobacteria decreased whereas that of proteobacteria, especially gamma-proteobacteria and beta-proteobacteria increased and gradually became the dominant groups in the subsoil (20-300 cm). Long-term fertilizing applications significantly affected soil microbial communities throughout the soil profile, and increased the relative abundance of ammonia-oxidizing archaea at 0-40 cm depth. In addition, agriculture management, e. g. irrigation may be an important driving factor for the distribution of ammonia-oxidizing bacteria in soil profile. Total nitrogen and organic carbon contents were the most influential factors on microbial community in the topsoil and in the subsoil, respectively. Long-term fertilizer applications altered soil nutrient availability within the soil profile, which was likely to result in the different microbial community structure between the fertilizer treatments, especially for the subsoil.
Oukali-Haouchine, Ouzna; Barriuso, Enrique; Mayata, Yamina; Moussaoui, Khadija M
2013-05-01
Metribuzin is a widely used herbicide around the world but it could lead to soil and water contamination. Metribuzin retention on a silty-clay agricultural soil of Algeria was studied in laboratory batch experiments to assess the contamination risk of the groundwater. Factors conditioning the fate of metribuzin were investigated: soil nature, metribuzin formulation, NPK fertilizer, and soil pH. Freundlich sorption isotherms gave the coefficients K F between 1.2 and 4.9 and 1/n a between 0.52 and 0.93. The adsorption is directly dependent on organic and clay soil contents. Formulated metribuzin (Metriphar) reduces the adsorption (K F = 1.25) compared to pure metribuzin (K F = 2.81). The addition of an NPK fertilizer decreases the soil pH (6.67 for the soil without fertilizer and 5.86 for 2 % of fertilizer) and increases metribuzin adsorption (K F is 4.83 for 2 % of fertilizer). The pH effect on the adsorption is corroborated in experiments changing the soil pH between 5 (K F is 4.17) and 8 (K F is 1.57) under controlled conditions. Desorption isotherms show a hysteresis and only 30 to 40 % of the initially adsorbed metribuzin is released. The estimated GUS index is ≥ 2.8 for a DT50 ≥ 30 days. K F values and the hysteresis show that metribuzin is little but strongly retained on the soil. Formulated metribuzin and addition of fertilizer affect the retention. However, the GUS index indicates a high mobility and a significant risk of leaching. The most appropriate risk management measure would be an important increase in organic matter content of the soil by addition of organic amendments.
Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J
2016-11-01
Incorporation of organic material into soils is an important element of organic farming practices that can affect the composition of the soil bacterial communities that carry out nutrient cycling and other functions crucial to crop health and growth. We conducted a field experiment to determine the effects of cover crops and fertilizers on bacterial community structure in agricultural soils under long-term organic management. Illumina sequencing of 16S rDNA revealed diverse communities comprising 45 bacterial phyla in corn rhizosphere and bulk field soil. Community structure was most affected by location and by the rhizosphere effect, followed by sampling time and amendment treatment. These effects were associated with soil physicochemical properties, including pH, moisture, organic matter, and nutrient levels. Treatment differences were apparent in bulk and rhizosphere soils at the time of peak corn growth in the season following cover crop and fertilizer application. Cover crop and fertilizer treatments tended to lower alpha diversity in early season samples. However, winter rye, oilseed radish, and buckwheat cover crop treatments increased alpha diversity in some later season samples compared to a no-amendment control. Fertilizer treatments and some cover crops decreased relative abundance of members of the ammonia-oxidizing family Nitrosomonadaceae. Pelleted poultry manure and Sustane® (a commercial fertilizer) decreased the relative abundance of Rhizobiales. Our data point to a need for future research exploring how (1) cover crops influence bacterial community structure and functions, (2) these effects differ with biomass composition and quantity, and (3) existing soil conditions and microbial community composition influence how soil microbial populations respond to agricultural management practices.
Zhao, Jun; Ni, Tian; Li, Yong; Xiong, Wu; Ran, Wei; Shen, Biao; Shen, Qirong; Zhang, Ruifu
2014-01-01
Soil physicochemical properties, soil microbial biomass and bacterial community structures in a rice-wheat cropping system subjected to different fertilizer regimes were investigated in two seasons (June and October). All fertilizer regimes increased the soil microbial biomass carbon and nitrogen. Both fertilizer regime and time had a significant effect on soil physicochemical properties and bacterial community structure. The combined application of inorganic fertilizer and manure organic-inorganic fertilizer significantly enhanced the bacterial diversity in both seasons. The bacterial communities across all samples were dominated by Proteobacteria, Acidobacteria and Chloroflexi at the phylum level. Permutational multivariate analysis confirmed that both fertilizer treatment and season were significant factors in the variation of the composition of the bacterial community. Hierarchical cluster analysis based on Bray-Curtis distances further revealed that bacterial communities were separated primarily by season. The effect of fertilizer treatment is significant (P = 0.005) and accounts for 7.43% of the total variation in bacterial community. Soil nutrients (e.g., available K, total N, total P and organic matter) rather than pH showed significant correlation with the majority of abundant taxa. In conclusion, both fertilizer treatment and seasonal changes affect soil properties, microbial biomass and bacterial community structure. The application of NPK plus manure organic-inorganic fertilizer may be a sound fertilizer practice for sustainable food production. PMID:24465530
Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana
2016-01-01
The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099
Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana
2016-01-01
The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees.
Koyama, Akihiro; Wallenstein, Matthew D.; Simpson, Rodney T.; Moore, John C.
2014-01-01
The pool of soil organic carbon (SOC) in the Arctic is disproportionally large compared to those in other biomes. This large quantity of SOC accumulated over millennia due to slow rates of decomposition relative to net primary productivity. Decomposition is constrained by low temperatures and nutrient concentrations, which limit soil microbial activity. We investigated how nutrients limit bacterial and fungal biomass and community composition in organic and mineral soils within moist acidic tussock tundra ecosystems. We sampled two experimental arrays of moist acidic tussock tundra that included fertilized and non-fertilized control plots. One array included plots that had been fertilized annually since 1989 and the other since 2006. Fertilization significantly altered overall bacterial community composition and reduced evenness, to a greater degree in organic than mineral soils, and in the 1989 compared to the 2006 site. The relative abundance of copiotrophic α-Proteobacteria and β-Proteobacteria was higher in fertilized than control soils, and oligotrophic Acidobacteria were less abundant in fertilized than control soils at the 1989 site. Fungal community composition was less sensitive to increased nutrient availability, and fungal responses to fertilization were not consistent between soil horizons and sites. We detected two ectomycorrhizal genera, Russula and Cortinarius spp., associated with shrubs. Their relative abundance was not affected by fertilization despite increased dominance of their host plants in the fertilized plots. Our results indicate that fertilization, which has been commonly used to simulate warming in Arctic tundra, has limited applicability for investigating fungal dynamics under warming. PMID:25324836
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-08
... silty clay loam. Due to the relatively low fertility of these soils, applications of lime and fertilizer... increased breakdown of organic material in the soil. The increased precipitation does not negatively affect...
Soil fertility shapes belowground food webs across a regional climate gradient.
Laliberté, Etienne; Kardol, Paul; Didham, Raphael K; Teste, François P; Turner, Benjamin L; Wardle, David A
2017-10-01
Changes in soil fertility during pedogenesis affect the quantity and quality of resources entering the belowground subsystem. Climate governs pedogenesis, yet how climate modulates responses of soil food webs to soil ageing remains unexplored because of the paucity of appropriate model systems. We characterised soil food webs along each of four retrogressive soil chronosequences situated across a strong regional climate gradient to show that belowground communities are predominantly shaped by changes in fertility rather than climate. Basal consumers showed hump-shaped responses to soil ageing, which were propagated to higher-order consumers. There was a shift in dominance from bacterial to fungal energy channels with increasing soil age, while the root energy channel was most important in intermediate-aged soils. Our study highlights the overarching importance of soil fertility in regulating soil food webs, and indicates that belowground food webs will respond more strongly to shifts in soil resources than climate change. © 2017 John Wiley & Sons Ltd/CNRS.
Tao, Rui; Wakelin, Steven A; Liang, Yongchao; Hu, Baowei; Chu, Guixin
2018-01-15
The effects of consecutive application of chemical fertilizer with or without organic fertilizer on soil N 2 O emissions and denitrifying community structure in a drip-irrigated field were determined. The four fertilizer treatments were (i) unfertilized, (ii) chemical fertilizer, (iii) 60% chemical fertilizer plus cattle manure, and (iv) 60% chemical fertilizer plus biofertilizer. The treatments with organic amendments (i.e. cattle manure and biofertilizer) reduced cumulative N 2 O emissions by 4.9-9.9%, reduced the N 2 O emission factor by 1.3-42%, and increased denitrifying enzyme activities by 14.3-56.2%. The nirK gene copy numbers were greatest in soil which received only chemical fertilizer. In contrast, nirS- and nosZ-copy numbers were greatest in soil amended with chemical fertilizer plus biofertilizer. Chemical fertilizer application with or without organic fertilizer significantly changed the community structure of nirK-type denitrifiers relative to the unfertilized soil. In comparison, the nirS- and nosZ-type denitrifier genotypes varied in treatments receiving organic fertilizer but not chemical fertilizer alone. The changes in the denitrifier communities were closely associated with soil organic carbon (SOC), NO 3 - , NH 4 + , water holding capacity, and soil pH. Modeling indicated that N 2 O emissions in this soil were primarily associated with the abundance of nirS type denitrifying bacteria, SOC, and NO 3 - . Overall, our findings indicate that (i) the organic fertilizers increased denitrifying enzyme activity, increased denitrifying-bacteria gene copy numbers, but reduced N 2 O emissions, and (ii) nirS- and nosZ-type denitrifiers were more sensitive than nirK-type denitrifiers to the organic fertilizers. Copyright © 2017. Published by Elsevier B.V.
San Francisco, Sara; Urrutia, Oscar; Martin, Vincent; Peristeropoulos, Angelos; Garcia-Mina, Jose Maria
2011-07-01
Some authors suggest that the absence of tillage in agricultural soils might have an influence on the efficiency of nitrogen applied in the soil surface. In this study we investigate the influence of no-tillage and soil characteristics on the efficiency of a urease inhibitor (N-(n-butyl)thiophosphoric triamide, NBPT) and a nitrification inhibitor (diciandiamide, DCD) in decreasing ammonia volatilization from urea and ammonium nitrate (AN), respectively. The results indicate that ammonia volatilization in soils amended with urea was significantly higher than in those fertilized with AN. Likewise, the main soil factors affecting ammonia volatilization from urea are clay and sand soil contents. While clay impedes ammonia volatilization, sand favours it. The presence of organic residues on soil surface (no-tillage) tends to increase ammonia volatilization from urea, although this fact depended on soil type. The presence of NBPT in urea fertilizer significantly reduced soil ammonia volatilization. This action of NBPT was negatively affected by acid soil pH and favoured by soil clay content. The presence of organic residues on soil surface amended with urea increased ammonia volatilization, and was particularly high in sandy compared with clay soils. Application of NBPT reduced ammonia volatilization although its efficiency is reduced in acid soils. Concerning AN fertilization, there were no differences in ammonia volatilization with or without DCD in no-tillage soils. Copyright © 2011 Society of Chemical Industry.
Soil C dynamics under intensive oil palm plantations in poor tropical soils
NASA Astrophysics Data System (ADS)
Guillaume, Thomas; Ruegg, Johanna; Quezada, Juan Carlos; Buttler, Alexandre
2017-04-01
Oil palm cultivation mainly takes place on heavily-weathered tropical soils where nutrients are limiting factors for plant growth and microbial activity. Intensive fertilization and changes of C input by oil palms strongly affects soil C and nutrient dynamics, challenging long-term soil fertility. Oil palm plantations management offers unique opportunities to study soil C and nutrients interactions in field conditions because 1) they can be considered as long-term litter manipulation experiments since all aboveground C inputs are concentrated in frond pile areas and 2) mineral fertilizers are only applied in specific areas, i.e. weeded circle around the tree and interrows, but not in harvest paths. Here, we determined impacts of mineral fertilizer and organic matter input on soil organic carbon dynamics and microbial activity in mature oil palm plantation established on savanna grasslands. Rates of savanna-derived soil organic carbon (SOC) decomposition and oil palm-derived SOC net stabilization were determined using changes in isotopic signature of in C input following a shift from C4 (savanna) to C3 (oil palm) vegetation. Application of mineral fertilizer alone did not affect savanna-derived SOC decomposition or oil palm-derived SOC stabilization rates, but fertilization associated with higher C input lead to an increase of oil palm-derived SOC stabilization rates, with about 50% of topsoil SOC derived from oil palm after 9 years. High carbon and nutrients inputs did not increase microbial biomass but microorganisms were more active per unit of biomass and SOC. In conclusion, soil organic matter decomposition was limited by C rather than nutrients in the studied heavily-weathered soils. Fresh C and nutrient inputs did not lead to priming of old savanna-derived SOC but increased turnover and stabilization of new oil palm-derived SOC.
K. Ellum; H.O. Liechty; M.A. Blazier
2013-01-01
Straw harvesting can supplement traditional revenues generated by loblolly pine (Pinus taeda L.) plantation management. However, repeated raking may alter soil properties and nutrition. In northcentral Louisiana, a study was conducted to evaluate the long-term effects of intensive straw raking and fertilizer source (inorganic or organic) on nitrogen...
Li, Junjian; Zheng, Yuanming; Yan, Junxia; Li, Hongjian; Wang, Xiang; He, Jizheng; Ding, Guangwei
2013-01-01
The soil microbial community in reclaimed mining areas is fundamental to vegetative establishment. However, how this community responds to different regeneration scenarios and fertilizer treatments is poorly understood. This research evaluated plant and soil microbial communities from different regeneration scenarios and different fertilizer treatments. Regeneration scenarios significantly influenced soil bacterial, archaeal, and fungal rDNA abundance. The ratios of fungi to bacteria or archaea were increased with fertilizer application. The diversity of both plants and microbes was lowest in Lotus corniculatus grasslands. Regeneration scenario, fertilizer treatment, and their interaction influenced soil microbial richness, diversity and evenness indices. Labile carbon pool 2 was a significant factor affected plant and microbe communities in July, suggesting that plants and microbes may be competing for nutrients. The higher ratios of positive to negative association were found in soil bacteria and total microbe than in archaea and fungi. Stronger clustering of microbial communities from the same regeneration scenario indicated that the vegetative composition of regeneration site may have a greater influence on soil microbial communities than fertilizer treatment. PMID:23658819
Magnetic mapping of distribution of wood ash used for fertilization of forest soil.
Petrovský, Eduard; Remeš, Jiří; Kapička, Aleš; Podrázský, Vilém; Grison, Hana; Borůvka, Luboš
2018-06-01
The effect of wood-ash fertilization on forest soils has been assessed mainly through geochemical methods (e.g., content of soil organic matter or nutrients). However, a simple and fast method of determining the distribution of the ash and the extent of affected soil is missing. In this study we present the use of magnetic susceptibility, which is controlled by Fe-oxides, in comparing the fertilized soil in the forest plantation of pine and oak with intact forest soil. Spatial and vertical distribution of magnetic susceptibility was measured in an oak and pine plantation next to stems of young plants, where wood ash was applied as fertilizer. Pattern of the susceptibility distribution was compared with that in non-fertilized part of the plantation as well as with a spot of intact natural forest soil nearby. Our results show that the wood-ash samples contain significant amount of ferrimagnetic magnetite with susceptibility higher than that of typical forest soil. Clear differences were observed between magnetic susceptibility of furrows and ridges. Moreover, the dispersed ash remains practically on the surface, does not penetrate to deeper layers. Finally, our data suggest significant differences in surface values between the pine and oak plants. Based on this study we may conclude that magnetic susceptibility may represent a simple and approximate method of assessing the extent of soil affected by wood-ash. Copyright © 2018 Elsevier B.V. All rights reserved.
Fernández-Luqueño, F; Reyes-Varela, V; Martínez-Suárez, C; Salomón-Hernández, G; Yáñez-Meneses, J; Ceballos-Ramírez, J M; Dendooven, L
2010-01-01
Wastewater sludge can be used to fertilize crops, especially after vermicomposting (composting with earthworms to reduce pathogens). How wastewater sludge or vermicompost affects bean (Phaseolus vulgaris L.) growth is still largely unknown. In this study the effect of different forms of N fertilizer on common bean plant characteristics and yield were investigated in a Typic Fragiudepts (sandy loam) soil under greenhouse conditions. Beans were fertilized with wastewater sludge, or wastewater sludge vermicompost, or urea, or grown in unamended soil, while plant characteristics and yield were monitored (the unamended soil had no fertilization). Yields of common bean plants cultivated in unamended soil or soil amended with urea were lower than those cultivated in wastewater sludge-amended soil. Application of vermicompost further improved plant development and increased yield compared with beans cultivated in wastewater amended soil. It was found that application of organic waste products improved growth and yield of bean plants compared to those amended with inorganic fertilizer.
Microbial Ecology in Vineyards
USDA-ARS?s Scientific Manuscript database
Soil health affects grapevine health, which, in turn, affects fruit quality. Soil health has chemical, physical, and biological components. The chemical components are the best understood, and there are relatively convenient methods to both evaluate and amend chemical soil fertility. The physical...
Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons
Barry, Karen M.; Janos, David P.; Nichols, Scott; Bowman, David M. J. S.
2015-01-01
Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations. PMID:25750650
Zhen, Zhen; Liu, Haitao; Wang, Na; Guo, Liyue; Meng, Jie; Ding, Na; Wu, Guanglei; Jiang, Gaoming
2014-01-01
The long-term application of excessive chemical fertilizers has resulted in the degeneration of soil quality parameters such as soil microbial biomass, communities, and nutrient content, which in turn affects crop health, productivity, and soil sustainable productivity. The objective of this study was to develop a rapid and efficient solution for rehabilitating degraded cropland soils by precisely quantifying soil quality parameters through the application of manure compost and bacteria fertilizers or its combination during maize growth. We investigated dynamic impacts on soil microbial count, biomass, basal respiration, community structure diversity, and enzyme activity using six different treatments [no fertilizer (CK), N fertilizer (N), N fertilizer + bacterial fertilizer (NB), manure compost (M), manure compost + bacterial fertilizer (MB), and bacterial fertilizer (B)] in the plowed layer (0–20 cm) of potted soil during various maize growth stages in a temperate cropland of eastern China. Denaturing gradient electrophoresis (DGGE) fingerprinting analysis showed that the structure and composition of bacterial and fungi communities in the six fertilizer treatments varied at different levels. The Shannon index of bacterial and fungi communities displayed the highest value in the MB treatments and the lowest in the N treatment at the maize mature stage. Changes in soil microorganism community structure and diversity after different fertilizer treatments resulted in different microbial properties. Adding manure compost significantly increased the amount of cultivable microorganisms and microbial biomass, thus enhancing soil respiration and enzyme activities (p<0.01), whereas N treatment showed the opposite results (p<0.01). However, B and NB treatments minimally increased the amount of cultivable microorganisms and microbial biomass, with no obvious influence on community structure and soil enzymes. Our findings indicate that the application of manure compost plus bacterial fertilizers can immediately improve the microbial community structure and diversity of degraded cropland soils. PMID:25302996
Fanin, Nicolas; Barantal, Sandra; Fromin, Nathalie; Schimann, Heidy; Schevin, Patrick; Hättenschwiler, Stephan
2012-01-01
Human-caused alterations of the carbon and nutrient cycles are expected to impact tropical ecosystems in the near future. Here we evaluated how a combined change in carbon (C), nitrogen (N) and phosphorus (P) availability affects soil and litter microbial respiration and litter decomposition in an undisturbed Amazonian rainforest in French Guiana. In a fully factorial C (as cellulose), N (as urea), and P (as phosphate) fertilization experiment we analyzed a total of 540 litterbag-soil pairs after a 158-day exposure in the field. Rates of substrate-induced respiration (SIR) measured in litter and litter mass loss were similarly affected by fertilization showing the strongest stimulation when N and P were added simultaneously. The stimulating NP effect on litter SIR increased considerably with increasing initial dissolved organic carbon (DOC) concentrations in litter, suggesting that the combined availability of N, P, and a labile C source has a particularly strong effect on microbial activity. Cellulose fertilization, however, did not further stimulate the NP effect. In contrast to litter SIR and litter mass loss, soil SIR was reduced with N fertilization and showed only a positive effect in response to P fertilization that was further enhanced with additional C fertilization. Our data suggest that increased nutrient enrichment in the studied Amazonian rainforest can considerably change microbial activity and litter decomposition, and that these effects differ between the litter layer and the underlying soil. Any resulting change in relative C and nutrient fluxes between the litter layer and the soil can have important consequences for biogeochemical cycles in tropical forest ecosystems. PMID:23272052
Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M
2017-12-01
The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m ), finite rate of increase (λ), net reproductive rate (R 0 ), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m , λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.
Dominant Douglas-fir respond to fertilizing and thinning in southwest Oregon
Richard E. Miller; Richard L. Williamson
1974-01-01
In 30-year-old, Site IV Douglas-fir in southwest Oregon, fertilizing increased average 4-year basal area growth of dominant trees by 57 and 28 percent on clay loam and sandy loam soils, respectively. Fertilizing with thinning increased growth by 94 and 132 percent over untreated growth. Thinning on clay loam soil increased growth by 53 percent. Treatment did not affect...
Nitrogen Alters Fungal Communities in Boreal Forest Soil: Implications for Carbon Cycling
NASA Astrophysics Data System (ADS)
Allison, S. D.; Treseder, K. K.
2005-12-01
One potential effect of climate change in high latitude ecosystems is to increase soil nutrient availability. In particular, greater nitrogen availability could impact decomposer communities and lead to altered rates of soil carbon cycling. Since fungi are the primary decomposers in many high-latitude ecosystems, we used molecular techniques and field surveys to test whether fungal communities and abundances differed in response to nitrogen fertilization in a boreal forest ecosystem. We predicted that fungi that degrade recalcitrant carbon would decline under nitrogen fertilization, while fungi that degrade labile carbon would increase, leading to no net change in rates of soil carbon mineralization. The molecular data showed that basidiomycete fungi dominate the active fungal community in both fertilized and unfertilized soils. However, we found that fertilization reduced peak mushroom biomass by 79%, although most of the responsive fungi were ectomycorrhizal and therefore their capacity to degrade soil carbon is uncertain. Fertilization increased the activity of the cellulose-degrading enzyme beta-glucosidase by 78%, while protease activity declined by 39% and polyphenol oxidase, a lignin-degrading enzyme, did not respond. Rates of soil respiration did not change in response to fertilization. These results suggest that increased nitrogen availability does alter the composition of the fungal community, and its potential to degrade different carbon compounds. However, these differences do not affect the total flux of CO2 from the soil, even though the contribution to CO2 respiration from different carbon pools may vary with fertilization. We conclude that in the short term, increased nitrogen availability due to climate warming or nitrogen deposition is more likely to alter the turnover of individual carbon pools rather than total carbon fluxes from the soil. Future work should determine if changes in fungal community structure and associated differences in substrate utilization will also affect total carbon fluxes over longer time scales.
Fertilization Shapes Bacterial Community Structure by Alteration of Soil pH.
Zhang, Yuting; Shen, Hong; He, Xinhua; Thomas, Ben W; Lupwayi, Newton Z; Hao, Xiying; Thomas, Matthew C; Shi, Xiaojun
2017-01-01
Application of chemical fertilizer or manure can affect soil microorganisms directly by supplying nutrients and indirectly by altering soil pH. However, it remains uncertain which effect mostly shapes microbial community structure. We determined soil bacterial diversity and community structure by 454 pyrosequencing the V1-V3 regions of 16S rRNA genes after 7-years (2007-2014) of applying chemical nitrogen, phosphorus and potassium (NPK) fertilizers, composted manure or their combination to acidic (pH 5.8), near-neutral (pH 6.8) or alkaline (pH 8.4) Eutric Regosol soil in a maize-vegetable rotation in southwest China. In alkaline soil, nutrient sources did not affect bacterial Operational Taxonomic Unit (OTU) richness or Shannon diversity index, despite higher available N, P, K, and soil organic carbon in fertilized than in unfertilized soil. In contrast, bacterial OTU richness and Shannon diversity index were significantly lower in acidic and near-neutral soils under NPK than under manure or their combination, which corresponded with changes in soil pH. Permutational multivariate analysis of variance showed that bacterial community structure was significantly affected across these three soils, but the PCoA ordination patterns indicated the effect was less distinct among nutrient sources in alkaline than in acidic and near-neural soils. Distance-based redundancy analysis showed that bacterial community structures were significantly altered by soil pH in acidic and near-neutral soils, but not by any soil chemical properties in alkaline soil. The relative abundance (%) of most bacterial phyla was higher in near-neutral than in acidic or alkaline soils. The most dominant phyla were Proteobacteria (24.6%), Actinobacteria (19.7%), Chloroflexi (15.3%) and Acidobacteria (12.6%); the medium dominant phyla were Bacterioidetes (5.3%), Planctomycetes (4.8%), Gemmatimonadetes (4.5%), Firmicutes (3.4%), Cyanobacteria (2.1%), Nitrospirae (1.8%), and candidate division TM7 (1.0%); the least abundant phyla were Verrucomicrobia (0.7%), Armatimonadetes (0.6%), candidate division WS3 (0.4%) and Fibrobacteres (0.3%). In addition, Cyanobacteria and candidate division TM7 were more abundant in acidic soil, whereas Gemmatimonadetes, Nitrospirae and candidate division WS3 were more abundant in alkaline soil. We conclude that after 7-years of fertilization, soil bacterial diversity and community structure were shaped more by changes in soil pH rather than the direct effect of nutrient addition.
Jia, Ka-La-Tie; Yu, Hua; Feng, Wen-Qiang; Qin, Yu-Sheng; Zhao, Jing; Liao, Ming-Lan; Wang, Chang-Quan; Tu, Shi-Hua
2009-11-01
In order to tackle the problem of Cd pollution in paddy soils and investigate soil available Cd as affected by different fertilizers, incubation experiments were carried out to study the effects of different N, P and K fertilizers and pH by adding acid or base on soil available Cd under waterlogged conditions. Results revealed that soil pH increased sharply after the soil was flooded, especially at the beginning of incubation, and gradually decreased with incubation time and finally tended to approach the neutral values. The patterns of soil pH change were just opposite to those of soil available Cd, a negative correlation observed between the two. Soil flooding made the soil available Cd drop by 58.2%-84.1%. There were significant differences between different fertilizer types/varieties on soil available Cd, being most complex with N fertilizers and followed by K and P fertilizers. Among the fertilizers studied, ammonium chloride showed the unique ability in reducing soil pH and enhancing soil available Cd, and urea, single super phosphate and potassium chloride also promoted to a less extent amounts of Cd extracted from the soil. Ammonium sulfate, potassium sulfate and mono-ammonium phosphate significantly decreased soil available Cd compared to the CK treatment. Whether or not the soil was flooded, soil available Cd was highly negatively correlated with soil pH after adding acid or base (R = - 0.994 without incubation and R = - 0.919 after incubation for 60 d). The results further suggest that in the Cd polluted paddy soil, use of ammonium chloride should be avoided, S bearing fertilizers in combination with alkaline materials can be adopted, and the rice field should be flooded all the time during growing season, all the these practices can effectively lower soil available Cd.
Effect of Increasing Nitrogen Deposition on Soil Microbial Communities
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xiao, Shengmu; Xue, Kai; He, Zhili
2010-05-17
Increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity are three main environmental changes occurring on a global scale. The BioCON (Biodiversity, CO2, and Nitrogen) ecological experiment site at the University of Minnesota's Cedar Creek Ecosystem Science Reserve started in 1997, to better understand how these changes would affect soil systems. To understand how increasing nitrogen deposition affects the microbial community diversity, heterogeneity, and functional structure impact soil microbial communities, 12 samples were collected from the BioCON plots in which nitrogenous fertilizer was added to simulate the effect of increasing nitrogen deposition and 12 samples from without added fertilizer. DNAmore » from the 24 samples was extracted using a freeze-grind protocol, amplified, labeled with a fluorescent dye, and then hybridized to GeoChip, a functional gene array containing probes for genes involved in N, S and C cycling, metal resistance and organic contaminant degradation. Detrended correspondence analysis (DCA) of all genes detected was performed to analyze microbial community patterns. The first two axes accounted for 23.5percent of the total variation. The samples fell into two major groups: fertilized and non-fertilized, suggesting that nitrogenous fertilizer had a significant impact on soil microbial community structure and diversity. The functional gene numbers detected in fertilized samples was less that detected in non-fertilizer samples. Functional genes involving in the N cycling were mainly discussed.« less
Han, Shun; Li, Xiang; Luo, Xuesong; Wen, Shilin; Chen, Wenli; Huang, Qiaoyun
2018-01-01
Nitrification is the two-step aerobic oxidation of ammonia to nitrate via nitrite in the nitrogen-cycle on earth. However, very limited information is available on how fertilizer regimes affect the distribution of nitrite oxidizers, which are involved in the second step of nitrification, across aggregate size classes in soil. In this study, the community compositions of nitrite oxidizers ( Nitrobacter and Nitrospira ) were characterized from a red soil amended with four types of fertilizer regimes over a 26-year fertilization experiment, including control without fertilizer (CK), swine manure (M), chemical fertilization (NPK), and chemical/organic combined fertilization (MNPK). Our results showed that the addition of M and NPK significantly decreased Nitrobacter Shannon and Chao1 index, while M and MNPK remarkably increased Nitrospira Shannon and Chao1 index, and NPK considerably decreased Nitrospira Shannon and Chao1 index, with the greatest diversity achieved in soils amended with MNPK. However, the soil aggregate fractions had no impact on that alpha-diversity of Nitrobacter and Nitrospira under the fertilizer treatment. Soil carbon, nitrogen and phosphorus in the soil had a significant correlation with Nitrospira Shannon and Chao1 diversity index, while total potassium only had a significant correlation with Nitrospira Shannon diversity index. However, all of them had no significant correlation with Nitrobacter Shannon and Chao1 diversity index. The resistance indices for alpha-diversity indexes (Shannon and Chao1) of Nitrobacter were higher than those of Nitrospira in response to the fertilization regimes. Manure fertilizer is important in enhancing the Nitrospira Shannon and Chao1 index resistance. Principal co-ordinate analysis revealed that Nitrobacter - and Nitrospira -like NOB communities under four fertilizer regimes were differentiated from each other, but soil aggregate fractions had less effect on the nitrite oxidizers community. Redundancy analysis and Mantel test indicated that soil nitrogen, carbon, phosphorus, and available potassium content were important environmental attributes that control the Nitrobacter - and Nitrospira -like NOB community structure across different fertilization treatments under aggregate levels in the red soil. In general, nitrite-oxidizing bacteria community composition and alpha-diversity are depending on fertilizer regimes, but independent of the soil aggregate.
Wang, Li; Li, Jun; Li, Juan; Bai, Wei-Xia
2014-03-01
A field experiment on effects of tillage rotation and fertilization on corn continuous cropping-practiced lands was carried out in Heyang of Shaanxi in 2007-2012. The tillage types included annual rotation of no-tillage and subsoiling (NT-ST), subsoiling and conventional tillage (ST-CT), or conventional tillage and no-tillage (CT-NT), and yearly practice of no tillage (NT-NT), subsoiling (ST-ST) or conventional tillage (CT-CT). The fertilization treatments included balanced fertilization, low-rate fertilization and conventional fertilization, which were separately practiced against the different tillage types. The experiment investigated compositions, mean mass diameters (MWD), geometrical mean diameters (GMD) and fraction dimension numbers (D) of soil aggregates in 0-40 cm soil and contents of organic carbon in 0-60 cm soil. The results indicated that: 1) The increased tillage intensity caused the reduced mechanical stability and content of soil aggregates and increased soil organic carbon loss. No-tillage or tillage rotation increased the MWD, GMD and contents of soil organic carbon and soil aggregates with diameters of more than 0.25 mm, but decreased D. Under the same fertilization treatment, the contents of soil aggregates with diameters of more than 0.25 mm were ranked in the order of NT-NT>NT-ST>NT-CT>ST-ST>CT-ST>CT-CT, and under the same tillage rotations, the soil aggregates were more stable with the balanced or low- rate fertilization than with the conventional fertilization. 2) Mathematical fractal dimension fitting of soil aggregates indicated that the fractal dimension numbers of soil aggregates ranged within 2.247-2.681 by dry sieving and 2.897-2.976 by wet sieving. In 0-30 cm soil, the fractal dimension numbers of soil aggregates were significantly lower under no-tillage or tillage rotation than under conventional tillage, and in 0-40 cm soil, the fractal dimensions of soil aggregates increased with soil depth, and tended to stabilize at the soil depth of 40 cm. 3) The different fertilization treatments exerted significantly different influences on the contents of soil organic carbon (P < 0.05), which tended to decline with soil depth. Compared to the conventional fertilization, the balanced fertilization increased the content of soil organic carbon by 6.9%, and the contents of soil organic carbon increased as the diameters of soil aggregates increased. The correlation analysis showed that the contents of soil aggregates with diameters of 0.25-2 mm significantly affected the content of soil organic carbon, with the coefficient of determination being 0.848 (P < 0.01).
Dai, Zhongmin; Su, Weiqin; Chen, Huaihai; Barberán, Albert; Zhao, Haochun; Yu, Mengjie; Yu, Lu; Brookes, Philip C; Schadt, Christopher W; Chang, Scott X; Xu, Jianming
2018-04-12
Long-term elevated nitrogen (N) input from anthropogenic sources may cause soil acidification and decrease crop yield, yet the response of the belowground microbial community to long-term N input alone or in combination with phosphorus (P) and potassium (K) is poorly understood. We explored the effect of long-term N and NPK fertilization on soil bacterial diversity and community composition using meta-analysis of a global dataset. Nitrogen fertilization decreased soil pH, and increased soil organic carbon (C) and available N contents. Bacterial taxonomic diversity was decreased by N fertilization alone, but was increased by NPK fertilization. The effect of N fertilization on bacterial diversity varied with soil texture and water management, but was independent of crop type or N application rate. Changes in bacterial diversity were positively related to both soil pH and organic C content under N fertilization alone, but only to soil organic C under NPK fertilization. Microbial biomass C decreased with decreasing bacterial diversity under long-term N fertilization. Nitrogen fertilization increased the relative abundance of Proteobacteria and Actinobacteria, but reduced the abundance of Acidobacteria, consistent with the general life history strategy theory for bacteria. The positive correlation between N application rate and the relative abundance of Actinobacteria indicates that increased N availability favored the growth of Actinobacteria. This first global analysis of long-term N and NPK fertilization that differentially affects bacterial diversity and community composition provides a reference for nutrient management strategies for maintaining belowground microbial diversity in agro-ecosystems worldwide. © 2018 John Wiley & Sons Ltd.
Ding, Long-Jun; Su, Jian-Qiang; Sun, Guo-Xin; Wu, Jin-Shui; Wei, Wen-Xue
2018-02-01
Microbes play key roles in diverse biogeochemical processes including nutrient cycling. However, responses of soil microbial community and functional genes to long-term integrated fertilization (chemical combined with organic fertilization) remain unclear. Here, we used pyrosequencing and a microarray-based GeoChip to explore the shifts of microbial community and functional genes in a paddy soil which received over 21-year fertilization with various regimes, including control (no fertilizer), rice straw (R), rice straw plus chemical fertilizer nitrogen (NR), N and phosphorus (NPR), NP and potassium (NPKR), and reduced rice straw plus reduced NPK (L-NPKR). Significant shifts of the overall soil bacterial composition only occurred in the NPKR and L-NPKR treatments, with enrichment of certain groups including Bradyrhizobiaceae and Rhodospirillaceae families that benefit higher productivity. All fertilization treatments significantly altered the soil microbial functional structure with increased diversity and abundances of genes for carbon and nitrogen cycling, in which NPKR and L-NPKR exhibited the strongest effect, while R exhibited the least. Functional gene structure and abundance were significantly correlated with corresponding soil enzymatic activities and rice yield, respectively, suggesting that the structural shift of the microbial functional community under fertilization might promote soil nutrient turnover and thereby affect yield. Overall, this study indicates that the combined application of rice straw and balanced chemical fertilizers was more pronounced in shifting the bacterial composition and improving the functional diversity toward higher productivity, providing a microbial point of view on applying a cost-effective integrated fertilization regime with rice straw plus reduced chemical fertilizers for sustainable nutrient management.
USDA-ARS?s Scientific Manuscript database
Weather and soil properties are known to affect soil nitrogen (N) availability and plant N uptake. Studies examining N response as affected by soil and weather sometimes give conflicting results. Meta-analysis is a statistical method for estimating treatment effects in a series of experiments...
Liu, Mohan; Li, Yang; Che, Yeye; Deng, Shaojun; Xiao, Yan
2017-10-01
This study aimed to explore the effects of different fertilizers and their combinations on growth and nutrient and Cd uptake of Lolium multiflorum. Compared with control treatment, chemical fertilizer, organic manure, and their conjunctions with biofertilizer increased shoot biomass. Biofertilizers were found to cause significant reductions in shoot biomass of plants grown in organic manure-treated and control soil. Decreased soil-available N and P and shoot N and K concentrations in biofertilizer amendment treatments indicated that plant growth and nutrient absorption might be negatively affected under nutrient deficiency conditions. Elevated shoot biomasses contributed to the highest shoot Cd contents in chemical fertilizer and chemical fertilizer + biofertilizer treatments among all treatments. But the maximum translocation efficiency occurred in biofertilizer + chemical fertilizer + organic manure treatment, followed by organic manure and chemical fertilizer + organic manure treatments. Based on the results, we can conclude that the application of only the biofertilizer Bacillus subtilis should be avoided in nutrient-limited soils. Chemical fertilizer application could benefit the amount of Cd in shoots, and organic manure application and its combinations could result in the higher translocation efficiency.
Sun, Kejun; Mao, Xiaoyun; Lu, Qiming; Jia, Aiping; Liao, Zongwen
2004-12-01
By using static absorption and soil column leaching methods, this paper studied the behaviors of several controlled-release N fertilizers in soil under laboratory conditions. The results showed that under the application rate of 450 mg x kg(-1), total ammonia volatilization from three controlled-release fertilizers decreased by 49.7%, 28.0% and 71.2%, respectively, in comparing with common urea. When the application rate was 600 mg x kg(-1), total ammonia volatilization decreased by 34.6%, 12.3%, 69.9%, respectively. Controlled-release fertilizers could markedly reduce total ammonia volatilization from soil and decrease environment pollution via fertilization. The results also indicated that total ammonia volatilization correlated significantly with soil urease activity, pH value and N leaching rate. The correlation coefficient between total ammonia volatilization and accumulated N leaching rate was 0.9533, and that between total ammonia volatilization and soil urease activity and pH value was 0.9533 and 0.9908, respectively.
Wang, Yanan; Ke, Xiubin; Wu, Liqin; Lu, Yahai
2009-02-01
Little information is available on the ecology of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in flooded rice soils. Consequently, a microcosm experiment was conducted to determine the effect of nitrogen fertilizer on the composition of AOB and AOA communities in rice soil by using molecular analyses of ammonia monooxygenase gene (amoA) fragments. Experimental treatments included three levels of N (urea) fertilizer, i.e. 50, 100 and 150 mgNkg(-1) soil. Soil samples were operationally divided into four fractions: surface soil, bulk soil deep layer, rhizosphere and washed root material. NH(4)(+)-N was the dominant form of N in soil porewater and increased with N fertilization. Cloning and sequencing of amoA gene fragments showed that the AOB community in the rice soil consisted of three major groups, i.e. Nitrosomonas communis cluster, Nitrosospira cluster 3a and cluster 3b. The sequences related to Nitrosomonas were predominant. There was a clear effect of N fertilizer and soil depth on AOB community composition based on terminal restriction fragment length polymorphism fingerprinting. Nitrosomonas appeared to be more abundant in the potentially oxic or micro-oxic fractions, including surface soil, rhizosphere and washed root material, than the deep layer of anoxic bulk soil. Furthermore, Nitrosomonas increased relatively in the partially oxic fractions and that of Nitrosospira decreased with the increasing application of N fertilizer. However, AOA community composition remained unchanged according to the denaturing gradient gel electrophoresis analyses.
[Effect of long-term fertilization on microbial community functional diversity in black soil].
Liu, Jing-xin; Chi, Feng-qin; Xu, Xiu-hong; Kuang, En-jun; Zhang, Jiu-ming; Su, Qing-rui; Zhou, Bao-ku
2015-10-01
In order to study the effects of long-term different fertilization on microbial community functional diversity in arable black. soil, we examined microbial metabolic activities in two soil la- yers (0-20 cm, 20-40 cm) under four treatments (CK, NPK, M, MNPK) from a 35-year continuous fertilization field at the Ministry of Agriculture Key Field Observation Station of Harbin Black Soil Ecology Environment using Biolog-ECO method. The results showed that: in the 0-20 cm soil layer, combined application of organic and inorganic fertilizer(MNPK) increased the rate of soil microbial carbon source utilization and community metabolism richness, diversity and dominance; In the 20-40 cm layer, these indices of the MNPK treatment was lower than that of the NPK treat- ment; while NPK treatment decreased soil microbial community metabolism evenness in both layers. Six groups of carbon sources used by soil microbes of all the treatments were different between the two soil layers, and the difference was significant among all treatments in each soil layer (P < 0.05) , while the variations among treatments were different in the two soil layers. Canonical correspondence analysis (CCA) showed that soil microbial community metabolic function of all the treatments was different between the two soil layers, and there was difference among all treatments in each soil layer, while the influences of soil nutrients on soil microbial community metabolic function of all treatments were similar in each soil layer. It was concluded that long-term different fertilization affected soil microbial community functional diversity in both tillage soil layer and down soil layers, and chemical fertilization alone had a larger influence on the microbial community functional diversity in the 20-40 cm layer.
NASA Astrophysics Data System (ADS)
Zaki, M. K.; Komariah; Pujiasmanto, B.; Noda, K.
2018-03-01
Water deficit is a problem on rainfed maize production but can be solved by proper land management. The objective of the study to determine the soil physical properties and maize yield affected by land management to adapt to drought. The experimental design was a randomized complete block using 5 treatments with 4 repetitions, including: (i) Control (KO), (ii) Rice Straw Mulched (MC), (iii) Compost Fertilizer (CF), (iv) In-Organic Fertilizer (AF), (v) Legume Cover crop (CC). Soil physical and maize growth properties namely soil moisture, soil texture, soil bulk density, plant height, biomass, and yield were investigated. The results showed that composting land increased soil water availability and provided nutrient to crops and thus increase soil physical properties, maize growth and yield. Although inorganic fertilizer also increased plant growth and yield, but it did not improve soil physical properties.
USDA-ARS?s Scientific Manuscript database
Soil properties and weather conditions are known to affect soil nitrogen (N) availability and plant N uptake. However, studies examining N response as affected by soil and weather sometimes give conflicting results. Meta-analysis is a statistical method for estimating treatment effects in a series o...
Guo, Fuyu; Ding, Changfeng; Zhou, Zhigao; Huang, Gaoxiang; Wang, Xingxiang
2018-02-01
Soil cadmium (Cd) contamination in China has become a serious concern due to its high toxicity to human health through food chains. A pot experiment was conducted to investigate the effects of hydrated lime (L), hydroxyapatite (H) and organic fertilizer (F) alone or in combination to remedy a mild (DY) and a moderate (YX) Cd contaminated agricultural soil under rice-wheat rotation. Results showed that crops grain yield and Cd concentration, soil pH, CaCl 2 extractable Cd and Cd speciation were markedly affected by the amendments. In both cropping seasons, hydrated lime and hydroxyapatite significantly immobilized soil Cd, and hydroxyapatite, organic fertilizer significantly increased grain yield. Hydrated lime mainly increased soil carbonates bound Cd fractions resulted from 16.7% to 36.2% and from 16.8% to 28.3%, and hydroxyapatite increased Fe/Mn oxides Cd fractions from 19.3% to 33.4% and from 31.4% to 42.1% in the DY and YX soils, respectively; while organic fertilizer slightly increased soil exchangeable and organic matter bound Cd fractions. Besides, combined amendments contain alkaline materials and organic materials have the potential to decrease grain Cd and increase grain yield simultaneously. Therefore, in view of the effects of amendments on grain yield and Cd concentration, the cost as well as the potential benefits expected, combined amendments like hydrated lime + organic fertilizer, hydrated lime + hydroxyapatite + organic fertilizer are recommended in practical application. Mechanisms of Cd immobilization affected by amendments are mainly attributed to the changes in soil Cd availability and crops root uptake rather than internal translocation in plants. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Pohl, Madlen; Hoffmann, Mathias; Hagemann, Ulrike; Jurisch, Nicole; Remus, Rainer; Sommer, Michael; Augustin, Jürgen
2016-04-01
The hummocky ground moraine landscape of north-east Germany is characterized by distinct small-scale soil heterogeneity on the one hand, and intensive energy crop cultivation on the other. Both factors are assumed to significantly influence gaseous C exchange, and thus driving the dynamics of soil organic carbon stocks in terrestrial, agricultural ecosystems. However, it is not yet clear to which extent fertilization and soil erosional status influence soil C dynamics and whether one of these factors is more relevant than the other. We present seasonal and dynamic soil C balances of biogas maize for the growing season 2011, recorded at different sites located within the CarboZALF experimental area. The sites differ regarding soils (non-eroded Albic Luvisols (Cutanic), extremely eroded Calcaric Regosol and depositional Endogleyic Colluvic Regosol,) and applied fertilizer (100% mineral N fertilizer, 50% mineral and 50% N organic fertilizer, 100% organic N fertilizer). Fertilization treatments were established on the Albic Luvisol (Cutanic). Net-CO2-exchange (NEE) and ecosystem respiration (Reco) were measured every four weeks using a dynamic flow-through non-steady-state closed manual chamber system. Gap filling was performed based on empirical temperature and PAR dependency functions to derive daily NEE values. At the same time, daily above-ground biomass production (NPP) was estimated based on biomass samples and final harvest, using a sigmoidal growth function. In a next step, dynamic soil C balances were generated as the balance of daily NEE and NPP considering the initial C input due to N fertilizers. The resulted seasonal soil C balances varied from strong C losses at the Endogleyic Colluvic Regosol (602 g C m-2) to C gains at the Calcaric Regosol (-132 g C m-2). In general, soils exerted a stronger impact on seasonal and dynamic C balances compared to differences in applied N fertilizer. There are indications that inter-annual variations in climate conditions and interactions between soil and fertilization types also seem to affect C-dynamics. Hence, long-term measurements of different fertilization treatments at characteristic soil landscape elements are needed.
Han, Shun; Li, Xiang; Luo, Xuesong; Wen, Shilin; Chen, Wenli; Huang, Qiaoyun
2018-01-01
Nitrification is the two-step aerobic oxidation of ammonia to nitrate via nitrite in the nitrogen-cycle on earth. However, very limited information is available on how fertilizer regimes affect the distribution of nitrite oxidizers, which are involved in the second step of nitrification, across aggregate size classes in soil. In this study, the community compositions of nitrite oxidizers (Nitrobacter and Nitrospira) were characterized from a red soil amended with four types of fertilizer regimes over a 26-year fertilization experiment, including control without fertilizer (CK), swine manure (M), chemical fertilization (NPK), and chemical/organic combined fertilization (MNPK). Our results showed that the addition of M and NPK significantly decreased Nitrobacter Shannon and Chao1 index, while M and MNPK remarkably increased Nitrospira Shannon and Chao1 index, and NPK considerably decreased Nitrospira Shannon and Chao1 index, with the greatest diversity achieved in soils amended with MNPK. However, the soil aggregate fractions had no impact on that alpha-diversity of Nitrobacter and Nitrospira under the fertilizer treatment. Soil carbon, nitrogen and phosphorus in the soil had a significant correlation with Nitrospira Shannon and Chao1 diversity index, while total potassium only had a significant correlation with Nitrospira Shannon diversity index. However, all of them had no significant correlation with Nitrobacter Shannon and Chao1 diversity index. The resistance indices for alpha-diversity indexes (Shannon and Chao1) of Nitrobacter were higher than those of Nitrospira in response to the fertilization regimes. Manure fertilizer is important in enhancing the Nitrospira Shannon and Chao1 index resistance. Principal co-ordinate analysis revealed that Nitrobacter- and Nitrospira-like NOB communities under four fertilizer regimes were differentiated from each other, but soil aggregate fractions had less effect on the nitrite oxidizers community. Redundancy analysis and Mantel test indicated that soil nitrogen, carbon, phosphorus, and available potassium content were important environmental attributes that control the Nitrobacter- and Nitrospira-like NOB community structure across different fertilization treatments under aggregate levels in the red soil. In general, nitrite-oxidizing bacteria community composition and alpha-diversity are depending on fertilizer regimes, but independent of the soil aggregate. PMID:29867799
For Better Soil, Let Earthworms Toil.
ERIC Educational Resources Information Center
Swinehart, Rebecca, Ed.
1995-01-01
This activity involves elementary students in investigating how earthworms affect soil fertility. An introduction discusses topsoil loss and the connections between soil and earthworm ecology. Materials needed and step-by-step procedure are provided. (LZ)
Nitrogen fertilizer recommendations for corn grown on soils amended with oily food waste.
Rashid, M T; Voroney, R P
2005-01-01
Soil and plant indices of soil fertility status have traditionally been developed using conventional soil and crop management practices. Data on managing N fertilizer for corn (Zea mays L.) produced on soils amended with C-rich organic materials, such as oily food waste (OFW) is scarce. Identification of a reliable method for making N fertilizer recommendations under these conditions is imperative. The objective of this research was to evaluate soil NO(3)-N (0- to 30-cm depth) at preplant and presidedress (PSNT) times of sampling for predicting N requirements for corn grown on fields receiving OFW. Experiments were conducted at two locations in Ontario, Canada over 3 yr (1995-1997) where OFW was applied at different rates (0, 10, and 20 Mg ha(-1)), times (fall and spring), and slope positions (upper, mid, and lower) within the same field. Presidedress soil NO(3)-N contents were higher compared with preplant time of sampling under all OFW management conditions. Corn grain yields were significantly affected by OFW management and N fertilizer application rates. Maximum economic rate of N application (MERN) varied depending on OFW management conditions. Presidedress soil NO(3)-N contents had a higher inverse relationship with MERN (r = -0.88) compared with soil NO(3)-N at preplant (r = -0.74) time of sampling. A linear regression model (Y = 180.1 - 8.22 NO(3)-N at PSNT) is proposed for making N fertilizer recommendations to corn grown on soils amended with OFW in this geographical region.
Lin, Sen; Wang, Shaoxian; Si, Yuanli; Yang, Wenhao; Zhu, Shaowei
2017-01-01
To investigate the effects of different nutrient management regimes on the soil chemical, eco-enzymatic stoichiometric and microbial characteristics, soil samples were collected from a 30-year, long-term field experiment with six plots growing rice. The results showed that as integrated fertilization increased, so did the concentrations of soil total or available nutrients and microbial biomass carbon (MBC). Our results also found enhanced soil basal respiration and cumulative carbon mineralization compared to chemical fertilization alone at the same nutrient doses. The activities of soil protease (Pro), β-glucosidase (βG), N-acetyl-glucosaminidase (NAG) and acid phosphatase (AP) from the integrated fertilization treatments were significantly higher than those of the treatments without organic manure, so did the activities of soil leucyl aminopeptidase (LAP) and urease (Ure) from the treatment with organic manure in addition to farmer practise fertilization (NPKM2). The stoichiometric ratios, expressed as lnβG/ln(NAG+LAP)/lnPro/lnUre/lnAP, ranged from 1:0.94:1.04:0.67:1.01 to 1:0.98:1.10:0.78:1.25, indicating that the acquisition of C, N and P changed consistently and synchronously under different nutrient management strategies. Integrated fertilization was more beneficial to the acquisition and utilization of soil organic carbon compared to low-molecular-weight organic nitrogen. We concluded that protease and urease should be considered in eco-enzymatic stoichiometric assessments for the hydrolysis of proteins, amino acids, carbohydrates and phosphomonoesters in soil, and integrated fertilization with chemical fertilizers and organic manure should be recommended as a preferable nutrient management system for intensive rice cultivation. PMID:29253000
Lin, Sen; Wang, Shaoxian; Si, Yuanli; Yang, Wenhao; Zhu, Shaowei; Ni, Wuzhong
2017-01-01
To investigate the effects of different nutrient management regimes on the soil chemical, eco-enzymatic stoichiometric and microbial characteristics, soil samples were collected from a 30-year, long-term field experiment with six plots growing rice. The results showed that as integrated fertilization increased, so did the concentrations of soil total or available nutrients and microbial biomass carbon (MBC). Our results also found enhanced soil basal respiration and cumulative carbon mineralization compared to chemical fertilization alone at the same nutrient doses. The activities of soil protease (Pro), β-glucosidase (βG), N-acetyl-glucosaminidase (NAG) and acid phosphatase (AP) from the integrated fertilization treatments were significantly higher than those of the treatments without organic manure, so did the activities of soil leucyl aminopeptidase (LAP) and urease (Ure) from the treatment with organic manure in addition to farmer practise fertilization (NPKM2). The stoichiometric ratios, expressed as lnβG/ln(NAG+LAP)/lnPro/lnUre/lnAP, ranged from 1:0.94:1.04:0.67:1.01 to 1:0.98:1.10:0.78:1.25, indicating that the acquisition of C, N and P changed consistently and synchronously under different nutrient management strategies. Integrated fertilization was more beneficial to the acquisition and utilization of soil organic carbon compared to low-molecular-weight organic nitrogen. We concluded that protease and urease should be considered in eco-enzymatic stoichiometric assessments for the hydrolysis of proteins, amino acids, carbohydrates and phosphomonoesters in soil, and integrated fertilization with chemical fertilizers and organic manure should be recommended as a preferable nutrient management system for intensive rice cultivation.
Michael Tyree; John Seiler; Thomas R. Fox
2006-01-01
Fertilization is becoming a common, cost effective treatment within managed forests of the Southeastern United States. However, there is little known about how fertilization will affect the belowground processes that drive soil CO2
Mitigation of Cd accumulation in paddy rice (Oryza sativa L.) by Fe fertilization.
Chen, Zhe; Tang, Ye-Tao; Yao, Ai-Jun; Cao, Jian; Wu, Zhuo-Hao; Peng, Zhe-Ran; Wang, Shi-Zhong; Xiao, Shi; Baker, Alan J M; Qiu, Rong-Liang
2017-12-01
Cadmium uptake in rice is believed to be mediated by the Fe transport system. Phyto-available Cd can be changed by Fe fertilization of substrates. This work investigated whether and how Fe fertilization affects mitigation of Cd accumulation in paddy rice. A 90-d soil column experiment was conducted to study the change of Cd and Fe availability in soil after Fe fertilization (ionic and chelated Fe). A low-Cd accumulating cultivar (TY116) and a high-Cd accumulating cultivar (JY841) were grown in two Cd-polluted paddy soils amended with chelated Fe fertilizers. Additionally, both cultivars were grown in hydroponics to compare Fe-related gene expression in EDDHAFe-deficient and EDDHAFe-sufficient roots. The column experiment showed that EDTANa 2 Fe(II) and EDDHAFe(III) fertilization had a better mitigation effect on soil Cd availability compared to FeSO 4 ·7H 2 O. Moreover, the field experiment demonstrated that these two chelated fertilizations could reduce Cd concentrations in brown rice by up to 80%. Iron concentrations in the brown rice were elevated by Fe chelates. Compared to EDDHAFe(III), EDTANa 2 Fe(II) fertilization had a stronger mitigation effect by generating more EDTANa 2 Cd(II) in the soil solution to decrease phyto-available Cd in the soil. While EDDHAFe(III) fertilization could increase soil pH and decrease soil Eh which contributed to decreasing phyto-available Cd in a contaminated soil. In the hydroponic experiment, Fe sufficiency significantly reduced Cd concentrations in above-ground organs. In some cases, the expression of OsIRT1, OsNRAMP1 and OsNRAMP5 was inhibited under Fe sufficiency relative to Fe deficiency conditions. These results suggest that mitigation of rice Cd by Fe chelate fertilization results from a decrease in available Cd in substrates and the inhibition of the expression of several Fe-related genes in the IRT and NRAMP families. Copyright © 2017 Elsevier Ltd. All rights reserved.
Yang, Lanqin; Huang, Biao; Mao, Mingcui; Yao, Lipeng; Hickethier, Martina; Hu, Wenyou
2015-05-01
Long-term heavy organic fertilizer application has linked greenhouse vegetable production (GVP) with trace metal contamination in north China. Given that trace metals release from fertilizers and their availability may be affected by discrepant environmental conditions, especially temperature under different greenhouses, this study investigated Cd, Cu, Pb, and Zn accumulation and contamination extent in soil as well as their phytoavailability under two major greenhouses in Tongshan, north China, namely solar greenhouse (SG) and round-arched plastic greenhouse (RAPG), to evaluate their presumed difference. The results showed significant Cd, Cu, Pb, and Zn accumulation in GVP soil by comparing with those in open-field soil, but their accumulation extent and rates were generally greater in SG than those in RAPG. This may be related to more release of trace metals to soil due to the acceleration of decomposition and humification process of organic fertilizers under higher soil temperature in SG relative to that in RAPG. Overall, soil in both greenhouses was generally less polluted or moderately polluted by the study metals. Similarly, decreased soil pH and elevated soil available metals in SG caused higher trace metals in leaf vegetables in SG than those in RAPG, although there was no obvious risk via vegetable consumption under both greenhouses. Lower soil pH may be predominantly ascribed to more intensive farming practices in SG while elevated soil available metals may be attributed to more release of dissolved organic matter-metal complexes from soil under higher temperature in SG. The data provided in this study may assist in developing reasonable and sustainable fertilization strategies to abate trace metal contamination in both greenhouses.
Tian, Jing; Wang, Jingyuan; Dippold, Michaela; Gao, Yang; Blagodatskaya, Evgenia; Kuzyakov, Yakov
2016-06-15
The application of biochar (BC) in conjunction with mineral fertilizers is one of the most promising management practices recommended to improve soil quality. However, the interactive mechanisms of BC and mineral fertilizer addition affecting microbial communities and functions associated with soil organic matter (SOM) cycling are poorly understood. We investigated the SOM in physical and chemical fractions, microbial community structure (using phospholipid fatty acid analysis, PLFA) and functions (by analyzing enzymes involved in C and N cycling and Biolog) in a 6-year field experiment with BC and NPK amendment. BC application increased total soil C and particulate organic C for 47.4-50.4% and 63.7-74.6%, respectively. The effects of BC on the microbial community and C-cycling enzymes were dependent on fertilization. Addition of BC alone did not change the microbial community compared with the control, but altered the microbial community structure in conjunction with NPK fertilization. SOM fractions accounted for 55% of the variance in the PLFA-related microbial community structure. The particulate organic N explained the largest variation in the microbial community structure. Microbial metabolic activity strongly increased after BC addition, particularly the utilization of amino acids and amines due to an increase in the activity of proteolytic (l-leucine aminopeptidase) enzymes. These results indicate that microorganisms start to mine N from the SOM to compensate for high C:N ratios after BC application, which consequently accelerate cycling of stable N. Concluding, BC in combination with NPK fertilizer application strongly affected microbial community composition and functions, which consequently influenced SOM cycling. Copyright © 2016 Elsevier B.V. All rights reserved.
Liu, Zhanjun; Rong, Qinlei; Zhou, Wei; Liang, Guoqing
2017-01-01
Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.
Liu, Zhanjun; Rong, Qinlei; Zhou, Wei; Liang, Guoqing
2017-01-01
Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil. PMID:28263999
Wang, Beibei; Wang, Qingling; Liu, Wuxing; Liu, Xiaoyan; Hou, Jinyu; Teng, Ying; Luo, Yongming; Christie, Peter
2017-09-01
Phytoremediation together with microorganisms may confer the advantages of both phytoremediation and microbial remediation of soils containing organic contaminants. In this system biosurfactants produced by Pseudomonas sp. SB may effectively help to increase the bioavailability of organic pollutants and thereby enhance their microbial degradation in soil. Plants may enhance the rhizosphere environment for microorganisms and thus promote the bioremediation of contaminants. In the present pot experiment study, dichlorodiphenyltrichloroethane (DDT) residues underwent an apparent decline after soil bioremediation compared with the original soil. The removal efficiency of fertilizer + tall fescue, fertilizer + tall fescue + Pseudomonas, fertilizer + perennial ryegrass, and fertilizer + perennial ryegrass + Pseudomonas treatments were 59.4, 65.6, 69.0, and 65.9%, respectively, and were generally higher than that in the fertilizer control (40.3%). Principal coordinates analysis (PCoA) verifies that plant species greatly affected the soil bacterial community irrespective of inoculation with Pseudomonas sp. SB. Furthermore, community composition analysis shows that Proteobacteria, Acidobacteria and Actinobacteria were the three dominant phyla in all groups. In particular, the relative abundance of Pseudomonas for fertilizer + tall fescue + Pseudomonas (0.25%) was significantly greater than fertilizer + tall fescue and this was related to the DDT removal efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.
Xia, Longlong; Lam, Shu Kee; Yan, Xiaoyuan; Chen, Deli
2017-07-05
Recycling of livestock manure in agroecosystems to partially substitute synthetic fertilizer nitrogen (N) input is recommended to alleviate the environmental degradation associated with synthetic N fertilization, which may also affect food security and soil greenhouse gas (GHG) emissions. However, how substituting livestock manure for synthetic N fertilizer affects crop productivity (crop yield; crop N uptake; N use efficiency), reactive N (Nr) losses (ammonia (NH 3 ) emission, N leaching and runoff), GHG (methane, CH 4 ; and nitrous oxide, N 2 O; carbon dioxide) emissions and soil organic carbon (SOC) sequestration in agroecosystems is not well understood. We conducted a global meta-analysis of 141 studies and found that substituting livestock manure for synthetic N fertilizer (with equivalent N rate) significantly increased crop yield by 4.4% and significantly decreased Nr losses via NH 3 emission by 26.8%, N leaching by 28.9% and N runoff by 26.2%. Moreover, annual SOC sequestration was significantly increased by 699.6 and 401.4 kg C ha -1 yr -1 in upland and paddy fields, respectively; CH 4 emission from paddy field was significantly increased by 41.2%, but no significant change of that was observed from upland field; N 2 O emission was not significantly affected by manure substitution in upland or paddy fields. In terms of net soil carbon balance, substituting manure for fertilizer increased carbon sink in upland field, but increased carbon source in paddy field. These results suggest that recycling of livestock manure in agroecosystems improves crop productivity, reduces Nr pollution and increases SOC storage. To attenuate the enhanced carbon source in paddy field, appropriate livestock manure management practices should be adopted.
Nivelle, Elodie; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry
2017-01-01
The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate. PMID:28552945
Nivelle, Elodie; Verzeaux, Julien; Chabot, Amélie; Roger, David; Spicher, Fabien; Lacoux, Jérôme; Nava-Saucedo, Jose-Edmundo; Catterou, Manuella; Tétu, Thierry
2017-01-01
The use of nitrogen (N) fertilizer and glyphosate-based herbicides is increasing worldwide, with agriculture holding the largest market share. The agronomic and socioeconomic utilities of glyphosate are well established; however, our knowledge of the potential effects of glyphosate applied in the presence or absence of long-term N fertilization on microbial functional activities and the availability of soil nutrients remains limited. Using an ex situ approach with soils that did (N+) or did not (N0) receive synthetic N fertilization for 6 years, we assessed the impact of different rates (no glyphosate, CK; field rate, FR; 100 × field rate, 100FR) of glyphosate application on biological and chemical parameters. We observed that, after immediate application (1 day), the highest dose of glyphosate (100FR) negatively affected the alkaline phosphatase (AlP) activity in soils without N fertilization history and decreased the cation exchange capacity (CEC) in N0 compared to CK and FR treatments with N+. Conversely, the 100FR application increased nitrate (NO3-) and available phosphorus (PO43-) regardless of N fertilization history. Then, after 8 and 15 days, the N+\\100FR and N+\\FR treatments exhibited the lowest values for dehydrogenase (DH) and AlP activities, respectively, while urease (URE) activity was mainly affected by N fertilization. After 15 days and irrespective of N fertilization history, the FR glyphosate application negatively affected the degradation of carbon substrates by microbial communities (expressed as the average well color development, AWCD). By contrast, the 100FR treatment positively affected AWCD, increasing PO43- by 5 and 16% and NO3- by 126 and 119% in the N+ and N0 treatments, respectively. In addition, the 100FR treatment resulted in an increase in the average net nitrification rate. Principal component analysis revealed that the 100FR glyphosate treatment selected microbial communities that were able to metabolize amine substrates. Overall, the lack of N fertilization in the 6 past years combined with the highest glyphosate application rate (100FR) induced the highest values of AWCD, functional diversity, NO3-, PO43- and nitrification. We concluded that the intensive use of N fertilization for 6 years may change the non-target effects of glyphosate application on enzyme activities. The functional activities, nitrification and nutrient contents were increased by glyphosate only when applied at 100 times the field application rate.
Fertilization of black spruce or poor site peatland in Minnesota.
David H. Alban; Richard F. Watt
1981-01-01
Fertilization of poor site black spruce on organic soil with various rates of nitrogen and phosphorus increased height and diameter growth from 2 to 4 times. The growth response declined with time but was still apparent 16 years after fertilization. Shrub biomass and coverage, and nutrient levels of spruce foliage were strongly affected by fertilization.
M.A. Radwan; Dean S. DeBell
1980-01-01
Twelve different nitrogen (N) fertilizer treatments were tested on potted western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings. Fertilizers affected soil N and pH, and growth and foliar chemical composition of seedlings. Urea plus N-Serve and sulfur-coated urea appear more promising for promoting growth than other fertilizers tested. Results...
USDA-ARS?s Scientific Manuscript database
Fertilizer use and tillage affect both the general soil microbial community and speci'c N-utilizing microbial groups, but likely to varying degrees. To assess these impacts, soil was collected on three key dates from a long-term (26+ years), rainfed, continuous maize site where tillage (no-till and ...
Effect of soil pH and organic matter on the adsorption and desorption of pentachlorophenol.
Chien, Shui-Wen Chang; Chen, Shou-Hung; Li, Chi-Jui
2018-02-01
Various properties of soil affect the partition of organic contaminants within, and conversely, the properties of the organic contaminants also directly affect their partition behavior in soil. Therefore, understanding the effects of various properties of soil on the partition of organic contaminants favors subsequent assessment and provides soil remediation methods for policymakers. This study selected pentachlorophenol (PCP), a common hydrophobic ionizable organic compound in contaminated sites worldwide, as the target contaminant. The effects of pH, organic matter, and the combination of both, on PCP adsorption/desorption behavior in soil were investigated. Phosphoric acid and potassium hydroxide were used as buffer solutions to modify the soil pH by the batch and column extraction methods. A common retail organic fertilizer and fulvic acid were selected as additives to manipulate the soil organic content. Modifying the pH of the soil samples revealed that acidic soil exhibited a greater PCP adsorption rate than alkaline soil. The amount of PCP desorption increased regardless of pH of the in situ contaminated soil. The adsorption of PCP increased with increasing amount of organic additive. However, addition of fulvic acid yielded different results compared to the addition of organic fertilizer. Specifically, the organic fertilizer could not compete with the in situ contaminated soil in PCP adsorption, whereas fulvic acids increased the PCP dissolution to facilitate adsorbing contaminant adsorption. The combined effect of pH modification and organic matter addition provides additional PCP adsorption sites; therefore, adding the organic fertilizer to decrease the soil pH elevated the PCP adsorption rates of the laterite, alluvial, and in situ contaminated soil samples. The study results revealed that both pH and organic matter content are crucial to PCP adsorption/desorption in soil. Therefore, the effects of soil pH and organic matter should be considered in facilitating PCP treatment for soil remediation.
Nitrous Oxide Emissions Affected by Biochar and Nitrogen Stabilizers
NASA Astrophysics Data System (ADS)
Gao, S.; Cai, Z.; Xu, M.
2016-12-01
Both biochar and N fertilizer stabilizers (N transformation inhibitors) are potential strategies to reduce nitrous oxide (N2O) emissions from fertilization, but the mechanisms and/or N transformation processes affecting the N dynamics are not fully understood. This research investigated N2O emissions and N transformations in soil amended with biochar and N transformation inhibitors. The soil was a sandy loam soil and adjusted to 10% soil water content and incubated at 25oC. Biochar amendment at 1% (w/w), Agrotain® Ultra (urease inhibitor), Agrotain® Plus (urease and nitrification inhibitor), and N-Serve® 24 (nitrification inhibitor) as well as another potential nitrification inhibitor, potassium thiosulfate (KTS), at 0.25-1:1 K2O/N ratios (w/w) were tested. Emissions of N2O, soil mineral N species change, and soil pH were determined for 35 days after fertilizers were applied. Biochar, Agrotain® Ultra or Plus, or N-Serve® 24 all effectively reduced N2O emissions by more than 60% as compared to no amendment control. The KTS, however, was only effective in reducing N2O emissions at a high ratio (1:1 K2O/N, w/w). There was a strong correlation between N2O emission and the concentration of nitrite (NO2-) in soil but not other mineral species. All the amendments showed that their effects on N transformation and N2O emissions were completed within a few weeks after application. Laboratory analysis indicated that biochar affected the N dynamics most likely via adsorption of ammonium (NH4+) and the inhibitors by affecting N transformation rate. This research has gained further understanding on how biochar and N stabilizers affect N2O emissions and the knowledge can assist in developing mitigation strategies.
Tang, Zhenya; Fan, Fangling; Wang, Xinyue; Shi, Xiaojun; Deng, Shiping; Wang, Dingyong
2018-04-15
High levels of mercury (Hg), especially methylmercury (MeHg), in rice is of concern due to its potential of entering food chain and the high toxicity to human. The level and form of Hg in rice could be influenced by fertilizers and other soil amendments. Studies were conducted to evaluate the effect of 24 years application of chemical fertilizers and organic amendments on total Hg (THg) and MeHg and their translocation in soil, plants, and rice grain. All treatments led to significantly higher concentrations of MeHg in grain than those from the untreated control. Of nine treatments tested, chemical fertilizers combining with returning rice straw (NPK1+S) led to highest MeHg concentration in grain and soil; while the nitrogen and potassium (NK) treatment led to significantly higher THg in grain. Concentrations of soil MeHg were significantly correlated with THg in soil (r = 0.59 *** ) and MeHg in grain (r = 0.48 *** ). Calcium superphosphate negatively affected plant bioavailability of soil Hg. MeHg concentration in rice was heavily influenced by soil Hg levels. Phosphorus fertilizer was a main source contributing to soil THg, while returning rice straw to the field contributed significantly to MeHg in soil and rice grain. As a result, caution should be exercised in soil treatment or when utilizing Hg-contaminated soils to produce rice for human consumption. Strategic management of rice straw and phosphorus fertilizer could be effective strategies of lowering soil Hg, which would ultimately lower MeHg in rice and the risk of Hg entering food chain. Copyright © 2017 Elsevier Inc. All rights reserved.
Li, Lihua; Fan, Fenliang; Song, Alin; Yin, Chang; Cui, Peiyuan; Li, Zhaojun; Liang, Yongchao
2017-06-01
The association between microbial communities and plant growth in long-term fertilization system has not been fully studied. In the present study, impacts of long-term fertilization have been determined on the size and activity of soil microbial communities and wheat performance in a red soil (Ultisol) collected from Qiyang Experimental Station, China. For this, different microbial communities originating from long-term fertilized pig manure (M), mineral fertilizer (NPK), pig manure plus mineral fertilizer (MNPK), and no fertilizer (CK) were used as inocula for the Ultisol tested. Changes in total bacterial and fungal community composition and structures using Ion Torrent sequencing were determined. The results show that the biomass of wheat was significantly higher in both sterilized soil inoculated with NPK (SNPK) and sterilized soil inoculated with MNPK (SMNPK) treatments than in other treatments (P < 0.05). The activities of β-1,4-N-acetylglucosaminidase (NAG) and cellobiohydrolase (CBH) were significantly correlated with wheat biomass. Among the microbial communities, the largest Ascomycota phylum in soils was negatively correlated with β-1,4-glucosidase (βG) (P < 0.05). The phylum Basidiomycota was negatively correlated with plant biomass (PB) and tillers per plant (TI) (P < 0.05). Nonmetric multidimensional scaling analysis shows that fungal community was strongly correlated with long-term fertilization strategy, while the bacterial community was strongly correlated with β-1,4-N-acetylglucosaminidase activity. According to the Mantel test, the growth of wheat was affected by fungal community. Taken together, microbial composition and diversity in soils could be a good player in predicting soil fertility and consequently plant growth.
Nutrient addition dramatically accelerates microbial community succession.
Knelman, Joseph E; Schmidt, Steven K; Lynch, Ryan C; Darcy, John L; Castle, Sarah C; Cleveland, Cory C; Nemergut, Diana R
2014-01-01
The ecological mechanisms driving community succession are widely debated, particularly for microorganisms. While successional soil microbial communities are known to undergo predictable changes in structure concomitant with shifts in a variety of edaphic properties, the causal mechanisms underlying these patterns are poorly understood. Thus, to specifically isolate how nutrients--important drivers of plant succession--affect soil microbial succession, we established a full factorial nitrogen (N) and phosphorus (P) fertilization plot experiment in recently deglaciated (∼3 years since exposure), unvegetated soils of the Puca Glacier forefield in Southeastern Peru. We evaluated soil properties and examined bacterial community composition in plots before and one year after fertilization. Fertilized soils were then compared to samples from three reference successional transects representing advancing stages of soil development ranging from 5 years to 85 years since exposure. We found that a single application of +NP fertilizer caused the soil bacterial community structure of the three-year old soils to most resemble the 85-year old soils after one year. Despite differences in a variety of soil edaphic properties between fertilizer plots and late successional soils, bacterial community composition of +NP plots converged with late successional communities. Thus, our work suggests a mechanism for microbial succession whereby changes in resource availability drive shifts in community composition, supporting a role for nutrient colimitation in primary succession. These results suggest that nutrients alone, independent of other edaphic factors that change with succession, act as an important control over soil microbial community development, greatly accelerating the rate of succession.
Nutrient Addition Dramatically Accelerates Microbial Community Succession
Knelman, Joseph E.; Schmidt, Steven K.; Lynch, Ryan C.; Darcy, John L.; Castle, Sarah C.; Cleveland, Cory C.; Nemergut, Diana R.
2014-01-01
The ecological mechanisms driving community succession are widely debated, particularly for microorganisms. While successional soil microbial communities are known to undergo predictable changes in structure concomitant with shifts in a variety of edaphic properties, the causal mechanisms underlying these patterns are poorly understood. Thus, to specifically isolate how nutrients – important drivers of plant succession – affect soil microbial succession, we established a full factorial nitrogen (N) and phosphorus (P) fertilization plot experiment in recently deglaciated (∼3 years since exposure), unvegetated soils of the Puca Glacier forefield in Southeastern Peru. We evaluated soil properties and examined bacterial community composition in plots before and one year after fertilization. Fertilized soils were then compared to samples from three reference successional transects representing advancing stages of soil development ranging from 5 years to 85 years since exposure. We found that a single application of +NP fertilizer caused the soil bacterial community structure of the three-year old soils to most resemble the 85-year old soils after one year. Despite differences in a variety of soil edaphic properties between fertilizer plots and late successional soils, bacterial community composition of +NP plots converged with late successional communities. Thus, our work suggests a mechanism for microbial succession whereby changes in resource availability drive shifts in community composition, supporting a role for nutrient colimitation in primary succession. These results suggest that nutrients alone, independent of other edaphic factors that change with succession, act as an important control over soil microbial community development, greatly accelerating the rate of succession. PMID:25050551
Cropping and sulfur fertilization influence on sulfur transformations in soil
DOE Office of Scientific and Technical Information (OSTI.GOV)
Castellano, S.D.; Dick, R.P.
A 2 year field study was conducted to determine the effects of two S fertilizers (CaSO{sub 4} {center dot} 2H{sub 2}O (CS) or elemental S (ES)) at two fertilization rates (0 or 50 kg S ha{sup {minus}1} year{sup {minus}1}) on the temporal distribution of soil S fractions (inorganic SO{sub 4}, ester sulfate, and C-bonded and residual S), arylsulfatase activity, and microbial-biomass C and S in soil. The soil studied (a fine-silty, mixed, mesic Aquultic Argixeroll) was cropped with winter rape, Brassica napus L. var. napus or left uncropped. Sulfate levels (0-15 cm depth) were significantly affected by S-fertilizer treatment. Duringmore » the rainy winter season,k SO{sub 4} levels ranged from 7 to 13 mg kg{sup {minus}1} in CS plots, compared with 2 to 7 mg kg{sup {minus}1} in control plots. In the months from March to May, biomass S increased and SO{sub 4} levels decreased (<6 mg SO{sub 4}-S kg{sup {minus}1} soil), indicating S immobilization was occurring in the spring. Ester sulfate and residual S varied seasonally, whereas C-bonded S showed minimal seasonal fluctuations. Cropping significantly increased biological activity (arylsulfatase activities and biomass C) over uncropped treatments. Subsoil SO{sub 4} in the 60- to 90-cm depth being significantly affected by cropping and S fertilization. The limitations of using extractable SO{sub 4} as a soil test were shown by wide variations in SO{sub 4} over time (2-14 mg SO{sub 4} hg{sup {minus}1} soil) in control plots, even though there was a seed yield response to S.« less
Giovannini, Camilla; Garcia-Mina, Josè M; Ciavatta, Claudio; Marzadori, Claudio
2009-06-10
The use of N-(n-butyl)thiophosphoric triamide (NBPT), as a urease inhibitor, is one of the most successful strategies utilized to increase the efficiency of urea-based fertilization. To date, NBPT has been added to the soil incorporated in fertilizers containing either urea or the inhibitor at a fixed percentage on the urea weight. The possibility of using NBPT physically separated from urea-based fertilizers could make its use more flexible. In particular, a granulated product containing NBPT could be utilized in soils treated with different urea-based fertilizers including livestock urine, the amount depending on soil characteristics and/or the urea source (e.g., mineral fertilizer, organo-mineral fertilizer, or animal slurry). In this study, a multilayer soil column device was used to investigate the influence of an experimental granular product (RV) containing NBPT and a garlic extract, combining the ability to protect NBPT by oxidation and nitrification inhibition activity, on (a) spatial variability of soil urease and nitrification activities and (b) timing of urea hydrolysis and mineral-N form accumulation (NO(2)(-), NO(3)(-), NH(4)(+)) in soil treated with urea. The results clearly demonstrated that RV can, effectively, inhibit the soil urease activity along the soil column profile up to 8-10 cm soil layer depth and that the inhibition power of RV was dependent on time and soil depth. However, nitrification activity is not significantly influenced by RV addition. In addition, the soil N transformations were clearly affected by RV; in fact, RV retarded urea hydrolysis and reduced the accumulation of NH(4)(+)-N and NO(2)(-)-N ions along the soil profile. The RV product was demonstrated to be an innovative additive able to modify some key ureic N trasformation processes correlated with the efficiency of the urea-based fertilization, in a soil column higher than 10 cm.
N fertilization reduces the losses of old soil organic carbon
NASA Astrophysics Data System (ADS)
Zang, H.; Blagodatskaya, E.; Wang, J.; Kuzyakov, Y.; Xu, X.
2016-12-01
Agricultural soils have experiencing large anthropogenic nitrogen (N) inputs, which directly and indirectly affect soil organic matter (SOM) stocks and CO2 emissions. However, current understanding of how these additional N inputs affect SOM pools of various ages and turnover remains incomplete. The δ13C values of SOM after wheat (C3) - maize (C4) vegetation change enable to calculate the contribution of C4-derived rhizodeposited C (rhizo-C) and C3-derived old SOM pools. Soil (Ap from Haplic Luvisol) sampled from maize rhizosphere was incubated over 56 days after increasing N fertilization (4 levels up to 300 kg N ha-1). N fertilization decreased soil CO2 emissions by 27-42% as compared to unfertilized control. This decrease was mainly caused by the retardation of old C mineralization. The relative availability of rhizo-C (released by maize roots within 4 weeks) for microorganisms was about 10 times higher than of old C (older than 4 weeks). Microbial biomass and dissolved organic C were unaffected by increasing N. N fertilization, however, increased relative contribution of rhizo-C to microbial biomass for 2 - 5 times and to CO2 for about 2 times. This clearly reflects acceleration of microbial biomass turnover by N addition. The decomposition rate of rhizo-C was 3.7 times higher than of old C, and it increased additionally by the factor of 6.5 under high N fertilization. Our study is the first estimated the turnover and incorporation of very recent rhizo-C (within 4 weeks). Compared with several-years old C4, the turnover of rhizo-C was about 2 times faster. Concluding, the contribution of rhizo-C to CO2 and microbial biomass was highly responsive to N fertilization. N fertilization facilitates C sequestration in agricultural soils by decreasing old SOM decomposition mainly through increase the turnover and C use efficiency of rhizo-C. Keywords: CO2 partitioning; C3-C4 vegetation; microbial biomass; SOM decomposition; Nutrient availability
Sainju, Upendra M; Stevens, William B; Caesar-Tonthat, Thecan; Liebig, Mark A
2012-01-01
Management practices, such as irrigation, tillage, cropping system, and N fertilization, may influence soil greenhouse gas (GHG) emissions. We quantified the effects of irrigation, tillage, crop rotation, and N fertilization on soil CO, NO, and CH emissions from March to November, 2008 to 2011 in a Lihen sandy loam in western North Dakota. Treatments were two irrigation practices (irrigated and nonirrigated) and five cropping systems (conventional-tilled malt barley [ L.] with N fertilizer [CT-N], conventional-tilled malt barley with no N fertilizer [CT-C], no-tilled malt barley-pea [ L.] with N fertilizer [NT-PN], no-tilled malt barley with N fertilizer [NT-N], and no-tilled malt barley with no N fertilizer [NT-C]). The GHG fluxes varied with date of sampling and peaked immediately after precipitation, irrigation, and/or N fertilization events during increased soil temperature. Both CO and NO fluxes were greater in CT-N under the irrigated condition, but CH uptake was greater in NT-PN under the nonirrigated condition than in other treatments. Although tillage and N fertilization increased CO and NO fluxes by 8 to 30%, N fertilization and monocropping reduced CH uptake by 39 to 40%. The NT-PN, regardless of irrigation, might mitigate GHG emissions by reducing CO and NO emissions and increasing CH uptake relative to other treatments. To account for global warming potential for such a practice, information on productions associated with CO emissions along with NO and CH fluxes is needed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Soil-test biological activity in corn production systems: II. Greenhouse growth bioassay
USDA-ARS?s Scientific Manuscript database
Soil N mineralization is variably affected by management and edaphic conditions. A routine soil test is needed to make better predictions for N fertilizer recommendations to cereal grains on different soil types and landscape settings. We collected soils from 47 corn production fields in North Car...
Jian, Siyang; Li, Jianwei; Chen, Ji; ...
2016-07-08
Nitrogen (N) fertilization affects the rate of soil organic carbon (SOC) decomposition by regulating extracellular enzyme activities (EEA). Extracellular enzymes have not been represented in global biogeochemical models. Understanding the relationships among EEA and SOC, soil N (TN), and soil microbial biomass carbon (MBC) under N fertilization would enable modeling of the influence of EEA on SOC decomposition. Based on 65 published studies, we synthesized the activities of α-1,4-glucosidase (AG), β-1,4-glucosidase (BG), β-d-cellobiosidase (CBH), β-1,4-xylosidase (BX), β-1,4-N-acetyl-glucosaminidase (NAG), leucine amino peptidase (LAP), urease (UREA), acid phosphatase (AP), phenol oxidase (PHO), and peroxidase (PEO) in response to N fertilization. Here, themore » proxy variables for hydrolytic C acquisition enzymes (C-acq), N acquisition (N-acq), and oxidative decomposition (OX) were calculated as the sum of AG, BG, CBH and BX; AG and LAP; PHO and PEO, respectively.« less
Urrutia, Oscar; Erro, Javier; Zabini, Andre; Hoshiba, Kent; Blandin, Anne F; Baigorri, Roberto; Martín-Pastor, Manuel; Alis, Yves; Yvin, Jean C; García-Mina, José M
2018-05-16
This study describes the efficiency of a new coating material for preparing granulated potassium-fertilizers with a potassium release to the soil solution sensitive to rainfall intensity. The composite is prepared by reaction of an alkyd-resin with cement in the absence of water. The complementary use of diverse analytical techniques showed that the presence of the cement fraction induced alkyd resin reticulation and gradual cement-resin hardening. Scanning electron microscopy revealed the formation of micro and nanopores within cement-clusters, whose water permeability is affected by the resin reticulation and amphiphilic character. Potassium release was evaluated in water, soil-columns, and in soil-plant trials in pots and open-field. Agronomic results were consistent with potassium release rates obtained in water solution and soil columns. The composite-coated potassium fertilizer was more efficient than the noncoated one in providing plant available potassium, with this effect being dependent on water presence in soil.
Fertilizer placement to maximize nitrogen use by fescue
USDA-ARS?s Scientific Manuscript database
The method of fertilizer nitrogen(N) application can affect N uptake in tall fescue and therefore its yield and quality. Subsurface-banding (knife) of fertilizer maximizes fescue N uptake in the poorly-drained clay–pan soils of southeastern Kansas. This study was conducted to determine if knifed N r...
[Effects of organic-inorganic mixed fertilizers on rice yield and nitrogen use efficiency].
Zhang, Xiao-li; Meng, Lin; Wang, Qiu-jun; Luo, Jia; Huang, Qi-wei; Xu, Yang-chun; Yang, Xing-ming; Shen, Qi-rong
2009-03-01
A field experiment was carried to study the effects of organic-inorganic mixed fertilizers on rice yield, nitrogen (N) use efficiency, soil N supply, and soil microbial diversity. Rapeseed cake compost (RCC), pig manure compost (PMC), and Chinese medicine residue compost (MRC) were mixed with chemical N, P and K fertilizers. All the treatments except CK received the same rate of N. The results showed that all N fertilizer application treatments had higher rice yield (7918.8-9449.2 kg x hm(-2)) than the control (6947.9 kg x hm(-2)). Compared with that of chemical fertilizers (CF) treatment (7918.8 kg x hm(-2)), the yield of the three organic-inorganic mixed fertilizers treatments ranged in 8532.0-9449.2 kg x hm(-2), and the increment was 7.7%-19.3%. Compared with treatment CF, the treatments of organic-inorganic mixed fertilizers were significantly higher in N accumulation, N transportation efficiency, N recovery rate, agronomic N use efficiency, and physiological N use efficiency. These mixed fertilizers treatments promoted rice N uptake and improved soil N supply, and thus, increased N use efficiency, compared with treatments CF and CK. Neighbor joining analysis indicated that soil bacterial communities in the five treatments could be classified into three categories, i.e., CF and CK, PMC and MRC, and RCC, implying that the application of exogenous organic materials could affect soil bacterial communities, while applying chemical fertilizers had little effect on them.
Wang, Bing; Liu, Huiling; Cai, Chen; Thabit, Mohamed; Wang, Pu; Li, Guomin; Duan, Ziheng
2016-10-01
The dry mycelium fertilizer (DMF) was produced from penicillin fermentation fungi mycelium (PFFM) following an acid-heating pretreatment to degrade the residual penicillin. In this study, it was applied into soil as fertilizer to investigate its effects on soil properties, phytotoxicity, microbial community composition, enzyme activities, and growth of snap bean in greenhouse. As the results show, pH, total nitrogen, total phosphorus, total potassium, and organic matter of soil with DMF treatments were generally higher than CON treatment. In addition, the applied DMF did not cause heavy metal and residual drug pollution of the modified soil. The lowest GI values (<0.3) were recorded at DMF8 (36 kg DMF/plat) on the first days after applying the fertilizer, indicating that severe phytotoxicity appeared in the DMF8-modified soil. Results of microbial population and enzyme activities illustrated that DMF was rapidly decomposed and the decomposition process significantly affected microbial growth and enzyme activities. The DMF-modified soil phytotoxicity decreased at the late fertilization time. DMF1 was considered as the optimum amount of DMF dose based on principal component analysis scores. Plant height and plant yield of snap bean were remarkably enhanced with the optimum DMF dose.
Koyama, Akihiro; Wallenstein, Matthew D.; Simpson, Rodney T.; Moore, John C.
2013-01-01
Climate-induced warming of the Arctic tundra is expected to increase nutrient availability to soil microbes, which in turn may accelerate soil organic matter (SOM) decomposition. We increased nutrient availability via fertilization to investigate the microbial response via soil enzyme activities. Specifically, we measured potential activities of seven enzymes at four temperatures in three soil profiles (organic, organic/mineral interface, and mineral) from untreated native soils and from soils which had been fertilized with nitrogen (N) and phosphorus (P) since 1989 (23 years) and 2006 (six years). Fertilized plots within the 1989 site received annual additions of 10 g N⋅m-2⋅year-1 and 5 g P⋅m-2⋅year-1. Within the 2006 site, two fertilizer regimes were established – one in which plots received 5 g N⋅m-2⋅year-1 and 2.5 g P⋅m-2⋅year-1 and one in which plots received 10 g N⋅m-2⋅year-1 and 5 g P⋅m-2⋅year-1. The fertilization treatments increased activities of enzymes hydrolyzing carbon (C)-rich compounds but decreased phosphatase activities, especially in the organic soils. Activities of two enzymes that degrade N-rich compounds were not affected by the fertilization treatments. The fertilization treatments increased ratios of enzyme activities degrading C-rich compounds to those for N-rich compounds or phosphate, which could lead to changes in SOM chemistry over the long term and to losses of soil C. Accelerated SOM decomposition caused by increased nutrient availability could significantly offset predicted increased C fixation via stimulated net primary productivity in Arctic tundra ecosystems. PMID:24204773
NASA Astrophysics Data System (ADS)
Chen, Zhaoming; Wang, Huoyan; Liu, Xiaowei; Lu, Dianjun; Zhou, Jianmin
2016-10-01
Appropriate fertilization practice is crucial to achieve maximum wheat grain yield with minimum nitrogen (N) loss. A field 15N micro-plot experiment was conducted to determine the effects of application methods [split application (SA) and band application (BA)] and N rates (60, 150 and 240 kg ha-1) on the wheat grain yield, urea-15N fate and N efficiency in Jiangyan County, China. At high N rates, wheat grain yield was significantly higher for SA than BA treatment, but there was no difference at the lower N rates. Plant N derived from fertilizer was higher in SA than in BA treatment. The high N fertilizer application increased total N uptake by wheat derived from fertilizer, but wheat plant N derived from soil was not affected by the N rate. Fertilizer-N recovery in SA treatment was higher than in BA treatment. Residual N recovery in the 0-80 cm soil layer was 31-51%, which decreased with increasing N rate. The highest N loss was found for BA treatment at the N application of 240 kg ha-1. The one-time BA of N fertilizer, especially for higher N rates, led to reduced wheat grain yield and N efficiency, and increased the N loss.
NASA Astrophysics Data System (ADS)
Hillhouse, Heidi L.; Schacht, Walter H.; Soper, Jonathan M.; Wienhold, Carol E.
2018-01-01
Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction ("cut-slope soils") is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warm-season grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and phosphorus fertilization, and also topsoil amendment, on the foliar cover of seeded and non-seeded species planted into two post-construction roadside sites in eastern Nebraska. We also examined soil movement to determine how planting protocols and plant growth may affect erosion potential. Three years after planting, we found no consistent effects of N or P fertilization on foliar cover. Plots receiving topsoil amendment had 14% greater cover of warm-season grasses, 10% greater total foliar cover, and 4-13% lower bare ground (depending on site) than plots without topsoil. None of the treatments consistently affected soil movement. We recommend that NDOT change their protocols to remove N and P fertilization and focus on stockpiling and spreading topsoil following construction.
Lu, Shuang; Quan, Wang; Wang, Shao-Ming; Liu, Hong-Ling; Tan, Yong; Zeng, Guang-Ping; Zhang, Xia
2013-04-01
Microbial community structure and ecological functions are influenced by interactions between above and belowground biota. There is an urgent need for intensive monitoring of microbes feedback of soil micro-ecosystem for setting up a good agricultural practice. Recent researches have revealed that many soils characteristic can effect microbial community structure. In the present study factors affecting microbial community structure and soil in Carthamus tinctorius plantations in arid agricultural ecosystem of northern Xinjiang, China were identified. The result of the study revealed that soil type was the key factor in safflower yield; Unscientific field management resulted high fertility level (bacteria dominant) of soil to turn to low fertility level (fungi dominant), and Detruded Canonical Correspondence Analysis (DCCA) showed that soil water content, organic matter, available N, P and K were the dominant factors affecting distribution of microbial community. Soil water content showed a significant positive correlation with soil microbes quantity (P < 0.01), while others showed a significant quantity correlation with soil microbe quantity (P < 0.05).
Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.
Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S
2016-09-01
We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality.
NASA Astrophysics Data System (ADS)
Zhao, Erni; Xu, Lirong; Wang, Rongzhen
2018-01-01
Unreasonable application of irrigation and fertilizer will cause the waste of water and nitrogen and environmental pollution. In this paper, a series of soil-pit experiments were carried out to study the distribution and leaching loss of nitrogen in winter wheat’s soil. The results showed that NO3 - concentration at 20-80cm depth mainly responded to fertilizer application at the beginning of field experiment, but the amount of irrigation became the dominant factor with the growth of winter wheat. It is noteworthy that the distribution of NO3 - was mainly affected by the amount of fertilizer applied at the depth of 120-160cm in the whole period of growth of winter wheat. The accumulation position of NH4 + was deepened as the amount of irrigation increased, however, the maximum aggregation depth of ammonium nitrogen was no more than 80cm owing to its poor migration. It can be concluded that the influence of irrigation amount on the concentration of NH4 + in soil solution was more obvious than that of fertilizer. Compared with fertilizer, the amount of irrigation played a leading role in the utilization ratio of nitrogen and the yield of winter wheat. In summary, the best water and fertilizer treatment occurred in No.3 soil-pit, which meant that the middle amount of water and fertilizer could get higher wheat yield and less nitrogen leaching losses in the study area.
NASA Astrophysics Data System (ADS)
Hobley, Eleanor; Honermeier, Bernd; Don, Axel; Amelung, Wulf; Kögel-Knabner, Ingrid
2017-04-01
Crop fertilization provides vital plant nutrients (e.g. NPK) to ensure yield security but is also associated with negative environmental impacts. In particular, inorganic, mineral nitrogen (Nmin) fertilization leads to emissions during its energy intensive production as well as Nmin leaching to receiving waters. Incorporating legumes into crop rotations can provide organic N to the soil and subsequent crops, reducing the need for mineral N fertilizer and its negative environmental impacts. An added bonus is the potential to enhance soil organic carbon stocks, thereby reducing atmospheric CO2 concentrations. In this study we assessed the effects of legumes in rotation and fertilization regimes on the depth distribution - down to 1 m - of total soil nitrogen (Ntot), soil organic carbon (SOC) as well as isotopic composition (δ13C, δ15N), electrical conductivity and bulk density as well as agricultural yields at a long-term field experiment in Gießen, Germany. Fertilization had significant but small impacts on the soil chemical environment, most particularly the salt content of the soil, with PK fertilization increasing electrical conductivity throughout the soil profile. Similarly, fertilization resulted in a small reduction of soil pH throughout the soil profile. N fertilization, in particular, significantly increased yields, whereas PK fertilizer had only marginal yield effects, indicating that these systems are N limited. This N limitation was confirmed by significant yield benefits with leguminous crops in rotation, even in combination with mineral N fertilizer. The soil was physically and chemically influenced by the choice of crop rotation. Adding clover as a green mulch crop once every 4 years resulted in an enrichment of total N and SOC at the surface compared with fava beans and maize, but only in combination with PK fertilization. In contrast, fava beans and to a lesser extent maize in rotation lowered bulk densities in the subsoil compared with clover. This resulted in a reduction of N density at depth, which was not mirrored in C densities, indicating that fava beans decouple C and N cycles in the deep soil profile. We then tested whether these effects are a result of plant (i.e. enhanced rooting depth associated with lowered subsoil bulk density) or microbial (i.e. N-cycling and denitrification processes) activities, by investigating the isotopic signatures of C and N down the profile. Our results indicate that the selection of crop rotation influences soil C and N cycling and depth distribution. Although mineral N fertilizer has significant benefits for yield, the choice of crop rotation has a greater influence on soil C and N cycling and specifically the addition of leguminous plants into rotation can provide additional yield benefits and stability. Incorporating legumes into crop rotations affects soil physical and chemical properties and decouples C and N cycles in the deep soil profile, indicating different nutrient and water cycling processes in the deep soil profile.
Mogren, Lars M; Caspersen, Siri; Olsson, Marie E; Gertsson, Ulla E
2008-01-23
Field-cured onions cv. Hyskin ( Allium cepa L.) supplied with organic nitrogen fertilizer were studied. The fertilizer was applied by broadcasting and harrowing, broadcasting and rotary cultivation, or placement between rows. Nitrogen dynamics were monitored throughout the growing season by soil sampling. Variation in quercetin content in the onion scales was analyzed by HPLC. The organically fertilized onions were compared with inorganically fertilized onions grown in the same field. Inoculation with arbuscular mycorrhizal fungi (AMF) in the row at sowing or during commercial transplant production was tested but did not significantly affect mycorrhizal root colonization levels in the field. Onions that received no fertilizer at all or that had fertilizer placed between rows had better establishment, probably due to more favorable soil nitrogen concentrations for seedling emergence. Broadcast application led to higher nitrogen concentration in the root zone, resulting in fewer but larger individual onions. Quercetin levels were not significantly altered as a result of nitrogen fertilizer source (inorganic or organic), application method, or mycorrhizal inoculation. However, variation between years was significant, with quercetin levels in 2004 almost twice as high as those in 2005.
Fungi benefit from two decades of increased nutrient availability in tundra heath soil.
Rinnan, Riikka; Michelsen, Anders; Bååth, Erland
2013-01-01
If microbial degradation of carbon substrates in arctic soil is stimulated by climatic warming, this would be a significant positive feedback on global change. With data from a climate change experiment in Northern Sweden we show that warming and enhanced soil nutrient availability, which is a predicted long-term consequence of climatic warming and mimicked by fertilization, both increase soil microbial biomass. However, while fertilization increased the relative abundance of fungi, warming caused only a minimal shift in the microbial community composition based on the phospholipid fatty acid (PLFA) and neutral lipid fatty acid (NLFA) profiles. The function of the microbial community was also differently affected, as indicated by stable isotope probing of PLFA and NLFA. We demonstrate that two decades of fertilization have favored fungi relative to bacteria, and increased the turnover of complex organic compounds such as vanillin, while warming has had no such effects. Furthermore, the NLFA-to-PLFA ratio for (13)C-incorporation from acetate increased in warmed plots but not in fertilized ones. Thus, fertilization cannot be used as a proxy for effects on warming in arctic tundra soils. Furthermore, the different functional responses suggest that the biomass increase found in both fertilized and warmed plots was mediated via different mechanisms.
NASA Astrophysics Data System (ADS)
Deppe, Marianna; Well, Reinhard; Giesemann, Anette; Kücke, Martin; Flessa, Heinz
2013-04-01
N2O emitted from soil originates either from denitrification of nitrate and/or nitrification of ammonium. N fertilization can have an important impact on N2O emission rates. Injection of nitrate-free ammonium-N fertilizer, in Germany also known as CULTAN (Controlled Uptake Long-Term Ammonium Nutrition), results in fertilizer depots with ammonium concentrations of up to 10 mg N g-1 soil-1. High concentrations of ammonium are known to inhibit nitrification. However, it has not yet been clarified how N2O fluxes are affected by CULTAN. In a field experiment, two application methods of nitrogen fertilizer were used at a loamy sand site: Ammonium sulphate was applied either by point injection or by surface application. 15N-ammonium sulphate was used to distinguish between N2O originating from either fertilizer-N or soil-N. Unfertilized plots and plots fertilized with unlabeled ammonium sulphate served as control. N2O emissions were measured using static chambers, nitrate and ammonium concentrations were determined in soil extracts. Stable isotope analysis of 15N in N2O, nitrate and ammonium was used to calculate the contribution of fertilizer N to N2O emissions and the fertilizer turnover in soil. 15N analysis clearly indicated that fertilizer derived N2O fluxes were higher from surface application plots. For the period of the growing season, about 24% of the flux measured in surface application treatment and less than 10% from injection treatment plots originated from the fertilizer. In addition, a lab experiment was conducted to gain insight into processes leading to N2O emission from fertilizer depots. One aim was to examine whether the ratio of N2O to nitrate formation differs depending on the ammonium concentration. Loamy sand soil was incubated in microcosms continuously flushed with air under conditions favouring nitrification. 15N-labeled nitrate was used to differentiate between nitrification and denitrification. Stable isotope analyses of 15N were performed on N2O in the gas phase and on ammonium and nitrate extracted from soil samples.
NASA Astrophysics Data System (ADS)
Setiawati, Mieke Rochimi; Damayani, Maya; Herdiyantoro, Diyan; Suryatmana, Pujawati; Anggraini, Derisfha; Khumairah, Fiqriah Hanum
2018-02-01
The yield of rice plants is strongly influenced by N fertilizer. Nitrogen in rice plants has roles in vegetative growth, tiller formation and increasing yield through rice protein formation. Nitrogen supplied from organic fertilizers is better than inorganic fertilizers that may have environmental problem effects. Organic fertilizers from Azolla pinnata water fern contain higher N than other organic fertilizers. Symbiosis between A. pinnata and the N-fixing cyanobacteria results in high content of nitrogen, 3 to 5%. A. pinnata can be added to the rice field as organic fertilizer in form of fresh biomass or composted. Composted form can be ground into powder which passes through 100 mesh sieve. Preparation of compost powder of A. pinnata is done to reduce the constraints of voluminous application of organic fertilizers and to improve the efficiency of its use. The objective of this research was to compare the effect of the use of fresh A. pinnata and compost powder of A. pinnata on some soil and plant chemical properties and rice yield. The treatments applied were fresh A. pinnata at the dose of 0, 10 and 20 ton ha-1 and A. pinnata compost powder at 12.5 and 25 kg ha-1. The results showed that incorporation of fresh A. pinnata at 20 tons ha-1 and its compost powder at 25 kg ha-1 increased the available P of soil, plant P content and tiller number, but did not affect the content of organic-C, total soil N, plant N content and rice yield. This study suggested the benefits of A. pinnata compost powder technology in organic fertilization of soil to increase the nutrient content of soil and rice plants.
Liu, Enke; Yan, Changrong; Mei, Xurong; Zhang, Yanqing; Fan, Tinglu
2013-01-01
An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0-100 cm) in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK), nitrogen fertilizer (N), nitrogen and phosphorus (P) fertilizers (NP), straw plus N and P fertilizers (NP+S), farmyard manure (FYM), and farmyard manure plus N and P fertilizers (NP+FYM). Results showed that SOC concentration in the 0-20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0-60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0-60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0-60 cm depth. The average concentration of particulate organic carbon (POC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM) in 0-60 cm depth were increased by 64.9-91.9%, 42.5-56.9%, and 74.7-99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization.
Liao, Hao; Zhang, Yuchen; Zuo, Qinyan; Du, Binbin; Chen, Wenli; Wei, Dan; Huang, Qiaoyun
2018-04-20
Soils, with non-uniform distribution of nutrients across different aggregate-size fractions, provide spatially heterogeneous microhabitats for microorganisms. However, very limited information is available on microbial distributions and their response to fertilizations across aggregate-size fractions in agricultural soils. Here, we examined the structures of bacterial and fungal communities across different aggregate-size fractions (2000-250 μm, 250-53 μm and <53 μm) in response to 35-years organic and/or chemical fertilization regimes in the soil of northeastern China by phospholipid fatty acid (PLFA) and high throughput sequencing (HTS) technology. Our results show that larger fractions (>53 μm), especially 250-53 μm aggregates, which contain more soil C and N, are associated with greater microbial biomass and higher fungi/bacteria ratio. We firstly reported the fungal community composition in different aggregate-size fractions by HTS technology and found more Ascomycota but less Zygomycota in larger fractions with higher C content across all fertilization regimes. Fertilization and aggregate-size fractions significantly affect the compositions of bacterial and fungal communities although their effects are different. The bacterial community is mainly driven by fertilization, especially chemical fertilizers, and is closely related to the shifts of soil P (phosphorus). The fungal community is preferentially impacted by different aggregate-size fractions and is more associated with the changes of soil C and N. The distinct responses of microbial communities suggest different mechanisms controlling the assembly of soil bacterial and fungal communities at aggregate scale. The investigations of both bacterial and fungal communities could provide a better understanding on nutrient cycling across aggregate-size fractions. Copyright © 2018. Published by Elsevier B.V.
Conifers growing on anthracite mine soils respond to fertilization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davidson, W.H.; Sowa, E.A.
1982-12-01
Anthracite mine soils will support vegetation. To confirm this one needs only to look at the sizeable number of acres revegetated since passage of the 1963 Pennsylvania Anthracite Strip Mine and Conservation Act. In spite of the large number of acres revegetated, many planted trees, particularly conifers, grow poorly on anthracite mine soils. It is not uncommon for trees of a single species to differ widely in growth, not only from one mine soil to another but even on the same one. Studies were conducted on anthracite mine soils and breaker refuse to examine the growth response of some plantedmore » conifers to 1) slow-release fertilizer and 2) granular fertilizer. Annual height growth was used to measure response. Japanese larch (Larix leptolepis) growing on mine soil responded to slow-release fertilizer in the first year. Red (Pinus resinosa), white (P. strobus), and Austrian (P. nigra) pines did not respond until the second year after treatment. The response lasted for 3 years. This fertilizer did not affect growth of white spruce (Picea glauca) on mine soil, but it had a significant effect for the full, 4 year term of the study on Austrian pine growing on coal breaker refuse. Red and Scotch (P. sylvestris) pines on breaker refuse did not respond to granular fertilizer until the third year and the response was short-lived. Even though significant growth responses were obtained with these treatments, the height differences were relatively small.« less
Meier, Elizabeth A; Thorburn, Peter J
2016-01-01
The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues ('trash'). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a 'trash blanket' in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer rates for crops when trash was retained (≤20 kg N ha(-1) per plant or ratoon crop) while maintaining ≥95% of maximum yields. While these savings in N fertilizer use were modest at the field scale, they were potentially important when aggregated at the regional level.
Oszust, Karolina; Frąc, Magdalena; Gryta, Agata; Bilińska, Nina
2014-01-01
The knowledge about microorganisms—activity and diversity under hop production is still limited. We assumed that, different systems of hop production (within the same soil and climatic conditions) significantly influence on the composition of soil microbial populations and its functional activity (metabolic potential). Therefore, we compared a set of soil microbial properties in the field experiment of two hop production systems (a) ecological based on the use of probiotic preparations and organic fertilization (b) conventional—with the use of chemical pesticides and mineral fertilizers. Soil analyses included following microbial properties: The total number microorganisms, a bunch of soil enzyme activities, the catabolic potential was also assessed following Biolog EcoPlates®. Moreover, the abundance of ammonia-oxidizing archaea (AOA) was characterized by terminal restriction fragment length polymorphism analysis (T-RFLP) of PCR ammonia monooxygenase α-subunit (amoA) gene products. Conventional and ecological systems of hop production were able to affect soil microbial state in different seasonal manner. Favorable effect on soil microbial activity met under ecological, was more probably due to livestock-based manure and fermented plant extracts application. No negative influence on conventional hopyard soil was revealed. Both type of production fulfilled fertilizing demands. Under ecological production it was due to livestock-based manure fertilizers and fermented plant extracts application. PMID:24897025
Using iron fertilizer to control Cd accumulation in rice plants: a new promising technology.
Shao, GuoSheng; Chen, MingXue; Wang, DanYing; Xu, ChunMei; Mou, RenXiang; Cao, ZhaoYun; Zhang, XiuFu
2008-03-01
Effects of two kinds of iron fertilizer, FeSO4 and EDTA.Na2Fe were studied on cadmium accumulation in rice plants with two rice genotypes, Zhongzao 22 and Zhongjiazao 02, with soil culture systems. The results showed that application of iron fertilizers could hardly make adverse effects on plant growth and rice grain yield. Soil application of EDTA.Na2Fe significantly reduced the Cd accumulation in rice roots, shoots and rice grain. Cd concentration in white rice of both rice genotypes in the treatment of soil application of EDTA.Na2Fe was much lower than 0.2 mg/kg, the maximal Cd permission concentration in cereal crop foods in State standard. However, soil application of FeSO4 or foliar application of FeSO4 or EDTA.Na2Fe resulted in the significant increase of Cd accumulation in rice plants including rice grain compared with the control. The results also showed iron fertilizers increased the concentration of iron, copper and manganese element in rice grain and also affected zinc concentration in plants. It may be a new promising way to regulate Cd accumulation in rice grain in rice production through soil application of EDTA.Na2Fe fertilizers to maintain higher content of available iron and ferrous iron in soils.
Williams, Alwyn; Manoharan, Lokeshwaran; Rosenstock, Nicholas P; Olsson, Pål Axel; Hedlund, Katarina
2017-01-01
Agricultural fertilization significantly affects arbuscular mycorrhizal fungal (AMF) community composition. However, the functional implications of community shifts are unknown, limiting understanding of the role of AMF in agriculture. We assessed AMF community composition at four sites managed under the same nitrogen (N) and phosphorus (P) fertilizer regimes for 55 yr. We also established a glasshouse experiment with the same soils to investigate AMF-barley (Hordeum vulgare) nutrient exchange, using carbon ( 13 C) and 33 P isotopic labelling. N fertilization affected AMF community composition, reducing diversity; P had no effect. In the glasshouse, AMF contribution to plant P declined with P fertilization, but was unaffected by N. Barley C allocation to AMF also declined with P fertilization. As N fertilization increased, C allocation to AMF per unit of P exchanged increased. This occurred with and without P fertilization, and was concomitant with reduced barley biomass. AMF community composition showed no relationship with glasshouse experiment results. The results indicate that plants can reduce C allocation to AMF in response to P fertilization. Under N fertilization, plants allocate an increasing amount of C to AMF and receive relatively less P. This suggests an alteration in the terms of P-C exchange under N fertilization regardless of soil P status. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
Boot, Claudia M.; Hall, Ed K.; Denef, Karolien; Baron, Jill S.
2016-01-01
Elevated nitrogen (N) deposition due to increased fossil fuel combustion and agricultural practices has altered global carbon (C) cycling. Additions of reactive N to N-limited environments are typically accompanied by increases in plant biomass. Soil C dynamics, however, have shown a range of different responses to the addition of reactive N that seem to be ecosystem dependent. We evaluated the effect of N amendments on biogeochemical characteristics and microbial responses of subalpine forest organic soils in order to develop a mechanistic understanding of how soils are affected by N amendments in subalpine ecosystems. We measured a suite of responses across three years (2011–2013) during two seasons (spring and fall). Following 17 years of N amendments, fertilized soils were more acidic (control mean 5.09, fertilized mean 4.68), and had lower %C (control mean 33.7% C, fertilized mean 29.8% C) and microbial biomass C by 22% relative to control plots. Shifts in biogeochemical properties in fertilized plots were associated with an altered microbial community driven by reduced arbuscular mycorrhizal (control mean 3.2 mol%, fertilized mean 2.5 mol%) and saprotrophic fungal groups (control mean 17.0 mol%, fertilized mean 15.2 mol%), as well as a decrease in N degrading microbial enzyme activity. Our results suggest that decreases in soil C in subalpine forests were in part driven by increased microbial degradation of soil organic matter and reduced inputs to soil organic matter in the form of microbial biomass.
Cong, Rihuan; Wang, Xiujun; Xu, Minggang; Ogle, Stephen M.; Parton, William J.
2014-01-01
Soil organic matter models are widely used to study soil organic carbon (SOC) dynamics. Here, we used the CENTURY model to simulate SOC in wheat-corn cropping systems at three long-term fertilization trials. Our study indicates that CENTURY can simulate fertilization effects on SOC dynamics under different climate and soil conditions. The normalized root mean square error is less than 15% for all the treatments. Soil carbon presents various changes under different fertilization management. Treatment with straw return would enhance SOC to a relatively stable level whereas chemical fertilization affects SOC differently across the three sites. After running CENTURY over the period of 1990–2050, the SOC levels are predicted to increase from 31.8 to 52.1 Mg ha−1 across the three sites. We estimate that the carbon sequestration potential between 1990 and 2050 would be 9.4–35.7 Mg ha−1 under the current high manure application at the three sites. Analysis of SOC in each carbon pool indicates that long-term fertilization enhances the slow pool proportion but decreases the passive pool proportion. Model results suggest that change in the slow carbon pool is the major driver of the overall trends in SOC stocks under long-term fertilization. PMID:24751981
NASA Astrophysics Data System (ADS)
Rebollo, Francisco J.; Jesús Moral García, Francisco
2016-04-01
Soil apparent electrical conductivity (ECa) is one of the simplest, least expensive soil measurements that integrates many soil properties affecting crop productivity, including, for instance, soil texture, water content, and cation exchange capacity. The ECa measurements obtained with a 3100 Veris sensor, operating in both shallow (0-30 cm), ECs, and deep (0-90 cm), ECd, mode, can be used as an additional and essential information to be included in a probabilistic model, the Rasch model, with the aim of quantifying the overall soil fertililty potential in an agricultural field. This quantification should integrate the main soil physical and chemical properties, with different units. In this work, the formulation of the Rasch model integrates 11 soil properties (clay, silt and sand content, organic matter -OM-, pH, total nitrogen -TN-, available phosphorus -AP- and potassium -AK-, cation exchange capacity -CEC-, ECd, and ECs) measured at 70 locations in a field. The main outputs of the model include a ranking of all soil samples according to their relative fertility potential and the unexpected behaviours of some soil samples and properties. In the case study, the considered soil variables fit the model reasonably, having an important influence on soil fertility, except pH, probably due to its homogeneity in the field. Moreover, ECd, ECs are the most influential properties on soil fertility and, on the other hand, AP and AK the less influential properties. The use of the Rasch model to estimate soil fertility potential (always in a relative way, taking into account the characteristics of the studied soil) constitutes a new application of great practical importance, enabling to rationally determine locations in a field where high soil fertility potential exists and establishing those soil samples or properties which have any anomaly; this information can be necessary to conduct site-specific treatments, leading to a more cost-effective and sustainable field management. Furthermore, from the measures of soil fertility potential at sampled locations, estimates can be computed using, for instance, a geostatistical algorithm, and these estimates can be utilized to map soil fertility potential and delineate with a rational basis the management zones in the field. Keywords: Rasch model; soil management; soil electrical conductivity; probabilistic algorithm.
Role of soil microbial processes in integrated pest management
DOE Office of Scientific and Technical Information (OSTI.GOV)
Francis, A.J.
1987-01-01
Soil microorganisms play a significant role in the carbon, nitrogen, phosphorus, and sulfur cycles in nature and are critical to the functioning of ecosystems. Microorganisms affect plant growth directly by regulating the availability of plant nutrients in soil, or indirectly by affecting the population dynamics of plant pathogens in soil. Any adverse effect on soil microorganisms or on the microbial processes will affect the soil fertility, availability of plant nutrients and the overall biogeochemical cycling of elements in nature. Soil microorganisms are responsible for the degradation and detoxification of pesticides; they control many insect pests, nematodes, and other plant pathogenicmore » microorganisms by parasitism, competition, production of antibiotics and other toxic substances. Also, they regulate the availability of major and minor nutrients as well as essential elements. The long-term effects of continuous and, in some instances, excessive application of pesticides on soil fertility is not fully understood. Although much information is available on the integrated pest management (IPM) system, we have very little understanding of the extent of soil microbial processes which modulate the overall effectiveness of various strategies employed in IPM. The purpose of this paper is to review briefly the key microbial processes and their relationship to the IPM system.« less
Nõlvak, Hiie; Truu, Marika; Kanger, Kärt; Tampere, Mailiis; Espenberg, Mikk; Loit, Evelin; Raave, Henn; Truu, Jaak
2016-08-15
Soil fertilization with animal manure or its digestate may facilitate an important antibiotic resistance dissemination route from anthropogenic sources to the environment. This study examines the effect of mineral fertilizer (NH4NO3), cattle slurry and cattle slurry digestate amendment on the abundance and proportion dynamics of five antibiotic resistance genes (ARGs) and two classes of integron-integrase genes (intI1 and intI2) in agricultural grassland soil. Fertilization was performed thrice throughout one vegetation period. The targeted ARGs (sul1, tetA, blaCTX-M, blaOXA2 and qnrS) encode resistance to several major antibiotic classes used in veterinary medicine such as sulfonamides, tetracycline, cephalosporins, penicillin and fluoroquinolones, respectively. The non-fertilized grassland soil contained a stable background of tetA, blaCTX-M and sul1 genes. The type of applied fertilizer significantly affected ARGs and integron-integrase genes abundances and proportions in the bacterial community (p<0.001 in both cases), explaining 67.04% of the abundance and 42.95% of the proportion variations in the grassland soil. Both cattle slurry and cattle slurry digestate proved to be considerable sources of ARGs, especially sul1, as well as integron-integrases. Sul1, intI1 and intI2 levels in grassland soil were elevated in response to each organic fertilizer's application event, but this increase was followed by a stage of decrease, suggesting that microbes possessing these genes were predominantly entrained into soil via cattle slurry or its digestate application and had somewhat limited survival potential in a soil environment. However, the abundance of these three target genes did not decrease to a background level by the end of the study period. TetA was most abundant in mineral fertilizer treated soil and blaCTX-M in cattle slurry digestate amended soil. Despite significantly different abundances, the abundance dynamics of bacteria possessing these genes were similar (p<0.05 in all cases) in different treatments and resembled the dynamics of the whole bacterial community abundance in each soil treatment. Copyright © 2016. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Eleshev, R. E.; Bakenova, Z. B.
2012-11-01
Experimental studies showed that irrigated chestnut soils on the piedmont of the Zailiiskiy Alatau Range are characterized by the moderate activity of the hydrolytic and redox enzymes. The use of these soils in the crop rotation system increases the hydrolytic activity of the enzymes (invertase, urease, and ATP synthase) by 30% in comparison with the monoculture; at the same time, it does not have a significant impact on the changes in the biological activity of the redox enzymes (catalase and dehydrogenase). The hydrolytic activity of the soils is activated to a greater extent in the crop rotation and in the monoculture against the background application of organic fertilizers. In this case, the recommended rates of mineral fertilizers do not inhibit the activity of the hydrolytic and redox enzymes. An increase in the hydrolytic activity of the enzymes directly affects the yield of oilseed flax. Therefore, indices of the hydrolytic activity of soils can be used as a test for the diagnostics of the efficiency of fertilizers both in crop rotation and monoculture systems.
von Tucher, Sabine; Hörndl, Dorothea; Schmidhalter, Urs
2018-01-01
Phosphorus (P), a plant macronutrient, must be adequately supplied for crop growth. In Germany, many soils are high in plant-available P; specifically in arable farming, P fertilizer application has been reduced or even omitted in the last decade. Therefore, it is important to understand how long these soils can support sustainable crop production, and what concentrations of soil P are required for it. We analyzed a 36-year long-term field experiment regarding the effects of different P application and liming rates on plant growth and soil P concentrations with a crop rotation of sugar beet, wheat, and barley. Sugar beet reacted to low soil P and low soil pH levels more sensitively than wheat, which was not significantly affected by the long-term omitted P application. All three crop species showed adequate growth at soil P levels lower than the currently recommended levels, if low soil pH was optimized by liming. The increase in efficacy of soil and fertilizer P by reduced P application rates therefore requires the adaptation of the soil pH to a soil type-specific optimal level.
The effects of ant nests on soil fertility and plant performance: a meta-analysis.
Farji-Brener, Alejandro G; Werenkraut, Victoria
2017-07-01
Ants are recognized as one of the major sources of soil disturbance world-wide. However, this view is largely based on isolated studies and qualitative reviews. Here, for the first time, we quantitatively determined whether ant nests affect soil fertility and plant performance, and identified the possible sources of variation of these effects. Using Bayesian mixed-models meta-analysis, we tested the hypotheses that ant effects on soil fertility and plant performance depend on the substrate sampled, ant feeding type, latitude, habitat and the plant response variable measured. Ant nests showed higher nutrient and cation content than adjacent non-nest soil samples, but similar pH. Nutrient content was higher in ant refuse materials than in nest soils. The fertilizer effect of ant nests was also higher in dry habitats than in grasslands or savannas. Cation content was higher in nests of plant-feeding ants than in nests of omnivorous species, and lower in nests from agro-ecosystems than in nests from any other habitat. Plants showed higher green/root biomass and fitness on ant nests soils than in adjacent, non-nest sites; but plant density and diversity were unaffected by the presence of ant nests. Root growth was particularly higher in refuse materials than in ant nest soils, in leaf-cutting ant nests and in deserts habitats. Our results confirm the major role of ant nests in influencing soil fertility and vegetation patterns and provide information about the factors that mediate these effects. First, ant nests improve soil fertility mainly through the accumulation of refuse materials. Thus, different refuse dump locations (external or in underground nest chambers) could benefit different vegetation life-forms. Second, ant nests could increase plant diversity at larger spatial scales only if the identity of favoured plants changes along environmental gradients (i.e. enhancing β-diversity). Third, ant species that feed on plants play a relevant role fertilizing soils, which may balance their known influence as primary consumers. Fourth, the effects of ant nests as fertility islands are larger in arid lands, possibly because fertility is intrinsically lower in these habitats. Overall, this study provide novel and quantitative evidence confirming that ant nests are key soil modifiers, emphasizing their role as ecological engineers. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.
Zaier, Hanen; Ghnaya, Tahar; Ben Rejeb, Kilani; Lakhdar, Abdelbasset; Rejeb, Salwa; Jemal, Fatima
2010-06-01
Sludge application is a reliable practice to ameliorate soil fertility. However, repetitive sludge addition represents a potential soil contamination source with heavy metals, which must be extracted. The aim of this study was to evaluate the capacity of Brassica napus to remove metals from soils amended with sludge, and to study the effect of EDTA on this process. Seedlings were cultivated in presence of sludge combined or not with EDTA. Results showed that sludge ameliorate significantly biomass production. This effect was accompanied with an increase in Pb, Zn and Mn shoot concentrations. EDTA application does not affect significantly plant growth. However, this chelator enhances shoot metals accumulation. It's therefore concluded that sludge has a beneficial effect on soil fertility, B. napus can be used for the decontamination of affected soils and that the EDTA addition increases the ability of B. napus to accumulate heavy metals. Published by Elsevier Ltd.
Aguilar-Chama, Ana; Guevara, Roger
2012-01-01
Heterogeneous distribution of resources in most plant populations results in a mosaic of plant physiological responses tending to maximize plant fitness. This includes plant responses to trophic interactions such as herbivory and mycorrhizal symbiosis which are concurrent in most plants. We explored fitness costs of 50% manual defoliation and mycorrhizal inoculation in Datura stramonium at different light availability and soil fertility environments in a greenhouse experiment. Overall, we showed that non-inoculated and mycorrhiza-inoculated plants did not suffer from 50% manual defoliation in all the tested combinations of light availability and soil fertility treatments, while soil nutrients and light availability predominately affected plant responses to the mycorrhizal inoculation. Fifty percent defoliation had a direct negative effect on reproductive traits whereas mycorrhiza-inoculated plants produced larger flowers than non-inoculated plants when light was not a limiting factor. Although D. stramonium is a facultative selfing species, other investigations had shown clear advantages of cross-pollination in this species; therefore, the effects of mycorrhizal inoculation on flower size observed in this study open new lines of inquiry for our understanding of plant responses to trophic interactions. Also in this study, we detected shifts in the limiting resources affecting plant responses to trophic interactions.
Bradley W. Miller; Thomas R. Fox
2010-01-01
While phosphorus (P) fertilization increases plant available or âlabileâ P immediately after fertilization, it is uncertain how it influences P pools over the long term in forest soils. Phosphorus pools from a 22-year-old loblolly pine (Pinus taeda L.) fertilization study were quantified using the Hedley sequential fractionation procedure, Mehlich-1...
Riber, Leise; Poulsen, Pernille H B; Al-Soud, Waleed A; Skov Hansen, Lea B; Bergmark, Lasse; Brejnrod, Asker; Norman, Anders; Hansen, Lars H; Magid, Jakob; Sørensen, Søren J
2014-10-01
We investigated immediate and long-term effects on bacterial populations of soil amended with cattle manure, sewage sludge or municipal solid waste compost in an ongoing agricultural field trial. Soils were sampled in weeks 0, 3, 9 and 29 after fertilizer application. Pseudomonas isolates were enumerated, and the impact on soil bacterial community structure was investigated using 16S rRNA amplicon pyrosequencing. Bacterial community structure at phylum level remained mostly unaffected. Actinobacteria, Proteobacteria and Chloroflexi were the most prevalent phyla significantly responding to sampling time. Seasonal changes seemed to prevail with decreasing bacterial richness in week 9 followed by a significant increase in week 29 (springtime). The Pseudomonas population richness seemed temporarily affected by fertilizer treatments, especially in sludge- and compost-amended soils. To explain these changes, prevalence of antibiotic- and mercury-resistant pseudomonads was investigated. Fertilizer amendment had a transient impact on the resistance profile of the soil community; abundance of resistant isolates decreased with time after fertilizer application, but persistent strains appeared multiresistant, also in unfertilized soil. Finally, the ability of a P. putida strain to take up resistance genes from indigenous soil bacteria by horizontal gene transfer was present only in week 0, indicating a temporary increase in prevalence of transferable antibiotic resistance genes. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.
Global warming potential of manure amended soils under rice-wheat system in the Indo-Gangetic plains
NASA Astrophysics Data System (ADS)
Bhatia, A.; Pathak, H.; Jain, N.; Singh, P. K.; Singh, A. K.
Use of organic amendments such as farmyard manure (FYM), green manure (GM) and crop residues is important to improve soil health and reduce the dependence on synthetic chemical fertilizer. However, these organic amendments also effect the emissions of greenhouse gas (GHG) from soil. Influence of different organic amendments on emissions of GHG from soil and their global warming potential (GWP) was studied in a field experiment in rice-wheat cropping system of Indo-Gangetic plains (IGP). There was 28% increase in CH 4 emissions on addition of 25% N through Sesbania GM along with urea compared to urea alone. Substitution of 100% inorganic N by organic sources lead to a 60% increase in CH 4 emissions. The carbon equivalent emission from rice-wheat systems varied between 3816 and 4886 kg C equivalent ha -1 depending upon fertilizer and organic amendment. GWP of rice-wheat system increased by 28% on full substitution of organic N by chemical N. However, the C efficiency ratios of the GM and crop residue treatments were at par with the recommended inorganic fertilizer treatment. Thus use of organic amendments along with inorganic fertilizer increases the GWP of the rice-wheat system but may improve the soil fertility status without adversely affecting the C efficiency ratio. However, the trade-off between improved yield and soil health versus GHG emissions should be taken into account while promoting the practice of farming with organic residues substitution for mineral fertilizer.
Qasim, Bashar; Motelica-Heino, Mikael; Bourgerie, Sylvain; Gauthier, Arnaud; Morabito, Domenico
2015-12-01
This study aimed at assessing the effect of nitrogen addition under two forms, nitrate and ammonium, on the stabilization of Zn, Pb, and Cd by Populus euramericana Dorskamp grown in contaminated soils for 35 days under controlled conditions. Temporal changes in the soil pore water (SPW) were monitored for pH, dissolved organic carbon (DOC), and total dissolved concentrations of metals in the soils rhizosphere. Rhizospheric SPW pH decreased gradually with NH4(+) addition and increased with NO3(-) addition up to one unit, while it slightly decreased initially then increased for the untreated control soil DOC increased with time up to six times, the highest increase occurring with NH4(+) fertilization. An increase in the metal concentrations in the rhizospheric SPW was observed for NH4(+) addition associated with the lowest rhizospheric SPW pH, whereas the opposite was observed for the control soil and NO3(-) fertilization. Fertilization did not affect plant shoots or roots biomass development compared to the untreated control (without N addition). Metals were mostly accumulated in the rhizosphere and N fertilization increased the accumulation for Zn and Pb while Cd accumulation was enhanced for NH4(+) addition. Collectively, our results suggest metal stabilization by P. euramericana Dorskamp rhizosphere with nitrogen fertilization and are potential for phytostabilization of contaminated technosol.
Zeolite Soil Application Method Affects Inorganic Nitrogen, Moisture, and Corn Growth
USDA-ARS?s Scientific Manuscript database
Adoption of new management techniques which improve soil water storage and soil nitrogen plant availability yet limit nitrogen leaching may help improve environmental quality. A benchtop study was conducted to determine the influence of a single urea fertilizer rate (224 kilograms of Nitrogen per ...
Excessive application of pig manure increases the risk of P loss in calcic cinnamon soil in China.
Yang, Yanju; Zhang, Haipeng; Qian, Xiaoqing; Duan, Jiannan; Wang, Gailan
2017-12-31
Soil phosphorus (P) is a critical factor affecting crop yields and water environmental quality. To investigate the degree of loss risk and forms of soil P in calcic cinnamon soil, the P fraction activities in soils were analysed using chemical methods, combined with an in situ field experiment. Seven treatments were set in this study, including control (unfertilized), no P fertilizer (No-P), mineral P fertilizer (Min-P), low (L-Man) and high (H-Man) quantities of pig manure, Min-P+L-Man, and Min-P+H-Man. The results showed that manure fertilizer could not only significantly increase maize yield but could also enhance the accumulation of soil P in organic and inorganic forms. After 23years of repeated fertilization, the soil Olsen-P contents respectively showed 64.7-, 43.7- and 31.9-fold increases in the Min-P+H-Man, Min-P+L-Man and H-Man treatments, while the soil Olsen-P in Min-P treatment only increased 23.7-fold. The soil Olsen-P thresholds ranged from 22.59 to 32.48mgkg -1 in calcic cinnamon soil to maintain a higher maize yield as well as a lower risk of P loss. Therefore, long-term excessive manure application could obviously raise the content of soil Olsen-P and increase the risk of P loss in calcic cinnamon soil. Copyright © 2017 Elsevier B.V. All rights reserved.
Chronic human disturbance affects plant trait distribution in a seasonally dry tropical forest
NASA Astrophysics Data System (ADS)
Sfair, Julia C.; de Bello, Francesco; de França, Thaysa Q.; Baldauf, Cristina; Tabarelli, Marcelo
2018-02-01
The effects of human disturbance on biodiversity can be mediated by environmental conditions, such as water availability, climate and nutrients. In general, disturbed, dry or nutrient-depleted soils areas tend to have lower taxonomic diversity. However, little is known about how these environmental conditions affect functional composition and intraspecific variability in tropical dry forests. We studied a seasonally dry tropical forest (SDTF) under chronic anthropogenic disturbance (CAD) along rainfall and soil nutrient gradients to understand how these factors influence the taxonomic and functional composition. Specifically we evaluated two aspects of CAD, wood extraction and livestock pressure (goat and cattle grazing), along soil fertility and rainfall gradients on shrub and tree traits, considering species turnover and intraspecific variability. In addition, we also tested how the traits of eight populations of the most frequent species are affected by wood extraction, livestock pressure, rainfall and soil fertility. In general, although CAD and environmental gradients affected each trait of the most widespread species differently, the most abundant species also had a greater variation of traits. Considering species turnover, wood extraction is associated with species with a smaller leaf area and lower investment in leaf mass, probably due to the indirect effects of this disturbance type on the vegetation, i.e. the removal of branches and woody debris clears the vegetation, favouring species that minimize water loss. Livestock pressure, on the other hand, affected intraspecific variation: the herbivory caused by goats and cattle promoted individuals which invest more in wood density and leaf mass. In this case, the change of functional composition observed is a direct effect of the disturbance, such as the decrease of palatable plant abundance by goat and cattle herbivory. In synthesis, CAD, rainfall and soil fertility can affect trait distribution at community and species levels, which can have significant implications for the ecosystem functioning of SDTF under increasing levels of disturbance, climate change and soil nutrient depletion.
Effect of mineral fertilizers on microbiological and biochemical characteristics of agrochernozem.
NASA Astrophysics Data System (ADS)
Tkhakakhova, Azida; Vasilenko, Elena; Kutovaya, Olga
2013-04-01
The problem of reproduction of soil fertility of chernozems are solved with integrated action, the ecological condition of the soil can be assessed by the activity of physiological groups of microorganisms. Microorganisms are the most important in the transformation of compounds of biogenic elements and therefore it is very interesting to study the nature of the relationship of some biochemical parameters with the development of microflora and micromycetes eco-trophic groups. Agrochemical researches have been conducted at agroecological station "Stone Steppe" in central Russia. Experiment variants: 1 - Control (without fertilizer); 2 - N10,5 P10,5 K10,5; 3 - N56,5 P56,5 K56,5; 4 - deposit soil. Mobile forms of humic substances (mobile carbon and carbon water extract) have changed during the cultivation of the chernozem soil. Amount of mobile humus has doubled in the variants with the use of mineral fertilizers. It's just mobile humus which determines the soil response to any impact, especially ecological. Water extract carbon - organic matter contained in the soil solution and the subject of assimilation of plants and microorganisms. It increased in agricultural soils. The total nitrogen and nitrate nitrogen amount in the variants of agricultural use is higher than in the deposit soil. This is probably because of the soil aeration, the release of nitrogen from the labile humus due to biological activity and nitrification. Amount of ammonia nitrogen has increased in the variant with the use of high doses of fertilizers. Deposit soil (40 years without agricultural use) has a lower, but more stable microbial activity. Process of anoxic decomposition of plant remains develops more active than others, due to the natural structure of the soil anaerobiosis in the spring time. Processes of nitrogen cycle (nitrogen accumulation - fixation of atmospheric nitrogen, nitrogen losses - denitrification) are progressing very intensively in agricultural soil with fertilizer. Content of humic substances in the soil affects all groups of microorganisms, except actinomycetes and cellulolytices. These microorganisms have an active system of hydrolytic enzymes that taking action on hard organic materials. Movable carbon largely affects the anaerobic microorganisms nitrogen cycle and inverse relationship takes place during with the developing of actinomycetes. Correlation between the aqueous extract carbon with cellulolitic bacteria, aerobic nitrogen-fixing bacteria and amylolytic microorganisms using mineral nitrogen is the highest. Organic material of the soil solution in the growing season associated with NO3-. The content of total nitrogen and nitrate associated with anaerobic denitrifying bacteria, nitrogen-fixing bacteria and amylolytic microorganisms. The content of ammonia nitrogen N-NH4+ renders very strong influence on soil microorganisms. A positive correlation is observed with ammonifiers, nitrogen-fixing bacteria, denitrifying bacteria. There is inverse relationship with actinomycetes (R = - 0,96) and anaerobic cellulolitic bacteria (R = - 0,80). Representatives of these microorganisms are active participants in the carbon cycle; their development in the presence of the ammonium form of nitrogen is possibly suspended. There is a complicated relationship of biochemical indicators of the development of soil microorganisms in the black earth. The problem preserving stable humus and physiologically active mobile forms that affect plant growth can only be achieved while maintaining the living organisms in it.
Effects of different forms of plant-derived organic matter on nitrous oxide emissions.
Qiu, Qingyan; Wu, Lanfang; Ouyang, Zhu; Li, Binbin; Xu, Yanyan
2016-07-13
To investigate the impact of different forms of plant-derived organic matter on nitrous oxide (N2O) emissions, an incubation experiment with the same rate of total nitrogen (N) application was carried out at 25 °C for 250 days. Soils were incorporated with maize-derived organic matter (i.e., maize residue-derived dissolved organic matter and maize residues with different C/N ratios) and an inorganic N fertilizer (urea). The pattern and magnitude of nitrous oxide (N2O) emissions were affected by the form of N applied. Single application of maize-derived organic matter resulted in a higher N2O emission than single application of the inorganic N fertilizer or combined application of the inorganic N fertilizer and maize-derived organic matter. The positive effect of maize residue-derived dissolved organic matter (DOM) addition on N2O emissions was relatively short-lived and mainly occurred at the early stage following DOM addition. In contrast, the positive effect induced by maize residue addition was more pronounced and lasted for a longer period. Single application of maize residues resulted in a substantial decrease in soil nitric nitrogen (NO3(-)-N), but it did not affect the production of N2O. No significant relationship between N2O emission and NO3(-)-N and ammonium nitrogen (NH4(+)-N) suggested that the availability of soil N was not limiting the production of N2O in our study. The key factors affecting soil N2O emission were the soil dissolved organic carbon (DOC) content and metabolism quotient (qCO2). Both of them could explain 87% of the variation in cumulative N2O emission. The C/N ratio of maize-derived organic matter was a poor predictor of N2O emission when the soil was not limited by easily available C and the available N content met the microbial N demands for nitrification and denitrification. The results suggested that the magnitude of N2O emission was determined by the impact of organic amendments on soil C availability and microbial activity rather than on soil N availability. In agricultural management practices, if the N inputs from organic and inorganic N fertilizers are equivalent, addition of organic N fertilizers that contain high amounts of available C will result in a higher N2O emission.
Wang, Xuexia; Dong, Shikui; Yang, Bing; Li, Yuanyuan; Su, Xukun
2014-10-01
A 3-year survey was conducted to explore the relationships among plant composition, productivity, and soil fertility characterizing four different degradation stages of an alpine meadow in the source region of the Yangtze and Yellow Rivers, China. Results showed that plant species diversity, productivity, and soil fertility of the top 30-cm soil layer significantly declined with degradation stages of alpine meadow over the study period. The productivity of forbs significantly increased with degradation stages, and the soil potassium stock was not affected by grassland degradation. The vegetation composition gradually shifted from perennial graminoids (grasses and sedges) to annual forbs along the degradation gradient. The abrupt change of response in plant diversity, plant productivity, and soil nutrients was demonstrated after heavy grassland degradation. Moreover, degradation can indicate plant species diversity and productivity through changing soil fertility. However, the clear relationships are difficult to establish. In conclusion, degradation influenced ecosystem function and services, such as plant species diversity, productivity, and soil carbon and nitrogen stocks. Additionally, both plant species diversity and soil nutrients were important predictors in different degradation stages of alpine meadows. To this end, heavy degradation grade was shown to cause shift of plant community in alpine meadow, which provided an important basis for sustaining ecosystem function, manipulating the vegetation composition of the area and restoring the degraded alpine grassland.
Hernández, Marcela; Jia, Zhongjun; Conrad, Ralf; Seeger, Michael
2011-12-01
s-Triazine herbicides are widely used for weed control, and are persistent in soils. Nitrification is an essential process in the global nitrogen cycle in soil, and involves ammonia-oxidizing Bacteria (AOB) and ammonia-oxidizing Archaea (AOA). In this study, we evaluated the effect of the s-triazine herbicide simazine on the nitrification and on the structure of ammonia-oxidizing microbial communities in a fertilized agricultural soil. The effect of simazine on AOB and AOA were studied by PCR-amplification of amoA genes of nitrifying Bacteria and Archaea in soil microcosms and denaturing gradient gel electrophoresis (DGGE) analyses. Simazine [50 μg g(-1) dry weight soil (d.w.s)] completely inhibited the nitrification processes in the fertilized agricultural soil. The inhibition by simazine of ammonia oxidation observed was similar to the reduction of ammonia oxidation by the nitrification inhibitor acetylene. The application of simazine-affected AOB community DGGE patterns in the agricultural soil amended with ammonium, whereas no significant changes in the AOA community were observed. The DGGE analyses strongly suggest that simazine inhibited Nitrosobacteria and specifically Nitrosospira species. In conclusion, our results suggest that the s-triazine herbicide not only inhibits the target susceptible plants but also inhibits the ammonia oxidation and the AOB in fertilized soils. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
Phosphorus runoff from turfgrass as affected by phosphorus fertilization and clipping management.
Bierman, Peter M; Horgan, Brian P; Rosen, Carl J; Hollman, Andrew B; Pagliari, Paulo H
2010-01-01
Phosphorus enrichment of surface water is a concern in many urban watersheds. A 3-yr study on a silt loam soil with 5% slope and high soil test P (27 mg kg(-1) Bray P1) was conducted to evaluate P fertilization and clipping management effects on P runoff from turfgrass (Poa pratensis L.) under frozen and nonfrozen conditions. Four fertilizer treatments were compared: (i) no fertilizer, (ii) nitrogen (N)+potassium (K)+0xP, (iii) N+K+1xP, and (iv) N+K+3xP. Phosphorus rates were 21.3 and 63.9 kg ha(-1) yr(-1) the first year and 7.1 and 21.3 kg ha(-1) yr(-1) the following 2 yr. Each fertilizer treatment was evaluated with clippings removed or clippings recycled back to the turf. In the first year, P runoff increased with increasing P rate and P losses were greater in runoff from frozen than nonfrozen soil. In year 2, total P runoff from the no fertilizer treatment was greater than from treatments receiving fertilizer. This was because reduced turf quality resulted in greater runoff depth from the no fertilizer treatment. In year 3, total P runoff from frozen soil and cumulative total P runoff increased with increasing P rate. Clipping management was not an important factor in any year, indicating that returning clippings does not significantly increase P runoff from turf. In the presence of N and K, P fertilization did not improve turf growth or quality in any year. Phosphorus runoff can be reduced by not applying P to high testing soils and avoiding fall applications when P is needed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lin, Qianxin; Mendelssohn, A.
1996-12-31
Oil spills in coastal wetlands often kill vegetation and leave oil in the wetland sediment for many years. The potential of phytoremediation as a means for habitat restoration and cleanup of oiled marshes was studied with marsh mesocosms. Soil sods of Spartina alterniflora and Spartina patens (common coastal marsh grasses) were dosed at the rates of 0, 4, 8, 16 and 24 1 m{sup {minus}2} of south Louisiana crude oil. Plant mortality occurred at high oil dosages (8 1 m{sup {minus}2} and above). Two years after application of the oil to the soil sods, these two Spartina species were transplantedmore » into oiled and unoiled sods to determine the potential for habitat restoration and oil phytoremediation. Fertilizer (at rates of 666 kg N/ha, 272 kg P/ha and 514 kg K/Ha) was applied after transplanting. Regrowth biomass of S. alterniflora, S. patens and the combination of these two species was significantly increased by application of fertilizer one year after transplanting. The regrowth biomass was not significantly affected by oil as high as 250 mg g{sup 1} dry soil for combined biomass of the two species and was significantly higher with oil for Spartina alterniflora although the biomass of S. patens was affected at the highest oil content in the soil, suggesting the potential of habitat restoration by transplanting after oil spills. Oil degradation was enhanced by phytoremediation in combination with fertilization. The oil degradation rate was negligible in the absence of vegetation, but it was significantly higher in the presence of transplanted vegetation and fertilizer. Whether increased degradation of residual oil was due to the enhancement of soil microbial activity by the fertilizer or by phytoremediation is presently being investigated.« less
Liu, Cui-Ying; Jiang, Xin
2013-04-01
A rice pot experiment was conducted in two soils, Hydragric Acrisols (Ac) and Gleyi-Stagnic Anthrosols (An). Three treatments including control and additions of 1% or 2% composting organic fertilizer were designed for each soil. The objective of this research was to evaluate the reductive dechlorination of hexachlorobenzene (HCB) as affected by organic fertilizer supplies in planted paddy soils, and to analyze the relationship between methane production and HCB dechlorination. The results showed that the HCB residues were decreased by 28.6%-30.1% of the initial amounts in Ac, and 47.3% -61.0% in An after 18 weeks of experiment. The amount of HCB and its metabolite uptake by rice plants was only a few thousandths of the initial HCB amount in soils. The main product of HCB dechlorination was pentachlorobenzene (PeCB). The rates of HCB dechlorination in An were higher than those in Ac, which was mainly attributed to the higher pH and dissolved organic carbon (DOC) content of An. The applications of both 1% and 2% composting organic fertilizer showed significant inhibition on PeCB production after the 6th and 10th week in Ac and An, respectively. In both tested soils, no significant difference of PeCB production rates was observed between the applications of 1% and 2% composting organic fertilizer. The role of methanogenic bacteria in HCB dechlorination was condition-dependent.
Effects of poultry manure on phosphorus availability to perennial ryegrass
USDA-ARS?s Scientific Manuscript database
Soil phosphorus (P) exists in numerous forms that differ in plant availability. High-P organic fertilizers, including poultry manure (PM), can alter the balance of these soil P forms and may affect plant nutrient status. To investigate the effects of PM on soil P distribution and plant utilization...
Vermicompost affects soil properties and spinach growth, physiology, and nutritional value
USDA-ARS?s Scientific Manuscript database
The use of vermicompost to improve soil fertility and enhance crop yield has gained considerable momentum due to its contribution to agroecological sustainability. Short-term (35-days after transplanting) effects of vermicompost, applied either as a soil amendment (5% and 10%, v/v), or a drench (40 ...
Meier, Elizabeth A.; Thorburn, Peter J.
2016-01-01
The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues (‘trash’). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a ‘trash blanket’ in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer rates for crops when trash was retained (≤20 kg N ha–1 per plant or ratoon crop) while maintaining ≥95% of maximum yields. While these savings in N fertilizer use were modest at the field scale, they were potentially important when aggregated at the regional level. PMID:27462340
NASA Astrophysics Data System (ADS)
Fuertes-Mendizábal, Teresa; Huérfano, Ximena; Menéndez, Sergio; González-Murua, Carmen; Begoña González-Moro, Mª; Ippolito, James; Kamann, Claudia; Wrage-Mönnig, Nicole; Borchard, Nils; Cayuela, Maria Luz; Spokas, Kurt; Sigua, Gilbert; Novak, Jeff; Estavillo, José Mª
2017-04-01
Nitrous oxide (N2O) is the strongest greenhouse gas associated with agricultural soils. Current agricultural practices, based on the use of N fertilizers, can lead to environmental N losses, with some losses occurring as N2O emissions. Among the strategies suggested by the Intergovernmental Panel on Climate Change to decrease N losses through agriculture is the utilization of nitrification inhibitors, such as DMPP (3,4-dimethylpyrazole phosphate). This compound inhibits nitrification, thus reducing N2O emissions. However, the efficiency of DMPP might be affected by soil amendments. One soil amendment is biochar, which typically increases soil C, can reduce N2O emissions, affect the retention of water, and alter the C and N cycle. Nevertheless, these effects are not uniformly observed across varying soil types, N fertilization schemes and biochar properties. Assuming that both DMPP and biochars with C/N > 30 ratios are presumably able to reduce soil N2O emissions, the aim of this study was to evaluate the synergic effect of a woody biochar applied in combination with DMPP on N2O emissions. For this purpose, a laboratory incubation study was conducted with a silt loam grassland soil and a biochar obtained from Pinus taeda at 500°C. The experimental design consisted of an arrangement including two biochar levels (0 and 2% (w/w)), three fertilization levels (unfertilized, fertilized and fertilized+DMPP) and two soil water content levels (40% and 80% of water filled pore space, WFPS), giving rise to 12 different individual treatments with four replications of each treatment. Soil N2O emissions were monitored over the incubation period (163 days). Results showed that DMPP reduced N2O emissions to levels comparable to the unfertilized controls. Biochar showed ability to mitigate N2O emissions only at the low soil water content (40% WFPS). However, when DMPP was applied to the biochar amended soil, a counteracting effect was observed, since the reduction in N2O emissions induced by DMPP was less than without biochar. This study demonstrates that the biochar amendment diminishes the efficiency of the nitrification inhibitor DMPP both at low and high soil water contents. Aknowledgements: FACCE-CSA n° 276610/MIT04-DESIGN-UPVASC; AGL2015-64582-C3-2-R MINECO/FEDER; IT-932-16.
NASA Astrophysics Data System (ADS)
Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla
2015-10-01
For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.
[Effects of mulching management on biomass of Phyllostachys praecox and soil fertility].
Zhai, Wan Lu; Yang, Chuan Bao; Zhang, Xiao Ping; Gao, Gui Bin; Zhong, Zhe Ke
2018-04-01
We analyzed the dynamics of stand growth and soil nutrient availability during the degradation processes of Phyllostachys praecox plantation, taking the advantage of bamboo forest stands with different mulching ages (0, 3, 6, 9 and 12 a). The results showed the aboveground and belowground biomass of bamboo forest reached the maximum value when they were covered by three years, which was significantly increased by 14.6% and 146.6% compared with the control. The soil nutrient content was affected by the mulching age and soil layer. Soil nutrients gradually accumulated in upper layer. Soil organic carbon and total nitrogen content were increased with the increases of coverage years. The soil total phosphorus content at different soil layers showed a trend of decreasing first and then increasing. It was the lowest level in the surface layer (0-20 cm) and the bottom (40-60 cm) in 6 years, and the subsurface (20-40 cm) soil reached the lowest level in three years. The total potassium content kept increasing in 0-20 cm soil layer, but decreased during the first three years of mulching and then increased in 20-60 cm soil layer. The comprehensive index of soil fertility quality was greatly improved after nine years mulching, with fertility of subsurface soil being better than that of surface and bottom soils. There was no relationship between the soil fertility index and biomass of different organs in bamboo in the different mulching ages. In the subsurface, however, nitrogen content was negatively related to leaf biomass and potassium was negatively correlated with the biomass of leaves and whip roots. Our results indicated that excessive accumulation of soil nutrients seriously inhibited the propagation and biomass accumulation of P. praecox after long-term mulching management and a large amount of fertilizer, which further aggravated the degradation of bamboo plantation.
Liu, Enke; Yan, Changrong; Mei, Xurong; Zhang, Yanqing; Fan, Tinglu
2013-01-01
An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0–100 cm) in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK), nitrogen fertilizer (N), nitrogen and phosphorus (P) fertilizers (NP), straw plus N and P fertilizers (NP+S), farmyard manure (FYM), and farmyard manure plus N and P fertilizers (NP+FYM). Results showed that SOC concentration in the 0–20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0–60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0–60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0–60 cm depth. The average concentration of particulate organic carbon (POC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM) in 0–60 cm depth were increased by 64.9–91.9%, 42.5–56.9%, and 74.7–99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization. PMID:23437161
Chen, Xiaopeng; Wang, Genxu; Zhang, Tao; Mao, Tianxu; Wei, Da; Song, Chunlin; Hu, Zhaoyong; Huang, Kewei
2017-12-01
Uncertainties in the seasonal changes of greenhouse gases (GHG) fluxes in wetlands limit our accurate understanding of the responses of permafrost ecosystems to future warming and increased nitrogen (N) deposition. Therefore, in an alpine swamp meadow in the hinterland of the Qinghai-Tibet Plateau, a simulated warming with N fertilization experiment was conducted to investigate the key GHG fluxes (ecosystem respiration [Re], CH 4 and N 2 O) in the early (EG), mid (MG) and late (LG) growing seasons. Results showed that warming (6.2 °C) increased the average seasonal Re by 30.9% and transformed the alpine swamp meadow from a N 2 O sink to a source, whereas CH 4 flux was not significantly affected. N fertilization (4 g N m -2 a -1 ) alone had no significant effect on the fluxes of GHGs. The interaction of warming and N fertilization increased CH 4 uptake by 69.6% and N 2 O emissions by 26.2% compared with warming, whereas the Re was not significantly affected. During the EG, although the soil temperature sensitivity of the Re was the highest, the effect of warming on the Re was the weakest. The primary driving factor for Re was soil surface temperature, whereas soil moisture controlled CH 4 flux, and the N 2 O flux was primarily affected by rain events. The results indicated: (i) increasing N deposition has both positive and negative feedbacks on GHG fluxes in response to climate warming; (ii) during soil thawing process at active layer, low temperature of deep frozen soils have a negative contribution to Re in alpine ecosystems; and (iii) although these alpine wetland ecosystems are buffers against increased temperature, their feedbacks on climate change cannot be ignored because of the large soil organic carbon pool and high temperature sensitivity of the Re. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Yao, Z.; Du, Y.; Tao, Y.; Zheng, X.; Liu, C.; Lin, S.; Butterbach-Bahl, K.
2014-11-01
To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS) is being increasingly adopted for rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere-atmosphere exchanges of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE) and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emissions) over a complete year, and the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN) and GCRPS (GUN and GNN), and solely chicken manure (GCM) and combined urea and chicken manure applications (GUM) for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40 and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.09 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN). The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of -1.33 Mg C ha-1 yr-1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80-11.02 Mg CO2-eq ha-1 yr-1 for the conventional paddy and 3.05-9.37 Mg CO2-eq ha-1 yr-1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effects from rice cultivation. Using organic fertilizers for GCRPS considerably reduced annual emissions of CH4 and N2O and increased soil carbon sequestration, resulting in the lowest NEGE (3.05-5.00 Mg CO2-eq ha-1 yr-1). Accordingly, water-saving GCRPS with organic fertilizer amendments was considered the most promising management regime for simultaneously achieving relatively high grain yield and reduced net greenhouse gas emission.
NASA Astrophysics Data System (ADS)
Yao, Z.; Du, Y.; Tao, Y.; Zheng, X.; Liu, C.; Lin, S.; Butterbach-Bahl, K.
2014-06-01
To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS) is being increasingly adopted for the rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere-atmosphere exchanges of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE) and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emission) over a complete year, as well as the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN) and GCRPS (GUN and GNN), solely chicken manure (GCM) and combined urea and chicken manure applications (GUM) for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40% and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.087 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN). The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of -1.33 Mg C ha-1 yr-1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80-11.02 Mg CO2-eq ha-1 yr-1 for the conventional paddy and 3.05-9.37 Mg CO2-eq ha-1 yr-1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effect from rice cultivation. Using organic fertilizers for GCRPS considerably reduced annual emissions of CH4 and N2O and increased soil carbon sequestration, resulting in the lowest NEGE (3.05-5.00 Mg CO2-eq ha-1 yr-1). Accordingly, water-saving GCRPS with organic fertilizer amendments was considered the most promising management regime for simultaneously achieving relatively high grain yield and reduced net greenhouse gas emission.
Efficient use of animal manure on cropland--economic analysis.
Araji, A A; Abdo, Z O; Joyce, P
2001-09-01
Manure contains all the macro- and microelements needed for plant growth; however, it represents one of the most underutilized resources in the US. The major problem with the use of manure on cropland is the direct effect of its composition on application cost. This cost is a function of the mineralization process of organic matter. The mineralization process is influenced by the properties of the manure, properties of the soil, moisture, and temperature. This study evaluates the simultaneous effect of these variables on the optimal use of manure on cropland. The results show that the properties of manure and soil significantly affect the mineralization of organic nitrogen and thus the optimal quantity of manure required to satisfy the nutrient requirement of crops in a given rotation system. Manure application costs range from a low of 18% of the cost of commercial fertilizer for chicken manure applied to one type of soil, to a high of 125% of the cost of commercial fertilizer for cow manure applied to another type of soil. The maximum distance to transfer manure to the field, that will equate its application cost to the cost of commercial fertilizer, ranges from a high of 35 km (22 miles) for chicken manure applied to one type of soil, to a low of 1 km (0.62 miles) for cow manure applied to another type of soil. For rotation system 2, manure application costs range from a low of 37% of the cost of commercial fertilizer for chicken manure applied to one type of soil, to a high of 136% of the cost of commercial fertilizer for cow manure applied to another type of soil. The maximum distance to transfer manure to the field, that will equate its cost to the cost of commercial fertilizer, ranges from a high of 20 km (12.5 miles) for chicken manure applied to one type of soil, to a low of 0 km (0 miles) for cow manure applied to another type of soil.
NASA Astrophysics Data System (ADS)
Niu, Yuhui; Chen, Zengming; Müller, Christoph; Zaman, Monhammad M.; Kim, Donggill; Yu, Hongyan; Ding, Weixin
2017-12-01
It is increasingly recognized that the addition of biochar to soil has potential to mitigate climate change and increase soil fertility by enhancing carbon (C) storage. However, the effect of biochar on yield and nitrous oxide (N2O) emissions from upland fields remains unclear. In this study, a one-year field experiment was conducted in an area of calcareous fluvo-aquic soil to assess and quantify the effect of maize straw biochar in reducing N2O loss during 2014-2015 in the North China Plain. Eight treatments were designed as follows: no nitrogen (N) fertilizer (control, CK); biochar application at rates of 3 (B3), 6 (B6) and 12 (B12) t ha-1; chemical fertilizer (NPK) application at 200 kg N ha-1 (F); and fertilizer plus biochar application at rates of 3 (FB3), 6 (FB6) and 12 (FB12) t ha-1. Crop yield, N2O fluxes, soil mineral N concentrations, and soil auxiliary parameters were measured following the application of treatments during each season. During the maize growing season, N2O emission was 0.57 kg N2O-N ha-1 under CK treatment, and increased to 0.88, 0.93 and 1.10 kg N2O-N ha-1 under B3, B6 and B12, respectively. In contrast, N2O emissions were significantly reduced by 31.4-39.9% (P < 0.05) under FB treatments compared with F, and the N2O emission factor of the applied N was reduced from 1.36% under F to 0.71-0.85% under FB. There was also a significant interaction effect of fertilizer and biochar on N2O emissions (P < 0.01). During the wheat growing season, biochar had no effect on N2O emissions regardless of the fertilizer regime. Biochar application did not affect maize yield; however, a significant increase in wheat yield of 16.6-25.9% (P < 0.05) was observed without N fertilization. Nevertheless, a reduction in wheat yield was measured at a biochar rate of 12 t ha-1 with fertilization. Overall, under maize cropping, N2O emissions per unit yield of grain, biomass, grain N and biomass N (yield-scaled N2O emissions) were significantly reduced by 32.4-39.9% under FB compared with F treatment, regardless of the biochar application rate. Biochar did not affect yield-scaled N2O emissions in wheat. Decreased soil bulk density with biochar is suggested to reduce the denitrification potential and N2O emissions; while increased retention capacity of fertilizer N in biochar-added soil decreased wheat growth and yield. These findings suggest that N fertilization plus biochar application at 3 t ha-1 is a practical strategy for reducing yield-scaled N2O emissions from maize fields in the North China Plain.
Wang, Youbao; Zhu, Chengfeng; Yang, Hongfei; Zhang, Xiaowei
2017-02-01
Experiments were conducted to investigate the effect of phosphate fertilization on chemical speciation of cadmium (Cd) in the rhizospheric soil of Chlorophytum comosum, a potential cadmium hyperaccumulator. The results revealed that when 200 mg kg -1 phosphate was applied into the soil, the Cd contents in the exchangeable fraction (EXC), carbonate-binding fraction (CA), and Fe-Mn oxides-binding fraction (Fe-Mn) were the highest, and the Cd content in the residual fraction (RES) was the lowest. Phosphate fertilization could enhance Cd conversion from RES into CA and weak RES, thereby improving the bioavailability of Cd and enhancing Cd enrichment and adsorption by C. comosum. The total Cd content in the soil was reduced by 10.15 mg kg -1 in the planted group, which was significantly different from the control group (p < 0.01). The highest bioaccumulation coefficient (BC) values in root and aboveground parts appeared when the phosphate rates were 276 and 217 mg kg -1 , whereas the highest translocation factor (TF) occurred with a phosphate rate of 188 mg kg -1 . Phosphate fertilization facilitated phytoremediation of Cd-polluted soil by C. comosum.
Factors Affecting Tocopherol Concentrations in Soybean Seeds.
Carrera, Constanza S; Seguin, Philippe
2016-12-21
Soybean seeds contain several health-beneficial compounds, including tocopherols, which are used by the nutraceutical and functional food industries. Soybean tocopherol concentrations are, however, highly variable. Large differences observed in tocopherol concentrations among soybean genotypes together with the relatively simple biosynthetic pathway involving few genes support the feasibility of selecting for high-tocopherol soybean. Tocopherol concentrations are also highly influenced by environmental factors and field management. Temperature during seed filling and soil moisture appear to be the main factors affecting tocopherol concentrations; other factors such as soil fertility and solar radiation also affect concentrations and composition. Field management decisions including seeding date, row spacing, irrigation, and fertilization also affect tocopherols. Knowledge of factors affecting soybean tocopherols is essential to develop management strategies that will lead to the production of seeds with consistent target concentrations that will meet the needs of the nutraceutical and functional food industries.
Anacker, Brian; Rajakaruna, Nishanta; Ackerly, David; Harrison, Susan; Keeley, Jon E.; Vasey, Michael
2011-01-01
Background: High values of specific leaf area (SLA) are generally associated with high maximal growth rates in resource-rich conditions, such as mesic climates and fertile soils. However, fire may complicate this relationship since its frequency varies with both climate and soil fertility, and fire frequency selects for regeneration strategies (resprouting versus seeding) that are not independent of resource-acquisition strategies. Shared ancestry is also expected to affect the distribution of resource-use and regeneration traits.Aims: We examined climate, soil, and fire as drivers of community-level variation in a key functional trait, SLA, in chaparral in California.Methods: We quantified the phylogenetic, functional, and environmental non-independence of key traits for 87 species in 115 plots.Results: Among species, SLA was higher in resprouters than seeders, although not after phylogeny correction. Among communities, mean SLA was lower in harsh interior climates, but in these climates it was higher on more fertile soils and on more recently burned sites; in mesic coastal climates, mean SLA was uniformly high despite variation in soil fertility and fire history.Conclusions: We conclude that because important correlations exist among both species traits and environmental filters, interpreting the functional and phylogenetic structure of communities may require an understanding of complex interactive effects.
NASA Astrophysics Data System (ADS)
Greenberg, Isabel; Kaiser, Michael; Polifka, Steven; Wiedner, Katja; Glaser, Bruno; Ludwig, Bernard
2017-04-01
Biochar and biochar/organic fertilizer combinations have been recommended as soil amendments to improve plant productivity and soil properties, as well as to increase soil organic C (OC) storage. However, these claims have been largely unverified by field experiments lasting several years. To address these issues, a field experiment was established in 2012 to analyze the effects of organic fertilizers and biochar/organic fertilizer combinations (five field replicates, fully randomized block design) on the fertility and organic matter dynamics of a sandy Cambisol. In 2016, samples were taken from the 0-10 cm and 10-30 cm soil depths of the following treatments: mineral fertilizer and maize digestate that were applied both individually and in combination with 1 t/ha or 40 t/ha biochar. Further treatments were compost and 10 t/ha composted biochar. The treatments were analyzed for the plant yield and the bulk soil samples were analyzed for the pH, cation exchange capacity (CEC), OC content, microbial biomass C and the distribution of aggregate-size fractions (i.e. >2 mm, 2 mm - 250 µm, 250 - 53 µm, <53 µm). The latter were also analyzed for OC content and by FTIR. In 2012, the combination of 40 t/ha biochar+digestate accounted for about 42% higher maize (Zea mays) yields (7.9 t/ha) than the mineral fertilization treatment. For winter rye (Secale cereale) in 2013, we detected the highest yield (10.4 t/ha) for the 10 t/ha composted biochar treatment. In 2014, the highest yield for blue lupine (Lupinus angustifolius) (1.84 t/ha) was detected for the 40 t/ha biochar+digestate treatment. The first data for the soil samples indicate that the 10 t/ha composted biochar and the compost treatment are most effective in increasing the CEC, and the microbial biomass C content of the soil, while pH was not significantly affected by any of the treatments. The bulk soil OC content of the treatments receiving 40 t/ha biochar+fertilizer (digestate or mineral), 10 t/ha composted biochar, and compost has been significantly increased by 43 to 88% in the 10-30 cm depth compared to the individual application of mineral fertilizer. The OC content of the water-stable macro- (2 mm - 250 µm) and micro-aggregates (250 - 53 µm) of the treatments receiving 40 t/ha biochar+fertilizer (digestate or mineral), 10 t/ha composted biochar, and compost was increased by 12 to 120% compared to the mineral fertilizer treatment. The magnitude of the demonstrated positive effect of biochar application on crop yield depends on the type and amount of the biochar+organic fertilizer mixture and the cultivated plant species. Besides benefiting biomass production, applications of 10 to 40 t/ha of biochar+fertilizer mixtures seem to result in increased bulk soil and aggregate protected OC contents, indicating a longer lasting positive effect on the OC storage and the structural stability of this sandy soil. Cost/benefit wise, the 10 t/ha composted biochar treatment seems to be most promising for improving soil properties and crop yield, while the compost treatment seems to be the best alternative for sandy soils where biochar is either unavailable or prohibitively expensive.
Rubio, G; Casasola, G; Lavado, R S
1995-04-01
We analysed the response of two grass species, Danthonia montevidensis and Paspalum dilatatum to waterlogging, soil-nutrient enrichment and the combination of both factors. Waterlogging did not affect total biomass of D. montevidensis, but it slightly promoted growth of P. dilatatum. Most analysed variables showed no significant interaction between fertilization and waterlogging. Therefore, waterlogging does not produce a detrimental effect either in the growth of these species or in their response capacity to stimulating growth factors, such as fertilization.
Tian, Xiaofei; Li, Chengliang; Zhang, Min; Wan, Yongshan; Xie, Zhihua; Chen, Baocheng; Li, Wenqing
2018-01-01
Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and on the soil nutrient distribution in the 0-100 cm soil profile. Biochar was applied at 0, 5, 10, and 20 t ha-1 (expressed as Control, BC5, BC10, and BC20, respectively) for each cotton season, with identical doses of chemical fertilizers. Biochar enhanced the cotton lint yield by 8.0-15.8%, 9.3-13.9%, and 9.2-21.9% in 2013, 2014, and 2015, respectively, and high levels of biochar application achieved high cotton yields each year. Leaching of soil nitrate was reduced, while the pH values, soil organic carbon, total nitrogen (N), and available K content of the 0-20 cm soil layer were increased in 2014 and 2015. However, the changes in the soil available P content were less substantial. This study suggests that successive biochar amendments have the potential to enhance cotton productivity and soil fertility while reducing nitrate leaching.
Akhtar, Muhammad
2013-01-01
In calcareous soils, phosphorus (P) retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA) required to produce desired soil solution P concentration was estimated using Freundlich sorption isotherms. Two soils from Faisalabad and T. T. Singh districts were spiked with 0, 10, and 20 % CaCO3 for 15 days. Freundlich adsorption isotherms (P = aC b/a) were constructed, and theoretical doses of PA and DAP to develop a desired soil solution P level (i.e., 0.20 mg L−1) were calculated. It was observed that P adsorption in soil increased with CaCO3. Moreover, at all the levels of CaCO3, P adsorption from PA was lower compared to that from DAP in both the soils. Consequently, lesser quantity of PA was required to produce desired solution P, 0.2 mg L−1, compared to DAP. However, extrapolating the developed relationship between soil CaCO3 contents and quantity of fertilizer to other similar textured soils needs confirmation. PMID:24307878
USDA-ARS?s Scientific Manuscript database
Biochar application to soils has been suggested to elevate nutrient sorption, improve soil fertility and reduce net greenhouse gas (GHG) emissions. We examined the impact of composting biochar together with a biologically active substrate (i.e., livestock manure-straw mixture). We hypothesized that ...
Change in soil quality due to grazing and oak tree removal in California blue oak woodlands
Trina J. Camping; Randy A. Dahlgren; Kenneth W. Tate; William R. Horwath
2002-01-01
The effects of grazing and oak tree removal on soil quality and fertility were examined in a blue oak (Quercus douglasii) woodland in the northern Sierra Nevada foothills. Low to moderate grazing intensity has little affect on soil quality; however, oak tree removal resulted in a decrease in most soil quality parameters investigated (carbon, nitrogen...
USDA-ARS?s Scientific Manuscript database
Poor rainfall distribution and soil conditions such as high soil strength, low water holding capacity of soils and poor soil fertility in the humid Coastal Plain region may affect production of grain crops. Nitrogen insufficiency and water stress can both reduce crop yield, but little information is...
Effect of rice husk biochar application to soil insect diversity on potato cultivation
NASA Astrophysics Data System (ADS)
Meilin, A.; Rubiana, R.
2018-02-01
High intensity of disease infection and the intensive use of fertilizers and pesticidescause saturated fertilizer and pesticide to the land. Remediation using biochar rice husk is one of the technology to decrease fertilizer and pesticide residue. The diversity of soil insects can be used as bioindicators because of their existence dependsg on soil structure and condition. This study was aimed to study the diversity and structure communities of soil insect in potatoes on difference husk rice biochar application. The sampling of soil insects was done on potato farmer’s land with four treatments i.e control (farmers’ technique), trichokompos without biochar, trichokompos + biochar with dose 1 ton/ha, and trichokompos + biochar with dose 2 ton / ha. At each point a single pitfall trap was installed for two nights and then it was taken for identification. The results showed that biochar application had significant effect on the number of soil insect species (P = 0.037). The soil insect species composition pattern also showed significant differences between the four treatments (R: 0.2306, Pvalue = 0.001). This mean that the application of biochar affects the number of insects species and plays a role in the formation of soil insect diversity beta patterns.
Imseng, Martin; Wiggenhauser, Matthias; Keller, Armin; Müller, Michael; Rehkämper, Mark; Murphy, Katy; Kreissig, Katharina; Frossard, Emmanuel; Wilcke, Wolfgang; Bigalke, Moritz
2018-02-20
The application of mineral phosphate (P) fertilizers leads to an unintended Cd input into agricultural systems, which might affect soil fertility and quality of crops. The Cd fluxes at three arable sites in Switzerland were determined by a detailed analysis of all inputs (atmospheric deposition, mineral P fertilizers, manure, and weathering) and outputs (seepage water, wheat and barley harvest) during one hydrological year. The most important inputs were mineral P fertilizers (0.49 to 0.57 g Cd ha -1 yr -1 ) and manure (0.20 to 0.91 g Cd ha -1 yr -1 ). Mass balances revealed net Cd losses for cultivation of wheat (-0.01 to -0.49 g Cd ha -1 yr -1 ) but net accumulations for that of barley (+0.18 to +0.71 g Cd ha -1 yr -1 ). To trace Cd sources and redistribution processes in the soils, we used natural variations in the Cd stable isotope compositions. Cadmium in seepage water (δ 114/110 Cd = 0.39 to 0.79‰) and plant harvest (0.27 to 0.94‰) was isotopically heavier than in soil (-0.21 to 0.14‰). Consequently, parent material weathering shifted bulk soil isotope compositions to lighter signals following a Rayleigh fractionation process (ε ≈ 0.16). Furthermore, soil-plant cycling extracted isotopically heavy Cd from the subsoil and moved it to the topsoil. These long-term processes and not anthropogenic inputs determined the Cd distribution in our soils.
Shen, Yufang; Chen, Yingying; Li, Shiqing
2016-01-01
Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L.) field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer), GMC (gravel mulching with inorganic N fertilizer), FMC (plastic-film mulching with inorganic N fertilizer) and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition). The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological quality of the soil and its sustainability in the rainfall-limited semiarid region. PMID:27414400
Soil fertility and plant diversity enhance microbial performance in metal-polluted soils.
Stefanowicz, Anna M; Kapusta, Paweł; Szarek-Łukaszewska, Grażyna; Grodzińska, Krystyna; Niklińska, Maria; Vogt, Rolf D
2012-11-15
This study examined the effects of soil physicochemical properties (including heavy metal pollution) and vegetation parameters on soil basal respiration, microbial biomass, and the activity and functional richness of culturable soil bacteria and fungi. In a zinc and lead mining area (S Poland), 49 sites were selected to represent all common plant communities and comprise the area's diverse soil types. Numerous variables describing habitat properties were reduced by PCA to 7 independent factors, mainly representing subsoil type (metal-rich mining waste vs. sand), soil fertility (exchangeable Ca, Mg and K, total C and N, organic C), plant species richness, phosphorus content, water-soluble heavy metals (Zn, Cd and Pb), clay content and plant functional diversity (based on graminoids, legumes and non-leguminous forbs). Multiple regression analysis including these factors explained much of the variation in most microbial parameters; in the case of microbial respiration and biomass, it was 86% and 71%, respectively. The activity of soil microbes was positively affected mainly by soil fertility and, apparently, by the presence of mining waste in the subsoil. The mining waste contained vast amounts of trace metals (total Zn, Cd and Pb), but it promoted microbial performance due to its inherently high content of macronutrients (total Ca, Mg, K and C). Plant species richness had a relatively strong positive effect on all microbial parameters, except for the fungal component. In contrast, plant functional diversity was practically negligible in its effect on microbes. Other explanatory variables had only a minor positive effect (clay content) or no significant influence (phosphorus content) on microbial communities. The main conclusion from this study is that high nutrient availability and plant species richness positively affected the soil microbes and that this apparently counteracted the toxic effects of metal contamination. Copyright © 2012 Elsevier B.V. All rights reserved.
Sawada, Kozue; Toyota, Koki
2015-01-01
Wet and dry anaerobic fermentation processes are operated for biogas production from organic matter, resulting in wet and dry digestates as by-products, respectively. The application of these digestates to soil as fertilizer has increased in recent years. Therefore, we herein compared the effects of applying wet digestates (pH 8.2, C/N ratio 4.5), dry digestates (pH 8.8, C/N ratio 23.4), and a chemical fertilizer to Japanese paddy and upland soils on short-term nitrification under laboratory aerobic conditions. Chloroform-labile C, an indicator of microbial biomass, was only minimally affected by these applications, indicating that a small amount of labile N was immobilized by microbes. All applications led to rapid increases in NO3 -N contents in both soils, and ammonia-oxidizing bacteria, but not archaea may play a critical role in net nitrification in the amended soils. The net nitrification rates for both soils were the highest after the application of dry digestates, followed by wet digestates and then the chemical fertilizer in order of decreasing soil pH. These results suggest that the immediate effects of applying digestates, especially dry digestates with the highest pH, on nitrate leaching need to be considered when digestates are used as alternative fertilizers. PMID:25740173
Fractions of calcium in the plant-soil system affected by the application of olive oil wastewater.
Gallardo-Lara, F; Azcón, M; Quesada, J L; Polo, A
1998-09-01
A pot experiment using calcareous soil was conducted in a growth chamber to examine the effects of olive oil wastewater applications on Ca fractions in the plant and on exchangeable Ca in soil after plant growth. The experimental treatments consisted of two rates of olive oil wastewater, two mineral fertilizer treatments including K, which supplied K in amounts equivalent to the K supplied by the olive oil wastewater treatments, a mineral fertilizer without K treatment (F), and a control. The pots were sown with ryegrass which was harvested 3 times at monthly intervals. The high rate of olive oil wastewater resulted in a prolonged increases in dry matter production. It also resulted in a reduction in the concentrations of soluble Ca, bound Ca, inorganic insoluble Ca and organic insoluble Ca in the plant shoots relative to the control and the F treatment. The low rate of olive oil wastewater produced similar but less marked effects, with decreases being observed in the soluble Ca and bound Ca fractions. After 3 months of plant growth, soil exchangeable Ca was higher in the control and F treatment soils than in the soils receiving olive oil wastewater or K fertilizer. At this time, there were no significant differences in exchangeable Ca between the soils receiving olive oil wastewater and those treated with K fertilizer.
Sawada, Kozue; Toyota, Koki
2015-01-01
Wet and dry anaerobic fermentation processes are operated for biogas production from organic matter, resulting in wet and dry digestates as by-products, respectively. The application of these digestates to soil as fertilizer has increased in recent years. Therefore, we herein compared the effects of applying wet digestates (pH 8.2, C/N ratio 4.5), dry digestates (pH 8.8, C/N ratio 23.4), and a chemical fertilizer to Japanese paddy and upland soils on short-term nitrification under laboratory aerobic conditions. Chloroform-labile C, an indicator of microbial biomass, was only minimally affected by these applications, indicating that a small amount of labile N was immobilized by microbes. All applications led to rapid increases in NO3 -N contents in both soils, and ammonia-oxidizing bacteria, but not archaea may play a critical role in net nitrification in the amended soils. The net nitrification rates for both soils were the highest after the application of dry digestates, followed by wet digestates and then the chemical fertilizer in order of decreasing soil pH. These results suggest that the immediate effects of applying digestates, especially dry digestates with the highest pH, on nitrate leaching need to be considered when digestates are used as alternative fertilizers.
Beauregard, M S; Gauthier, M-P; Hamel, C; Zhang, T; Welacky, T; Tan, C S; St-Arnaud, M
2013-02-01
Arbuscular mycorrhizal (AM) fungi are key components of most agricultural ecosystems. Therefore, understanding the impact of agricultural practices on their community structure is essential to improve nutrient mobilization and reduce plant stress in the field. The effects of five different organic or mineral sources of phosphorus (P) for a maize-soybean rotation system on AM fungal diversity in roots and soil were assessed over a 3-year period. Total DNA was extracted from root and soil samples collected at three different plant growth stages. An 18S rRNA gene fragment was amplified and taxa were detected and identified using denaturing gradient gel electrophoresis followed by sequencing. AM fungal biomass was estimated by fatty acid methyl ester analysis. Soil P fertility parameters were also monitored and analyzed for possible changes related with fertilization or growth stages. Seven AM fungal ribotypes were detected. Fertilization significantly modified soil P flux, but had barely any effect on AM fungi community structure or biomass. There was no difference in the AM fungal community between plant growth stages. Specific ribotypes could not be significantly associated to P treatment. Ribotypes were associated with root or soil samples with variable detection frequencies between seasons. AM fungal biomass remained stable throughout the growing seasons. This study demonstrated that roots and soil host distinct AM fungal communities and that these are very temporally stable. The influence of contrasting forms of P fertilizers was not significant over 3 years of crop rotation.
Carbon mineralization and soil fertility at high altitude grasslands in the Bolivian Andean
NASA Astrophysics Data System (ADS)
Zornoza, R.; Muñoz, M. A.; Faz, A.
2012-04-01
The high grasslands of Apolobamba provide a natural habitat for a high number of wild and domestic camelids such as vicuna (Vicugna vicugna) and alpaca (Lama pacos) in Bolivia. Because of the importance of the camelid raising for the Apolobambás inhabitant economy, it is fundamental to determine the natural resources condition and their availability for the camelid support. The soil organic matter plays a crucial role in the maintenance of the soil fertility at high grasslands. On the other hand, soil respiration is the primary pathway for CO2 fixed by plants returning to the atmosphere and its study is essential to evaluate the soil organic matter mineralization and the global C cycle. Based on this, the objectives of this research were to: (i) evaluate the soil fertility and (ii) determine soil organic matter mineralization on the basis of CO2 releases in Apolobamba. Regarding the lastly vicuna censuses carried out in the studied area, eight representative zones with dissimilar vicuna densities were selected. Other characteristics were also considered to select the study zones: (1) alpaca densities, (2) vegetation communities (3) plant cover and (4) landscape and geo-morphological description. Soil samples from different samplings were collected. Soil respiration was determined at two temperatures: 15 °C (based on the highest atmosphere temperature that was registered in the area) and 25 °C, in order to monitor the increase in soil respiration (Q10). The physico-chemical soil results pointed out the good soil fertility. However, erosive processes could be taken place likely caused by the alpaca grazing. High total organic carbon contents were observed corresponding to the highest soil respiration at 15 °C. This observation was supported by the relationship found between the total organic carbon and the soil respiration. A noticeable increase of the soil respiration when the temperature increased 10 °C was reported (from 1083 ± 47 g C m-2 yr-1 at 15 °C to 2786 ± 343 g C m-2 yr-1 at 25 °C ) which indicated the organic matter mineralization increase and likely the high C reservoirs decrease. Additionally, high Q10 values were observed (13.8 ± 1.5 in subsurface). This indicates that basically climate conditions are actually controlling organic matter mineralization and it is more evident in zones with high total organic carbon contents. Although no vicuna affection on the soil fertility was observed, the camelid grazing generally causes a reduction in the soil respiration rate in Apolobamba. Therefore, it should be undertaken some protection actions to prevent the biodiversity affection bringing camelid overexploitation under control in Bolivian Andean. Keywords: biodiversity, high grasslands, camelid grazing, carbon mineralization, soil respiration
NASA Astrophysics Data System (ADS)
Sardiana, I. K.; Susila, D.; Supadma, A. A.; Saifulloh, M.
2017-12-01
The landuse of Tegallalang Subdistrict is dominated by dryland farming. The practice of cultivation on agricultural dryland that ignores the carrying capacity of the environment can lead to land degradation that makes the land vulnerable to the deterioration of soil fertility. Soil fertility evaluation and land management of dryland farming in Tegallalang Sub-district, Gianyar Regency were aimed at (1) identifying the soil fertility and it’s respective limiting factors, (2) mapping the soil fertility using Geographic Information Systems (GIS) and (3) developing land management for dryland farming in Tegallalang Sub-district. This research implementing explora-tory method which followed by laboratory analysis. Soil samples were taken on each homogene-ous land units which developed by overlay of slope, soil type, and land use maps. The following soil fertility were measured, such as CEC, base saturation, P2O5, K- Total and C-Organic. The values of soil fertility were mapping using QGIS 2.18.7 and refer to land management evaluation. The results showed that the soil fertility in the research area considered high, and low level. The High soil fertility presents on land units at the flat to undulating slope with different land management systems (fertilizer, without fertilizer, soil tillage and without soil tillage). The low soil fertility includes land units that present on steep slope, and without land managements. The limiting factors of soil fertility were texture, C-Organic, CEC, P2O5, and K- total. It was recommended to applying organic fertilizer, Phonska, and dolomite on the farming area.
Delgado-Baquerizo, Manuel; Powell, Jeff R; Hamonts, Kelly; Reith, Frank; Mele, Pauline; Brown, Mark V; Dennis, Paul G; Ferrari, Belinda C; Fitzgerald, Anna; Young, Andrew; Singh, Brajesh K; Bissett, Andrew
2017-08-01
The current theoretical framework suggests that tripartite positive feedback relationships between soil biodiversity, fertility and plant productivity are universal. However, empirical evidence for these relationships at the continental scale and across different soil depths is lacking. We investigate the continental-scale relationships between the diversity of microbial and invertebrate-based soil food webs, fertility and above-ground plant productivity at 289 sites and two soil depths, that is 0-10 and 20-30 cm, across Australia. Soil biodiversity, fertility and plant productivity are strongly positively related in surface soils. Conversely, in the deeper soil layer, the relationships between soil biodiversity, fertility and plant productivity weaken considerably, probably as a result of a reduction in biodiversity and fertility with depth. Further modeling suggested that strong positive associations among soil biodiversity-fertility and fertility-plant productivity are limited to the upper soil layer (0-10 cm), after accounting for key factors, such as distance from the equator, altitude, climate and physicochemical soil properties. These findings highlight the importance of surface soil biodiversity for soil fertility, and suggest that any loss of surface soil could potentially break the links between soil biodiversity-fertility and/or fertility-plant productivity, which can negatively impact nutrient cycling and food production, upon which future generations depend. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.
Wang, Hua; Yang, Shao-hui; Yang, Jing-ping; Lv, Ya-min; Zhao, Xing; Pang, Ji-liang
2014-11-01
It is important to understand the effects of temporal changes in microbial communities in the acidic soils of tea orchards with different fertilizers. A field experiment involving organic fertilizer (OF), chemical fertilizer (CF), and unfertilized control (CK) treatments was arranged to analyze the temporal changes in the bacterial and archaeal communities at bimonthly intervals based on the 16S ribosomal RNA (rRNA) gene using terminal restriction fragment length polymorphism (T-RFLP) profiling. The abundances of total bacteria, total archaea, and selected functional genes (bacterial and archaeal amoA, bacterial narG, nirK, nirS, and nosZ) were determined by quantitative polymerase chain reaction (qPCR). The results indicate that the structures of bacterial and archaeal communities varied significantly with time and fertilization based on changes in the relative abundance of dominant T-RFs. The abundancy of the detected genes changed with time. The total bacteria, total archaea, and archaeal amoA were less abundant in July. The bacterial amoA and denitrifying genes were less abundant in September, except the nirK gene. The OF treatment increased the abundance of the observed genes, while the CF treatment had little influence on them. The soil temperature significantly affected the bacterial and archaeal community structures. The soil moisture was significantly correlated with the abundance of denitrifying genes. Of the soil chemical properties, soil organic carbon was the most important factor and was significantly correlated with the abundance of the detected genes, except the nirK gene. Overall, this study demonstrated the effects of both temporal alteration and organic fertilizer on the structures of microbial communities and the abundance of genes involved in the nitrogen cycle.
Wang, Hua; Yang, Shao-hui; Yang, Jing-ping; Lv, Ya-min; Zhao, Xing; Pang, Ji-liang
2014-01-01
It is important to understand the effects of temporal changes in microbial communities in the acidic soils of tea orchards with different fertilizers. A field experiment involving organic fertilizer (OF), chemical fertilizer (CF), and unfertilized control (CK) treatments was arranged to analyze the temporal changes in the bacterial and archaeal communities at bimonthly intervals based on the 16S ribosomal RNA (rRNA) gene using terminal restriction fragment length polymorphism (T-RFLP) profiling. The abundances of total bacteria, total archaea, and selected functional genes (bacterial and archaeal amoA, bacterial narG, nirK, nirS, and nosZ) were determined by quantitative polymerase chain reaction (qPCR). The results indicate that the structures of bacterial and archaeal communities varied significantly with time and fertilization based on changes in the relative abundance of dominant T-RFs. The abundancy of the detected genes changed with time. The total bacteria, total archaea, and archaeal amoA were less abundant in July. The bacterial amoA and denitrifying genes were less abundant in September, except the nirK gene. The OF treatment increased the abundance of the observed genes, while the CF treatment had little influence on them. The soil temperature significantly affected the bacterial and archaeal community structures. The soil moisture was significantly correlated with the abundance of denitrifying genes. Of the soil chemical properties, soil organic carbon was the most important factor and was significantly correlated with the abundance of the detected genes, except the nirK gene. Overall, this study demonstrated the effects of both temporal alteration and organic fertilizer on the structures of microbial communities and the abundance of genes involved in the nitrogen cycle. PMID:25367788
Zheng, Xuebo; Fan, Jianbo; Xu, Lei; Zhou, Jing
2017-01-01
Unreasonable use of chemical fertilizer (CF) on agricultural soil leads to massive losses of soil organic carbon (SOC) and total nitrogen (TN) in tropical and subtropical areas, where soil conditions are unfavorable for aggregate formation. This study evaluated the effects of combined application of biogas slurry (BS) plus CF on soil aggregation and aggregate-associated C/N concentration and storage in an Ultisol. Six treatments included: no fertilizer (T1), CF only (T2), partial (15% (T3), 30% (T4) and 45% (T5)) substitution of TN with BS and BS only (T6). Soil mechanical-stable aggregates (MSAs) formation and stability as well as MSAs-associated C/N concentration and storage were observed in different aggregate sizes (>5, 5-2, 2-1, 1.0-0.5, 0.50-0.25 and <0.25 mm). The proportion of MSAs >5 mm significantly increased with BS substitution (T5), while the proportions of MSAs 1.0-0.5 mm, MSAs 0.50-0.25 mm and MSAs <0.25 mm significantly decreased. Both mean weight diameter and geometric mean diameter were highest in T5, which improved soil aggregation stability as well as resulted in significantly higher SOC and TN concentrations and storage in MSAs >0.5 mm that constituted 72-82% of MSAs. Stepwise regression analysis showed that MSAs >5 mm, SOC in MSAs >5 mm and TN in MSAs >5 mm were the dominant variables affecting aggregate stability. Meanwhile SOC in MSAs <0.25 mm and TN in MSAs 2-1 mm were independent variables affecting SOC and TN concentrations in bulk soils. Therefore, certain rate of combined application of BS plus CF is an effective, eco-friendly way to improve soil quality in an Ultisol.
de Solla, Shane Raymond; Martin, Pamela Anne; Mikoda, Paul
2011-09-15
Many reptiles oviposit in soils associated with agricultural landscapes. We evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in Ontario on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. The herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial mixtures within chemical classes, as well as complete mixtures. Eggs were incubated in the soil in a garden plot in which these mixtures were applied at a typical field application rate, and higher rates. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed at male producing temperatures in the laboratory in covered bins in the same soil, where there was less opportunity for loss through volatilization or leaching. Egg mortality was 100% at 10× the typical field application rate of the complete mixture, both with and without tefluthrin. At typical field application rates, hatching success ranged between 91.7 and 95.8%. Eggs exposed only to herbicides were not negatively affected at any application rates. Although fertilizer treatments at typical field application rates did not affect eggs, mortality was remarkably higher at three times this rate, and 100% at higher rates. The frequency of deformities of hatchlings was elevated at the highest application rate of the insecticide tefluthrin. The majority of the toxicity of the mixture was not due to the herbicides or insecticide, but was due to the ammonia fertilizer. At typical field application rates, the chemical regime associated with corn production does not appear to have any detrimental impacts upon turtle egg development; however toxicity dramatically increases if this threshold is passed. Copyright © 2011. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
mudi, Sanku Datta; Wang, Jim J.; Dodla, Syam Kumar; Arceneaux, Allen; Viator, H. P.
2016-08-01
Ammonia (NH3) emission from soil is a loss of nitrogen (N) nutrient for plant production as well as an issue of air quality, due to the fact that it is an active precursor of airborne particulate matters. Ammonia also acts as a secondary source of nitrous oxide (N2O) emission when present in the soil. In this study, the impacts of different sources of N fertilizers and harvest residue management schemes on NH3 emissions from sugarcane production were evaluated based on an active chamber method. The field experiment plots consisting of two sources of N fertilizer (urea and urea ammonium nitrate (UAN)) and two common residue management practices, namely residue retained (RR) and residue burned (RB), were established on a Commerce silt loam. The NH3 volatilized following N fertilizer application was collected in an impinger containing diluted citric acid and was subsequently analyzed using ion chromatography. The NH3 loss was primarily found within 3-4 weeks after N application. Average seasonal soil NH3 flux was significantly greater in urea plots with NH3-N emission factor (EF) twice or more than in UAN plots (2.4-5.6% vs. 1.2-1.7%). The RR residue management scheme had much higher NH3 volatilization than the RB treatment regardless of N fertilizer sources, corresponding to generally higher soil moisture levels in the former. Ammonia-N emissions in N fertilizer-treated sugarcane fields increased with increasing soil water-filled pore space (WFPS) up to 45-55% observed in the field. Both N fertilizer sources and residue management approaches significantly affected NH3 emissions.
USDA-ARS?s Scientific Manuscript database
Biochar as a soil amendment and the use of fertilizer stabilizers (N transformation inhibitors) have been shown to reduce N2O emissions, but the mechanisms or processes involved are not well understood. The objective of this research was to investigate N transformation processes and the relationship...
NASA Astrophysics Data System (ADS)
Dang, Tinghui; Dong, Qiang
2017-04-01
【Objectives】Excessive fertilization in farmland caused nitrate leaching and accumulation in soil, which not only reduced the fertilizer utilization rate, but also had potential environmental problems. The effects of different nitrogen reduction modes on yield of spring maize and soil NO3-N in the southern Loess Plateau were discussed, and scientific fertilization suggestions were put forward, which were of great significance to instruct local maize fertilization and protect environment safety. 【Methods】A field experiment was conducted in the south of the Loess Plateau for three years. Spring maize was planted with half plastic film mulching in one crop per annum.The experiment consisted of 5 N fertilization treatments: control treatment (CK),conventional N fertilization rate (Con), optimal N fertilizationⅠ(OptⅠ), optimal N fertilizationⅡ (Opt Ⅱ) and optimal N fertilization Ⅲ(Opt Ⅲ), The changes of yield of maize, nitrogen uptake and soil NO3-N were measured.【Results】The results showed that, compared with the conventional fertilization, the grain yield and N uptake of maize had no significant change under the three optimal N fertilization application models, the rate of the grain yield's change is 100 300kg/hm2. Compared with the conventional fertilization, agronomic efficiency of fertilizer-nitrogen and N partial fertilizer productivity were increased by 20.2% 23.2% and 21.9% 23.7%, respectively. The accumulation of nitrate nitrogen in profile (0-200 cm) decreased by 90.7 kg / hm2, 97.3 kg / hm2, 100.7 kg / hm2 ,respectively, with the decreases of 44.7%, 47.9% and 49.6% respectively.【Conclusions】The optimum nitrogen fertilization pattern did not affect spring maize yield and N uptake, and could improve agronomic efficiency of fertilizer-nitrogen and N partial fertilizer productivity. Under the same nitrogen application rate, the effects of adding nitrification inhibitor or slow-release fertilizer on nitrate-N residue were not obvious. The amount of nitrogen applied, the mode and type of fertilization had a certain effect on the migration of nitrate nitrogen. Optimized N - application model could significantly reduce the NO3—N residue in soil profile. It is suggested to reduce the amount of nitrogen fertilizer by 20% on the basis of the traditional nitrogen fertilizer when the spring maize is planted with half plastic film mulching, which can guarantee the yield and protect the environment.
[Variations of soil fertility level in red soil region under long-term fertilization].
Yu, Han-qing; Xu, Ming-gang; Lü, Jia-long; Bao, Yao-xian; Sun, Nan; Gao, Ju-sheng
2010-07-01
Based on the long-term (1982-2007) field experiment of "anthropogenic mellowing of raw soil" at the Qiyang red soil experimental station under Chinese Academy of Agricultural Sciences, and by using numerical theory, this paper studied the variations of the fertility level of granite red soil, quaternary red soil, and purple sandy shale soil under six fertilization patterns. The fertilization patterns included non-fertilization (CK), straw-returning without fertilizers (CKR), chemical fertilization (NPK), NPK plus straw-return (NPKR), rice straw application (M), and M plus straw-return (MR). The soil integrated fertility index (IFI) was significantly positively correlated with relative crop yield, and could better indicate soil fertility level. The IFI values of the three soils all were in the order of NPK, NPKR > M, MR > CK, CKR, with the highest value in treatment NPKR (0.77, 0.71, and 0.71 for granite red soil, quaternary red soil, and purple sandy shale soil, respectively). Comparing with that in the treatments of no straw-return, the IFI value in the treatments of straw return was increased by 6.72%-18.83%. A turning point of the IFI for all the three soils was observed at about 7 years of anthropogenic mellowing, and the annual increasing rate of the IFI was in the sequence of purple sandy shale soil (0.016 a(-1)) > quaternary red clay soil (0.011 a(-1)) > granite red soil (0.006 a(-1)). It was suggested that a combined application of organic and chemical fertilizers and/or straw return could be an effective and fast measure to enhance the soil fertility level in red soil region.
Effect of different kinds of crop residues on aggregate-protected soil organic matter fractions.
NASA Astrophysics Data System (ADS)
Huisz, A.
2009-04-01
Organic matter content of soils determines many important soil properties, such as soil structure, fertility and water-management. To improve its fertility and quality, returning different kinds of organic matter to soil has a long historical tradition. Ameliorating of soil and enhancing its fertility by enhancing its carbon stock with organic matter incorporation (like farmyard manure, crop residues or green manure) are general practices, but the extent of the amelioration depends much on several factors such as quantity, quality of the used organic matters. Quality of soil organic matters is affected by their chemical build-up, which differs by their origin (i.e. plant species); and their decomposability is affected by particle-size, protection by soil aggregates and the extent of their association to mineral surfaces. In our paper we investigated the effect of three different kinds of organic matter incorporation on aggregate-protected organic matter fractions: (1) Maize stem (M), (2) Wheat straw (W), and (3) Maize stem & Wheat straw (MW). Our samples were originated from Keszthely, Western Hungary, where the texture of the investigated soil is Sandy loam, the type of soil is Eutric Cambisol (soil type FAO), or Alfisol (soil type USDA). SOM fractions might be isolated and measured by physical fractionation of soil (Cambardella and Elliott (1992), Jensen et al. (1992)). Firstly, microaggregates were separated according to their particle-size with physical fractionation (i.e. wet sieving) (Six et al. (2000a)). Each sample was pre-treated by capillary wetting and was sieved for 2 min in an analytic sieve shaker machine with the following aperture sizes: 2 mm, 250 μm, 53 μm. Therefore 4 fractions were resulted: (1) the >2000 μm large macro-, (2) the 250-2000 μm small macro-, (3) the 53-250 μm microaggregates, and (4) the
Effect of N fertilization and tillage on nitrous oxide (N2O) loss from soil under wheat production
Bansal, Sheel; Aberle, Ezra; Teboh, Jasper; Yuja, Szilvia; Liebig, Mark; Meier, Jacob; Boyd, Alec
2017-01-01
Nitrous oxide (N2O-N) is one of the most important gases in the atmosphere because it is 300 times more powerful than carbon dioxide in its ability to trap heat, and is a key chemical agent of ozone depletion. The amount of N2O-N emitted from agricultural fields can be quite high, depending on the complex interplay between N fertility and residue management, plant N uptake, microbial processes, environmental conditions, and wet-up and dry-down events. High N fertilizer rates generally increase yields, but may disproportionately increase N2O-N losses due to prolonged residence time in soil when not used by the crop, and incomplete decomposition of excess N-compounds by microbes. Tillage could also affect N2O-N losses through changes in soil moisture content. Though nitrogen monoxide (NO) is one form of N lost from the soil, especially under conventional tillage, this study objective was to quantify N2O loss in wheat fields from applied urea on soil under no-till (NT) versus incorporated urea under conventional till (CT).
Tian, Xiaofei; Zhang, Min; Wan, Yongshan; Xie, Zhihua; Chen, Baocheng; Li, Wenqing
2018-01-01
Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and on the soil nutrient distribution in the 0–100 cm soil profile. Biochar was applied at 0, 5, 10, and 20 t ha-1 (expressed as Control, BC5, BC10, and BC20, respectively) for each cotton season, with identical doses of chemical fertilizers. Biochar enhanced the cotton lint yield by 8.0–15.8%, 9.3–13.9%, and 9.2–21.9% in 2013, 2014, and 2015, respectively, and high levels of biochar application achieved high cotton yields each year. Leaching of soil nitrate was reduced, while the pH values, soil organic carbon, total nitrogen (N), and available K content of the 0–20 cm soil layer were increased in 2014 and 2015. However, the changes in the soil available P content were less substantial. This study suggests that successive biochar amendments have the potential to enhance cotton productivity and soil fertility while reducing nitrate leaching. PMID:29324750
Wang, Shaojun; Chen, Han Y. H.; Tan, Yan; Fan, Huan; Ruan, Honghua
2016-01-01
Soil fauna are critical for ecosystem function and sensitive to the changes of soil fertility. The effects of fertilization on soil fauna communities, however, remain poorly understood. We examined the effects of fertilization form and quantity on the abundance, diversity and composition of soil fauna across an age-sequence of poplar plantations (i.e., 4-, 9- and 20-yr-old) in the coastal region of eastern China. We found that the effects of fertilization on faunal abundance, diversity, and composition differed among stand ages. Organic fertilizers increased the total abundance of soil fauna, whereas low level inorganic fertilizers imparted increases only in the 4- and 9-yr-old stands. The number of faunal groups did not change with fertilization, but Shannon’s and Margalef diversity indices increased under low level organic fertilization, and decreased under inorganic fertilization in the 9- and 20-yr-old stands. Community composition of soil fauna differed strongly with fertilization and stand age. The changes in soil fauna were strongly associated with the changes in microbial biomass carbon, dissolved organic carbon and nitrogen, and available phosphorus and potassium. Our findings suggest that the responses of soil fauna to fertilization may be mediated through the fertilization effects on soil nutrient availability. PMID:26857390
Wang, Shaojun; Chen, Han Y H; Tan, Yan; Fan, Huan; Ruan, Honghua
2016-02-09
Soil fauna are critical for ecosystem function and sensitive to the changes of soil fertility. The effects of fertilization on soil fauna communities, however, remain poorly understood. We examined the effects of fertilization form and quantity on the abundance, diversity and composition of soil fauna across an age-sequence of poplar plantations (i.e., 4-, 9- and 20-yr-old) in the coastal region of eastern China. We found that the effects of fertilization on faunal abundance, diversity, and composition differed among stand ages. Organic fertilizers increased the total abundance of soil fauna, whereas low level inorganic fertilizers imparted increases only in the 4- and 9-yr-old stands. The number of faunal groups did not change with fertilization, but Shannon's and Margalef diversity indices increased under low level organic fertilization, and decreased under inorganic fertilization in the 9- and 20-yr-old stands. Community composition of soil fauna differed strongly with fertilization and stand age. The changes in soil fauna were strongly associated with the changes in microbial biomass carbon, dissolved organic carbon and nitrogen, and available phosphorus and potassium. Our findings suggest that the responses of soil fauna to fertilization may be mediated through the fertilization effects on soil nutrient availability.
Effects of long-term fertilization on soil humic acid composition and structure in Black Soil
Zhang, Jiuming; Wang, Jingkuan; An, Tingting; Wei, Dan; Chi, Fengqin; Zhou, Baoku
2017-01-01
The composition and structure of humic acid (HA) can be affected by fertilization, but the short-term effects are difficult to detect using traditional analysis methods. Using a 35-year long-term experiment in Black Soil, the molecular structure of HA was analyzed with Fourier transform infrared spectroscopy (FTIR), 13C nuclear magnetic resonance spectroscopy (NMR), and fluorescence spectroscopy. Variation in HA was analyzed after long-term fertilization, including fertilization with manure (M), inorganic N, P and K fertilizer (NPK), manure combined with inorganic N, P, and K fertilizer (MNPK), and a no-fertilizer control (CK). The application of each fertilizer treatment increased crop yields compared with the CK treatment, and the MNPK treatment increased crop yield the most. The ratio of main IR absorption peak of HA at 2,920 cm−1 compared with the peak at 2,850 cm−1 (2920/2850) was higher in the NPK and MNPK treatments compared with the CK treatment. The application of manure (MNPK and M treatments) increased the ratio of hydrogen to carbon (H/C) in HA, and raised the ratio of the main IR absorption peak of HA at 2920 cm−1 to that at 1720 cm−1 (2920/1720). Manure treatments also raised the ratio of aliphatic carbon (C) to aromatic C, alkyl C to alkoxy C and hydrophobic C to hydrophilic C and the fluorescence index (f 450/500), but decreased the degree of aromatization of HA, when compared with the CK treatment. The ratio between each type of C in HA was similar among all the fertilizer treatments, but NPK had a lower ratio of H/C and a lower content of aliphatic C compared with the CK treatment. These results indicated that the molecular structure of HA in Black Soil tends to be aliphatic, simpler, and younger after the application of manure. While the application of inorganic fertilizers increased in the degree of condensation of HA and made HA structure complicated. The application of manure alone or combined with inorganic fertilizers may be an effective way to increase crop yield and improve the structure of soil organic matter. PMID:29095840
The Challenge of Improving Soil Fertility in Yam Cropping Systems of West Africa
Frossard, Emmanuel; Aighewi, Beatrice A.; Aké, Sévérin; Barjolle, Dominique; Baumann, Philipp; Bernet, Thomas; Dao, Daouda; Diby, Lucien N.; Floquet, Anne; Hgaza, Valérie K.; Ilboudo, Léa J.; Kiba, Delwende I.; Mongbo, Roch L.; Nacro, Hassan B.; Nicolay, Gian L.; Oka, Esther; Ouattara, Yabile F.; Pouya, Nestor; Senanayake, Ravinda L.; Six, Johan; Traoré, Orokya I.
2017-01-01
Yam (Dioscorea spp.) is a tuber crop grown for food security, income generation, and traditional medicine. This crop has a high cultural value for some of the groups growing it. Most of the production comes from West Africa where the increased demand has been covered by enlarging cultivated surfaces while the mean yield remained around 10 t tuber ha−1. In West Africa, yam is traditionally cultivated without input as the first crop after a long-term fallow as it is considered to require a high soil fertility. African soils, however, are being more and more degraded. The aims of this review were to show the importance of soil fertility for yam, discuss barriers that might limit the adoption of integrated soil fertility management (ISFM) in yam-based systems in West Africa, present the concept of innovation platforms (IPs) as a tool to foster collaboration between actors for designing innovations in yam-based systems and provide recommendations for future research. This review shows that the development of sustainable, feasible, and acceptable soil management innovations for yam requires research to be conducted in interdisciplinary teams including natural and social sciences and in a transdisciplinary manner involving relevant actors from the problem definition, to the co-design of soil management innovations, the evaluation of research results, their communication and their implementation. Finally, this research should be conducted in diverse biophysical and socio-economic settings to develop generic rules on soil/plant relationships in yam as affected by soil management and on how to adjust the innovation supply to specific contexts. PMID:29209341
Johnston, A. E.
2018-01-01
Summary Long‐term field experiments that test a range of treatments and are intended to assess the sustainability of crop production, and thus food security, must be managed actively to identify any treatment that is failing to maintain or increase yields. Once identified, carefully considered changes can be made to the treatment or management, and if they are successful yields will change. If suitable changes cannot be made to an experiment to ensure its continued relevance to sustainable crop production, then it should be stopped. Long‐term experiments have many other uses. They provide a field resource and samples for research on plant and soil processes and properties, especially those properties where change occurs slowly and affects soil fertility. Archived samples of all inputs and outputs are an invaluable source of material for future research, and data from current and archived samples can be used to develop models to describe soil and plant processes. Such changes and uses in the Rothamsted experiments are described, and demonstrate that with the appropriate crop, soil and management, acceptable yields can be maintained for many years, with either organic manure or inorganic fertilizers. Highlights Long‐term experiments demonstrate sustainability and increases in crop yield when managed to optimize soil fertility.Shifting individual response curves into coincidence increases understanding of the factors involved.Changes in inorganic and organic pollutants in archived crop and soil samples are related to inputs over time.Models describing soil processes are developed from current and archived soil data. PMID:29527119
Chen, L; Zhou, L
2000-08-01
Pot experiment studies on the fertility regulation and improvement of fertile and infertile brown earth type vegetable garden soils and their functionary essence show that under conditions of taking different soil fertility improvement measures, the nutrient contents in fertile and infertile soils were not always higher than the controls, but the aggregation densities of soil microaggregates were increased, and the proportion of different microaggregates was more rational. There was no significant relationship between soil productivity and soil microaggregates proportion. It is proved that the essence of soil fertility improvement consists in the ultimate change of the preservation and supply capacities of soil nutrients, and the proportion of soil microaggregates could be an integrative index to evaluate the level of soil fertility and the efficiency of soil improvement.
NASA Astrophysics Data System (ADS)
Shi, Qingwen; Wang, Huixin; Bai, Chunming; Wu, Di; Song, Qiaobo; Gao, Depeng; Dong, Zengqi; Cheng, Xin; Dong, Qiping; Zhang, Yahao; Mu, Jiahui; Chen, Qinghong; Liao, Wenqing; Qu, Tianru; Zhang, Chunling; Zhang, Xinyu; Liu, Yifei; Han, Xiaori
2017-05-01
Experiments for mechanized soil fertilization for corns were conducted in Faku demonstration zone. On this basis, we studied effects on corn soil fertility under continuous cropping due to different mechanized soil fertilization methods. Our study would serve as a theoretical basis further for mechanized soil fertilization improvement and soil quality improvement in brown soil area. Based on the survey of soil physical characteristics during different corn growth periods, we collected soil samples from different corn growth periods to determine and make statistical analysis accordingly. Stalk returning to field with deep tillage proved to be the most effective on available nutrient improvement for arable soil in the demonstration zone. Different mechanized soil fertilization methods were remarkably effective on total phosphorus improvement for arable soil in the demonstration zone, while less effective on total nitrogen or total potassium, and not so effective on C/N ratio in soil. Stalk returning with deep tillage was more favorable to improve content of organic matter in soil, when compared with surface application, and organic granular fertilizer more favorable when compared with decomposed cow dung for such a purpose, too.
Does Gray-Tailed Vole Activity Affect Soil Quality?
USDA-ARS?s Scientific Manuscript database
Voles are well-known crop pests, especially when peak populations are present, but their role in soil fertility and impacts on agricultural sustainability are not well understood. Five months after the abrupt disappearance of a peak in a gray-tailed vole (Microtus canicaudus) population, we examined...
Zhou, Jing; Jiang, Xin; Wei, Dan; Zhao, Baisuo; Ma, Mingchao; Chen, Sanfeng; Cao, Fengming; Shen, Delong; Guan, Dawei; Li, Jun
2017-06-12
Long-term use of inorganic nitrogen (N) fertilization has greatly influenced the bacterial community in black soil of northeast China. It is unclear how N affects the bacterial community in two successive crop seasons in the same field for this soil type. We sampled soils from a long-term fertilizer experimental field in Harbin city with three N gradients. We applied sequencing and quantitative PCR targeting at the 16S rRNA gene to examine shifts in bacterial communities and test consistent shifts and driving-factors bacterial responses to elevated N additions. N addition decreased soil pH and bacterial 16S rDNA copy numbers, and increased soil N and crop yield. N addition consistently decreased bacterial diversity and altered bacterial community composition, by increasing the relative abundance of Proteobacteria, and decreasing that of Acidobacteria and Nitrospirae in both seasons. Consistent changes in the abundant classes and genera, and the structure of the bacterial communities across both seasons were observed. Our results suggest that increases in N inputs had consistent effects on the richness, diversity and composition of soil bacterial communities across the crop seasons in two continuous years, and the N addition and the subsequent edaphic changes were important factors in shaping bacterial community structures.
Influence of long-term fertilization on soil physicochemical properties in a brown soil
NASA Astrophysics Data System (ADS)
Li, Dongdong; Luo, Peiyu; Han, Xiaori; Yang, Jinfeng
2018-01-01
This study aims to explore the influence on soil physicochemical properties under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen and phosphate fertilizer).The results showed thatthe long-term application of chemical fertilizers reduced soil pH value, while the application of organic fertilizers increased pH value. Fertilization significantly increased the content of AHN, TN and SOM. Compared with the CK treatment and chemical fertilizer treatments, organic fertilizer treatments significantly increased the content of AP and TP. The content of AK and TK were no significant difference in different treatment.
Joa, Jae Ho; Weon, Hang Yeon; Hyun, Hae Nam; Jeun, Young Chull; Koh, Sang Wook
2014-12-01
This study was conducted to assess bacterial species richness, diversity and community distribution according to different fertilization regimes for 16 years in citrus orchard soil of volcanic ash. Soil samples were collected and analyzed from Compost (cattle manure, 2,000 kg/10a), 1/2 NPK+compost (14-20-14+2,000 kg/10a), NPK+compost (28-40-28+2,000 kg/10a), NPK (28-40-28 kg/10a), 3 NPK (84-120-84 kg/10a), and Control (no fertilization) plot which have been managed in the same manners with compost and different amount of chemical fertilization. The range of pyrosequencing reads and OTUs were 4,687-7,330 and 1,790-3,695, respectively. Species richness estimates such as Ace, Chao1, and Shannon index were higher in 1/2 NPK+compost than other treatments, which were 15,202, 9,112, 7.7, respectively. Dominant bacterial groups at level of phylum were Proteobacteria, Acidobacteria, and Actinobacteria. Those were occupied at 70.9% in 1/2 NPK+compost. Dominant bacterial groups at level of genus were Pseudolabrys, Bradyrhizobium, and Acidobacteria. Those were distributed at 14.4% of a total of bacteria in Compost. Soil pH displayed significantly closely related to bacterial species richness estimates such as Ace, Chao1 (p<0.05) and Shannon index (p<0.01). However, it showed the negative correlation with exchangeable aluminum contents (p<0.05). In conclusion, diversity of bacterial community in citrus orchard soil was affected by fertilization management, soil pH changes and characteristics of volcanic ash.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jian, Siyang; Li, Jianwei; Chen, Ji
Nitrogen (N) fertilization affects the rate of soil organic carbon (SOC) decomposition by regulating extracellular enzyme activities (EEA). Extracellular enzymes have not been represented in global biogeochemical models. Understanding the relationships among EEA and SOC, soil N (TN), and soil microbial biomass carbon (MBC) under N fertilization would enable modeling of the influence of EEA on SOC decomposition. Based on 65 published studies, we synthesized the activities of α-1,4-glucosidase (AG), β-1,4-glucosidase (BG), β-d-cellobiosidase (CBH), β-1,4-xylosidase (BX), β-1,4-N-acetyl-glucosaminidase (NAG), leucine amino peptidase (LAP), urease (UREA), acid phosphatase (AP), phenol oxidase (PHO), and peroxidase (PEO) in response to N fertilization. Here, themore » proxy variables for hydrolytic C acquisition enzymes (C-acq), N acquisition (N-acq), and oxidative decomposition (OX) were calculated as the sum of AG, BG, CBH and BX; AG and LAP; PHO and PEO, respectively.« less
NASA Astrophysics Data System (ADS)
Canfora, Loredana; Pinzari, Flavia; Lo Papa, Giuseppe; Vittori Antisari, Livia; Vendramin, Elisa; Salvati, Luca; Dazzi, Carmelo; Benedetti, Anna
2017-04-01
Soils preserve and sustain life. Their health and functioning are crucial for crop production and for the maintenance of major ecosystem services. Human induced salinity is one of the main soil threats that reduces soil fertility and affect crop yields. In recent times, great attention has been paid to the general shortage of arable land and to the increasing demand for ecological restoration of areas affected by salinization processes. Despite the diffuse interest on the effects of salinization on plants' growth, and all the derived socioeconomic issues, very few studies analyzed the ecology of the microbial species in naturally saline soils and the resilience of biological fertility in these extreme habitats. Microorganisms inhabiting such environments may share a strategy, may have developed multiple adaptations for maintaining their populations, and cope eventually to extreme conditions by altruistic or cooperative behaviors for maintaining their metabolism active. The understanding and the knowledge of the composition and distribution of microbial communities in natural hypersaline soils can be interesting for ecological reasons but also to develop new restoration strategy where soil fertility was compromised by natural accidents or human mismanagement. The aim of this research was to provide specific information on saline soils in Italy, stressing mainly their distribution, the socioeconomic issues and the understanding of the characterizing ecological processes. Moreover, natural saline soils were used as a model for understanding to what extent the concentration of salt can affect some basic microbial processes. In the present study, physical, chemical and microbiological soil properties were investigated in the shallower horizons of natural salt affected soils in Sicily (Italy), where some ecological contrasting variables acted as strong drivers in fungal and bacterial spatial distribution. Furthermore, the interface between biological and geochemical components in the surface of that peculiar habitat was investigated to evaluate the organization and diversity of the phototrophic and heterotrophic microorganisms. Sixteen soil samples from A horizons were collected according to a random sampling scheme. Bacterial and archaeal communities were characterized by their 16S rDNA genes with T-RFLP method. A total of 92 genera were identified from the 16S pyrosequencing analysis suggesting that cyanobacteria and communities of sulfur bacteria might directly or indirectly promote the formation of protective envelope. Some bacterial phyla appeared spread in the whole area, whatever the salinity gradient, while other groups showed a distribution linked to very compartmentalised soil properties, such as the presence of saline crusts in the soil surface. Results show that saline soils couldn't contain just one single microbial community selected to withstand extreme osmotic phenomena, but many communities that can be variously correlated to one or more environmental parameters having great importance for the maintenance of the overall homeostasis.
NASA Astrophysics Data System (ADS)
Sánchez Reparaz, Maite; de Vente, Joris; Famba, Sebastiao; Rougier, Jean-Emmanuel; Ángel Sánchez-Monedero, Miguel; Barberá, Gonzalo G.
2015-04-01
Integrated water and nutrient management are key factors to increase productivity and to reduce the yield gap in irrigated systems in Sub-Saharan Africa. These two elements are affected by an ensemble of abiotic, biotic, management and socio-economic factors that need to be taken into account to reduce the yield gap, as well as farmers' perceptions and knowledge. In the framework of the project European Union and African Union cooperative research to increase Food production in irrigated farming systems in Africa (EAU4Food project) we are carrying out a participatory innovation process in Chókwè irrigation scheme (Mozambique) based on stakeholders engagement, to test new practices for soil fertility management that can increase yields reducing costs. Through a method combining interviews with three farmers' associations and other relevant stakeholders and soil sampling from the interviewed farmers' plots with the organization of Communities of Practices, we tried to capture how soil fertility is managed by farmers, the constraints they find as well as their perceptions about soil resources. This information was the basis to design and conduct a participatory innovation process where compost made with rice straw and manure is being tested by a farmers' association. Most important limitations of the method are also evaluated. Our results show that socio-economic characteristics of farmers condition how they manage soil fertility and their perceptions. The difficulties they face to adopt new practices for soil fertility management, mainly related to economic resources limitations, labour availability, knowledge time or farm structure, require a systemic understanding that takes into account abiotic, biotic, management and socio-economic factors and their implication as active stakeholders in all phases of the innovation process.
Fertility and acidity status of latossolos (oxisols) under pasture in the Brazilian Cerrado.
Vendrame, Pedro R S; Brito, Osmar R; Guimarães, Maria F; Martins, Eder S; Becquer, Thierry
2010-12-01
The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55% of Brazilian beef production. Previous investigations have shown that about 70-80% of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1) a surface horizon (0.0-0.2 m) in order to evaluate its fertility and acidity status for pasture, and (2) a subsurface horizon (0.6-0.8 m), used for classification. Most of soils had levels of nutrients below the reference values for adequate pasture development. Whatever the texture, about 90% of soils had low or very low availability of phosphorus. Only 7 to 14% of soils had low pH, high exchangeable aluminum, and aluminum saturation above the critical acidity level. Except for nitrogen, no significant difference was found between Latossolos Vermelhos and Latossolos Vermelho-Amarelos.
Tang, Dong; Mao, Liang; Zhi, Yue-e; Zhang, Jin-Zhong; Zhou, Pei; Chai, Xiao-Tong
2014-12-01
The salinity characteristics of greenhouse soils with cropping obstacles in Shanghai suburb were investigated and analyzed. The salinity contents of the salinization greenhouse soils showed a trend of first increasing and then decreasing with the increasing cropping duration. The salinized soils mainly included slightly salted, mildly salted and salted soils, which accounted for 17.39%, 56.52% and 13.04%, respectively. Among them, the degree of salinity in greenhouse soil planted with asparagus in Chongming County was the highest. Among the salt ions in greenhouse soils, the cations were mainly Ca2+ and Na+, while the anions were mainly NO3- and SO4(2-). The degree of salinity was mainly influenced by fertilization mode, cropping duration, crop type and management level, which led to the great variation in the salinity contents and salt ions. Canonical correspondence analysis found that the contents of Ca2+, Mg2+ and NO3- in greenhouse soils were greatly affected by cropping duration, and the degree of salinity would be enhanced and attenuated with long-term application of single fertilizer and mixed application of chemical fertilizer and organic manure, respectively. The greenhouse soils in Shanghai suburb could be classified as four patterns influenced by the relationship between salinity ions and samples, and the most soils were influenced by Ca2+, Mg2+, NO3- and Cl-, which required to be primarily controlled.
Paredes, Debora da S; Alves, Bruno J R; dos Santos, Marco A; Bolonhezi, Denizart; Sant'Anna, Selenobaldo A C; Urquiaga, Segundo; Lima, Magda A; Boddey, Robert M
2015-09-15
This study aimed to quantify nitrous oxide (N2O) and methane (CH4) emission/sink response from sugar cane soil treated with fertilizer nitrogen (N) and vinasse applied separately or in sequence, the latter being investigated with regard to the time interval between applications for a possible effect on emissions. The study was carried out in a traditional area of unburned sugar cane in São Paulo state, Brazil. Two levels of N fertilization (0 and 100 kg N ha(-1)) with no added vinasse and combined with vinasse additions at different times (100 m(-3) ha(-1) at 3 and 15 days after N fertilization) were evaluated. Methane and N2O fluxes were monitored for 211 days. On average, the soil was a sink for CH4, which was not affected by the treatments. Emissions of N2O were induced by N fertilizer and vinasse applications. For ammonium sulfate, 0.6% of the added N was emitted as N2O, while for vinasse, this ranged from 1.0 to 2.2%. Changes in N2O fluxes were detected the day after application of vinasse on the N fertilized areas, but although the emission factor (EF) was 34% greater, the EF was not significantly different from fertilizer N alone. Nevertheless, we recommend to not apply vinasse after N fertilization to avoid boosting N2O emissions.
DMPP-added nitrogen fertilizer affects soil N2O emission and microbial activity in Southern Italy
NASA Astrophysics Data System (ADS)
Vitale, Luca; De Marco, Anna; Maglione, Giuseppe; Polimeno, Franca; Di Tommasi, Paul; Magliulo, Vincenzo
2014-05-01
Arable sites contributes to global N2O emission due to massive utilization of nitrogen fertilizers. N2O derives from the biological processes such as nitrification and denitrification influenced by soil nitrogen availability. The use of nitrogen fertilizers added with nitrification inhibitors represents one among the proposed strategy to reduce soil N2O emission form arable sites. The aim of this work was to evaluate the effects of 3,4-dimethylphyrazole phosphate (DMPP), a nitrification inhibitor, on N2O emission and microbial activity of a soil cropped to potato in Southern Italy. The experiment was a randomized block design with two treatments applied and three replicates: control (C) and DMPP (Entec®, K+S Nitrogen) plots, both supplied with the same amount of ammonium nitrate. The nitrogen fertilizer was supplied in three events: at 0 Day After Sowing (DAS; 100 kg N ha-1), at 57 DAS (30 kg N ha-1), and at 71 DAS (30 kg N ha-1). Soil N2O emission was monitored by both dynamic and static chambers. Static chambers were located both on hills and furrows whereas dynamic chambers were located on furrows. Air samples were collected from chambers at different times and analysed by a gas chromatograph (SRI 8610C, Gas Chromatograph). Fluxes were estimated as a linear interpolation of N2O changes over a 30 min time. Microbial biomass and basal respiration were determined as CO2 evolution, analysed by means of an IRGA (Li6200, Licor), on 2 g of fresh soil over a 4h incubation time. Microbial biomass was determined by Substrate Induced Respiration method. Data show no statistical differences in N2O fluxes measured with either dynamic chambers between C and DMPP plots in studied period. However, after the first fertilization event, when the fertilizer was applied as 100 kg N ha-1, the average N2O fluxes measured with static chambers were higher in DMPP plots compared to C plots. In the same period, the microbial biomass significantly decreased in DMPP plots as compared to C plots, whereas an opposite trend for basal respiration was observed, thus evidencing a stressful condition for nitrifying microbial population. After 57 and 71 DAS, when fertilizer was applied as 30 kg N ha-1, the microbial biomass was similar between C and DMPP plots, whereas basal respiration resulted statistically lower in DMPP plots than C plots. During these periods, average DMPP N2O fluxes were also comparable or lower. In conclusion, our data evidence a stressful condition for soil microbes and in particular for nitrifiers when a higher DMPP quantity is supplied. On the contrary, when lower quantities of DMPP-added fertilizers are supplied (e.s. 30 kg N ha-1) effectiveness of DMPP in reducing soil N2O emission is guaranteed by reducing the nitrifiers activity without negatively affecting their growth.
Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan
2015-01-01
Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition.
Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan
2015-01-01
Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition. PMID:25774529
Decomposition and nutrient release from fresh and dried pine roots under two fertilizer regimes
Kim H. Ludovici; Lance W. Kress
2006-01-01
Root decomposition and nutrient release are typically estimated from dried root tissues; however, it is unlikely that roots dehydrate prior to decomposing. Soil fertility and root diameter may also affect the rate of decomposition. This study monitored mass loss and nutrient concentrations of dried and fresh roots of two size classes (
Effects of Successive Harvests on Soil Nutrient Stocks in Established Tropical Plantation Forests
NASA Astrophysics Data System (ADS)
Mendoza, L.; McMahon, D.; Jackson, R. B.
2017-12-01
Large-scale plantation forests in tropical regions alter biogeochemical processes, raising concerns about the long-term sustainability of this land use. Current commercial practices result in nutrient export with removed biomass that may not be balanced by fertilizer application. Consequent changes in a landscape's nutrient distributions can affect the growth of future plantations or other vegetation. Prior studies have reported changes in soil chemical and physical properties when plantation forests replace pastures or native vegetation, but few have examined the impacts of multiple harvest cycles following plantation establishment. This study analyzed macronutrient and carbon content of soil samples from the world's most productive plantation forests, in southeastern Brazil, to understand the long-term effects of plantation forests on soil nutrient stocks and soil fertility. Soil was collected from Eucalyptus plantation sites and adjacent vegetation in 2004 and again in 2016, after at least one full cycle of harvesting and replanting. We found that within surface soil (0-10 cm) Mg and N did not change significantly and C, P, K and Ca concentrations generally increased, but to varying extents within individual management units. This trend of increasing nutrient concentrations suggests that additional harvests do not result in cumulative nutrient depletion. However, large changes in Ca and K concentrations in individual plantation units indicate that added fertilizer does not consistently accumulate in the surface soil. Analysis of deeper soil layers and comparison to unfertilized vegetation will help to determine the fate of fertilizers and native soil nutrients in repeatedly harvested plantations. These results address the necessity of long-term investigation of nutrient changes to better understand and determine the impacts of different types of land use in the tropics.
Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J
2016-10-01
Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were better explained using both soil physicochemical test values and bacterial community structure data than using soil tests alone. Pursuing a better understanding of bacterial community composition and how it is affected by farming practices is a promising avenue for increasing our ability to predict the impact of management practices on important soil functions. Copyright © 2016. Published by Elsevier B.V.
Bayesian Inference of Baseline Fertility and Treatment Effects via a Crop Yield-Fertility Model
Chen, Hungyen; Yamagishi, Junko; Kishino, Hirohisa
2014-01-01
To effectively manage soil fertility, knowledge is needed of how a crop uses nutrients from fertilizer applied to the soil. Soil quality is a combination of biological, chemical and physical properties and is hard to assess directly because of collective and multiple functional effects. In this paper, we focus on the application of these concepts to agriculture. We define the baseline fertility of soil as the level of fertility that a crop can acquire for growth from the soil. With this strict definition, we propose a new crop yield-fertility model that enables quantification of the process of improving baseline fertility and the effects of treatments solely from the time series of crop yields. The model was modified from Michaelis-Menten kinetics and measured the additional effects of the treatments given the baseline fertility. Using more than 30 years of experimental data, we used the Bayesian framework to estimate the improvements in baseline fertility and the effects of fertilizer and farmyard manure (FYM) on maize (Zea mays), barley (Hordeum vulgare), and soybean (Glycine max) yields. Fertilizer contributed the most to the barley yield and FYM contributed the most to the soybean yield among the three crops. The baseline fertility of the subsurface soil was very low for maize and barley prior to fertilization. In contrast, the baseline fertility in this soil approximated half-saturated fertility for the soybean crop. The long-term soil fertility was increased by adding FYM, but the effect of FYM addition was reduced by the addition of fertilizer. Our results provide evidence that long-term soil fertility under continuous farming was maintained, or increased, by the application of natural nutrients compared with the application of synthetic fertilizer. PMID:25405353
NASA Astrophysics Data System (ADS)
Erhagen, Bjorn; Nilsson, Mats; Oquist, Mats; Ilstedt, Ulrik; Sparrman, Tobias; Schleucher, Jurgen
2014-05-01
Over the last century, the greenhouse gas concentrations in the atmosphere have increased dramatically, greatly exceeding pre-industrial levels that had prevailed for the preceding 420 000 years. At the same time the annual anthropogenic contribution to the global terrestrial nitrogen cycle has increased and currently exceeds natural inputs. Both temperature and nitrogen levels have profound effects on the global carbon cycle including the rate of organic matter decomposition, which is the most important biogeochemical process that returns CO2 to the atmosphere. Here we show for the first time that increasing the availability of nitrogen not only directly affects the rate of organic matter decomposition but also significantly affects its temperature dependence. We incubated litter and soil organic matter from a long-term (40 years) nitrogen fertilization experiment in a boreal Scots pine (Pinus silvestris L.) forest at different temperatures and determined the temperature dependence of the decomposition of the sample's organic matter in each case. Nitrogen fertilization did not affect the temperature sensitivity (Q10) of the decomposition of fresh plant litter but strongly reduced that for humus soil organic matter. The Q10 response of the 0-3 cm soil layer decreased from 2.5±0.35 to an average of 1.9±0.21 over all nitrogen treatments, and from 2.2±0.19 to 1.6±0.16 in response to the most intense nitrogen fertilization treatment in the 4-7 cm soil layer. Long-term nitrogen additions also significantly affected the organic chemical composition (as determined by 13C CP-MAS NMR spectroscopy) of the soil organic matter. These changes in chemical composition contributed significantly (p<0.05) to the reduced Q10 response. These new insights into the relationship between nitrogen availability and the temperature sensitivity of organic matter decomposition will be important for understanding and predicting how increases in global temperature and rising anthropogenic nitrogen inputs will affect the global carbon cycle and the associated climatic feedback processes.
DeLaune, Paul B; Moore, Philip A; Carman, Dennis K; Sharpley, Andrew N; Haggard, Brian E; Daniel, Tommy C
2004-01-01
Currently, several state and federal agencies are proposing upper limits on soil test phosphorus (P), above which animal manures cannot be applied, based on the assumption that high P concentrations in runoff are due to high soil test P. Recent studies show that other factors are more indicative of P concentrations in runoff from areas where manure is being applied. The original P index was developed as an alternative P management tool incorporating factors affecting both the source and transport of P. The objective of this research was to evaluate the effects of multiple variables on P concentrations in runoff water and to construct a P source component of a P index for pastures that incorporates these effects. The evaluated variables were: (i) soil test P, (ii) soluble P in poultry litter, (iii) P in poultry diets, (iv) fertilizer type, and (v) poultry litter application rate. Field studies with simulated rainfall showed that P runoff was affected by the amount of soluble P applied in the fertilizer source. Before manure applications, soil test P was directly related to soluble P concentrations in runoff water. However, soil test P had little effect on P runoff after animal manure was applied. Unlike most other P indices, weighting factors of the P source components in the P index for pastures are based on results from runoff studies conducted under various management scenarios. As a result, weighting factors for the P source potential variables are well justified. A modification of the P index using scientific data should strengthen the ability of the P index concept to evaluate locations and management alternatives for P losses.
Parental material and cultivation determine soil bacterial community structure and fertility.
Sun, Li; Gao, Jusheng; Huang, Ting; Kendall, Joshua R A; Shen, Qirong; Zhang, Ruifu
2015-01-01
Microbes are the key components of the soil environment, playing important roles during soil development. Soil parent material provides the foundation elements that comprise the basic nutritional environment for the development of microbial community. After 30 years artificial maturation of cultivation, the soil developments of three different parental materials were evaluated and bacterial community compositions were investigated using the high-throughput sequencing approach. Thirty years of cultivation increased the soil fertility and soil microbial biomass, richness and diversity, greatly changed the soil bacterial communities, the proportion of phylum Actinobacteria decreased significantly, while the relative abundances of the phyla Acidobacteria, Chloroflexi, Gemmatimonadetes, Armatimonadetes and Nitrospira were significantly increased. Soil bacterial communities of parental materials were separated with the cultivated ones, and comparisons of different soil types, granite soil and quaternary red clay soil were similar and different with purple sandy shale soil in both parental materials and cultivated treatments. Bacterial community variations in the three soil types were affected by different factors, and their alteration patterns in the soil development also varied with soil type. Soil properties (except total potassium) had a significant effect on the soil bacterial communities in all three soil types and a close relationship with abundant bacterial phyla. The amounts of nitrogen-fixing bacteria as well as the abundances of the nifH gene in all cultivated soils were higher than those in the parental materials; Burkholderia and Rhizobacte were enriched significantly with long-term cultivation. The results suggested that crop system would not deplete the nutrients of soil parental materials in early stage of soil maturation, instead it increased soil fertility and changed bacterial community, specially enriched the nitrogen-fixing bacteria to accumulate nitrogen during soil development. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Zhang, Shuiqing; Huang, Shaomin; Li, Jianwei; Guo, Doudou; Lin, Shan; Lu, Guoan
2017-06-01
The carbon sequestration potential is affected by cropping system and management practices, but soil organic carbon (SOC) sequestration potential under fertilizations remains unclear in north China. This study examined SOC change, total C input to soil and, via integration of these estimates over years, carbon sequestration efficiency (CSE, the ratio of SOC change over C input) under no fertilization (control), chemical nitrogen fertilizer alone (N) or combined with phosphorus and potassium fertilizers (NP, NK, PK and NPK), or chemical fertilizers combined with low or high (1.5×) manure input (NPKM and 1.5NPKM). Results showed that, as compared with the initial condition, SOC content increased by 0.03, 0.06, 0.05, 0.09, 0.16, 0.26, 0.47 and 0.68 Mg C ha -1 year -1 under control, N, NK, PK, NP, NPK, NPKM and 1.5NPKM treatments respectively. Correspondingly, the C inputs of wheat and maize were 1.24, 1.34, 1.55, 1.33, 2.72, 2.96, 2.97 and 3.15 Mg ha -1 year -1 respectively. The long-term fertilization-induced CSE showed that about 11% of the gross C input was transformed into SOC pool. Overall, this study demonstrated that decade-long manure input combined with chemical fertilizers can maintain high crop yield and lead to SOC sequestration in north China. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Witheetrirong, Yongyoot; Tripathi, Nitin Kumar; Tipdecho, Taravudh; Parkpian, Preeda
2011-08-01
The use of chemical fertilizers in Thailand increased exponentially by more than 100-fold from 1961 to 2004. Intensification of agricultural production causes several potential risks to water supplies, especially nitrate-nitrogen (NO(3) (-)-N) pollution. Nitrate is considered a potential pollutant because its excess application can move into streams by runoff and into groundwater by leaching. The nitrate concentration in groundwater increases more than 3-fold times after fertilization and it contaminates groundwater as a result of the application of excess fertilizers for a long time. Soil texture refers to the relative proportion of particles of various sizes in a given soil and it affects the water permeability or percolation rate of a soil. Coarser soils have less retention than finer soils, which in the case of NO(3) (-)-N allows it to leach into groundwater faster, so there is positive relationship between the percentage of sands and NO(3) (-)-N concentration in groundwater wells. This study aimed to estimate the effect of soil texture on NO(3) (-)-N content in groundwater. Optical reflectance data obtained by remote sensing was used in this study. Our hypothesis was that the quantity of nitrogen leached into groundwater through loam was higher than through clay. Nakhon Pathom province, Thailand, was selected as a study area where the terrain is mostly represented by a flat topography. It was found that classified LANDSAT images delineated paddy fields as covering 29.4% of the study area, while sugarcane covered 10.4%, and 60.2% was represented by "others". The reason for this classified landuse was to determine additional factors, such as vegetation, which might directly affect the quantity of NO(3) (-)-N in soil. Ideally, bare soil would be used as a test site, but in fact, no such places were available in Thailand. This led to an indirect method to estimate NO(3) (-)-N on various soil textures. Through experimentation, it was found that NO(3) (-)-N measured through the loam in sugarcane (I = 0.0054, p < 0.05) was lower than clay represented by paddies (I = 0.0305, p < 0.05). This had a significant negative impact on the assumption. According to the research and local statistical data, farmers have always applied an excess quantity of fertilizer on paddy fields. This is the main reason for the higher quantity of NO(3) (-)-N found in clay than loam in this study. This case might be an exceptional study in terms of quantity of fertilizers applied to agricultural fields.
Wu, Qihua; Zhang, Shuxiang; Zhu, Ping; Huang, Shaomin; Wang, Boren; Zhao, LinPing; Xu, Minggang
2017-01-01
The phosphorus activation coefficient (PAC, the ratio of available P to total P) is an important indicator of soil P availability and the transformation of P fractions. Understanding the details of the PAC is useful to estimate soil available P status and to provide P management guidance. In this research, soils from five long-term (23 years) fertilization treatments in three croplands were selected to examine the relationships between the PAC and P fractions and to analyse the influencing factors. PAC was affected by both soil types and fertilization treatments. Compared to the unfertilized control (CK) treatment, long-term P application significantly increased the PAC, all of the inorganic P (Pi) fractions and most of the organic P (Po) fractions in all the three soils, particularly in chemical fertilizer combined with manure treatment (NPKM). The PAC was significantly correlated to all of the Pi fractions proportions (P<0.05) except for Dil. HCl-Pi and Conc. HCl-Pi. Compared with CK, the chemical P and chemical P combined with manure treatments increased the ratio of total Pi fractions to total Po fractions (Pit/Pot); furthermore, NPKM significantly increased the organic C (Co) content and decreased the Co/Pot ratio. Stepwise multiple regressions showed that PAC = 0.93 Co+0.69 Pit/Pot-0.07 Co/Pot-0.27CaCO3-3.79 (R2 = 0.924, P<0.001). In addition, the variance partitioning analysis showed that more variance of PAC is explained by soil factors (29.53%) than by P input (0.19%) and climate (0.25%) factors. Our findings demonstrate that P application increased the PAC by changing the Co content and the proportion of P fractions. Moreover, soil factors were the most important drivers of P transformations, and NPKM was optimal for improving soil fertility in Chinese croplands.
Wu, Qihua; Zhang, Shuxiang; Zhu, Ping; Huang, Shaomin; Wang, Boren; Zhao, LinPing; Xu, Minggang
2017-01-01
The phosphorus activation coefficient (PAC, the ratio of available P to total P) is an important indicator of soil P availability and the transformation of P fractions. Understanding the details of the PAC is useful to estimate soil available P status and to provide P management guidance. In this research, soils from five long-term (23 years) fertilization treatments in three croplands were selected to examine the relationships between the PAC and P fractions and to analyse the influencing factors. PAC was affected by both soil types and fertilization treatments. Compared to the unfertilized control (CK) treatment, long-term P application significantly increased the PAC, all of the inorganic P (Pi) fractions and most of the organic P (Po) fractions in all the three soils, particularly in chemical fertilizer combined with manure treatment (NPKM). The PAC was significantly correlated to all of the Pi fractions proportions (P<0.05) except for Dil. HCl-Pi and Conc. HCl-Pi. Compared with CK, the chemical P and chemical P combined with manure treatments increased the ratio of total Pi fractions to total Po fractions (Pit/Pot); furthermore, NPKM significantly increased the organic C (Co) content and decreased the Co/Pot ratio. Stepwise multiple regressions showed that PAC = 0.93 Co+0.69 Pit/Pot-0.07 Co/Pot-0.27CaCO3-3.79 (R2 = 0.924, P<0.001). In addition, the variance partitioning analysis showed that more variance of PAC is explained by soil factors (29.53%) than by P input (0.19%) and climate (0.25%) factors. Our findings demonstrate that P application increased the PAC by changing the Co content and the proportion of P fractions. Moreover, soil factors were the most important drivers of P transformations, and NPKM was optimal for improving soil fertility in Chinese croplands. PMID:28467425
NASA Astrophysics Data System (ADS)
Schiavone, K.; Barbieri, L.; Adair, C.
2015-12-01
Agricultural fields in Vermont's Lake Champlain Basin have problems with the loss of nutrients due to runoff which creates eutrophic conditions in the lakes, ponds and rivers. In efforts to retain nitrogen and other nutrients in the soil farmers have started to inject manure rather than spraying it. Our understanding of the effects this might have on the volatilization of nitrogen into nitrous oxide is limited. Already, agriculture produces 69% of the total nitrous oxide emissions in the US. Understanding that climate change will affect the future of agriculture in Vermont, we set up a soil core incubation test to monitor the emissions of CO₂ and N₂O using a Photoacoustic Gas Sensor (PAS). Four 10 cm soil cores were taken from nine different fertilizer management plots in a No Till corn field; Three Injected plots, three Broadcast plots, and three Plow plots. Frozen soil cores were extracted in early April, and remained frozen before beginning the incubation experiment to most closely emulate three potential spring environmental conditions. The headspace was monitored over one week to get emission rates. This study shows that environmental and fertilizer treatments together do not have a direct correlation to the amount of CO₂ and N₂O emissions from agricultural soil. However, production of CO₂ was 26% more in warmer environmental conditions than in variable(freeze/thaw) environmental conditions. The injected fertilizer produced the most emissions, both CO₂ and N₂O. The total N₂O emissions from Injected soil cores were 2.2x more than from traditional broadcast manure cores. We believe this is likely due to the addition of rich organic matter under anaerobic soil conditions. Although, injected fertilizer is a better application method for reducing nutrient runoff, the global warming potential of N₂O is 298 times that of CO₂. With climate change imminent, assessing the harmful effects and benefits of injected fertilizer is a crucial next step in agricultural management.
Tritrophic interactions between parasitoids and cereal aphids are mediated by nitrogen fertilizer.
Aqueel, Muhammad A; Raza, Abu-bakar M; Balal, Rashad M; Shahid, Muhammad A; Mustafa, Irfan; Javaid, Muhammad M; Leather, Simon R
2015-12-01
Host plant nutritional quality can directly and indirectly affect the third trophic levels. The aphid-parasitoid relationship provides an ideal system to investigate tritrophic interactions (as the parasitoids are completely dependent for their development upon their hosts) and assess the bottom up forces operating at different concentrations of nitrogen applications. The effects of varying nitrogen fertilizer on the performance of Aphidius colemani (V.) reared on Sitobion avenae (F.) and Aphidius rhopalosiphi (D.) reared on Rhopalosiphum padi (L.) were measured. Parasitism and percent emergence of parasitoids were positively affected by nitrogen fertilizer treatments while developmental duration (egg, larval, and pupal stages) was not affected by increasing nitrogen inputs. In males and females of both parasitoid species, adult longevity increased with the increasing nitrogen fertilizer. Hind tibia length and mummy weight of both parasitoid species increased with nitrogen fertilizer concentrations, as a result of larger aphids. This study showed that nitrogen application to the soil can have important consequences for aboveground multitrophic interactions. © 2014 Institute of Zoology, Chinese Academy of Sciences.
[Effects of long-term fertilization on pH buffer system of sandy loam calcareous fluvor-aquic soil].
Wang, Ji-Dong; Qi, Bing-Jie; Zhang, Yong-Chun; Zhang, Ai-Jun; Ning, Yun-Wang; Xu, Xian-Ju; Zhang, Hui; Ma, Hong-Bo
2012-04-01
Soil samples (0-80 cm) were collected from a 30-year fertilization experimental site in Xuzhou, Jiangsu Province of East China to study the variations of the pH, calcium carbonate and active calcium carbonate contents, and pH buffer capacity of sandy loam calcareous fluvor-aquic soil under different fertilization treatments. Thirty-year continuous application of different fertilizers accelerated the acidification of topsoil (0-20 cm), with the soil pH decreased by 0.41-0.70. Under different fertilization, the soil pH buffer capacity (pHBC) varied from 15.82 to 21.96 cmol x kg(-1). As compared with no fertilization, single N fertilization decreased the pHBC significantly, but N fertilization combined with organic fertilization could significantly increase the pHBC. The soil pHBC had significant positive correlations with soil calcium carbonate and active calcium carbonate contents, but less correlation with soil organic matter content and soil cation exchange capacity, suggesting that after a long-term fertilization, the sandy loam calcareous fluvor-aquic soil was still of an elementary calcium carbonate buffer system, and soil organic matter and cation exchange capacity contributed little to the buffer system. The soil calcium carbonate and active calcium carbonate contents were greater in 0-40 cm than in 40-80 cm soil layer. Comparing with soil calcium carbonate, soil active calcium carbonate was more sensitive to reflect the changes of soil physical and chemical properties, suggesting that the calcium carbonate buffer system could be further classified as soil active calcium carbonate buffer system.
Zhou, Shiwei; Liu, Jing; Xu, Minggang; Lv, Jialong; Sun, Nan
2015-10-01
Fertilization is important to increase crop yields, but long-term application of fertilizers probably aggravated the risk of heavy metals in acidic soils. In this study, the effect of 22-year fertilization and cropping on accumulation, availability, and uptake of heavy metals in red soil was investigated. The results showed that pig manure promoted significantly cadmium (Cd) accumulation (average 1.1 mg kg(-1)), nearly three times higher than national soil standards and, thus, increased metal availability. But the enrichment of heavy metals decreased remarkably by 50.5 % under manure fertilization, compared with CK (control without fertilization). On the contrary, chemical fertilizers increased greatly lead (Pb) availability and Cd activity; in particular, exceeding 85 % of soil Cd became available to plant under N (nitrogen) treatment during 9-16 years of fertilization, which correspondingly increased their enrichment by 29.5 %. Long-term application of chemical fertilizers caused soil acidification and manure fertilization led to the increase in soil pH, soil organic matter (SOM), and available phosphorus (Olsen P), which influenced strongly metal behavior in red soil, and their effect had extended to deeper soil layer (20∼40 cm). It is advisable to increase application of manure alone with low content of heavy metals or in combination with chemical fertilizers to acidic soils in order to reduce toxic metal risk.
Chu, Haiyan; Fujii, Takeshi; Morimoto, Sho; Lin, Xiangui; Yagi, Kazuyuki; Hu, Junli; Zhang, Jiabao
2007-01-01
The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammonia-oxidizing bacteria (AOB) was investigated in a long-term (16-year) fertilizer experiment. The experiment included seven treatments: organic manure, half organic manure N plus half fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). N fertilization greatly increased soil nitrification potential, and mineral N fertilizer had a greater impact than organic manure, while N deficiency treatment (PK) had no significant effect. AOB community structure was analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) of the amoA gene, which encodes the alpha subunit of ammonia monooxygenase. DGGE profiles showed that the AOB community was more diverse in N-fertilized treatments than in the PK-fertilized treatment or the control, while one dominant band observed in the control could not be detected in any of the fertilized treatments. Phylogenetic analysis showed that the DGGE bands derived from N-fertilized treatments belonged to Nitrosospira cluster 3, indicating that N fertilization resulted in the dominance of Nitrosospira cluster 3 in soil. These results demonstrate that long-term application of N fertilizers could result in increased soil nitrification potential and the AOB community shifts in soil. Our results also showed the different effects of mineral fertilizer N versus organic manure N; the effects of P and K on the soil AOB community; and the importance of balanced fertilization with N, P, and K in promoting nitrification functions in arable soils.
Zheng, Yong; Chen, Liang; Luo, Cai-Yun; Zhang, Zhen-Hua; Wang, Shi-Ping; Guo, Liang-Dong
2016-10-01
Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.
Essentials of Chemical Fertilizer Use in PRC.
1978-09-06
fertilizer contains even more effective nutrient. So proper amounts of chemical fertilizer in each mou in addition to farmyard manure, according to soil ...learn about soil composition and characteristics and their effect on fertilizing power. Composition and Function of Soil The soil is composed of matter...fertilizing effect is still good. Sandy soil has low water-retaining capability, so nutrients are easily leached. When easily-soluble fast- release
D. Andrew Scott; John Novosad; Gala Golddsmith
2007-01-01
Forest management operations have the greatest potential to reduce soil productivity through altered soil fertility and air/water balance, which are most affected by organic matter removal and compaction, respectively. The objectives of this study were to assess the early growth response to compaction, organic matter removal, and weed control on the ten locations of...
G. Gonzalez; X. Zou
1999-01-01
This greenhouse study examines the effects of Pontoscolex corethrurus on the growth of Cecropia scheberiana in forest and pasture soils. Four treatments (0, 2, 20 worms and 0 worms + urea fertilizer) were applied to the soils to test if earthworms affect nitrogen availability, and consequently the growth of C. scheberiana. We recorded the number of seedlings, leaves,...
Effect of fertilizers on faba bean (V. faba) growth and soil pH
NASA Astrophysics Data System (ADS)
Angel, C.
2013-12-01
The purpose of this experiment was to see the effect of fertilizers on faba bean (V. faba) growth and soil pH. This experiment is important because of the agriculture here in California and the damage fertilizers are doing to the soil. Three Broad Fava Windsor beans (Vicia faba) were planted per pot, with at least three pots per treatment. There were four treatments: soil with phosphorus (P) fertilizer, soil with nitrogen (N) fertilizer, soil with both N and P fertilizer, and soil without any fertilizers (control). The soil pH was 7.7, and it had 26.6mg/kg Olsen-P, 2.2mg/kg ammonium-N and no nitrate-N (Data from UCD Horwath Lab). All pots were put in a greenhouse with a stable temperature of 80 degrees. I watered them 2-3 times a week. After two months I measured the soil pH using a calibrated pHep HI 98107 pocket-sized pH meter. After letting the plants dry I weighed the shoots and roots separately for dry biomass. From testing pH of the soil of the faba bean plants with and without fertilizer I found that only the nitrogen fertilizer made the soil more acidic than the other ones. The other ones became more basic. Also the N-fertilized plants weighed more than the other ones. This shows how the nitrogen fertilizer had a greater impact on the plants. I think the reason why the nitrogen and the phosphorus fertilizers didn't work as well is because there was an interaction between the fertilizers and the nitrogen one made the soil more acidic because of the way nitrogen is made.
Zavišić, Aljosa; Yang, Nan; Marhan, Sven; Kandeler, Ellen; Polle, Andrea
2018-01-01
Phosphorus (P) is an important nutrient, whose plant-available form phosphate is often low in natural forest ecosystems. Mycorrhizal fungi mine the soil for P and supply their host with this resource. It is unknown how ectomycorrhizal communities respond to changes in P availability. Here, we used young beech (Fagus sylvatica L.) trees in natural forest soil from a P-rich and P-poor site to investigate the impact of P amendment on soil microbes, mycorrhizas, beech P nutrition, and photosynthesis. We hypothesized that addition of P to forest soil increased P availability, thereby, leading to enhanced microbial biomass and mycorrhizal diversity in P-poor but not in P-rich soil. We expected that P amendment resulted in increased plant P uptake and enhanced photosynthesis in both soil types. Young beech trees with intact soil cores from a P-rich and a P-poor forest were kept in a common garden experiment and supplied once in fall with triple superphosphate. In the following summer, labile P in the organic layer, but not in the mineral top soil, was significantly increased in response to fertilizer treatment. P-rich soil contained higher microbial biomass than P-poor soil. P treatment had no effect on microbial biomass but influenced the mycorrhizal communities in P-poor soil and shifted their composition toward higher similarities to those in P-rich soil. Plant uptake efficiency was negatively correlated with the diversity of mycorrhizal communities and highest for trees in P-poor soil and lowest for fertilized trees. In both soil types, radioactive P tracing (H333PO4) revealed preferential aboveground allocation of new P in fertilized trees, resulting in increased bound P in xylem tissue and enhanced soluble P in bark, indicating increased storage and transport. Fertilized beeches from P-poor soil showed a strong increase in leaf P concentrations from deficient to luxurious conditions along with increased photosynthesis. Based on the divergent behavior of beech in P-poor and P-rich forest soil, we conclude that acclimation of beech to low P stocks involves dedicated mycorrhizal community structures, low P reserves in storage tissues and photosynthetic inhibition, while storage and aboveground allocation of additional P occurs regardless of the P nutritional status. PMID:29706979
NASA Astrophysics Data System (ADS)
Tang, J.; Wang, Y.
2013-12-01
Red soils, a typical Udic Ferrosols, widespread throughout the subtropical and tropical region in southern China, support the majority of grain production in this region. The red soil is naturally low in pH values, cation exchange capacity, fertility, and compaction, resulting in low organic matter contents and soil aggregation. Application of chemical fertilizers and a combination of organic-chemical fertilizers are two basic approaches to improve soil structure and organic matter contents. We studied the soil aggregation and the distribution of aggregate-associated organic carbon in red soils with a long-term fertilization experiment during 1988-2009. We established treatments including 1) NPK and NK in the chemical fertilizer plots, 2) CK (Control), and 3) CK+ Peanut Straw (PS), CK+ Rice Straw (RS), CK+ Fresh Radish (FR), and CK + Pig Manure (PM) in the organic-chemical fertilizer plots. Soil samples were fractionated into 6 different sized aggregate particles through the dry-wet sieving method according to the hierarchical model of aggregation. Organic carbon in the aggregate/size classes was analyzed. The results showed that the distribution of mechanically stable aggregates in red soils after long-term fertilization decreased with the size, from > 5mm, 5 ~ 2 mm, 2 ~ 1 mm, 1~ 0.25 mm, to < 0.25 mm, but the distribution of water-stable aggregates did not follow this pattern. Compared with the chemical fertilizer application alone, the addition of pig manure and green manure can significantly improve the distribution of aggregates in the 5-2 mm, 2-1 mm and 1-0.25 mm classes. The organic carbon (OC) contents in red soils were all increased after the long-term fertilization. Compared with Treatment NK, soil OC in Treatment NPK was increased by 45.4%. Compared with Treatment CK (low chemical fertilizer), organic fertilizer addition increased soil OC. The OC in the different particle of water-stable aggregates were all significantly increased after long-term fertilization. OC mainly existed in the macroaggregate (> 0.25 mm) of red soils after the long-term fertilization, and the organic matter was the most important colloid material for macroaggregates. We conclude that the long-term, appropriate application of chemical fertilizer and the combination with organic manure were the most effective measures to improve soil structure and organic carbon contents in red soil regions.
Gao, Jianmin; Xie, Yingxin; Jin, Haiyang; Liu, Yuan; Bai, Xueying; Ma, Dongyun; Zhu, Yunji; Wang, Chenyang; Guo, Tiancai
2016-01-01
The application of crop residues combined with Nitrogen (N) fertilizer has been broadly adopted in China. Crop residue amendments can provide readily available C and N, as well as other nutrients to agricultural soils, but also intensify the N fixation, further affecting N2O emissions. N2O pulses are obviously driven by rainfall, irrigation and fertilization. Fertilization before rainfall or followed by flooding irrigation is a general management practice for a wheat-maize rotation in the North China Plain. Yet, little is known on the impacts of crop residues combined with N fertilizer application on N2O emission under high soil moisture content. A laboratory incubation experiment was conducted to investigate the effects of two crop residue amendments (maize and wheat), individually or in combination with N fertilizer, on N2O emissions and denitrifier abundance in two main agricultural soils (one is an alluvial soil, pH 8.55, belongs to Ochri-Aquic Cambosols, OAC, the other is a lime concretion black soil, pH 6.61, belongs to Hapli-Aquic Vertosols, HAV) under 80% WFPS (the water filled pore space) in the North China Plain. Each type soil contains seven treatments: a control with no N fertilizer application (CK, N0), 200 kg N ha-1 (N200), 250 kg N ha-1 (N250), maize residue plus N200 (MN200), maize residue plus N250 (MN250), wheat residue plus N200 (WN200) and wheat residue plus N250 (WN250). Results showed that, in the HAV soil, MN250 and WN250 increased the cumulative N2O emissions by 60% and 30% compared with N250 treatment, respectively, but MN200 and WN200 decreased the cumulative N2O emissions by 20% and 50% compared with N200. In the OAC soil, compared with N200 or N250, WN200 and WN250 increased the cumulative N2O emission by 40%-50%, but MN200 and MN250 decreased the cumulative N2O emission by 10%-20%. Compared with CK, addition of crop residue or N fertilizer resulted in significant increases in N2O emissions in both soils. The cumulative N2O emissions from the treatments of 250 kg N ha-1 were 1.1-3.3 times higher than those of treatments with 200 kg N ha-1 in both soils with adding equal amounts of the same type of crop residue. Abundance of the 16S rRNA gene did not significantly change in all treatments in two soils, but the nosZ and nirS genes were more abundant in soils amended with crop residues compared with CK or N-only treatments. N2O emission, however, were not related to the abundance of denitrifier containing nirS or nosZ. The research provided some information regarding the effect of crop residues with N fertilizer on N2O emissions and denitrifier abundances in two soils. Our results imply the property of crop residue and rate of N fertilizer are important influencing factors of N2O emission when crop residues combined with N fertilizer are applied to different agricultural soils.
Wang, Yongsheng; Cheng, Shulan; Fang, Huajun; Yu, Guirui; Xu, Minjie; Dang, Xusheng; Li, Linsen; Wang, Lei
2014-01-01
To date, few studies are conducted to quantify the effects of reduced ammonium (NH4+) and oxidized nitrate (NO3-) on soil CH4 uptake and N2O emission in the subtropical forests. In this study, NH4Cl and NaNO3 fertilizers were applied at three rates: 0, 40 and 120 kg N ha(-1) yr(-1). Soil CH4 and N2O fluxes were determined twice a week using the static chamber technique and gas chromatography. Soil temperature and moisture were simultaneously measured. Soil dissolved N concentration in 0-20 cm depth was measured weekly to examine the regulation to soil CH4 and N2O fluxes. Our results showed that one year of N addition did not affect soil temperature, soil moisture, soil total dissolved N (TDN) and NH4+-N concentrations, but high levels of applied NH4Cl and NaNO3 fertilizers significantly increased soil NO3(-)-N concentration by 124% and 157%, respectively. Nitrogen addition tended to inhibit soil CH4 uptake, but significantly promoted soil N2O emission by 403% to 762%. Furthermore, NH4+-N fertilizer application had a stronger inhibition to soil CH4 uptake and a stronger promotion to soil N2O emission than NO3(-)-N application. Also, both soil CH4 and N2O fluxes were driven by soil temperature and moisture, but soil inorganic N availability was a key integrator of soil CH4 uptake and N2O emission. These results suggest that the subtropical plantation soil sensitively responses to atmospheric N deposition, and inorganic N rather than organic N is the regulator to soil CH4 uptake and N2O emission.
Li, Rui; Tai, Rui; Wang, Dan; Chu, Gui-Xin
2017-10-01
A four year field study was conducted to determine how soil biological properties and soil aggregate stability changed when organic fertilizer and biofertilizer were used to reduce chemical fertilizer application to a drip irrigated cotton field. The study consisted of six fertilization treatments: unfertilized (CK); chemical fertilizer (CF, 300 kg N·hm -2 ; 90 kg P2O5 · hm -2 , 60 kg K2 O·hm -2 ); 80% CF plus 3000 kg·hm -2 organic fertilizer (80%CF+OF); 60% CF plus 6000 kg·hm -2 organic fertilizer (60%CF+OF); 80% CF plus 3000 kg·hm -2 biofertilizer (80%CF+BF); and 60% CF plus 6000 kg·hm -2 biofertilizer (60%CF+BF). The relationships among soil organic C, soil biological properties, and soil aggregate size distribution were determined. The results showed that organic fertilizer and biofertilizer both significantly increased soil enzyme activities. Compared with CF, the biofertilizer treatments increased urease activity by 55.6%-84.0%, alkaline phosphatise activity by 53.1%-74.0%, invertase activity by 15.1%-38.0%, β-glucosidase activity by 38.2%-68.0%, polyphenoloxidase activity by 29.6%-52.0%, and arylsulfatase activity by 35.4%-58.9%. Soil enzyme activity increased as the amount of organic fertilizer and biofertilizer increased (i.e., 60%CF+OF > 80%CF+OF, 60%CF+BF > 80%CF+BF). Soil basal respiration decreased significantly in the order BF > OF > CF > CK. Soil microbial biomass C and N were 22.3% and 43.5% greater, respectively, in 60%CF+BF than in CF. The microbial biomass C:N was significantly lower in 60%CF+BF than in CF. The organic fertilizer and the biofertilizer both improved soil aggregate structure. Soil mass in the >0.25 mm fraction was 7.1% greater in 80%CF+OF and 8.0% greater in (60%CF+OF) than in CF. The geometric mean diameter was 9.2% greater in 80%CF+BF than in 80%CF+OF. Redundancy analysis and cluster analysis both demonstrated that soil aggregate structure and biological activities increased when organic fertilizer and biofertilizer were used to reduce chemical fertilizer application. In conclusion, the organic fertilizer and the biofertilizer significantly increased SOC, soil enzyme activity, and soil microbial biomass C and N. The organic fertilizers also improved soil aggregation. Therefore, soil quality could be improved by using these fertilizers to reduce chemical fertilizer application, especially under drip-irrigation.
Sun, Feng-xia; Zhang, Wei-hua; Xu, Ming-gang; Zhang, Wen-ju; Li, Zhao-qiang; Zhang, Jing-ye
2010-11-01
In order to explore the effects of long-term fertilization on the microbiological characters of red soil, soil samples were collected from a 19-year long-term experimental field in Qiyang of Hunan, with their microbial biomass carbon (MBC) and nitrogen (MBN) and microbial utilization ratio of carbon sources analyzed. The results showed that after 19-year fertilization, the soil MBC and MBN under the application of organic manure and of organic manure plus inorganic fertilizers were 231 and 81 mg x kg(-1) soil, and 148 and 73 mg x kg(-1) soil, respectively, being significantly higher than those under non-fertilization, inorganic fertilization, and inorganic fertilization plus straw incorporation. The ratio of soil MBN to total N under the application of organic manure and of organic manure plus inorganic fertilizers was averagely 6.0%, significantly higher than that under non-fertilization and inorganic fertilization. Biolog-ECO analysis showed that the average well color development (AWCD) value was in the order of applying organic manure plus inorganic fertilizers = applying organic manure > non-fertilization > inorganic fertilization = inorganic fertilization plus straw incorporation. Under the application of organic manure or of organic manure plus inorganic fertilizers, the microbial utilization rate of carbon sources, including carbohydrates, carboxylic acids, amino acids, polymers, phenols, and amines increased; while under inorganic fertilization plus straw incorporation, the utilization rate of polymers was the highest, and that of carbohydrates was the lowest. Our results suggested that long-term application of organic manure could increase the red soil MBC, MBN, and microbial utilization rate of carbon sources, improve soil fertility, and maintain a better crop productivity.
Nitrous oxide fluxes from upland soils in central Hokkaido, Japan.
Mu, Zhijian; Kimura, Sonoko D; Toma, Yo; Hatano, Ryusuke
2008-01-01
Nitrous oxide (N2O) fluxes from soils were measured using the closed chamber method during the snow-free seasons (middle April to early November), for three years, in a total of 11 upland crop fields in central Hokkaido, Japan. The annual mean N2O fluxes ranged from 2.95 to 164.17 microgN/(m2 x h), with the lowest observed in a grassland and the highest in an onion field. The instantaneous N2O fluxes showed a large temporal variation with peak emissions generally occurring following fertilization and heavy rainfall events around harvesting in autumn. No clear common factor regulating instantaneous N2O fluxes was found at any of the study sites. Instead, instantaneous N2O fluxes at different sites were affected by different soil variables. The cumulative N2O emissions during the study period within each year varied from 0.15 to 7.05 kgN/hm2 for different sites, which accounted for 0.33% to 5.09% of the applied fertilizer N. No obvious relationship was observed between cumulative N2O emission and applied fertilizer N rate (P > 0.4). However, the cumulative N2O emission was significantly correlated with gross mineralized N as estimated by CO2 emissions from bare soils divided by C/N ratios of each soil, and with soil mineral N pool (i.e., the sum of gross mineralized N and fertilizer N) (P < 0.001).
Kaestli, Mirjam; Harrington, Glenda; Mayo, Mark; Chatfield, Mark D.; Harrington, Ian; Hill, Audrey; Munksgaard, Niels; Gibb, Karen; Currie, Bart J.
2015-01-01
Melioidosis is an often fatal infectious disease affecting humans and animals in tropical regions and is caused by the saprophytic environmental bacterium Burkholderia pseudomallei. Domestic gardens are not only a common source of exposure to soil and thus to B. pseudomallei, but they also have been found to contain more B. pseudomallei than other environments. In this study we addressed whether anthropogenic manipulations common to gardens such as irrigation or fertilizers change the occurrence of B. pseudomallei. We conducted a soil microcosm experiment with a range of fertilizers and soil types as well as a longitudinal interventional study over three years on an experimental fertilized field site in an area naturally positive for B. pseudomallei. Irrigation was the only consistent treatment to increase B. pseudomallei occurrence over time. The effects of fertilizers upon these bacteria depended on soil texture, physicochemical soil properties and biotic factors. Nitrates and urea increased B. pseudomallei load in sand while phosphates had a positive effect in clay. The high buffering and cation exchange capacities of organic material found in a commercial potting mix led to a marked increase in soil salinity with no survival of B. pseudomallei after four weeks in the potting mix sampled. Imported grasses were also associated with B. pseudomallei occurrence in a multivariate model. With increasing population density in endemic areas these findings inform the identification of areas in the anthropogenic environment with increased risk of exposure to B. pseudomallei. PMID:25803046
Revitalization of plant growth promoting rhizobacteria for sustainable development in agriculture.
Gouda, Sushanto; Kerry, Rout George; Das, Gitishree; Paramithiotis, Spiros; Shin, Han-Seung; Patra, Jayanta Kumar
2018-01-01
The progression of life in all forms is not only dependent on agricultural and food security but also on the soil characteristics. The dynamic nature of soil is a direct manifestation of soil microbes, bio-mineralization, and synergistic co-evolution with plants. With the increase in world's population the demand for agriculture yield has increased tremendously and thereby leading to large scale production of chemical fertilizers. Since the use of fertilizers and pesticides in the agricultural fields have caused degradation of soil quality and fertility, thus the expansion of agricultural land with fertile soil is near impossible, hence researchers and scientists have sifted their attention for a safer and productive means of agricultural practices. Plant growth promoting rhizobacteria (PGPR) has been functioning as a co-evolution between plants and microbes showing antagonistic and synergistic interactions with microorganisms and the soil. Microbial revitalization using plant growth promoters had been achieved through direct and indirect approaches like bio-fertilization, invigorating root growth, rhizoremediation, disease resistance etc. Although, there are a wide variety of PGPR and its allies, their role and usages for sustainable agriculture remains controversial and restricted. There is also variability in the performance of PGPR that may be due to various environmental factors that might affect their growth and proliferation in the plants. These gaps and limitations can be addressed through use of modern approaches and techniques such as nano-encapsulation and micro-encapsulation along with exploring multidisciplinary research that combines applications in biotechnology, nanotechnology, agro biotechnology, chemical engineering and material science and bringing together different ecological and functional biological approaches to provide new formulations and opportunities with immense potential. Copyright © 2017 Elsevier GmbH. All rights reserved.
Response to elevated CO2 in the temperate C3 grass Festuca arundinaceae across a wide range of soils
Nord, Eric A.; Jaramillo, Raúl E.; Lynch, Jonathan P.
2015-01-01
Soils vary widely in mineral nutrient availability and physical characteristics, but the influence of this variability on plant responses to elevated CO2 remains poorly understood. As a first approximation of the effect of global soil variability on plant growth response to CO2, we evaluated the effect of CO2 on tall fescue (Festuca arundinacea) grown in soils representing 10 of the 12 global soil orders plus a high-fertility control. Plants were grown in small pots in continuously stirred reactor tanks in a greenhouse. Elevated CO2 (800 ppm) increased plant biomass in the high-fertility control and in two of the more fertile soils. Elevated CO2 had variable effects on foliar mineral concentration—nitrogen was not altered by elevated CO2, and phosphorus and potassium were only affected by CO2 in a small number of soils. While leaf photosynthesis was stimulated by elevated CO2 in six soils, canopy photosynthesis was not stimulated. Four principle components were identified; the first was associated with foliar minerals and soil clay, and the second with soil acidity and foliar manganese concentration. The third principle component was associated with gas exchange, and the fourth with plant biomass and soil minerals. Soils in which tall fescue did not respond to elevated CO2 account for 83% of global land area. These results show that variation in soil physical and chemical properties have important implications for plant responses to global change, and highlight the need to consider soil variability in models of vegetation response to global change. PMID:25774160
de Almeida, Rodrigo Estevam Munhoz; Pierozan Junior, Clovis; Lago, Bruno Cocco; Trivelin, Paulo Cesar Ocheuze
2018-01-01
Early fertilizer nitrogen (N) application on cover crops or their residues during the off-season is a practice adopted in Brazil subtropical conditions under no-tillage corn (Zea mays L.) systems. However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15N isotope. The N fertilization timings were: (i) oat tillering, (ii) 15 days before corn planting time, over the oat residues, (iii) at corn planting time, (iv) in-season at the three-leaf growth stage (V3), and (v) in-season split application at V3 and six-leaf (V6) growth stages. Based on the statistical analysis, the N fertilization timings were separated into three groups: 1) N-OATS, designated to N applied at oat; 2) N-PLANT, referred to pre-plant and planting N applications; and 3) N-CORN, designated to in-season corn N applications. Corn yield was not affected by the N fertilization timing. However, the N-CORN N fertilization timings enhanced NRE by 17% and 35% and final N recovery system (plant plus soil) by 16% and 24% all relative to N-OATS and N-PLANT groups, respectively. Overall, N-OATS resulted in the largest N derived from fertilizer (NDFF) amount in the deeper soil layer, in overall a delta of 10 kg N ha-1 relative to the rest of the groups. Notwithstanding corn yield was not affected, early N fertilization under subtropical conditions is not a viable option since NRE was diminished and the non-recovery N increased relative to the in-season N applications. PMID:29462178
Agricultural management affects below ground carbon input estimations
NASA Astrophysics Data System (ADS)
Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Mayer, Jochen
2017-04-01
Root biomass and rhizodeposition carbon (C release by living roots) are among the most relevant root parameters for studies of plant response to environmental change, soil C modelling or estimations of soil C sequestration. Below ground C inputs of agricultural crops are typically estimated from above ground biomass or yield, thereby implying constant below to above ground C ratios. Agricultural management practices affect above ground biomass considerably; however, their effects on below ground C inputs are only poorly understood. Our aims were therefore to (i) quantify root biomass C and rhizodeposition C of maize and wheat grown in agricultural management systems with different fertilization intensities and (ii) determine management effects on below/above ground C ratios and vertical distribution of below ground C inputs into soil. We conducted a comprehensive field study on two Swiss long-term field trials, DOK (Basel) and ZOFE (Zurich), with silage (DOK) and grain (ZOFE) maize in 2013 and winter wheat in 2014 (ZOFE) and 2015 (DOK). Three treatments in DOK (2 bio-organic, 1 mixed conventional) and 4 treatments in ZOFE (1 without, 1 manure, 2 mineral fertilization) reflected increasing fertilization intensities. In each of 4 replicated field plots per treatment, one microplot (steel tube of 0.5m depth) was inserted into soil, covering an area of 0.1m2. The microplot plants were pulse-labelled with 13C-CO2 in weekly intervals throughout the respective growing season. After harvest, the microplot soil was sampled in three soil depths (0 - 0.25, 0.25 - 0.5, 0.5 - 0.75m), roots were separated from soil by picking and wet sieving, and root and soil samples were analysed for their δ13C values by IRMS. Carbon rhizodeposition was calculated from 13C-excess values in bulk soil and roots. (i) Average root biomasses of maize and wheat were 1.9 and 1.4 tha 1, respectively, in DOK and 0.9 and 1.1 tha 1, respectively, in ZOFE. Average amounts of C rhizodeposition of maize and wheat were 1.4 and 0.7 tha 1, respectively, in DOK and 0.5 and 0.6 tha 1, respectively, in ZOFE. Both root biomass and C rhizodeposition were similar among treatments on both sites but were significantly higher for silage maize (DOK) than for grain maize (ZOFE) and winter wheat (DOK and ZOFE). (ii) With increasing fertilization intensities, below/above ground C ratios of both maize and wheat significantly decreased from 0.43 to 0.16 for maize and 0.57 to 0.15 for wheat. Vertical distribution of below ground C inputs into soil was not affected by agricultural management but differed significantly between crops: In the subsoil (0.5 - 0.75m), below ground C inputs of wheat were twice as high as those of maize on both sites. Increasing fertilization intensity leads to a considerable increase in above ground biomass but does not affect below ground C inputs of maize and wheat on two Swiss agricultural sites. This finding shows that below ground C inputs cannot be estimated from above ground biomass in order to provide soil C models with input data. A differentiation according to the management system is strongly needed.
USDA-ARS?s Scientific Manuscript database
Soil fumigation is important for food production but has the potential to discharge toxic chemicals into the environment, which may adversely affect human and ecosystem health. A field experiment was conducted to evaluate the effect of applying ammonium thiosulfate fertilizer to the soil surface pr...
Accounting for Organic Carbon Change in Deep Soil Altered Carbon Sequestration Efficiency
NASA Astrophysics Data System (ADS)
Li, J.; Liang, F.; Xu, M.; Huang, S.
2017-12-01
Study on soil organic carbon (SOC) sequestration under fertilization practices in croplands lacks information of soil C change at depth lower than plow layer (i.e. 20 30-cm). By synthesizing long-term datasets of fertilization experiments in four typical Chinese croplands representing black soil at Gongzhuling(GZL), aquatic Chao soil at Zhengzhou(ZZ), red soil at Qiyang(QY) and purple soil at Chongqing(CQ) city, we calculated changes in SOC storage relative to initial condition (ΔSOC) in 0-20cm and 0-60cm, organic C inputs (OC) from the stubble, roots and manure amendment, and C sequestration efficiency (CSE: the ratio of ΔSOC over OC) in 0-20cm and 0-60cm. The fertilization treatments include cropping with no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed SOC storage generally decreased with soil depth (i.e. 0-20 > 20-40, 40-60 cm) and increased with fertilizations (i.e. initial < CK < NPK < NPKM). The annual OC input to soil remained relatively stable and manure input was the primary source of OC input under NPKM treatment. Assuming all OC input remained at 0-60cm and 50 90% distributed at 0-20cm, our results supported that CSE at 0-60cm was consistently larger than that at 0-20cm under NPK and NPKM at GZL (p-value<0.05), but significantly lower under NPK at ZZ and QY (p-value<0.05). These results demonstrated that under long-term fertilizations, soil at depth (>20cm) can act as important soil carbon sinks in intrinsically high fertility soils (i.e. black soil) but less likely at poor fertility soil (i.e. aquatic Chao soil). It thus informs the need to account for C change in deep soils for estimating soil C sequestration capacity particularly with indigenously fertile cropland soils.
NASA Astrophysics Data System (ADS)
Kamiri, Hellen; Kreye, Christine; Becker, Mathias
2013-04-01
Wetland soils play an important role as storage compartments for water, carbon and nutrients. These soils implies various conditions, depending on the water regimes that affect several important microbial and physical-chemical processes which in turn influence the transformation of organic and inorganic components of nitrogen, carbon, soil acidity and other nutrients. Particularly, soil carbon and nitrogen play an important role in determining the productivity of a soil whereas management practices could determine the rate and magnitude of nutrient turnover. A study was carried out in a floodplain wetland planted with rice in North-west Tanzania- East Africa to determine the effects of different management practices and soil water regimes on paddy soil organic carbon and nitrogen. Four management treatments were compared: (i) control (non weeded plots); (ii) weeded plots; (iii) N fertilized plots, and (iv) non-cropped (non weeded plots). Two soil moisture regimes included soil under field capacity (rainfed conditions) and continuous water logging compared side-by-side. Soil were sampled at the start and end of the rice cropping seasons from the two fields differentiated by moisture regimes during the wet season 2012. The soils differed in the total organic carbon and nitrogen between the treatments. Soil management including weeding and fertilization is seen to affect soil carbon and nitrogen regardless of the soil moisture conditions. Particularly, the padddy soils were higher in the total organic carbon under continuous water logged field. These findings are preliminary and a more complete understanding of the relationships between management and soil moisture on the temporal changes of soil properties is required before making informed decisions on future wetland soil carbon and nitrogen dynamics. Keywords: Management, nitrogen, paddy soil, total carbon, Tanzania,
Yuan, Yuwei; Hu, Guixian; Zhao, Ming; Chen, Tianjin; Zhang, Yongzhi; Zhu, Jiahong; Wang, Qiang
2014-11-26
To further investigate the method of using δ(15)N as a marker for organic vegetable discrimination, the effects of different fertilizers on the δ(15)N in different growing stages of Brassica chinensis (B. chinensis) grown in uncultivated soil were investigated with a pot experiment. B. chinensis was planted with uncultivated soil and different fertilizer treatments and then harvested three times in three seasons consecutively. For the spring experiments in the years of 2011 and 2012, the δ(15)N value of B. chinensis, which increased due to organic manure application and decreased due to chemical fertilizer application, was significantly different (p < 0.05) with manure treatment and chemical treatment. The δ(15)N value of vegetables varied among three growing stages and ranged from +8.6‰ to +11.5‰ for the control, from +8.6‰ to +12.8‰ for the compost chicken manure treatment, from +2.8‰ to +7.7‰ for the chemical fertilizer urea treatment, and from +7.7‰ to +10.9‰ for the compost-chemical fertilizer treatment. However, the δ(15)N values observed in the autumn experiment of 2011 without any fertilizer application increased ranging from +13.4‰ to +15.4‰, + 11.2‰ to +17.7‰, +10.7‰ to +17.1‰, and +10.6‰ to +19.1‰, respectively, for the same treatments mentioned above. This result was not significantly different between manure treatment and chemical treatment. The δ(15)N values of soil obtained in the spring of 2011 during three growing stages were slightly affected by fertilizers and varied in the range of +1.6‰ to +2.5‰ for CK, +4.7‰ to +6.5‰ for compost treatment, +2.1‰ to +2.4‰ for chemical treatment, and +2.7‰ to +4.6‰ for chemical-compost treatment, respectively. High δ(15)N values of B. chinensis were observed in these experiments, which would be useful to supplement a δ(15)N database for discriminating organic vegetables. Although there was a significant difference between manure treatment and chemical treatment, it was still difficult to discriminate whether a labeled organic vegetable was really grown without chemical fertilizer just with a fixed high δ(15)N value, especially for the vegetables planted simultaneously with chemical and compost fertilizer.
Zhang, Xianxian; Yin, Shan; Li, Yinsheng; Zhuang, Honglei; Li, Changsheng; Liu, Chunjiang
2014-02-15
Rice is one of the major crops of southern China and Southeast Asia. Rice paddies are one of the largest agricultural greenhouse gas (GHG) sources in this region because of the application of large quantities of nitrogen (N) fertilizers to the plants. In particular, the production of methane (CH4) is a concern. Investigating a reasonable amount of fertilizers to apply to plants is essential to maintaining high yields while reducing GHG emissions. In this study, three levels of fertilizer application [high (300 kg N/ha), moderate (210 kg N/ha), and low (150 kg N/ha)] were designed to examine the effects of variation in N fertilizer application rate on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions from the paddy fields in Chongming Island, Shanghai, China. The high level (300 kg N/ha) represented the typical practice adopted by the local farmers in the area. Maximum amounts of CH4 and N2O fluxes were observed upon high-level fertilizer application in the plots. Cumulative N2O emissions of 23.09, 40.10, and 71.08 mg N2O/m(2) were observed over the growing season in 2011 under the low-, moderate-, and high-level applications plots, respectively. The field data also indicated that soil temperatures at 5 and 10 cm soil depths significantly affected soil respiration; the relationship between Rs and soil temperature in this study could be described by an exponential model. Our study showed that reducing the high rate of fertilizer application is a feasible way of attenuating the global-warming potential while maintaining the optimum yield for the studied paddy fields. Copyright © 2013 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Benninger-Truax, M.; Taylor, D.H.
1993-10-01
Mechanisms of ecosystem recovery following 11 years of sewage sludge disposal were addressed by examining the effects of tilling and/or liming on soil chemistry and the heavy metal (Cd, Cu, Pb, and Zn) concentrations in soil, earthworms, vegetation, spiders, and crickets. In 1989 and 1990, subplots in each of three former 0.1-ha, long-term treatments (sludge, fertilizer, and control) were either unmanipulated or manipulated via tilling and/or liming. Liming significantly increased the pH of soil from the long-term sludge and fertilizer plots, and the combination of tilling and liming affected the heavy metal concentrations in earthworms, as lower concentrations of Cd,more » Cu, Pb, and Zn were found in earthworms collected from subplots that had been both tilled and limed. However, most observed significant differences in heavy metal concentrations reflected the long-term treatments, as heavy metal concentrations tended to be greater in the soil and biota collected from sludge-treated plots. Thus, heavy metals remained in the soil in forms available to the biota, regardless of the cessation of sludge application or subplot manipulations (liming and/or tilling) for two years following cessation of sludge application.« less
Ma, Mingchao; Zhou, Jing; Ongena, Marc; Liu, Wenzheng; Wei, Dan; Zhao, Baisuo; Guan, Dawei; Jiang, Xin; Li, Jun
2018-02-13
Bacteria play vital roles in soil biological fertility; however, it remains poorly understood about their response to long-term fertilization in Chinese Mollisols, especially when organic manure is substituted for inorganic nitrogen (N) fertilizer. To broaden our knowledge, high-throughput pyrosequencing and quantitative PCR were used to explore the impacts of inorganic fertilizer and manure on bacterial community composition in a 35-year field experiment of Chinese Mollisols. Soils were collected from four treatments: no fertilizer (CK), inorganic phosphorus (P) and potassium (K) fertilizer (PK), inorganic P, K, and N fertilizer (NPK), and inorganic P and K fertilizer plus manure (MPK). All fertilization differently changed soil properties. Compared with CK, the PK and NPK treatments acidified soil by significantly decreasing soil pH from 6.48 to 5.53 and 6.16, respectively, while MPK application showed no significant differences of soil pH, indicating alleviation of soil acidification. Moreover, all fertilization significantly increased soil organic matter (OM) and soybean yields, with the highest observed under MPK regime. In addition, the community composition at each taxonomic level varied considerably among the fertilization strategies. Bacterial taxa, associated with plant growth promotion, OM accumulation, disease suppression, and increased soil enzyme activity, were overrepresented in the MPK regime, while they were present at low abundant levels under NPK treatment, i.e. phyla Proteobacteria and Bacteroidetes, class Alphaproteobacteria, and genera Variovorax, Chthoniobacter, Massilia, Lysobacter, Catelliglobosispora and Steroidobacter. The application of MPK shifted soil bacterial community composition towards a better status, and such shifts were primarily derived from changes in soil pH and OM.
Rainer, Georg; Kuhnert, Regina; Unterholzer, Mara; Dresch, Philipp; Gruber, Andreas; Peintner, Ursula
2015-01-01
Ectomycorrhizae (EM) are important for the survival of seedlings and trees, but how they will react to global warming or changes in soil fertility is still in question. We tested the effect of soil temperature manipulation and nitrogen fertilization on EM communities in a high-altitude Pinus cembra afforestation. The trees had been inoculated in the 1960s in a nursery with a mixture of Suillus placidus, S. plorans and S. sibircus. Sampling was performed during the third year of temperature manipulation in June and October 2013. Root tips were counted, sorted into morphotypes, and sequenced. Fungal biomass was measured as ergosterol and hyphal length. The EM potential of the soil was assessed with internal transcribed spacers (ITS) clone libraries from in-growth mesh bags (MB). Temperature manipulation of ± 1 °C had no effect on the EM community. A total of 33 operational taxonomic units (OTUs) were identified, 20 from the roots, 13 from MB. The inoculated Suillus spp. colonized 82% of the root tips, thus demonstrating that the inoculation was sustainable. Nitrogen fertilization had no impact on the EM community, but promoted depletion in soil organic matter, and caused a reduction in soil fungal biomass. PMID:29376899
Kim, Seungdo; Dale, Bruce E
2008-08-15
Nitrogen fertilizer plays an important role in corn cultivation in terms of both economic and environmental aspects. Nitrogen fertilizer positively affects corn yield and the soil organic carbon level, but it also has negative environmental effects through nitrogen-related emissions from soil (e.g., N20, NOx, NO3(-) leaching, etc.). Effects of nitrogen fertilizer on greenhouse gas emissions associated with corn grain are investigated via life cycle assessment. Ecoefficiency analysis is also used to determine an economically and environmentally optimal nitrogen application rate (NAR). The ecoefficiency index in this study is defined as the ratio of economic return due to nitrogen fertilizer to the greenhouse gas emissions of corn cultivation. Greenhouse gas emissions associated with corn grain decrease as NAR increases at a lower NAR until a minimum greenhouse gas emission level is reached because corn yield and soil organic carbon level increase with NAR. Further increasing NAR after a minimum greenhouse gas emission level raises greenhouse gas emissions associated with corn grain. Increased greenhouse gas emissions of corn grain due to nitrous oxide emissions from soil are much higher than reductions of greenhouse gas emissions of corn grain due to corn yield and changes in soil organic carbon levels at a higher NAR. Thus, there exists an environmentally optimal NAR in terms of greenhouse gas emissions. The trends of the ecoefficiency index are similar to those of economic return to nitrogen and greenhouse gas emissions associated with corn grain. Therefore, an appropriate NAR could enhance profitability as well as reduce greenhouse gas emissions associated with corn grain.
[Phosphorus use efficiency of wheat on three typical farmland soils under long-term fertilization].
Gao, Jing; Zhang, Shu-xiang; Xu, Ming-gang; Huang, Shao-min; Yang, Xue-yun
2009-09-01
Field experiments were conducted on three typical farmland soils (loess soil, fluvo-aquic soil, and cinnamon fluvo-aquic soil) in Northern China to study the grain yield, phosphorus agronomic efficiency (PAE), and phosphorus use efficiency (PUE) of wheat under effects of long-term fertilizations. Seven treatments were installed, i.e., non-fertilization (CK), nitrogen fertilization (N), nitrogen-potassium fertilization (NK), nitrogen-phosphorus fertilization (NP), nitrogen-phosphorus-potassium fertilization (NPK), NPK plus straw returning (NPKS), and NPK plus manure application (NPKM). The averaged wheat grain yields under long-term P fertilizations (treatments NP, NPK, NPKS, and NPKM) ranged from 2914 kg x hm(-2) to 6219 kg x hm(-2), being 200%-400% higher than those under no P fertilizations (treatments CK, N, and NK), and no significant differences were observed between the P fertilizations. In the early years of the experiment, the PAE in treatment NPK on the loess soil, fluvo-aquic soil, and cinnamon fluvo-aquic soil was 17.0 kg x kg(-1), 20.3 kg x kg(-1), and 13.3 kg x kg(-1), and the PUE was 15.3%, 31.2%, and 23.8%, respectively. After 15-year fertilization, the PAE and PUE in treatment NPK increased annually by 3.9 kg x kg(-1) and 1.3% on loess soil, 2.5 kg x kg(-1) and 0.9% on fluvo-aquic soil, and 2.8 kg x kg(-1) and 1.0% on cinnamon fluvo-aquic soil, respectively. There were no significant differences in the PAE and PUE among the P treatments for the same soils. In Northern China, long-term P fertilization could increase the wheat grain yield and PUE significantly, and the mean annual increase of PAE and PUE in treatment NPKM was higher on loess soil than on fluvo-aquic soil and cinnamon fluvo-aquic soil.
Soil fertility status and challenges in Burundi: an overview
NASA Astrophysics Data System (ADS)
Kaboneka, Salvator
2015-04-01
Landlocked and thousands miles away from international sea ports, Burundi is one of the poorest country in the world. 58% of the population suffers chronic malnutrition, 67% live in absolute poverty (MDG report 2012). 90% of the estimated 10 million people depends on subsistence agriculture, on about 3 million ha of cultivable land. The average size of a family farm is less than 0.5 ha which has to support a family of typically 7 people . As a consequence, fallow practices are no longer possible and continuous land cultivation leads to enormous soil losses by erosion. As much as 100-200 metric tons per hectare of soil losses have been reported on the hill sides of the Mumirwa region, whose landscape is currently so degraded that the local community now say that "stones grow" in the zone. In medium to high altitude areas, about 1 million of ha are acidic (pH < 5) with a high risk of Al toxicity and deficiencies in major (P, Ca, Mg, K) and micro-nutrients (Cu, Zn). Some parts of the low land of the Imbo zone, dedicated to rice cultivation, manifest indications of salinity. A recent survey showed that 14% of the 2.800 ha of land committed to rice production is affected by rising salinity. Although soil salinity constitutes a challenge to rice producers in that region, soil acidity, often combined with Al toxicity, is the major limitation to soil productivity throughout Burundi. Almuminum saturation up to 60% and pH as low as 4.5 are observed. As elsewhere, technical solutions do exist, but the level of poverty of the population is such that access to fertilizers and adoption of sustainable practices is very weak. We believe that the main challenge to soil productivity in Burundi is more socio-economic than technical, and farmers should be helped with simple tools that should be linked to their indigenous knowledge about soil fertility. Sustainable management of soil fertility is the key challenge for farmers to optimize a sustainable yield. Key words: micro nutrient, soil fertility, nutrient depletion, soil acidity.
NASA Astrophysics Data System (ADS)
Tolpeshta, I. I.; Erkenova, M. I.
2018-02-01
The effect of native palygorskite clay and that modified with dodecyltrimethylammonium chloride on the degradation of oil products in an oligotrophic peat soil under complete flooding at the application of lime and mineral fertilizers has been studied under laboratory conditions. It has been shown that the incubation of oil-contaminated soil with unmodified clay and fertilizers at the application of lime under complete flooding with water affects the dynamics of pH and Eh and slows the development of reducing conditions compared to the use of clay without fertilizers. The addition of organoclay under similar conditions favors the formation of potential-determining system with a high redox capacity, which is capable of retaining the potential on a level of 100-200 mV at pH ˜ 7 for two months. It has been found that, under the experimental conditions, unmodified and modified clay, which has no toxic effect on the bacterial complex, does not increase the biodegradation efficiency of oil products in the oligotrophic peat soil compared to the experimental treatments without clay addition. Possible reasons for no positive effect of palygorskite clay on the biodegradation rate of oil products under experimental conditions have been analyzed.
Heavy Metal Leaching as Affected by Long-Time Organic Waste Fertilizer Application.
Lekfeldt, Jonas Duus Stevens; Holm, Peter E; Kjærgaard, Charlotte; Magid, Jakob
2017-07-01
The recycling of urban waste products as fertilizers in agriculture may introduce contaminants such as heavy metals into soil that may leach and contaminate groundwater. In the present study, we investigated the leaching of heavy metals from intact soil cores collected in the long-term agricultural field trial CRUCIAL. At the time of sampling, the equivalent of >100 yr of urban waste fertilizers following Danish legislation had been applied. The leaching of Cu was significantly increased in the treatments receiving organic waste products compared with the unfertilized control but remained below the permissible level following Danish drinking water guidelines. The leaching of Cu was controlled primarily by the topsoil Cu content and by the leaching of dissolved organic carbon (DOC) but at the same time significantly correlated with leaching of colloids in soils that had not received fertilizer or had received an organic fertilizer with a low concentration of Cu. The leaching of Zn, Cd, and Co was not significantly increased in urban waste-fertilized treatments. The leaching of Mo was elevated in accelerated waste treatments (both agricultural and urban), and the leaching of Mo was linked to the leaching of DOC. Since leaching of Cr and Pb was strongly linked to the level of colloid leaching, leaching of these metals was reduced in the urban waste treatments. Overall, the results presented should not raise concern regarding the agricultural use of urban waste products in agriculture as long as the relevant guidelines are followed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Xu, Fuli; Liang, Yinli; Zhang, Chenge; Du, Sheni; Chen, Zhijie
2004-07-01
This paper studied the effect of fertilization on cucumber growth and yield, soil microbial biomass and soil enzyme activities in sunlight greenhouse in Loess Plateau. The results indicated that the growth and yield of cucumber were increased with application of manure and methane. Foliage application reduced the application rate of NP and manure. Fertilization had an obvious effect on the biological characteristics of soil in sunlight greenhouse. The number of bacteria was increased by manure and foliage fertilization, and that of fungi was increased by NP and methane fertilization but decreased by manure fertilization. Fertilization with manure, NP and methane also remarkably increased the number of actinomyces and the activities of urease, phosphatase and sucrase in soil. The activities of soil urease and phosphatase were increased by fertilization of manure, but little effect was found with fertilization of NP and methane.
Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare
2014-01-01
Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.
NASA Astrophysics Data System (ADS)
Grüter, Roman; Costerousse, Benjamin; Mayer, Jochen; Mäder, Paul; Thonar, Cécile; Frossard, Emmanuel; Schulin, Rainer; Tandy, Susan
2017-04-01
Zinc (Zn) deficiency is a widespread problem in human mineral nutrition. It is mainly caused by imbalanced diets with low contents of bioavailable Zn. This is in particular a problem in populations depending on cereals such as wheat (Triticum aestivum L.) as a major source of this essential micronutrient element. Increasing Zn concentrations in wheat grains (biofortification) is therefore an important challenge. At the same time, increased uptake of the toxic heavy metal cadmium (Cd) must be prevented. Agronomic practises influence soil properties such as pH and soil organic carbon and thus also have an indirect effect on phytoavailable soil Zn and Cd concentrations and the uptake of these metals by wheat in addition to direct inputs with fertilizers and other amendments. This study investigated the effects of long-term organic matter management on the phytoavailability of soil Zn and Cd and their uptake by wheat on plots of two Swiss long-term field trials. In one trial (DOK), a farming system comparison trial established in 1978, we compared plots under conventional management with mineral fertilization either in combination or not with farmyard manure application to plots under biodynamic organic management and control plots with no fertilizer application. In the second trial (ZOFE), established in 1949, we compared different fertilizer regimes on conventionally managed plots, including plots with application of mineral fertilizers only, farmyard manure, or compost and control plots with no fertilizer application. Soil physico-chemical and biological properties were determined at the beginning of the growing season. Soil Zn and Cd availabilities were assessed by the Diffusive Gradients in Thin Films (DGT) method and by DTPA extraction before and after wheat cultivation. Additionally, various wheat yield components and element concentrations in shoots and grains were measured at harvest. In the ZOFE trial, soil Zn and Cd concentrations were lowest in the mineral fertilizer and highest in the farmyard manure treatments, where metal export via crop harvests and inputs through farmyard manure dominated soil metal mass balances in the long-term, respectively. DGT-available Zn and Cd correlated negatively with soil pH, total organic carbon and microbial biomass in both trials. They were lowest in the biodynamic and compost treatments and highest in the control treatments. In the ZOFE trial, wheat yields on mineral fertilized plots exceeded the other treatments by more than a factor of two. Cd concentrations in wheat shoots and grains showed a strong positive correlation with DGT-available soil Cd. They were lowest in biodynamic and compost treatments. In contrast, shoot and grain Zn concentrations correlated more closely with total and DTPA-extractable than with DGT-available soil Zn in the ZOFE trial and they poorly correlated with both Zn availability indicators in the DOK trial. Despite these differences, the study reveals that long-term organic matter management has an important influence on the availability of both elements in soil and their uptake by wheat.
USDA-ARS?s Scientific Manuscript database
Research has shown poultry litter is a superior fertilizer for cotton and other row crops. The productivity of soil that had received poultry litter as a fertilizer is not known after cessation of litter application and returning to conventional fertilization with inorganic fertilizers. This study ...
Ahamd, Maqshoof; Abbasi, Waleed Mumtaz; Jamil, Moazzam; Iqbal, Muhammad; Hussain, Azhar; Akhtar, Muhammad Fakhar-U-Zaman; Nazli, Farheen
2017-06-01
Incorporation of genetically modified crops in the cropping system raises the need for studying the effect of these crops on the soil ecosystem. The current study aimed to compare the effect of Bacillus thuringiensis (Bt)- and non-Bt-cotton (Gossypium hirsutum L.) genotypes on rhizosphere properties under fertilized and unfertilized soil conditions. One non-Bt-cotton (IUB 75) and four Bt-cotton varieties (IUB-222, MM-58, IUB-13, FH-142) were sown in a Randomized Complete Block Design (RCBD) in a factorial fashion with three replications under unfertilized (T1) and fertilized (T2 at NPK 310-170-110 kg ha -1 ) soil conditions. The culturable soil bacterial population was recorded at flowering, boll opening, and harvesting stages, while other rhizosphere biological and chemical properties were recorded at harvesting. Results revealed that Bt-cotton genotypes IUB-222 and FH-142 showed significantly higher rhizosphere total nitrogen, NH 4 + -N, available phosphorus, and available potassium. Total organic carbon and microbial biomass carbon was also maximum in the rhizosphere of IUB-222 under fertilized conditions. Similarly, bacterial population (CFU g -1 ) at flowering stage and at harvesting was significantly higher in the rhizosphere of IUB-222 as compared to non-Bt- (IUB-75) and other Bt-cotton genotypes under same growth conditions. It showed that Bt genotypes can help in maintaining soil macronutrients (total nitrogen, available phosphorus, and available potassium) under proper nutrient management. Moreover, Bt-cotton genotypes seem to strengthen certain biological properties of the soil, thus increasing the growth and yield capability, maintaining available nutrients in the soil as compared to non-Bt cotton, while no harmful effects of Bt cotton on soil properties was detected.
Duan, Yinghua; Xu, Minggang; Gao, Suduan; Liu, Hua; Huang, Shaomin; Wang, Boren
2016-01-01
Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dynamics and N changes in soil profile (0–100 cm) were examined during 1990–2009 under chemical fertilization, manure incorporation with fertilizer, and fertilizer with straw return treatments. We employed a mass balance approach to estimate the N loss to the environment after taking into account soil N change. Results showed a significant increase in soil N storage under manure incorporation treatments, accompanied with the lowest N loss (ave.20–24% of total N input) compared to all other treatments (ave.35–63%). Both soil N distribution and mass balance data suggested higher leaching risk from chemical fertilization in acidic soil of southern China with higher precipitation than the other two sites. This research concludes that manure incorporation with chemical fertilizer not only can achieve high N use efficiency and improve soil fertility, but also leads to the lowest total N loss or damage to the environment. PMID:27650801
Duan, Yinghua; Xu, Minggang; Gao, Suduan; Liu, Hua; Huang, Shaomin; Wang, Boren
2016-09-21
Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dynamics and N changes in soil profile (0-100 cm) were examined during 1990-2009 under chemical fertilization, manure incorporation with fertilizer, and fertilizer with straw return treatments. We employed a mass balance approach to estimate the N loss to the environment after taking into account soil N change. Results showed a significant increase in soil N storage under manure incorporation treatments, accompanied with the lowest N loss (ave.20-24% of total N input) compared to all other treatments (ave.35-63%). Both soil N distribution and mass balance data suggested higher leaching risk from chemical fertilization in acidic soil of southern China with higher precipitation than the other two sites. This research concludes that manure incorporation with chemical fertilizer not only can achieve high N use efficiency and improve soil fertility, but also leads to the lowest total N loss or damage to the environment.
Chu, Haiyan; Fujii, Takeshi; Morimoto, Sho; Lin, Xiangui; Yagi, Kazuyuki; Hu, Junli; Zhang, Jiabao
2007-01-01
The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammonia-oxidizing bacteria (AOB) was investigated in a long-term (16-year) fertilizer experiment. The experiment included seven treatments: organic manure, half organic manure N plus half fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). N fertilization greatly increased soil nitrification potential, and mineral N fertilizer had a greater impact than organic manure, while N deficiency treatment (PK) had no significant effect. AOB community structure was analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) of the amoA gene, which encodes the α subunit of ammonia monooxygenase. DGGE profiles showed that the AOB community was more diverse in N-fertilized treatments than in the PK-fertilized treatment or the control, while one dominant band observed in the control could not be detected in any of the fertilized treatments. Phylogenetic analysis showed that the DGGE bands derived from N-fertilized treatments belonged to Nitrosospira cluster 3, indicating that N fertilization resulted in the dominance of Nitrosospira cluster 3 in soil. These results demonstrate that long-term application of N fertilizers could result in increased soil nitrification potential and the AOB community shifts in soil. Our results also showed the different effects of mineral fertilizer N versus organic manure N; the effects of P and K on the soil AOB community; and the importance of balanced fertilization with N, P, and K in promoting nitrification functions in arable soils. PMID:17098920
Farming with rocks and minerals: challenges and opportunities.
Van Straaten, Peter
2006-12-01
In many parts of the world food security is at risk. One of the biophysical root causes of falling per-capita food production is the declining quality and quantity of soils. To reverse this trend and increase soil fertility soil and plant nutrients have to be replenished. This review provides a literature survey of experiences of using multi-nutrient rock fertilizers for soil fertility enhancement from temperate and tropical environments. Advantages and limitations of the application of rock fertilizers are discussed. Examples are provided from two successful nutrient replenishment projects in Africa where locally available rock fertilizers are used on highly leached acid soils. The potential of combining organic materials alongside rock fertilizers in soil fertility replenishment strategies is stressed.
Zheng, Xuebo; Fan, Jianbo; Xu, Lei; Zhou, Jing
2017-01-01
Unreasonable use of chemical fertilizer (CF) on agricultural soil leads to massive losses of soil organic carbon (SOC) and total nitrogen (TN) in tropical and subtropical areas, where soil conditions are unfavorable for aggregate formation. This study evaluated the effects of combined application of biogas slurry (BS) plus CF on soil aggregation and aggregate—associated C/N concentration and storage in an Ultisol. Six treatments included: no fertilizer (T1), CF only (T2), partial (15% (T3), 30% (T4) and 45% (T5)) substitution of TN with BS and BS only (T6). Soil mechanical—stable aggregates (MSAs) formation and stability as well as MSAs—associated C/N concentration and storage were observed in different aggregate sizes (>5, 5–2, 2–1, 1.0–0.5, 0.50–0.25 and <0.25 mm). The proportion of MSAs >5 mm significantly increased with BS substitution (T5), while the proportions of MSAs 1.0–0.5 mm, MSAs 0.50–0.25 mm and MSAs <0.25 mm significantly decreased. Both mean weight diameter and geometric mean diameter were highest in T5, which improved soil aggregation stability as well as resulted in significantly higher SOC and TN concentrations and storage in MSAs >0.5 mm that constituted 72–82% of MSAs. Stepwise regression analysis showed that MSAs >5 mm, SOC in MSAs >5 mm and TN in MSAs >5 mm were the dominant variables affecting aggregate stability. Meanwhile SOC in MSAs <0.25 mm and TN in MSAs 2–1 mm were independent variables affecting SOC and TN concentrations in bulk soils. Therefore, certain rate of combined application of BS plus CF is an effective, eco—friendly way to improve soil quality in an Ultisol. PMID:28125647
Cao, Dan; Zong, Liang-gang; Xiao, Jun; Zhang, Qian; Zhao, Yan
2010-10-01
Field trials of organic farming were conducted to examine the effects of different bio-fertilizers on the organically cultured cucumber growth, soil enzyme activities, and soil microbial biomass. Four treatments were installed, i. e., organic fertilizer only (CK), bio-fertilizer "Zhonghe" combined with organic fertilizer (ZHH), bio-fertilizer "NST" combined with organic fertilizer (NST), and bio-fertilizer "Bio" combined with organic fertilizer (BIO). Bio-fertilizers combined with organic fertilizer increased the cucumber yield significantly, and improved the root growth and leaf chlorophyll content. Comparing with that in CK, the cucumber yield in treatments ZHH, NST, and BIO was increased by 10.4%, 12.4%, and 29.2%, respectively. At the seedling stage, early flowering stage, and picking time of cucumber, the soil microbial biomass C and N in treatments ZHH, NST, and BIO were significantly higher than that in CK, and the activities of soil urease, acid phosphatase, and catalase were also higher.
Wang, Yu; Zhu, Guibing; Song, Liyan; Wang, Shanyun; Yin, Chengqing
2014-03-01
Manure fertilizers are widely used in agriculture and highly impacted the soil microbial communities such as ammonia oxidizers. However, the knowledge on the communities of archaeal versus bacterial ammonia oxidizers in paddy soil affected by manure fertilization remains largely unknown, especially for a long-term influence. In present work, the impact of manure fertilization on the population of ammonia oxidizers, related potential nitrification rates (PNRs) and the key factors manipulating the impact were investigated through studying two composite soil cores (long-term fed with manure fertilization versus undisturbed). Moreover, soil incubated with NH(4)(+) for 5 weeks was designed to verify the field research. The results showed that the copy numbers of bacterial amoA gene in the manure fed soil were significant higher than those in the unfed soil (p < 0.05), suggesting a clear stimulating effect of long-term manure fertilization on the population of ammonia-oxidizing bacteria (AOB). The detected PNRs in the manure fed soil core (14-218 nmol L(-1) N g(-1) h(-1)) were significant higher than those in the unfed soil core (5-72 nmol L(-1) N g(-1) h(-1) ; p < 0.05). Highly correlations between the PNRs and the bacterial amoA gene copies rather than archaeal amoA gene were observed, indicating strong nitrification capacity related to bacterial ammonia oxidizers. The NH(4)(+) -N significantly correlated to the abundance of AOB (p < 0.01) and explained 96.1% of the environmental variation, showing the NH(4)(+) -N was the main factor impacting the population of AOB. The incubation experiment demonstrated a clear increase of the bacterial amoA gene abundance (2.0 × 10(6) to 8.4 × 10(6) g(-1) d.w.s. and 1.6 × 10(4) to 4.8 × 10(5) g(-1) d.w.s.) in both soil but not for the archaeal amoA gene, in agreement with the field observation. Overall, our results suggested that manure fertilization promoted the population size of bacterial ammonia oxidizers rather than their archaeal counterparts whether in long-term or short-term usage and the NH(4)(+) -N was the key impact factor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Lü, Wen-zhou; Qiao, Yu-xiang; Yu, Ning; Shi, Rong-hua; Wang, Guang-ming
2015-09-01
The disposal of urban scattered human feces has become a difficult problem for the management of modern city. In present study, the scattered human feces underwent the collection, scum removal, flocculation and dehydration, finally became the granular fertilizer; the effects of the ratio of fertilizer to soil on the growth of the pakchoi and the quality of soil and leaching water were evaluated, and the feasibility of granular fertilizer manuring the pakchoi was discussed by pot experiments. The results showed that the granular fertilizer significantly enhanced the production of the pakchoi which were not polluted by the intestinal microorganisms under the experiment conditions; meanwhile, at the proper ratio of fertilizer to soil, the concentration of these microorganisms in the leaching water was lower than that in the control check. Chemical analyses of soil revealed that the nutrient content of nitrogen, phosphorus, potassium and organic matters in soil became much richer in all treatments. In addition, the granular fertilizer improved the physical- chemical properties of soil, including raising the level of soil porosity and reducing the volume weight of soil. Application of granular fertilizer won't pollute the soil or leaching water; instead, it can also prevent nitrogen, potassium and intestinal microorganisms from leaching inio ground water at the proper ratio of granular fertilizer to soil.
Shan, Linan; He, Yunfeng; Chen, Jie; Huang, Qian; Wang, Hongcai
2015-12-01
Ammonia (NH3) volatilization is a major pathway of nitrogen (N) loss from soil-crop systems. As vegetable cultivation is one of the most important agricultural land uses worldwide, a deeper understanding of NH3 volatilization is necessary in vegetable production systems. We therefore conducted a 3-year (2010-2012) field experiment to characterize NH3 volatilization and evaluate the effect of different N fertilizer treatments on this process during the growth period of Chinese cabbage. Ammonia volatilization rate, rainfall, soil water content, pH, and soil NH4(+) were measured during the growth period. The results showed that NH3 volatilization was significantly and positively correlated to topsoil pH and NH4(+) concentration. Climate factors and fertilization method also significantly affected NH3 volatilization. Specifically, organic fertilizer (OF) increased NH3 volatilization by 11.77%-18.46%, compared to conventional fertilizer (CF, urea), while organic-inorganic compound fertilizer (OIF) reduced NH3 volatilization by 8.82%-12.67% compared to CF. Furthermore, slow-release fertilizers had significantly positive effects on controlling NH3 volatilization, with a 60.73%-68.80% reduction for sulfur-coated urea (SCU), a 71.85%-78.97% reduction for biological Carbon Power® urea (BCU), and a 77.66%-83.12% reduction for bulk-blend controlled-release fertilizer (BBCRF) relative to CF. This study provides much needed baseline information, which will help in fertilizer choice and management practices to reduce NH3 volatilization and encourage the development of new strategies for vegetable planting. Copyright © 2015. Published by Elsevier B.V.
Degradation of soil fertility can cancel pollination benefits in sunflower.
Tamburini, Giovanni; Berti, Antonio; Morari, Francesco; Marini, Lorenzo
2016-02-01
Pollination and soil fertility are important ecosystem services to agriculture but their relative roles and potential interactions are poorly understood. We explored the combined effects of pollination and soil fertility in sunflower using soils from a trial characterized by different long-term input management in order to recreate plausible levels of soil fertility. Pollinator exclusion was used as a proxy for a highly eroded pollination service. Pollination benefits to yield depended on soil fertility, i.e., insect pollination enhanced seed set and yield only under higher soil fertility indicating that limited nutrient availability may constrain pollination benefits. Our study provides evidence for interactions between above- and belowground ecosystem services, highlighting the crucial role of soil fertility in supporting agricultural production not only directly, but also indirectly through pollination. Management strategies aimed at enhancing pollination services might fail in increasing yield in landscapes characterized by high soil service degradation. Comprehensive knowledge about service interactions is therefore essential for the correct management of ecosystem services in agricultural landscapes.
[Effects of different fertilization treatments on soil humic acid structure characteristics].
Zhao, Nan; Lü, Yi-Zhong
2012-07-01
The present article used soil humic acid as research object to study effects on the structure characteristics of soil humic acid under the condition of applying cake fertilizer, green manure, straw fertilizer with the same contents of nitrogen and phosphorus. It used element analysis, micro infrared, and solid 13C-NMR for structure analysis, the results indicated that: The chemical composition and structure characteristics of humic acids were similar, but they also had many obvious differences. (1) The atomic ratios of H/C, O/C, and C/N were all different for the humic acids, the soil humic acid of cake fertilizer processing had the highest contents of H and N, green manure processing of soil humic acid contained the highest content of O, while straw fertilizer processing of soil humic acid contained highest content of C. (2) Infrared analysis displayed that the three soil humic acids contained protein Cake fertilizer processing of soil humic acid contained the most amino compounds, green manure processing of soil humic acid contained the maximum contents of hydroxyl and aliphatic hydrocarbon, while straw fertilizer processing of soil humic acid contained the highest contents of alcohol and phenol. (3) Solid 13C-NMR data indicated that cake fertilizer processing of soil humic acid contained the most carboxyl carbon, green manure processing of soil humic acid contained the highest contents of alkyl carbon and carbonyl carbon, while straw fertilizer processing of soil humic acids had the most alkoxy carbon and aromatic carbon
Liu, Dongyan; Tago, Kanako; Hayatsu, Masahito; Tokida, Takeshi; Sakai, Hidemitsu; Nakamura, Hirofumi; Usui, Yasuhiro; Hasegawa, Toshihiro; Asakawa, Susumu
2016-01-01
Elevated concentrations of atmospheric CO2 ([CO2]) enhance the production and emission of methane in paddy fields. In the present study, the effects of elevated [CO2], elevated temperature (ET), and no nitrogen fertilization (LN) on methanogenic archaeal and methane-oxidizing bacterial community structures in a free-air CO2 enrichment (FACE) experimental paddy field were investigated by PCR-DGGE and real-time quantitative PCR. Soil samples were collected from the upper and lower soil layers at the rice panicle initiation (PI) and mid-ripening (MR) stages. The composition of the methanogenic archaeal community in the upper and lower soil layers was not markedly affected by the elevated [CO2], ET, or LN condition. The abundance of the methanogenic archaeal community in the upper and lower soil layers was also not affected by elevated [CO2] or ET, but was significantly increased at the rice PI stage and significantly decreased by LN in the lower soil layer. In contrast, the composition of the methane-oxidizing bacterial community was affected by rice-growing stages in the upper soil layer. The abundance of methane-oxidizing bacteria was significantly decreased by elevated [CO2] and LN in both soil layers at the rice MR stage and by ET in the upper soil layer. The ratio of mcrA/pmoA genes correlated with methane emission from ambient and FACE paddy plots at the PI stage. These results indicate that the decrease observed in the abundance of methane-oxidizing bacteria was related to increased methane emission from the paddy field under the elevated [CO2], ET, and LN conditions. PMID:27600710
Liu, Dongyan; Tago, Kanako; Hayatsu, Masahito; Tokida, Takeshi; Sakai, Hidemitsu; Nakamura, Hirofumi; Usui, Yasuhiro; Hasegawa, Toshihiro; Asakawa, Susumu
2016-09-29
Elevated concentrations of atmospheric CO2 ([CO2]) enhance the production and emission of methane in paddy fields. In the present study, the effects of elevated [CO2], elevated temperature (ET), and no nitrogen fertilization (LN) on methanogenic archaeal and methane-oxidizing bacterial community structures in a free-air CO2 enrichment (FACE) experimental paddy field were investigated by PCR-DGGE and real-time quantitative PCR. Soil samples were collected from the upper and lower soil layers at the rice panicle initiation (PI) and mid-ripening (MR) stages. The composition of the methanogenic archaeal community in the upper and lower soil layers was not markedly affected by the elevated [CO2], ET, or LN condition. The abundance of the methanogenic archaeal community in the upper and lower soil layers was also not affected by elevated [CO2] or ET, but was significantly increased at the rice PI stage and significantly decreased by LN in the lower soil layer. In contrast, the composition of the methane-oxidizing bacterial community was affected by rice-growing stages in the upper soil layer. The abundance of methane-oxidizing bacteria was significantly decreased by elevated [CO2] and LN in both soil layers at the rice MR stage and by ET in the upper soil layer. The ratio of mcrA/pmoA genes correlated with methane emission from ambient and FACE paddy plots at the PI stage. These results indicate that the decrease observed in the abundance of methane-oxidizing bacteria was related to increased methane emission from the paddy field under the elevated [CO2], ET, and LN conditions.
Ryegrass uptake of carbamazepine and ibuprofen applied by urine fertilization.
Winker, Martina; Clemens, Joachim; Reich, Margrit; Gulyas, Holger; Otterpohl, Ralf
2010-03-15
Human urine is a potential alternative fertilizer for agriculture. However, its usage is associated with a risk of spreading pharmaceutical residues to fields. The individual and combined behavior of carbamazepine and ibuprofen was investigated by GC/MS analysis in a greenhouse experiment using ryegrass fertilized with pharmaceutical-spiked urine. Only carbamazepine could be detected in soil, roots, and aerial plant parts. Fifty-three per cent of carbamazepine originally present in the urine was recovered in soil samples taken after three months. Additionally, 34% of carbamazepine was found in aerial plant parts and 0.3% in roots. Model calculations showed that neither roots nor Casparian strip posed a considerable barrier to uptake. Carbamazepine transport was clearly driven by transpiration. Ibuprofen was not detected in the soil or in any plant parts after three months. This was assumed to be due to biodegradation of ibuprofen. Carbamazepine and ibuprofen, singly or in combination, did not adversely affect the growth of ryegrass.
Effects of supplementation of fertilizers on human selenium status in Finland.
Aro, A; Alfthan, G; Varo, P
1995-03-01
The Se concentration of foods can be increased by supplementing fertilizers with soluble Se compounds. In Finland the availability of soil Se for plants is poor owing to the relatively low Se concentration, low pH and high iron content of the soil. Since 1984 multimineral fertilizers have been supplemented with Se (16 mg kg-1 to fertilizers for grain production and 6 mg kg-1 to those for fodder production) in the form of sodium selenate. Within two years a three-fold increase of mean Se intake was observed. The supplementation affected the Se content of all major food groups with the exception of fish. The concomitant human serum Se concentration increased by 70%. In 1990 the amount of Se that was supplemented was reduced to 6 mg kg-1 for all fertilizers. This reduced the mean Se intake by 30% and the serum Se concentration decreased by 25% from the highest levels observed in 1989. Plants take up part of the supplemented selenate and transform it into organic Se compounds, mainly selenomethionine. This affects human nutrition by increasing the Se content of foods of both animal and vegetable origin. According to data obtained in Finland, supplementation of fertilizers with Se is a safe and effective means of increasing the Se intake of both animals and humans that is feasible in countries with relatively uniform geochemical conditions. This kind of intervention requires careful monitoring of the effects on both animal and human nutrition and the environment.
Fertilization increases paddy soil organic carbon density.
Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun
2012-04-01
Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.
Fertilization increases paddy soil organic carbon density*
Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun
2012-01-01
Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC. PMID:22467369
Measuring and modeling of soil N2O emissions - How well are we doing?
NASA Astrophysics Data System (ADS)
Butterbach-Bahl, K.; Ralf, K.; Werner, C.; Wolf, B.
2017-12-01
Microbial processes in soils are the primarily source of atmospheric N2O. Fertilizer use to boost food and feed production of agricultural systems as well as nitrogen deposition to natural and semi-natural ecosystems due to emissions of NOx and NH3 from agriculture and energy production and re-deposition to terrestrial ecosystems has likely nearly doubled the pre-industrial source strength of soils for atmospheric N2O. Quantifying soil emissions and identifying mitigation options is becoming a major focus in the climate debate as N2O emissions from agricultural soils are a major contributor to the greenhouse gas footprint of agricultural systems, with agriculture incl. land use change contributing up to 30% to total anthropogenic GHG emissions. The increasing number of annual datasets show that soil emissions a) are largely depended on soil N availability and thus e.g. fertilizer application, b) vary with management (e.g. timing of fertilization, residue management, tillage), c) depend on soil properties such as organic matter content and pH, e) are affected by plant N uptake, and e) are controlled by environmental factors such as moisture and temperature regimes. It is remarkable that the magnitude of annual emissions is largely controlled by short-term N2O pulses occurring due to fertilization, wetting and drying or freezing and thawing of soils. All of this contributes to a notorious variability of soil N2O emissions in space and time. Overcoming this variability for quantification of source strengths and identifying tangible mitigation options requires targeted measuring approaches as well as the translation of our knowledge on mechanisms underlying emissions into process oriented models, which finally might be used for upscaling and scenario studies. This paper aims at reviewing current knowledge on measurements, modelling and upscaling of soil N2O emissions, thereby identifying short comes and uncertainties of the various approaches and fields for future research.
Soil fertility, crop biodiversity, and farmers' revenues: Evidence from Italy.
Di Falco, Salvatore; Zoupanidou, Elisavet
2017-03-01
This paper analyzes the interplay between soil fertility, crop biodiversity, and farmers' revenues. We use a large, original, farm-level panel dataset. Findings indicate that both crop biodiversity and soil fertility have positive effects on farmers' revenues. It is also shown that crop biodiversity and soil fertility may act as substitutes. These results provide evidence for the important role of diversity in the resilience of agroecosystems. Crop diversification can be a potential strategy to support productivity when soils are less fertile.
Shelton, Rebecca E.; Jacobsen, Krista L.; McCulley, Rebecca L.
2018-01-01
Agroecosystem nitrogen (N) loss produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, conservation agricultural management practices aimed at reducing N loss are increasingly adopted. However, the ecosystem consequences of these practices have not been well-studied. We quantified N loss via leaching, NH3 volatilization, N2O emissions, and N retention in plant and soil pools of corn conservation agroecosystems in Kentucky, USA. Three systems were evaluated: (1) an unfertilized, organic system with cover crops hairy vetch (Vicia villosa), winter wheat (Triticum aestivum), or a mix of the two (bi-culture); (2) an organic system with a hairy vetch cover crop employing three fertilization schemes (0 N, organic N, or a fertilizer N-credit approach); and (3) a conventional system with a winter wheat cover crop and three fertilization schemes (0 N, urea N, or organic N). In the unfertilized organic system, cover crop species affected NO3-N leaching (vetch > bi-culture > wheat) and N2O-N emissions and yield during corn growth (vetch, bi-culture > wheat). Fertilization increased soil inorganic N, gaseous N loss, N leaching, and yield in the organic vetch and conventional wheat systems. Fertilizer scheme affected the magnitude of growing season N2O-N loss in the organic vetch system (organic N > fertilizer N-credit) and the timing of loss (organic N delayed N2O-N loss vs. urea) and NO3-N leaching (urea >> organic N) in the conventional wheat system, but had no effect on yield. Cover crop selection and N fertilization techniques can reduce N leaching and greenhouse gas emissions without sacrificing yield, thereby enhancing N conservation in both organic and conventional conservation agriculture systems. PMID:29403512
NASA Astrophysics Data System (ADS)
Rahayu Prastyaningsih, Sri; Azwin
2017-12-01
The development of agar wood plants in oil palm plantation requires the forestry techniques in order to obtain maximum production. In an oil palm stands, the age of plant will affect the height, diameter, population and stands density. The older age of an oil palm stands will affect the canopy cover on the forest floor. Agar wood plants are semi-tolerant growth and oil palm can be used as shade. Unilak has an oil palm plantation area of 10 hectares around the campus with 10 years old and 20 years old. The soil condition at the study is Podsolik Merah Kuning (PMK) which poor nutrient and needs fertilization to increase soil fertility. This study aims to find out the effect of age of oil palm stands and fertilization for optimal growth. The split plot design with 2 main plots of the age of palm tree ( 10 years old and 20 years old) and five kinds of fertilizing sub plot (without fertilizer, 40 gram/plant of NPK, 80 gram/plat of NPK, 120 gram/plant of NPK and 180 gram/plant of NPK were used. The results of this research showed that the age of palm tree (canopy cover) treatment gave non-significant influence on the growing of agar wood until it reaches 4 months of growth. The canopyy cover by 10 years old of oil palm tree produce the best response on height (15 cm) and diameter (0,4 cm) growth of agar woods..Fertilizing treatment di not give any significant influence on the heigh and diameter growth of agarwood plants until reach 3 months. The interaction by 10 years old of palm with fertilizing gave non significant results.
USDA-ARS?s Scientific Manuscript database
Organic production in Puerto Rico is at an early stage and research is needed to validate the sustainability of different management practices. This research initiated evaluation of selected soil properties including the microbial communities to evaluate the effects of Tropic sunn (Crotalaria juncea...
A Loblolly Pine Management Guide: Foresters' Primer in Nutrient Cycling
Jacques R. Jorgensen; Carol G. Wells
1986-01-01
The nutrient cycle, which includes the input of nutrients to the site, their losses, and their movement from one soil or vegetation component to another, can be modified by site preparation, rotation length, harvest system, fertilization, and fire, and by using soil-improving plants. Included is a report on how alternative procedures affect site nutrients, and provides...
Chris A. Maier; L.W. Kress
2000-01-01
We measured soil CO2 evolution rates with (Sff) and without (Sms) the forest floor litter and root respiration monthly in 11-year-old loblolly pine (Pinus taeda L.) plantations during the fourth year of fertilization and irrigation treatments. Values of Sff...
Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils
Braddock, J.F.
1999-01-01
A study was carried out to test a simple bioremediation treatment strategy in the Arctic and analyze the influence of fertilization the degradation of aliphatic and aromatic hydrocarbons, e.g., pristine, n-tetradecane, n-pentadecane, 2-methylnaphthalene, naphthalene, and acenaphthalene. The site was a coarse sand pad that once supported fuel storage tanks. Diesel-range organics concentrations were 250-860 mg/kg soil at the beginning of the study. Replicate field plots treated with fertilizer yielded final concentrations of 0, 50, 100, or 200 mg N/kg soil. Soil pH and soil-water potentials decreased due to fertilizer application. The addition of fertilizer considerably increased soil respiration potentials, but not the populations of microorganisms measured. Fertilizer addition also led to ??? 50% loss of measured aliphatic and aromatic hydrocarbons in surface and subsurface soils. For fertilized plots, hydrocarbon loss was not associated with the quantity of fertilizer added. Losses of aliphatic hydrocarbons were ascribed to biotic processes, while losses of aromatic hydrocarbons were due to biotic and abiotic processes.
Iqbal, Javed; Mitchell, David C; Barker, Daniel W; Miguez, Fernando; Sawyer, John E; Pantoja, Jose; Castellano, Michael J
2015-05-01
Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha, the recommended rate of 135 kg N ha, and a high rate of 225 kg N ha); soybean received no N fertilizer. We further investigated the potential for a winter cereal rye ( L.) cover crop to interact with N fertilizer rate to affect NO emissions from both crops. The cover crop did not consistently affect NO emissions. Across all years and irrespective of cover crop, N fertilizer application above the recommended rate resulted in a 16% increase in mean NO flux rate during the corn phase of the rotation. In 2 of the 3 yr, N fertilizer application to corn (0-225 kg N ha) did not affect mean NO flux rates from the subsequent unfertilized soybean crop. However, in 1 yr after a drought, mean NO flux rates from the soybean crops that received 135 and 225 kg N ha N application in the corn year were 35 and 70% higher than those from the soybean crop that received no N application in the corn year. Our results are consistent with previous studies demonstrating that cover crop effects on NO emissions are not easily generalizable. When N fertilizer affects NO emissions during a subsequent unfertilized crop, it will be important to determine if total fertilizer-induced NO emissions are altered or only spread across a greater period of time. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Bond, C Ryan; Maguire, R O; Havlin, J L
2006-01-01
There is a lack of information on how fertilization and initial Mehlich-3 phosphorus (M3P) interact to affect water soluble P (WSP) in soils. Our objectives were to (i) quantify the relationship between WSP and M3P for four textural diverse benchmark soils of North Carolina (NC) and (ii) quantify the change in WSP concentrations following P additions to soils over a wide range of initial M3P. Soils known to represent a wide range in M3P were collected from an Autryville loamy sand (loamy, siliceous, subactive, thermic Arenic Paleudults), Wasda muck (fine-loamy, mixed, semiactive, acid, thermic Histic Humaquepts), Georgeville silt loam (fine, kaolinitic, thermic Typic Kanhapludults), and Pacolet sandy clay loam (fine, kaolinitic, thermic Typic Kanhapludults) and analyzed for M3P, Fe, Al, and WSP. An incubation study was also conducted where four samples representing a range in M3P from each series were fertilized at rates of 150 and 300 kg P ha(-1), and WSP was measured at 1, 7, and 21 d after fertilization. The Wasda muck exhibited a change point at 115 mg P kg(-1) across a broad range of M3P concentrations (60-238 mg kg(-1)) while Autryville, Georgeville, and Pacolet series (with ranges in M3P of 32-328, 119-524, 0-1034 mg P kg(-1), respectively) maintained linear relationships between WSP and M3P. For the fertilized soils, significant increases in WSP occurred regardless of P rate. Yet, WSP concentrations were greater in soils with greater initial M3P. Thus, these data suggest that shifting animal waste applications to fields of relatively lower M3P concentrations would have an immediate impact on reducing risk for P losses, if all other factors are equal.
Florio, Alessandro; Felici, Barbara; Migliore, Melania; Dell'Abate, Maria Teresa; Benedetti, Anna
2016-05-01
A laboratory incubation experiment and greenhouse studies investigated the impact of organo-mineral (OM) fertilization as an alternative practice to conventional mineral (M) fertilization on nitrogen (N) uptake and losses in perennial ryegrass (Lolium perenne) as well as on soil microbial biomass and ammonia oxidizers. While no significant difference in plant productivity and ammonia emissions between treatments could be detected, an increase in soil total N content and an average 17.9% decrease in nitrates leached were observed in OM fertilization compared with M fertilization. The microbial community responded differentially to treatments, suggesting that the organic matter fraction of the OM fertilizer might have influenced N immobilization in the microbial biomass in the short-medium term. Furthermore, nitrate contents in fertilized soils were significantly related to bacterial but not archaeal amoA gene copies, whereas in non-fertilized soils a significant relationship between soil nitrates and archaeal but not bacterial amoA copies was found. The application of OM fertilizer to soil maintained sufficient productivity and in turn increased N use efficiency and noticeably reduced N losses. Furthermore, in this experiment, ammonia-oxidizing bacteria drove nitrification when an N source was added to the soil, whereas ammonia-oxidizing archaea were responsible for ammonia oxidation in non-fertilized soil. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.
Witheetrirong, Yongyoot; Tripathi, Nitin Kumar; Tipdecho, Taravudh; Parkpian, Preeda
2011-01-01
The use of chemical fertilizers in Thailand increased exponentially by more than 100-fold from 1961 to 2004. Intensification of agricultural production causes several potential risks to water supplies, especially nitrate-nitrogen (NO3−-N) pollution. Nitrate is considered a potential pollutant because its excess application can move into streams by runoff and into groundwater by leaching. The nitrate concentration in groundwater increases more than 3-fold times after fertilization and it contaminates groundwater as a result of the application of excess fertilizers for a long time. Soil texture refers to the relative proportion of particles of various sizes in a given soil and it affects the water permeability or percolation rate of a soil. Coarser soils have less retention than finer soils, which in the case of NO3−-N allows it to leach into groundwater faster, so there is positive relationship between the percentage of sands and NO3−-N concentration in groundwater wells. This study aimed to estimate the effect of soil texture on NO3−-N content in groundwater. Optical reflectance data obtained by remote sensing was used in this study. Our hypothesis was that the quantity of nitrogen leached into groundwater through loam was higher than through clay. Nakhon Pathom province, Thailand, was selected as a study area where the terrain is mostly represented by a flat topography. It was found that classified LANDSAT images delineated paddy fields as covering 29.4% of the study area, while sugarcane covered 10.4%, and 60.2% was represented by “others”. The reason for this classified landuse was to determine additional factors, such as vegetation, which might directly affect the quantity of NO3−-N in soil. Ideally, bare soil would be used as a test site, but in fact, no such places were available in Thailand. This led to an indirect method to estimate NO3−-N on various soil textures. Through experimentation, it was found that NO3−-N measured through the loam in sugarcane (I = 0.0054, p < 0.05) was lower than clay represented by paddies (I = 0.0305, p < 0.05). This had a significant negative impact on the assumption. According to the research and local statistical data, farmers have always applied an excess quantity of fertilizer on paddy fields. This is the main reason for the higher quantity of NO3−-N found in clay than loam in this study. This case might be an exceptional study in terms of quantity of fertilizers applied to agricultural fields. PMID:21909315
Calvo, Pamela; Watts, Dexter B; Kloepper, Joseph W; Torbert, H Allen
2016-12-01
Nitrous oxide (N 2 O) emissions are increasing at an unprecedented rate owing to the increased use of nitrogen (N) fertilizers. Thus, new innovative management tools are needed to reduce emissions. One potential approach is the use of microbial inoculants in agricultural production. In a previous incubation study, we observed reductions in N 2 O emissions when microbial-based inoculants were added to soil (no plants present) with N fertilizers under laboratory incubations. This present study evaluated the effects of microbial-based inoculants on N 2 O and carbon dioxide (CO 2 ) emissions when applied to soil planted with corn (Zea mays L.) under controlled greenhouse conditions. Inoculant treatments consisted of (i) SoilBuilder (SB), (ii) a metabolite extract of SoilBuilder (SBF), and (iii) a mixture of 4 strains of plant-growth-promoting Bacillus spp. (BM). Experiments included an unfertilized control and 3 N fertilizers: urea, urea - ammonium nitrate with 32% N (UAN-32), and calcium - ammonium nitrate with 17% N (CAN-17). Cumulative N 2 O fluxes from pots 41 days after planting showed significant reductions in N 2 O of 15% (SB), 41% (BM), and 28% (SBF) with CAN-17 fertilizer. When UAN-32 was used, reductions of 34% (SB), 35% (SBF), and 49% (BM) were obtained. However, no reductions in N 2 O emissions occurred with urea. Microbial-based inoculants did not affect total CO 2 emissions from any of the fertilized treatments or the unfertilized control. N uptake was increased by an average of 56% with microbial inoculants compared with the control (nonmicrobial-based treatments). Significant increases in plant height, SPAD chlorophyll readings, and fresh and dry shoot mass were also observed when the microbial-based treatments were applied (with and without N). Overall, results demonstrate that microbial inoculants can reduce N 2 O emissions following fertilizer application depending on the N fertilizer type used and can enhance N uptake and plant growth. Future studies are planned to evaluate the effectiveness of these microbial inoculants in field-based trials and determine the mechanisms involved in N 2 O reduction.
Liu, Ting; Ye, Cheng-Long; Chen, Xiao-Yun; Ran, Wei; Shen, Qi-Rong; Hu, Feng; Li, Hui-Xin
2013-12-01
A comparative study was conducted to investigate the effects of different fertilization modes on the soil nematode community structure in a paddy field with paddy rice and wheat rotation in Jintan County (31 degrees 39'41.8" N, 119 degrees 28'23.5" E) of Jiangsu Province, East China. Six treatments were installed, i. e., no fertilization (CK), 100% chemical NPK fertilization (F), pig manure compost plus 50% chemical fertilization (PF), straw returning plus 100% chemical fertilization (SF), pig manure compost and straw returning plus 50% chemical fertilization (PSF), and application of commercial pig manure-inorganic complex fertilizer (PMF). The soil samples were collected from the field after the paddy rice harvested in autumn. The two continuous years study showed that the soil nematode community structure varied with fertilization treatments and years. The combined application of chemical fertilizers and organic manures increased the total number of soil nematodes, decreased the abundance of soil bacterivorous nematodes, and made the abundance of predator- and omnivore nematodes increased significantly. No significant differences were observed in the abundance of soil fungivorous nematodes among all the treatments. Chemical fertilization alone and the application of commercial pig manure-inorganic complex fertilizer had no obvious suppression effect on the soil phytophagous nematodes. The abundance of soil bacteriavorous nematodes under the combined application of chemical fertilizers and organic manures was relatively increased in the second year, as compared with that in the first year, while the abundance of soil phytophagous nematodes (Hirschmanniella) was relatively decreased in the second year. From the aspect of nematode ecological indices, the Margalef diversity index (H) under the combined application of chemical fertilizers and organic manures in the second year had an increasing trend, while the NCR index had less change. The Wasilewka index had a relative increase in the second year, while the plant-parasitic index had a relative decrease. It was suggested that the application of organic manure could increase the abundance of soil microbivorous nematodes, and made the soil environment tend to be healthy.
[Rhizosphere effect of nutrients in different maize soils with different fertility levels].
Wu, L; Zhang, S
2000-08-01
Maize plants and soil samples were collected from Jilin Province to study the nutrient dynamics in soil-maize plant rhizosphere and their relationship with plant uptake. The results showed that NH4(+)-N and NO3(-)-N were accumulated in rhizospheric soil, and mainly controlled by the application of chemical fertilizers. Soil available P was depleted in high fertility fields, especially in high seedling density, while accumulated in low fertility fields. Soil available K was accumulated in rhizospheric soil, and its accumulation rate was higher in high fertility than in low fertility fields. The nutrient absorption amount was N approximately K > P for maize plant shoots and roots, but was N > K > P for seeds. The contribution rate of chemical fertilizers to maize yield was only 1/5-1/3 in Jilin Province, and the rest was contributed by the application of organic manure, such as chicken feces or cow feces, and by the mineralization of soil organic matter.
Wu, Wencheng; Wu, Jiahui; Liu, Xiaowen; Chen, Xianbin; Wu, Yingxin; Yu, Shixiao
2017-09-01
Recently, several studies have showed that both organic and inorganic fertilizers are effective in immobilizing heavy metals at low cost, in comparison to other remediation strategies for heavy metal-contaminated farmlands. A pot trial was conducted in this study to examine the effects of inorganic P fertilizer and organic fertilizer, in single application or in combination, on growth of maize, heavy metal availabilities, enzyme activities, and microbial community structure in metal-contaminated soils from an electronic waste recycling region. Results showed that biomass of maize shoot and root from the inorganic P fertilizer treatments were respectively 17.8 and 10.0 folds higher than the un-amended treatments (CK), while the biomass in the organic fertilizer treatments was only comparable to the CK. In addition, there were decreases of 85.0% in Cd, 74.3% in Pb, 66.3% in Cu, and 91.9% in Zn concentrations in the roots of maize grown in inorganic P fertilizer amended soil. Consistently, urease and catalase activities in the inorganic P fertilizer amended soil were 3.3 and 2.0 times higher than the CK, whereas no enhancement was observed in the organic fertilizer amended soil. Moreover, microbial community structure was improved by the application of inorganic P fertilizer, but not by organic fertilizer; the beneficial microbial groups such as Kaistobacter and Koribacter were most frequently detected in the inorganic P fertilizer amended soil. The negligible effect from the organic fertilizer might be ascribed to the decreased pH value in soils. The results suggest that the application of inorganic P fertilizer (or in combination with organic fertilizer) might be a promising strategy for the remediation of heavy metals contaminated soils in electronic waste recycling region. Copyright © 2017. Published by Elsevier Inc.
Ma, Li; Yang, Lin-Zhang; Ci, En; Wang, Yan; Yin, Shi-Xue; Shen, Ming-Xing
2008-09-01
Soil samples were collected from an experimental paddy field with long-term (26 years) fertilization in Taihu Lake region of Jiangsu Province to study the effects of different fertilization on the organic carbon distribution and stable carbon isotope natural abundance (delta 13C) in the soil profile, and on the humus composition. The results showed that long-term fertilization increased the organic carbon content in top soil significantly, and there was a significantly negative exponential correlation between soil organic carbon content and soil depth (P < 0.01). The organic carbon content in 10-30 cm soil layer under chemical fertilizations and in 20-40 cm soil layer under organic fertilizations was relatively stable. Soil delta 13C increased gradually with soil depth, its variation range being from -24% per thousand to -28 per thousand, and had a significantly negative linear correlation with soil organic carbon content (P < 0.05). In 0-20 cm soil layer, the delta 13C in treatments organic manure (M), M + NP, M + NPK, M + straw (R) + N, and R + N decreased significantly; while in 30-50 cm soil layer, the delta 13C in all organic fertilization treatments except R + N increased significantly. Tightly combined humus (humin) was the main humus composition in the soil, occupying 50% or more, and the rest were loosely and stably combined humus. Long-term fertilization increased the content of loosely combined humus and the ratio of humic acid (HA) to fulvic acid (FA).
Li, Yilin; Shi, Weiming; Wang, Xingxiang
2014-01-01
The differences in rhizosphere nitrification activities between high- and low- fertility soils appear to be related to differences in dissolved oxygen concentrations in the soil, implying a relationship to differences in the radial oxygen loss (ROL) of rice roots in these soils. A miniaturised Clark-type oxygen microelectrode system was used to determine rice root ROL and the rhizosphere oxygen profile, and rhizosphere nitrification activity was studied using a short-term nitrification activity assay. Rice planting significantly altered the oxygen cycling in the water-soil system due to rice root ROL. Although the oxygen content in control high-fertility soil (without rice plants) was lower than that in control low-fertility soil, high rice root ROL significantly improved the rhizosphere oxygen concentration in the high-fertility soil. High soil fertility improved the rice root growth and root porosity as well as rice root ROL, resulting in enhanced rhizosphere nitrification. High fertility also increased the content of nitrification-induced nitrate in the rhizosphere, resulting in enhanced ammonium uptake and assimilation in the rice. Although high ammonium pools in the high-fertility soil increased rhizosphere nitrification, rice root ROL might also contribute to rhizosphere nitrification improvement. This study provides new insights into the reasons that an increase in soil fertility may enhance the growth of rice. Our results suggest that an amendment of the fertiliser used in nutrient- and nitrification-poor paddy soils in the red soil regions of China may significantly promote rice growth and rice N nutrition. PMID:25291182
Wang, Xiaoying; Tong, Yanan; Gao, Yimin; Gao, Pengcheng; Liu, Fen; Zhao, Zuoping; Pang, Yan
2014-01-01
Increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. We used data from published papers and a soil testing and fertilization project in Shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (Triticum aestivum L.) and maize (Zea mays L.) on the farmers' level, and soil fertility change from the 1970s to the 2000s in the Loess Plateau in China. The results showed that in different regions of the province, chemical fertilizer NPK inputs and yields of wheat and maize increased. With regard to soil nutrient balance, N and P gradually changed from deficit to surplus levels, while K deficiency became more severe. In addition, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium increased during the same period. The PFP of N, NP and NPK on wheat and maize all decreased from the 1970s to the 2000s as a whole. With the increase in N fertilizer inputs, both soil total nitrogen and alkali-hydrolysis nitrogen increased; P fertilizer increased soil available phosphorus and K fertilizer increased soil available potassium. At the same time, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium all had positive impacts on crop yields. In order to promote food safety and environmental protection, fertilizer requirements should be assessed at the farmers' level. In many cases, farmers should be encouraged to reduce nitrogen and phosphate fertilizer inputs significantly, but increase potassium fertilizer and organic manure on cereal crops as a whole. PMID:25380401
NASA Astrophysics Data System (ADS)
Dou, Xiaolin; He, Ping; Cheng, Xiaoli; Zhou, Wei
2016-01-01
Quantification of dynamics of soil organic carbon (SOC) pools under the influence of long-term fertilization is essential for predicting carbon (C) sequestration. We combined soil chemical fractionation with stable C isotope analyses to investigate the C dynamics of the various SOC pools after 25 years of fertilization. Five types of soil samples (0-20, 20-40 cm) including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, IN; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into recalcitrant and labile fractions, and the fractions were analysed for C content, C:N ratios, δ13C values, soil C and N recalcitrance indexes (RIC and RIN). Chemical fractionation showed long-term MNPK fertilization strongly increased the SOC storage in both soil layers (0-20 cm = 1492.4 gC m2 and 20-40 cm = 1770.6 gC m2) because of enhanced recalcitrant C (RC) and labile C (LC). The 25 years of inorganic fertilizer treatment did not increase the SOC storage mainly because of the offsetting effects of enhanced RC and decreased LC, whereas no clear SOC increases under the SNPK fertilization resulted from the fast decay rates of soil C.
Dou, Xiaolin; He, Ping; Cheng, Xiaoli; Zhou, Wei
2016-01-11
Quantification of dynamics of soil organic carbon (SOC) pools under the influence of long-term fertilization is essential for predicting carbon (C) sequestration. We combined soil chemical fractionation with stable C isotope analyses to investigate the C dynamics of the various SOC pools after 25 years of fertilization. Five types of soil samples (0-20, 20-40 cm) including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, IN; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into recalcitrant and labile fractions, and the fractions were analysed for C content, C:N ratios, δ(13)C values, soil C and N recalcitrance indexes (RIC and RIN). Chemical fractionation showed long-term MNPK fertilization strongly increased the SOC storage in both soil layers (0-20 cm = 1492.4 gC m(2) and 20-40 cm = 1770.6 gC m(2)) because of enhanced recalcitrant C (RC) and labile C (LC). The 25 years of inorganic fertilizer treatment did not increase the SOC storage mainly because of the offsetting effects of enhanced RC and decreased LC, whereas no clear SOC increases under the SNPK fertilization resulted from the fast decay rates of soil C.
NASA Astrophysics Data System (ADS)
Hartill, Jodie; Hergoualc'h, Kristell; Comeau, Louis-Pierre; Jo, Smith; Lou, Verchot
2017-04-01
Half of the peatlands across Peninsular Malaysia, Borneo and Sumatra are 'managed'. Conversion of peat swamp forest to workable oil palm plantation requires a drastic, potentially irreversible, change to the landscape, to which fertilizers are then routinely applied. A combination of these factors is now widely thought to increase soil nitrous oxide (N2O) emissions, although there is high uncertainty due to gaps in the knowledge, both regionally and nationally. Despite the widespread use of fertilizers in plantations on peats, studies observing their effects remain very limited. Therefore, there is a need for in situ studies to evaluate how environmental parameters (edaphic properties, climate, soil moisture and N availability indicators) influence soil emissions. This 18 month study was located in plots local to each other, representing the start, intermediate and end of the land conversion process; namely mixed peat swamp forest, drained and logged forest and industrial oil palm plantation. Spatial variability was taken into account by differentiating the hollows and hummocks in the mixed peat swamp forest, and the fertilized zone and the zone without fertilizer addition in the oil palm plantation. Gas samples were collected each month from static chambers at the same time as key environmental parameters were measured. Intensive sampling was performed during a 35 day period following two fertilizer applications, in which urea was applied to palms at rates of 0.5 and 1 kg urea palm-1. Soil N2O emissions (kg N ha-1 y-1 ± SE) were low overall, but they were greater in the oil palm plantation (0.8 ± 0.1) than in the mixed peat swamp forest (0.3 ± 0.0) and the drained/logged forest (0.2 ± 0.0). In the mixed peat swamp forest, monthly average fluxes of N2O (g N ha-1 d-1 ± SE) were similar in the hollows (0.6 ± 0.2) and the hummocks (0.3 ± 0.1), whereas in the oil palm plantation they were consistently higher in the zone without fertilizer (2.5 ± 0.4) than in the fertilized zone (0.5 ± 0.1), even after fertilizer application. In the fertilized zones, the N2O fluxes following the two fertilizer applications were 2.4 and 4.5 times higher respectively than fluxes observed in the absence of fertilizers. No change in emissions was observed in the neighboring unfertilized zone at the time of fertilizer application. Soil N2O emissions were related to changes in air and soil temperature in the mixed peat swamp forest, air temperature and water table depth in the drained and logged forest, and rainfall on the day of measurement in the oil palm plantation. This research confirms that peat forest conversion to oil palm plantation has negative consequences on the emissions of N2O. It also corroborates an increase in emission due to fertilizer application, with a magnitude comparable to the emission factor provided by the IPCC guidelines, but this is restricted to the limited area of fertilizer application.
Soil Quality in Mining Areas Undergoing Ecological Restoration
NASA Astrophysics Data System (ADS)
Dinarowski, Marcela; Casagrande, José Carlos; Bizuti, Denise T. G.; Silva, Luiz Gabriel; Soares, Marcio Roberto; Brancalion, Pedro H. S.
2014-05-01
Mining is one of the anthropogenic activities most impactful to natural resources, and can profoundly affect the resilience of ecosystems depending on the level of soil degradation. Ecological restoration has generated promising results even in situations of degradation as intense as those of mining. The aim of this study was to evaluate the quality of the soil in areas explored by the bauxite extraction undergoing restoration: recently mined, seven years, 20 years and native forest. The studied areas are located in the municipality of Poços de Caldas-MG, belonging to ALCOA Alumínio. The mined-out areas for seven and twenty years were uncompressed and received topsoil, liming and fertilization with nitrogen, phosphorus and potassium. Samples for chemical analyses of soil fertility were carried out at depths of 0-5, 5-10, 10-20, 20-40 and 40-60 cm. Soil quality was evaluated by pondered additive model. The parameters were considered organic matter (0.6) and bases saturation (0.4) for soil fertility function (0.6) and calcium (0.5) and aluminum saturation (0.5) for the function root development (0.4) - (the numbers in parentheses represent the weights attributed). Despite the high content, only the organic matter was not a parameter enough to classify the soil quality, once the native forest has very low base saturation (7%). The soil quality index(SQI) obtained allowed to classify the areas, being the first restored 20 years ago with SQI equal to 0.7 followed of the restored 7 years ago, native forest and newly mined with SQIs equal to 0.6, 04 and 0.3, respectively. The native tropical forests have low soil fertility, keeping by the cycling of nutrients. This demonstrates the need for the degraded areas, especially the mined, are uncompressed to allow storage of water and root development, in addition to the replacement of nutrients and soil acidity correction, especially high levels of aluminum saturation (66%) and low calcium (3 mmolcdm-3).
NASA Astrophysics Data System (ADS)
Mayor, Ángeles G.; Keizer, Jan Jacob; González-Pelayo, Óscar; Valdecantos, Alejandro; Vallejo, Ramón; de Ruiter, Peter
2015-04-01
Since the mid of the last century fire recurrence has increased in the Iberian peninsula and the overall Mediterranean basin due to changes in land use and climate. The warmer and drier climate projected for this region will further increase the risk of wildfire occurrence and of increasing fire recurrence. Although the impact of wildfires on soil nutrient content in this region has been extensively studied, still few works have assessed this impact on the basis of fire recurrence. This study assesses the changes in soil nutrient status of two Iberian ecosystems, Várzea (N Portugal) and Valencia (E Spain), affected by different levels of fire recurrence and where short inter-fire periods have promoted a transition from pine woodlands to shrublands. Trends towards soil fertility loss with increasing fire recurrence (one, two, three or four fires in 37 years) were observed in the two study sites. The sites differed when soil fertility of areas burned several times were compared with long unburned references. In Valencia, overall soil fertility of the surface mineral soil was lower in areas burned two or three times than in long unburned areas, twenty and eight years after the last fire, respectively. On the contrary, total organic matter in Várzea was higher in burned than in unburned soils one year after the occurrence of one or four fires. However, a negative impact of fire was observed for integrated indicators of soil quality, such as hot-water carbon and potentially mineralizable nitrogen, suggesting that fire also had an adverse effect on substrate quality in Várzea. Our results suggest that the current trend of increasing fire recurrence in Southern Europe may result in losses or alterations of soil organic matter, particularly when fire promotes a transition from pine woodland to shrubland.
NASA Astrophysics Data System (ADS)
Leifeld, Jens; Conen, Franz; Oberholzer, Hans Rudolf; Jochen, Mayer
2014-05-01
Soil carbon dynamics are controlled by the delicate balance between carbon inputs and outputs which both are co-regulated by land use and management (LUM) as important anthropogenic drivers. Upon land use change to cropland carbon stocks generally tend to decline but often the contribution of two opposing factors, namely changes in input and decomposition rates, to soil carbon stock changes is indistinguishable. Here we report on an ongoing cropland experiment in Zurich, Switzerland, named ZOFE (Zurich Organic Fertilization Experiment), established on former grassland in 1949. ZOFE encompasses a range of mineral and organic fertilization practices and a zero fertilizer treatment as control. The experiment has a block design with five replicates per treatment. We make use of productivity and fertilization gradients in selected treatments of the ZOFE trial to evaluate how low or high inputs (induced by differential yields and organic fertilization) may affect soil organic carbon storage and transformation. For the most recent sampling that also included subsoil down to 0.9 m, all properties were measured for every single replicate. Topsoil carbon storage declined after grassland conversion at rates of c. 0.2 t C ha-1 a-1, particularly in treatments with mineral fertilizer and high yields, and without fertilization and low yields. Organic matter amendments such as manure or compost could partially offset but not fully compensate some of the topsoil carbon loss. Over time the soil's delta 15N signature declined as well, probably due to increased atmospheric nitrogen deposition. It increased from the top- to the subsoil, indicating increasing microbial transformation, particularly with manure added. The soil's radiocarbon signature revealed distinct bomb peak patterns in all treatments but only in the topsoil. The 14C data confirmed that with higher productivity more recent organic matter was incorporated, both in top and subsoil. Because, in contrast to topsoil, subsoil carbon storage was similar among treatments, the results tentatively indicate that in the ZOFE trial higher subsoil carbon inputs, owing to high productivity and additional organic amendments, do not enhance subsoil carbon storage but higher inputs are counterbalanced by faster soil organic matter decomposition.
NASA Astrophysics Data System (ADS)
Badagliacca, Giuseppe; Petrovičová, Beatrix; Zumbo, Antonino; Romeo, Maurizio; Gullì, Tommaso; Martire, Luigi; Monti, Michele; Gelsomino, Antonio
2017-04-01
Soil incorporation of digestate represents a common practice to dispose the solid residues from biogas producing plants. Although the digestate constitutes a residual biomass rich in partially decomposed organic matter and nutrients, whose content is often highly variable and unbalanced, its potential fertilizer value can vary considerably depending on the recipient soil properties. The aim of the work was to assess short-term changes in the fertility status of two contrasting agricultural soils in Southern Italy (Calabria), olive grove on a clay acid soil (Typic Hapludalfs) and citrus grove on a sandy loam slightly calcareous soil (Typic Xerofluvents), respectively located along the Tyrrhenian or the Ionian coast. An amount of 30 t ha-1 digestate was incorporated into the soil by ploughing. Unamended tilled soil was used as control. The following soil physical, chemical and biochemical variables were monitored during the experimental period: aggregate stability, pH, electrical conductivity, organic C, total N, Olsen-P, N-NH4+, N-NO3-, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and the mineralization quotient (qM). Moreover, in the olive grove soil CO2 emissions have been continuously measured at field scale for 5 months after digestate incorporation. Digestate application in both site exerted a significant positive effect on soil aggregate stability with a greater increase in clay than in sandy loam soil. Over the experimental period, digestate considerably affected the nutrient availability, namely Olsen-P, N-NH4+, N-NO3-, along with the electrical conductivity. The soil type increased significantly the soil N-NH4+ content, which was always higher in the olive than in citrus grove soil. N-NO3- content was markedly increased soon after the organic amendment, followed by a seasonal decline more evident in the sandy loam soil. Moreover, soil properties as CaCO3 content and the pH selectively affected the Olsen-P dynamics. No appreciable variation was recorded in total C and N pools. Interestingly, amendment with digestate altered the soil microbial community size in both soils as MBC and MBN were increased, although the response was more evident in the clay soil (olive) than in the sandy loam (citrus) one. The considerably higher qM observed in the clay soil suggests that the C mineralization was selectively stimulated in this soil. This finding was confirmed by the increase of CO2 emissions. As a whole our results show that digestate application selectively stimulated soil C dynamics and determined an unbalanced nutrient release, strongly depending on the soil physical-chemical properties. The use of digestate can therefore represent an interesting strategy for managing the soil fertility in Mediterranean agroecosystem soils, provided that digestate and recipient soil properties are carefully taken into account.
NASA Astrophysics Data System (ADS)
Vyborova, Oxana
2010-05-01
The fertility of soil is a capacity for ensuring plants by water, nutrients, air and capacity for making optimal conditions for growth and development of plants. The result of it is a yield. The main characteristic of fertility of soil is maintenance of humus. The humus is important part of organic matter. The supporting of soil fertility is impossible by traditional methods. The amount of receiving mineral fertilizers in agriculture will not increase in future, because mineral fertilizers are very expensive. The mineral fertilizers don't influence on maintenance of total amount of humus in soil and improve the circulation of nutrients. Every hectare of fields have to receive no less than 8-10 tons of organic fertilizers, therefore we will have self-supporting balance of humus and the fertility of soils will be increasing. Consequently we are looking for new types of organic materials and we include them in modern agro technologies. One of them is an organomineral fertilizer (lignitic materials). The humic chemicals in the form of lignitic materials of natrium, potassium and ammonium are permitted for using them in agriculture at the beginning of 1984. The Department of agriculture in Russian Federation considered the problem of using humic chemicals and made a decision to use them on the fields of our country, because the lignitic materials can restore the fertility of our fields. The lignitic materials increase the amount of spore-forming bacteria, mold fungi and actinomycete. Therefore the organic decomposition occurs more strongly, the processes of humification increase the speed and the amount of humus rises in the soil. The new forming humus has a high biological activity and it improves chemical and physical soil properties. The addition of lignitic materials in soil activates different groups of microorganisms, which influence on mobilization of nutrients and transformation from potential to effective fertility. The inclusion of humic fertilizers improves physical, physicochemical properties of soils, its air, water and thermal rate. Humic acids with mineral and organomineral particles of soil form the soil absorbent complex. The inclusion of humic fertilizers promotes the process when humic substances form a very valuable water-stable clumpy-granular structure, which improves water-carrying and water-holding capacity, its air permeability by agglutination of mineral particles with each other. The soils, where humic fertilizers are carried in soils regularly, are more stable for influence of chemical polluting substances (for example, radioactive nuclides, heavy metals, pesticides) than poor soils. The inclusion of humic fertilizers is very important in period of urbanization and cropping on the plough-lands not far from a big industrial area. The lignitic materials tie together the detrimental compounds formed the insoluble complex in soil solution. The detrimental compounds don't go into plants, subsoil waters and atmosphere. The lignitic watering of soils (in concentration from 0.1 to 0.01%) increases biological activity of soil in a man-caused zones and it promotes to stability of plants to detrimental emission of enterprises. Today the problem of processing of sugar-beet industry is very important. In the result of storing sugar-beet wastes the pollution of environment is occurred, examples of this pollution are gassing, salinization of soils and ground waters by filtrational sediments. One of these wastes is defecation sludge. The defecation sludge consists of CaCO3, organic matter, nitrogen, phosphorus, potassium and microelements. The technology of receiving N-Ca fertilizer based on defecate was developed because of impossibility of using this waste in pure form. For available data, using of these fertilizers improves the soil fertility and degree of pollution by heavy metals don't exceed an acceptance limits.
Almond tree and organic fertilization for soil quality improvement in southern Italy.
Macci, Cristina; Doni, Serena; Peruzzi, Eleonora; Masciandaro, Grazia; Mennone, Carmelo; Ceccanti, Brunello
2012-03-01
The semi-arid Mediterranean region, characterized by long dry periods followed by heavy bursts of rainfall, is particularly prone to soil erosion. The main goal of this study is to evaluate the soil quality under different practices of bio-physical amelioration which involve the soil-plant system (almond trees) and microorganism-manure. This study, carried out in the South of Italy (Basilicata Region- Pantanello farm), considered two types of fertilization (mineral and organic) and three slope gradients (0, 2 and 6%), in order to evaluate the effects of management practices in resisting soil erosion. Chemical (organic carbon and nitrogen), physical (soil shrinkage and bulk density) and biochemical (dehydrogenase activity and hydrolytic enzyme activities) parameters were selected as markers to follow agro-ecological changes with time. The organic treatment affected soil microbiological and physico-chemical properties by increasing soil nutrient availability, microbial activity, and improving soil structure. The consistently higher values of the hydrolytic enzyme activities (β-glucosidase, phosphatase, urease and protease) often observed in the presence of plants and on the 0 and 2% slopes, suggested the stimulation of nutrient cycles by tree roots, which improve the conditions for soil microorganisms in carrying out their metabolic activity. In the 6% slope and, in particular, in the mineral fertilizer treatment, soil metabolism was lower as suggested by the dehydrogenase activity which was 50% lower than that found in the 0 and 2% slopes, this seemed to be related to a slowdown in the nutrient cycling and organic carbon metabolism. However, on this slope, in both mineral and organic treatments, a significant stimulation of hydrolytic enzyme activities and an improvement of soil structure (reduction of bulk density of about 10% and increase in total shrinkage from 20 to 60%) were observed with plants compared to the control soil. The combination of organic fertilization and almond trees resulted effective, also in the highest slope, in mitigating the degradation processes through the improvement of chemico-nutritional, biochemical and physical soil properties. Copyright © 2010 Elsevier Ltd. All rights reserved.
Effect of Soil Washing for Lead and Zinc Removal on Soil Hydraulic Properties
NASA Astrophysics Data System (ADS)
Kammerer, Gerhard; Zupanc, Vesna; Gluhar, Simon; Lestan, Domen
2017-04-01
Soil washing as a metal pollution remediation process, especially part with intensive mixing of the soil slurry and soil compression after de-watering, significantly deteriorates physical properties of soil compared to those of non-remediated soil. Furthermore, changed physical characteristics of remediated soil influence interaction of plant roots with soil system and affect soil water regime. Remediated soils showed significant differences to their original state in water retention properties and changed structure due to the influence of artificial structure created during remediation process. Disturbed and undisturbed soil samples of remediated and original soils were analyzed. We evaluated soil hydraulic properties as a possible constraint for re-establishing soil structure and soil fertility after the remediation procedure.
NASA Astrophysics Data System (ADS)
Li, Haixiao; Mollier, Alain; Ziadi, Noura; Messiga, Aimé Jean; Parent, Leon-Étienne; Morel, Christian
2017-04-01
Plant-available soil phosphorus (P) accumulates primarily in the topsoil due to P fertilization and P released from crop residues. In contrast with conventional tillage (moldboard plough, MP), conservation tillage [e.g. no-till, (NT)] often leads to higher P concentrations in the topsoil mainly due to the absence of mixing between soil, fertilizer, and crop residues. Our objective was to estimate the proportion of P uptake from a given soil mass across the soil profile under maize and soybean as the product of root surface density proportions and local plant-available soil P. This study was conducted on a long-term field experiment initiated in 1992 in southern Quebec, Canada, and established on a clay-loam soil under MP and NT systems. The experiment was factorially treated with three P doses (0, 17.5 and 35 kg P ha-1 applied as triple superphosphate on maize at 5 cm depth and at 5 cm on one side of the crop row). Soil was sampled at flowering stage at five depths (0-5, 5-10, 10-20, 20-30 and 30-40 cm) and three horizontal distances perpendicular to the crop row (5, 15 and 25 cm) in 2014 and 2015 to map a grid soil P availability to plants, e.g. phosphate ion concentrations in solution and the time-dependent amount of phosphate ions that can equilibrate- solution by diffusion, root distribution, and consequently crop P uptake, which was calculated as the fraction of plant-available soil P intercepted by surface roots. In general, NT tended to have higher soil P status in the upper soil layer and lower soil P status in the deeper soil layer compared to MP ; confirming previous results obtained from the same experimental site. This variation along the soil profile was significantly affected by sampling distance to crop row with higher concentration observed at 5-cm distance mainly because of the placement of P fertilizers. The 2D distribution of P uptake depended on tillage practice and P fertilization. There was higher proportions of P uptake from the 0-10 and 0-20 cm layers in NT (46% and 79%, respectively) compared to MP (25% and 68%, respectively). On average 8% of P uptake originated from the 30-40 cm layer irrespective of tillage, indicating that plant P uptake from deeper soil layers also influenced the P cycling in agroecosystems.
Zhang, Xuelin; Wang, Qun; Xu, Jun; Gilliam, Frank S; Tremblay, Nicolas; Li, Chaohai
2015-01-01
Nitrogen (N) fertilization potentially affects soil N mineralization and leaching, and can enhance NH3 volatilization, thus impacting crop production. A fertilizer experiment with five levels of N addition (0, 79, 147, 215 and 375 kg N ha(-1)) was performed in 2009 and 2010 in a maize field in Huanghuaihai region, China, where > 300 kg N ha(-1) has been routinely applied to soil during maize growth period of 120 days. Responses of net N mineralization, inorganic N flux (0-10 cm), NH3 volatilization, and maize yield to N fertilization were measured. During the growth period, net N mineralization and nitrification varied seasonally, with higher rates occurring in August and coinciding with the R1 stage of maize growth. Soil NO3(-)-N contributed to more than 60% of inorganic N flux during maize growth. Cumulative NH3 volatilization increased with N additions, with total NH3 volatilization during maize growth accounting for about 4% of added N. Relative to the control, mean maize yield in the fertilizer treatments increased by 17% and 20% in 2009 and 2010, respectively. However, grain yield, aboveground biomass, and plant N accumulation did not increase with added N at levels > 215 kg N ha(-1). These results suggest that the current N rate of 300 kg N ha(-1) is not only excessive, but also reduces fertilizer efficacy and may contribute to environmental problems such as global warming and eutrophication of ground water and streams.
ERIC Educational Resources Information Center
Farouque, Md. Golam; Takeya, Hiroyuki
2007-01-01
This study aimed to determine farmers' perception of integrated soil fertility and nutrient management for sustainable crop production. Integrated soil fertility (ISF) and nutrient management (NM) is an advanced approach to maintain soil fertility and to enhance crop productivity. A total number of 120 farmers from eight villages in four districts…
Navarrete, Acacio Aparecido; Soares, Tielle; Rossetto, Raffaella; van Veen, Johannes Antonie; Tsai, Siu Mui; Kuramae, Eiko Eurya
2015-09-01
Here we show that verrucomicrobial community structure and abundance are extremely sensitive to changes in chemical factors linked to soil fertility. Terminal restriction fragment length polymorphism fingerprint and real-time quantitative PCR assay were used to analyze changes in verrucomicrobial communities associated with contrasting soil nutrient conditions in tropical regions. In case study Model I ("Slash-and-burn deforestation") the verrucomicrobial community structures revealed disparate patterns in nutrient-enriched soils after slash-and-burn deforestation and natural nutrient-poor soils under an adjacent primary forest in the Amazonia (R = 0.819, P = 0.002). The relative proportion of Verrucomicrobia declined in response to increased soil fertility after slash-and-burn deforestation, accounting on average, for 4 and 2 % of the total bacterial signal, in natural nutrient-poor forest soils and nutrient-enriched deforested soils, respectively. In case study Model II ("Management practices for sugarcane") disparate patterns were revealed in sugarcane rhizosphere sampled on optimal and deficient soil fertility for sugarcane (R = 0.786, P = 0.002). Verrucomicrobial community abundance in sugarcane rhizosphere was negatively correlated with soil fertility, accounting for 2 and 5 % of the total bacterial signal, under optimal and deficient soil fertility conditions for sugarcane, respectively. In nutrient-enriched soils, verrucomicrobial community structures were related to soil factors linked to soil fertility, such as total nitrogen, phosphorus, potassium and sum of bases, i.e., the sum of calcium, magnesium and potassium contents. We conclude that community structure and abundance represent important ecological aspects in soil verrucomicrobial communities for tracking the changes in chemical factors linked to soil fertility under tropical environmental conditions.
Wang, Xin-Xin; Zhao, Fengyan; Zhang, Guoxian; Zhang, Yongyong; Yang, Lijuan
2017-01-01
A greenhouse pot test was conducted to study the impacts of replacing mineral fertilizer with organic fertilizers for one full growing period on soil fertility, tomato yield and quality using soils with different tomato planting history. Four types of fertilization regimes were compared: (1) conventional fertilizer with urea, (2) chicken manure compost, (3) vermicompost, and (4) no fertilizer. The effects on plant growth, yield and fruit quality and soil properties (including microbial biomass carbon and nitrogen, NH4+-N, NO3--N, soil water-soluble organic carbon, soil pH and electrical conductivity) were investigated in samples collected from the experimental soils at different tomato growth stages. The main results showed that: (1) vermicompost and chicken manure compost more effectively promoted plant growth, including stem diameter and plant height compared with other fertilizer treatments, in all three types of soil; (2) vermicompost improved fruit quality in each type of soil, and increased the sugar/acid ratio, and decreased nitrate concentration in fresh fruit compared with the CK treatment; (3) vermicompost led to greater improvements in fruit yield (74%), vitamin C (47%), and soluble sugar (71%) in soils with no tomato planting history compared with those in soils with long tomato planting history; and (4) vermicompost led to greater improvements in soil quality than chicken manure compost, including higher pH (averaged 7.37 vs. averaged 7.23) and lower soil electrical conductivity (averaged 204.1 vs. averaged 234.6 μS/cm) at the end of experiment in each type of soil. We conclude that vermicompost can be recommended as a fertilizer to improve tomato fruit quality and yield and soil quality, particularly for soils with no tomato planting history. PMID:29209343
Wang, Xin-Xin; Zhao, Fengyan; Zhang, Guoxian; Zhang, Yongyong; Yang, Lijuan
2017-01-01
A greenhouse pot test was conducted to study the impacts of replacing mineral fertilizer with organic fertilizers for one full growing period on soil fertility, tomato yield and quality using soils with different tomato planting history. Four types of fertilization regimes were compared: (1) conventional fertilizer with urea, (2) chicken manure compost, (3) vermicompost, and (4) no fertilizer. The effects on plant growth, yield and fruit quality and soil properties (including microbial biomass carbon and nitrogen, [Formula: see text]-N, [Formula: see text]-N, soil water-soluble organic carbon, soil pH and electrical conductivity) were investigated in samples collected from the experimental soils at different tomato growth stages. The main results showed that: (1) vermicompost and chicken manure compost more effectively promoted plant growth, including stem diameter and plant height compared with other fertilizer treatments, in all three types of soil; (2) vermicompost improved fruit quality in each type of soil, and increased the sugar/acid ratio, and decreased nitrate concentration in fresh fruit compared with the CK treatment; (3) vermicompost led to greater improvements in fruit yield (74%), vitamin C (47%), and soluble sugar (71%) in soils with no tomato planting history compared with those in soils with long tomato planting history; and (4) vermicompost led to greater improvements in soil quality than chicken manure compost, including higher pH (averaged 7.37 vs. averaged 7.23) and lower soil electrical conductivity (averaged 204.1 vs. averaged 234.6 μS/cm) at the end of experiment in each type of soil. We conclude that vermicompost can be recommended as a fertilizer to improve tomato fruit quality and yield and soil quality, particularly for soils with no tomato planting history.
Improving Water Use Efficiency of Lettuce (Lactuca sativa L.) Using Phosphorous Fertilizers.
Alkhader, Asad M F; Abu Rayyan, Azmi M
2013-01-01
A greenhouse pot experiment was conducted to evaluate the effect of phosphorous (P) fertilizers application to an alkaline calcareous soil on the water use efficiency (WUE) of lettuce cultivar "robinson" of iceberg type. Head fresh and dry weights, total water applied and WUE were affected significantly by the P fertilizer type and rate. P fertilizers addition induced a significant enhancement in the WUE and fresh and dry weights of the crop. A local phosphate rock (PR) applied directly was found to be inferior to the other types of P fertilizers (Mono ammonium phosphate (MAP), Single superphosphate (SSP), and Di ammonium phosphate ((DAP)). MAP fertilizer at 375 and 500 kg P2O5/ha application rates recorded the highest significant values of head fresh weight and WUE, respectively.
Cheng-Fang, Li; Dan-Na, Zhou; Zhi-Kui, Kou; Zhi-Sheng, Zhang; Jin-Ping, Wang; Ming-Li, Cai; Cou-Gui, Cao
2012-01-01
Quantifying carbon (C) sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT) and no-tillage (NT)] and the application of nitrogen (N) fertilizer (0 and 210 kg N ha(-1)) on fluxes of CH(4) and CO(2), and soil organic C (SOC) sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH(4) emissions by 13%-66% and SOC by 21%-94% irrespective of soil sampling depths, but had no effect on CO(2) emissions in either year. Tillage significantly affected CH(4) and CO(2) emissions, where NT significantly decreased CH(4) emissions by 10%-36% but increased CO(2) emissions by 22%-40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%-48% in the 0-5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0-20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered.
Dou, Xiaolin; He, Ping; Cheng, Xiaoli; Zhou, Wei
2016-01-01
Quantification of dynamics of soil organic carbon (SOC) pools under the influence of long-term fertilization is essential for predicting carbon (C) sequestration. We combined soil chemical fractionation with stable C isotope analyses to investigate the C dynamics of the various SOC pools after 25 years of fertilization. Five types of soil samples (0–20, 20–40 cm) including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, IN; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into recalcitrant and labile fractions, and the fractions were analysed for C content, C:N ratios, δ13C values, soil C and N recalcitrance indexes (RIC and RIN). Chemical fractionation showed long-term MNPK fertilization strongly increased the SOC storage in both soil layers (0–20 cm = 1492.4 gC m2 and 20–40 cm = 1770.6 gC m2) because of enhanced recalcitrant C (RC) and labile C (LC). The 25 years of inorganic fertilizer treatment did not increase the SOC storage mainly because of the offsetting effects of enhanced RC and decreased LC, whereas no clear SOC increases under the SNPK fertilization resulted from the fast decay rates of soil C. PMID:26750143
Wang, Wen Feng; Li, Chun Hua; Huang, Shao Wen; Gao, Wei; Tang, Ji Wei
2016-03-01
A fixed-site greenhouse vegetable fertilization experiment was carried out to study effects of 6 fertilization patterns on soil enzyme activities in Tianjin City, Northern China. The results showed that during the growing stages of tomato, activities of soil α-glucosidase, β-xylosidase, β-glucosidase, β-cellobiosidase, chitinase and phosphatase in different treatments all increased first and then decreased, while soil urease activities increased first and then became flat. Compared with the chemical nitrogen fertilizer treatment, soil enzyme activities were much higher in treatments of combined application of organic materials with chemical fertilizers, and rose with the increasing input of pig manure and especially the application of straw. A significant positive correlation was found between soil enzyme activities, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) contents at different growing stages of tomato. Under the condition of same nutrient input, the combined application of inorganic fertilizers with organic materials, especially a certain amount of corn straw, was capable of increasing soil enzyme activities and keeping soil fertility and sustainability in greenhouse vegetable production.
Perennial crop phase effects on soil fertility
USDA-ARS?s Scientific Manuscript database
There is a need to develop agricultural management systems that enhance soil fertility and reduce reliance on external inputs. Perennial phases in crop rotations are effective at restoring soil fertility, though little information exists in the northern Great Plains regarding soil-based outcomes re...
Fertilization effects on the electrical conductivity measured by EMI, ERT, and GPR
NASA Astrophysics Data System (ADS)
Weihermueller, L.; Kaufmann, M.; Steinberger, P.; Pätzold, S.; Vereecken, H.; Van Der Kruk, J.
2017-12-01
Near surface geophysics such as electromagnetic induction (EMI), electrical resistivity tomography (ERT), and ground penetrating radar (GPR) are widely used for field characterization, to delineate soil units, and to estimate soil texture, bulk densities and/or soil water contents. Hereby, the measured soil apparent conductivity (ECa) is often used. Soil ECa is governed by horizontal and vertical changes in soil texture, mineralogy, soil water content, and temperature, and the single contributions are not easy to disentangle. Within single fields and between fields fertilization management may vary spatially, which holds especially for field trials. As a result, ECa might vary due to differences in electrolyte concentration and subsequent pore fluid conductivity, but secondary fertilization effects might also play a major role in ECa differences such as differences in soil water uptake by growing plants. To study the direct effect of mineral fertilization on ECa, a field experiment was performed on 21 bare soil plots each of a size of 9 m2, where 7 different fertilization treatments were established in triplicates. As mineral fertilizers, commercial calcium ammonium nitrate and potassium chloride were chosen and applied in dosages of 200, 400, and 2000 kg ha-1 N equivalent. Additionally, soil water, soil temperature, and EC were recorded in a pit at different depths using commercial sensors. Changes in ECa were measured every 10 days using EMI and monthly using GPR and ERT. Additionally, soil samples were monthly taken at all plots and nitrate, chloride, and potassium contents were measured in the lab. The poster will show the effect of ECa changes due to fertilization and corresponding leaching of the fertilized elements over time. The experimental results provide information of how fertilization is influencing ECa readings and how long the fertilizers are influencing ECa measurements with geophysical instruments. This study helps to overcome restricted interpretation of ECa measurements on managed agricultural soils.
Silica fractionation and reactivity in soils
NASA Astrophysics Data System (ADS)
Unzué Belmonte, Dácil; Barão, Lúcia; Vandevenne, Floor; Schoelynck, Jonas; Struyf, Eric; Meire, Patrick
2014-05-01
The Si cycle is a globally important biogeochemical cycle, with strong connections to other biogeochemical cycles, including C. Silica is taken up by plants to form protective structures called phytoliths, which become a part of the soil and contribute strongly to soil Si cycling upon litter burial. Different silica fractions are found in soils, with phytoliths among the most easily soluble, especially compared to silicate minerals. A whole set of secondary non-biogenic fractions exist, that also have a high reactivity (adsorbed Si, reactive secondary minerals…). A good characterization of the different fractions of reactive silica is crucial to move forward knowledge on ecosystem Si cycling, which has been recognized in the last decade as crucial for terrestrial Si fluxes. A new method to analyze the different fractions of silica in soils has been described by Koning et al. (2002) and adapted by our research team (Barão et al. 2013). Using a continuous extraction of Si and aluminum in 0.5M NaOH, biogenic and non-biogenic reactive fractions are separated based on their Si/Al ratios and their reactivity in NaOH. Applying this new method I will investigate three emerging ideas on how humans can affect directly terrestrial Si fluxes. -Land use. I expect strong silica fractionation and reactivity differences in different land uses. These effects due to agricultural and forestry management have already been shown earlier in temperate soils (Vandevenne et al. 2012). Now we will test this hypothesis in recently deforested soils, in the south of Brazil. 'Pristine' forest, managed forest and tobacco field soils (with and without rotation crops) will be studied. This research belongs to an interdisciplinary project on soils and global change. -Fire. According to the IPCC report, extreme events such as fires (number and intensity) would increase due to climate change. We analyzed litter from spruce forest, beech forest and peat soils at two burning levels, after 350°C and 550°C burnings. The first results showed differences in silica fractions between treatments and between soil types. This project is a close collaboration with University of Dresden. -Fertilization. Humans use fertilizers to increase crops growth and to avoid plagues affecting soil biogeochemistry. We set up a greenhouse experiment where olivine (a relatively easily weatherable silicate mineral) fertilization is applied to two crops (barley and wheat), at two rain application regimes (daily rain and weekly heavy rain) and with different fertilizer grain sizes. The aim of this project is to investigate how olivine application affects Si fractionation and reactivity in the soil profile. Barão, L., Clymans, W., Vandevenne, F., Meire, P., Conley, D.J. and Struyf, E. Pedogenic and biogenic amorphous Si distribution along a temperate land use gradient. Submitted, European Journal of Soil Science, 2013. Koning, E., Epping, E., and Van Raaphorst, W.: Determining bio- genic silica in marine samples by tracking silicate and aluminium concentrations in alkaline leaching solutions, Aquat. Geochem., 8, 37-67, 2002. Vandevenne, F.I., Struyf, E., Clymans, W. & Meire, P. 2012. Agricultural silica harvest: have humans created a new and important loop in the global silica cycle? Frontiers in Ecology and the Environment 10: 243-248.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Power, J.F.
1981-01-01
Progress is reported in a study designed to evaluate the effects of quantity of crop residues left on soil surface on soil properties, plant growth, and crop yield and to determine the effects of quantity of surface residues upon soil, fertilizer, and residue N transformations, availability, and efficiency of use. In a dryland corn-sorghum-soybean rotation produced on a clay loam, residues remaining after harvest of the previous crop were removed and respread on plots at rates of 0, 0.5, 1.0, and 1.5 times the quantity of residues originally present. The above crops were planted in four replications the following springmore » without tillage, after broadcasting 50 kg N/ha as ammonium nitrate. In 1980, /sup 15/N-depleted NH/sub 4/NO/sub 3/ was applied to half of each plot. After harvest, crop residues produced on the half-plot receiving the N-isotope were transferred to the half-plot receiving regular fertilizer, and visa versa. In 1981, /sup 15/N-depleted NH/sub 4/NO/sub 3/ was applied to half of each plot again, except at right angles to the fertilizer applied in 1980. After planting each year, thermocouples were installed in each plot and soil temperatures were recorded. Also access tubes were installed in all plots and soil water content was measured to the 150 cm soil depth periodically during the growing season. Dry matter production and N uptake by the plant tissue was measured periodically during the growing season and at maturity. Additional measurements taken included leaf area index, xylem water potentials, and soil microbial populations. Data are presented on corn and soybean production characteristics as affected by rate of crop residue on soil surface. Results are also given on leaf area index (LAI) and dry matter production of corn and soybeans as affected by surface residue rate. Total N content of corn and soybean plant materials and surface residues, and total and inorganic soil N (1980) are reported.« less
7 CFR 205.203 - Soil fertility and crop nutrient management practice standard.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 3 2014-01-01 2014-01-01 false Soil fertility and crop nutrient management practice... Requirements § 205.203 Soil fertility and crop nutrient management practice standard. (a) The producer must..., and biological condition of soil and minimize soil erosion. (b) The producer must manage crop...
7 CFR 205.203 - Soil fertility and crop nutrient management practice standard.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 3 2013-01-01 2013-01-01 false Soil fertility and crop nutrient management practice... Requirements § 205.203 Soil fertility and crop nutrient management practice standard. (a) The producer must..., and biological condition of soil and minimize soil erosion. (b) The producer must manage crop...
7 CFR 205.203 - Soil fertility and crop nutrient management practice standard.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 3 2012-01-01 2012-01-01 false Soil fertility and crop nutrient management practice... Requirements § 205.203 Soil fertility and crop nutrient management practice standard. (a) The producer must..., and biological condition of soil and minimize soil erosion. (b) The producer must manage crop...
7 CFR 205.203 - Soil fertility and crop nutrient management practice standard.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 3 2011-01-01 2011-01-01 false Soil fertility and crop nutrient management practice... Requirements § 205.203 Soil fertility and crop nutrient management practice standard. (a) The producer must..., and biological condition of soil and minimize soil erosion. (b) The producer must manage crop...
NASA Astrophysics Data System (ADS)
Schillem, Steffi; Schneider, Bernd-Uwe; Zeihser, Uwe; Hüttl, Reinhard F.
2017-04-01
Land degradation is recognized as the main environmental problem that adversely depletes soil organic carbon (SOC) and nitrogen (SON) stocks, which in turn directly affects the fertility and productivity of soils. Degraded soils and marginal lands are characterized by low fertility, poor physicochemical and biological properties and are almost free of soil organic matter (SOM), limiting their functional properties and, hence, their productivity. To enhance or restore the fertility of these soils, natural soil amendments such as biochar, lignite or humic acids can be added. A greenhouse experiment was carried out to investigate the effect of different application rates (5, 7.5, 11, 15, 28 t ha-1) of N-modified lignite (NL) incorporated in a nutrient-poor sandy soil from a recultivation site on plant growth, water use and nitrogen use efficiency of summer wheat. Additionally activated biochar (BC) was tested to see whether any differences exist between N-modified lignite and activated biochar at the same C-application rates. All variants with soil amendments displayed a much higher grain and straw yield and water use efficiency compared to the control sample. The differences were significant for the 28 t ha-1variant followed by the variant with 5 t ha-1 NL. With the 7.5 t ha-1 NL higher biomasses, water and nitrogen use efficiency could be achieved compared to the variant treated with BC at the same C-content. This study shows that even small amounts of N-modified lignite can increase growth, water and nitrogen use efficiency of summer wheat on marginal lands.
Zhang, Kai; Zheng, Hua; Chen, Falin; Li, Ruida; Yang, Miao; Ouyang, Zhiyun; Lan, Jun; Xiang, Xuewu
2017-01-01
Nitrogen (N) fertilization is necessary to sustain productivity in eucalypt plantations, but it can increase the risk of greenhouse gas emissions. However, the response of soil greenhouse gas emissions to N fertilization might be influenced by soil characteristics, which is of great significance for accurately assessing greenhouse gas budgets and scientific fertilization in plantations. We conducted a two-year N fertilization experiment (control [CK], low N [LN], middle N [MN] and high N [HN] fertilization) in two eucalypt plantations with different soil characteristics (higher and lower soil organic carbon sites [HSOC and LSOC]) in Guangxi, China, and assessed soil-atmosphere greenhouse gas exchanges. The annual mean fluxes of soil CO2, CH4, and N2O were separately 153-266 mg m-2 h-1, -55 --40 μg m-2 h-1, and 11-95 μg m-2 h-1, with CO2 and N2O emissions showing significant seasonal variations. N fertilization significantly increased soil CO2 and N2O emissions and decreased CH4 uptake at both sites. There were significant interactions of N fertilization and SOC level on soil CO2 and N2O emissions. At the LSOC site, the annual mean flux of soil CO2 emission was only significantly higher than the CK treatment in the HN treatment, but, at the HSOC site, the annual mean flux of soil CO2 emission was significantly higher for both the LN (or MN) and HN treatments in comparison to the CK treatment. Under the CK and LN treatments, the annual mean flux of N2O emission was not significantly different between HSOC and LSOC sites, but under the HN treatment, it was significantly higher in the HSOC site than in the LSOC site. Correlation analysis showed that changes in soil CO2 and N2O emissions were significantly related to soil dissolved organic carbon, ammonia, nitrate and pH. Our results suggested significant interactions of N fertilization and soil characteristics existed in soil-atmosphere greenhouse gas exchanges, which should be considered in assessing greenhouse gas budgets and scientific fertilization strategies in eucalypt plantations.
Dong, Wenyi; Zhang, Xinyu; Wang, Huimin; Dai, Xiaoqin; Sun, Xiaomin; Qiu, Weiwen; Yang, Fengting
2012-01-01
Appropriate fertilizer application is an important management practice to improve soil fertility and quality in the red soil regions of China. In the present study, we examined the effects of five fertilization treatments [these were: no fertilizer (CK), rice straw return (SR), chemical fertilizer (NPK), organic manure (OM) and green manure (GM)] on soil pH, soil organic carbon (SOC), total nitrogen (TN), C/N ratio and available nutrients (AN, AP and AK) contents in the plowed layer (0–20 cm) of paddy soil from 1998 to 2009 in Jiangxi Province, southern China. Results showed that the soil pH was the lowest with an average of 5.33 units in CK and was significantly higher in NPK (5.89 units) and OM (5.63 units) treatments (P<0.05). The application of fertilizers have remarkably improved SOC and TN values compared with the CK, Specifically, the OM treatment resulted in the highest SOC and TN concentrations (72.5% and 51.2% higher than CK) and NPK treatment increased the SOC and TN contents by 22.0% and 17.8% compared with CK. The average amounts of C/N ratio ranged from 9.66 to 10.98 in different treatments, and reached the highest in OM treatment (P<0.05). During the experimental period, the average AN and AP contents were highest in OM treatment (about 1.6 and 29.6 times of that in the CK, respectively) and second highest in NPK treatment (about 1.2 and 20.3 times of that in the CK). Unlike AN and AP, the highest value of AK content was observed in NPK treatments with 38.10 mg·kg−1. Thus, these indicated that organic manure should be recommended to improve soil fertility in this region and K fertilizer should be simultaneously applied considering the soil K contents. Considering the long-term fertilizer efficiency, our results also suggest that annual straw returning application could improve soil fertility in this trial region. PMID:23028550
Contamination of soils and groundwater with new organic micropollutants: A review
NASA Astrophysics Data System (ADS)
Vodyanitskii, Yu. N.; Yakovlev, A. S.
2016-05-01
The input of organic micro- and nanopollutants to the environment has grown in recent years. This vast class of substances is referred to as emerging micropollutants, and includes organic chemicals of industrial, agricultural, and municipal provenance. There are three main sources of emerging pollutants coming to the environment, i.e., (1) upon soil fertilization with sewage and sewage sludge; (2) soil irrigation with reclaimed wastewater and (3) due to filtration from municipal landfills of solid wastes. These pollutants contaminate soil, affect its inhabitants; they are also consumed by plants and penetrate to the groundwater. The pharmaceuticals most strongly affect the biota (microorganisms, earthworms, etc.). The response of microorganisms in the contaminated soil is controlled not only by the composition and the number of emerging pollutants but also by the geochemical environment.
Enwall, Karin; Philippot, Laurent; Hallin, Sara
2005-12-01
The objective of this study was to explore the long-term effects of different organic and inorganic fertilizers on activity and composition of the denitrifying and total bacterial communities in arable soil. Soil from the following six treatments was analyzed in an experimental field site established in 1956: cattle manure, sewage sludge, Ca(NO3)2, (NH4)2SO4, and unfertilized and unfertilized bare fallow. All plots but the fallow were planted with corn. The activity was measured in terms of potential denitrification rate and basal soil respiration. The nosZ and narG genes were used as functional markers of the denitrifying community, and the composition was analyzed using denaturing gradient gel electrophoresis of nosZ and restriction fragment length polymorphism of narG, together with cloning and sequencing. A fingerprint of the total bacterial community was assessed by ribosomal intergenic spacer region analysis (RISA). The potential denitrification rates were higher in plots treated with organic fertilizer than in those with only mineral fertilizer. The basal soil respiration rates were positively correlated to soil carbon content, and the highest rates were found in the plots with the addition of sewage sludge. Fingerprints of the nosZ and narG genes, as well as the RISA, showed significant differences in the corresponding communities in the plots treated with (NH4)2SO4 and sewage sludge, which exhibited the lowest pH. In contrast, similar patterns were observed among the other four treatments, unfertilized plots with and without crops and the plots treated with Ca(NO3)2 or with manure. This study shows that the addition of different fertilizers affects both the activity and the composition of the denitrifying communities in arable soil on a long-term basis. However, the treatments in which the denitrifying and bacterial community composition differed the most did not correspond to treatments with the most different activities, showing that potential activity was uncoupled to community composition.
Ganade, G; Brown, V K
1997-02-01
The effects of, and interactions between, insect root feeders, vesicular-arbuscular mycorrhizal fungi and soil fertility on the establishment, growth and reproduction of Vicia sativa and V. hirsuta (Fabaceae) were investigated in an early-successional grassland community. Seeds of both species were sown into plots where soil insecticide (Dursban 5G), soil fungicide (Rovral) and soil fertiliser (NPK) were applied in a factorial randomised block design. Fertiliser addition reduced growth, longevity and reproduction of both Vicia species, due to the commonly recorded increase in the competitive advantage of the non-nitrogen-fixing species when nitrogen is added to the plant community. However, in plots where fertiliser was not applied, a reduction in root feeders and mycorrhizal infection led to an increase in seedling establishment and fruit production of V. sativa, and to an increase in flower production for both Vicia species. The interaction between all three soil treatments explained much of the variation in growth and longevity of V. sativa. Plants grew larger and survived longer in plots where natural levels of mycorrhizal infection and root feeders were low compared with plots where all the treatments were applied. This suggests that, although soil nutrient availability was a strong determinant of the performance of these two leguminous species, at natural levels of soil fertility biotic factors acting in the soil, such as mycorrhizal fungi and soil-dwelling insects, were important in shaping the competitive interactions between the two Vicia species and the plant community. Our results indicate that non-additive interactions between ecological factors in the soil environment may strongly affect plant performance.
Mayor, A G; Valdecantos, A; Vallejo, V R; Keizer, J J; Bloem, J; Baeza, J; González-Pelayo, O; Machado, A I; de Ruiter, P C
2016-12-15
Since the mid of the last century, fire recurrence has increased in the Iberian Peninsula and in the overall Mediterranean basin due to changes in land use and climate. The warmer and drier climate projected for this region will further increase the risk of wildfire occurrence and recurrence. Although the impact of wildfires on soil nutrient content in this region has been extensively studied, still few works have assessed this impact on the basis of fire recurrence. This study assesses the changes in soil organic C and nutrient status of mineral soils in two Southern European areas, Várzea (Northern Portugal) and Valencia (Eastern Spain), affected by different levels of fire recurrence and where short fire intervals have promoted a transition from pine woodlands to shrublands. At the short-term (<1year), the amount of soil organic matter was higher in burned than in unburned soils while its quality (represented as labile to total organic matter) was actually lower. In any case, total and labile soil organic matter showed decreasing trends with increasing fire recurrence (one to four fires). At the long-term (>5years), a decline in overall soil fertility with fire recurrence was also observed, with a drop between pine woodlands (one fire) and shrublands (two and three fires), particularly in the soil microsites between shrubs. Our results suggest that the current trend of increasing fire recurrence in Southern Europe may result in losses or alterations of soil organic matter, particularly when fire promotes a transition from pine woodland to shrubland. The results also point to labile organic matter fractions in the intershrub spaces as potential early warning indicators for shifts in soil fertility in response to fire recurrence. Copyright © 2016 Elsevier B.V. All rights reserved.
Arctic Tundra Soils: A Microbial Feast That Shrubs Will Cease
NASA Astrophysics Data System (ADS)
Machmuller, M.; Calderon, F.; Cotrufo, M. F.; Lynch, L.; Paul, E. A.; Wallenstein, M. D.
2016-12-01
Rapid climate warming may already be driving rapid decomposition of the vast stocks of carbon in Arctic tundra soils. However, stimulated decomposition may also release nitrogen and support increased plant productivity, potentially counteracting soil carbon losses. At the same time, these two processes interact, with plant derived carbon potentially fueling soil microbes to attack soil organic matter (SOM) to acquire nitrogen- a process known as priming. Thus, differences in the physiology, stoichiometry and microbial interactions among plant species could affect climate-carbon feedbacks. To reconcile these interactive mechanisms, we examined how vegetation type (Betula nana and Eriophorum vaginatum) and fertilization (short-term and long-term) influenced the decomposition of native SOM after labile carbon and nutrient addition. We hypothesized that labile carbon inputs would stimulate the loss of native SOM, but the magnitude of this effect would be indirectly related to soil nitrogen concentrations (e.g. SOM priming would be highest in N-limited soils). We added isotopically enriched (13C) glucose and ammonium nitrate to soils under shrub (B. nana) and tussock (E. vaginatum) vegetation. We found that nitrogen additions stimulated priming only in tussock soils, characterized by lower nutrient concentrations and microbial biomass (p<0.05). There was no evidence of priming in soils that had been fertilized for >20yrs. Rather, we found that long-term fertilization shifted SOM chemistry towards a greater abundance of recalcitrant SOM, lower microbial biomass, and decreased SOM respiration (p<0.05). Our results suggest that, in the short-term, the magnitude of SOM priming is dependent on vegetation and soil nitrogen concentrations, but this effect may not persist if shrubs increase in abundance under climate warming. Therefore, including nitrogen as a control on SOM decomposition and priming is critical to accurately model the effects of climate change on arctic carbon storage.
Rahman, M Mizanur; Shan, Jun; Yang, Pinpin; Shang, Xiaoxia; Xia, Yongqiu; Yan, Xiaoyuan
2018-05-09
Previous studies of long-term manure applications in paddy soil mostly focused on the effects on denitrification, occurrence of antibiotics and antibiotic resistance genes (ARGs) without considering the effects on anaerobic ammonium oxidation (anammox). Here, we investigated the potential rates of anammox and denitrification, occurrence of antibiotics and AGRs in response to three fertilization regimes (C, no fertilizer; N, mineral fertilizer; and NM, N plus pig manure) in six long-term paddy experiment sites across China. The potential rates of anammox (0.11-3.64 nmol N g -1 h -1 ) and denitrification (1.5-29.05 nmol N g -1 h -1 ) were correlated with the abundance of anammox genes (hzsB) and denitrification functional genes (narG, nirK, nirS and nosZ), respectively. The anammox and denitrification rates were affected by soil organic carbon (SOC) and significantly (p < 0.05) increased in NM treatments relative to those in N treatments. Although pig manure application increased antibiotic concentrations and abundance of ARGs compared with N treatments, the increased antibiotics did not directly affect the anammox and denitrification rates. Our results suggested that long-term pig manure application significantly increased antibiotic concentrations, abundance of ARGs, and rates of anammox and denitrification, and that the effects of pig manure-derived antibiotics on anammox and denitrification were marginal. This is the first report that investigates the effects of long-term pig manure application on anammox in paddy soils. More attention should be paid to the potential ecological risk of increased ARGs caused by pig manure application in paddy soils. Copyright © 2018 Elsevier Ltd. All rights reserved.
Fujita, Yuki; van Bodegom, Peter M; Witte, Jan-Philip M
2013-01-01
Soil fertility and nutrient-related plant functional traits are in general only moderately related, hindering the progress in trait-based prediction models of vegetation patterns. Although the relationships may have been obscured by suboptimal choices in how soil fertility is expressed, there has never been a systematic investigation into the suitability of fertility measures. This study, therefore, examined the effect of different soil fertility measures on the strength of fertility-trait relationships in 134 natural plant communities. In particular, for eight plot-mean traits we examined (1) whether different elements (N or P) have contrasting or shared influences, (2) which timescale of fertility measures (e.g. mineralization rates for one or five years) has better predictive power, and (3) if integrated fertility measures explain trait variation better than individual fertility measures. Soil N and P had large mutual effects on leaf nutrient concentrations, whereas they had element-specific effects on traits related to species composition (e.g. Grime's CSR strategy). The timescale of fertility measures only had a minor impact on fertility-trait relationships. Two integrated fertility measures (one reflecting overall fertility, another relative availability of soil N and P) were related significantly to most plant traits, but were not better in explaining trait variation than individual fertility measures. Using all fertility measures together, between-site variations of plant traits were explained only moderately for some traits (e.g. 33% for leaf N concentrations) but largely for others (e.g. 66% for whole-canopy P concentration). The moderate relationships were probably due to complex regulation mechanisms of fertility on traits, rather than to a wrong choice of fertility measures. We identified both mutual (i.e. shared) and divergent (i.e. element-specific and stoichiometric) effects of soil N and P on traits, implying the importance of explicitly considering the roles of different elements to properly interpret fertility-trait relationships.
Effect of different fertilization measures on soil CO2 emissions of spring corn in Northeast China
NASA Astrophysics Data System (ADS)
Xu, Shicai; Qiao, Shaoqing
2018-04-01
To research the sustainability of efficient utilization approaches and modes of nitrogen in spring corns. Taking different fertilization measures to research the influence on soil respiration and microbial biomass carbon and nitrogen; the experiment takes the spring corns and black soil of Harbin in Northeast China as research objects. It researches the influence of 4 different fertilization measures by using field long-term located experiment on soil respiration of the spring corns and analyzes the yield. The four measures are as follows: farmer's fertilization practice FP; Tl mode of decreasing 20% of nitrogenous fertilizer on the basis of FP; T2 mode of 20% of Tl nitrogenous fertilizer replaced by organic fertilizer and other 20% replaced by slow-release nitrogen fertilizer; T3 mode of adding 2t/hm2 of corn stalk carbon on the basis of T2. There are significant differences of CO2 emission flux in spring corn soil with four fertilization measures (P<0.05). The rank of CO2 emission flux is: T3>Tl>T2>FP and the yield rank of spring corns is: T3>T2>Tl>FP. (1) The rational nitrogen-decrease fertilization measure has no obvious influence on spring corn yield and the replacement of organic fertilizer and slow-release nitrogen fertilizer and the addition of active carbon can improve the spring corn yield. (2) Utilization of organic fertilizer can accelerate the emission of CO2 from the soil. (3) Addition of biological carbon can promote the emission of CO2 from soil during the growing period of spring corns.
[Effects of alkaline fertilizer on cadmium content in rice and paddy soil.
Zhang, Liang Liang; Fan, Xiao Lin; Zhang, Li Dan; Liu, Fang
2016-03-01
A field plot trial was conducted at Songbai Village, Chenzhou, Hunan Province to exa-mine the effects of alkaline fertilizer with and without combination application of bacterial regent on cadmium accumulation in rice and paddy soil. Compared with the conventional fertilizer, the alkaline fertilizer reduced the available cadmium content in soil at the tillering, filling and the harvest stages by 8.3%, 6.7% and 16.4% respectively. Compared with the Cd content in soil before transplanting, it was reduced by 7.2% at harvest time in alkaline fertilizer treatment, while increased by 11.0% in the conventional fertilizer treatment. The available cadmium content in soil was increased by 1.2% to 23.3% by bacterial regent. Compared with the conventional fertilizer, the cadmium content of root, stem sheath, leaf, grain and brown rice of the alkaline fertilizer treatment reduced by 54.9%, 56.6%, 41.8%, 62.7% and 67.6% respectively. The alkaline fertilizer treatment combined with bacterial regent increased the cadmium content of brown rice by 63.2%. It was concluded that the alkaline fertilizer could significantly reduce the available cadmium content in both soil and the different organs of the rice, however, when it was combined with bacterial regent together, the effect of alkaline fertilizer to reduce Cd content of brown rice would be declined.
Connections Between Soil Fertility Declines, Land Use, Ethnicity, Education, and Wealth In Uganda
NASA Astrophysics Data System (ADS)
Tiemann, L. K.; Hartter, J.; Grandy, S.
2016-12-01
Food security issues are particularly acute in Uganda, where the world's 8th highest population growth rate will lead to cultivation of all land available for agriculture by 2022. Agricultural intensification in Uganda, which includes continuous cropping, mono-cropping and expansion of agriculture into marginal areas, has put unprecedented pressure on soils. In western Uganda, we surveyed 474 households, collecting demographic data, information on land use practices and perceptions of risk to crop yields and food security. We also sampled soils from maize fields associated with each surveyed household and measured total organic C and nutrients such as nitrogen (N) and phosphorus (P). Using these data, we sought to determine how risk perceptions, ethnicity, household wealth and education combine to determine land use decisions and ultimately, declines in soil organic matter and soil nutrients. We conducted our study within 5 km of an un-cultivated native tropical forest reserve, Kibale National Park (KNP), which serves as a reference point for potential soil fertility. Of 470 respondents, only 29 answered `no' when asked if they noticed year to year declines in crop yields. Across all maize fields we found soil C has been reduced by 30% and soil N by 45% relative to KNP soils and declines were more pronounced when survey respondents were Bakiga rather than Batooro. Households that indicated they were "very much" dependent upon profits from maize had a 31% increase in soil C:N while those indicating no dependence on maize profits had a significantly lower increase in soil C:N of 21%. Ethnicity and education influenced land use decisions; the Batooro and people with a lower level of education were more likely to burn their fields or crop residues. Additionally, the Bakiga were more likely to use rock P in their fields and in consequence had 108% while Batooro soils had 65% of the P found in KNP soils. Across all respondents, the top two ranked risks to crop yields and food security were weather related, with soil fertility ranked third on average, regardless of ethnicity, education or wealth. While crop yields are being noticeably affected by declining soil organic matter and soil nutrients, in particular soil N, people in this region continue to be worried more about changing weather patterns than soil fertility.
Liu, Peng; Jia, Shuyu; He, Xiwei; Zhang, Xuxiang; Ye, Lin
2017-12-01
Both manure and chemical fertilizers are widely used in modern agriculture. However, the impacts of different fertilizers on bacterial community structure and antibiotic resistance genes (ARGs) in arable soils still remain unclear. In this study, high-throughput sequencing and quantitative PCR were employed to investigate the bacterial community structure, ARGs and mobile genetic elements (MGEs) influenced by the application of different fertilizers, including chemical fertilizers, piggery manure and straw ash. The results showed that the application of fertilizers could significantly change the soil bacterial community and the abundance of Gaiella under phylum Actinobacteria was significantly reduced from 12.9% in unfertilized soil to 4.1%-7.4% in fertilized soil (P < 0.05). It was also found that the application of manure could cause a transient effect on soil resistome composition and the relative abundance of ARGs increased from 7.37 ppm to 32.10 ppm. The abundance of aminoglycoside, sulfonamide and tetracycline resistance genes greatly increased after manure fertilization and then gradually returned to normal levels with the decay of some intestinal bacteria carrying ARGs. In contrast, the application of chemical fertilizers and straw ash significantly changed the bacterial community structure but exerted little effect on soil resistome. Overall, the results of this study illustrated the different effects of different fertilizers on the soil resistome and revealed that the changes of soil resistome induced by manure application mainly resulted from alteration of bacteria community rather than the horizontal gene transfer. Copyright © 2017 Elsevier Ltd. All rights reserved.
Zhang, Lili; Chen, Wei; Burger, Martin; Yang, Lijie; Gong, Ping; Wu, Zhijie
2015-01-01
In order to discover the advantages and disadvantages of different fertilization regimes and identify the best management practice of fertilization in greenhouse fields, soil enzyme activities involved in carbon (C) transformations, soil chemical characteristics, and crop yields were monitored after long-term (20-year) fertilization regimes, including no fertilizer (CK), 300 kg N ha-1 and 600 kg N ha-1 as urea (N1 and N2), 75 Mg ha-1 horse manure compost (M), and M with either 300 or 600 kg N ha-1 urea (MN1 and MN2). Compared with CK, fertilization increased crop yields by 31% (N2) to 69% (MN1). However, compared with CK, inorganic fertilization (especially N2) also caused soil acidification and salinization. In the N2 treatment, soil total organic carbon (TOC) decreased from 14.1±0.27 g kg-1 at the beginning of the long-term experiment in 1988 to 12.6±0.11 g kg-1 (P<0.05). Compared to CK, N1 and N2 exhibited higher soil α-galactosidase and β-galactosidase activities, but lower soil α-glucosidase and β-glucosidase activities (P<0.05), indicating that inorganic fertilization had different impacts on these C transformation enzymes. Compared with CK, the M, MN1 and MN2 treatments exhibited higher enzyme activities, soil TOC, total nitrogen, dissolved organic C, and microbial biomass C and N. The fertilization regime of the MN1 treatment was identified as optimal because it produced the highest yields and increased soil quality, ensuring sustainability. The results suggest that inorganic fertilizer alone, especially in high amounts, in greenhouse fields is detrimental to soil quality. PMID:25706998
Cadmium and zinc in soil solution extracts following the application of phosphate fertilizers.
Lambert, Raphaël; Grant, Cynthia; Sauvé, Sébastien
2007-06-01
This study investigated the solubility of cadmium and zinc in soils after the application of phosphate fertilizers containing those two metals. The solubility of cadmium and zinc was assessed by measuring their concentration in soil water extracts. Three monoammonium phosphate fertilizers containing various amounts of metals were applied on cultivated fields for 3 years at three different rates. In order to investigate the effects of long-term applications of fertilizers on the solubility of Cd and Zn, a similar design was used to apply contaminated fertilizers to soils in a laboratory experiment using a single fertilizer addition equivalent to 15 years of application. Phosphate fertilizers increased the concentration of Cd in soil extracts compared to control in 87% and 80% of the treatments in field and laboratory experiments respectively. Both increasing the rate of application and using fertilizer containing more Cd lead to higher Cd concentrations in extracts for the field and the laboratory experiments. The addition of the equivalent of 15 years of fertilizer application in the laboratory results in higher Cd concentration in extracts compared to the field experiment. For Zn, the fertilizer treatments enhanced the metal solution concentration in 83% of field treatments, but no significant correlations could be found between Zn inputs and its concentration in solution. In the laboratory, fertilizer additions increase the Zn concentrations in 53% of the treatments and decrease it in most of the other treatments. The decrease in Zn concentrations in the laboratory trial is attributed to the higher phosphate concentrations in the soil solution; which is presumed to have contributed to the precipitation of Zn-phosphates. For both trials, the metal concentrations in soil extracts cannot be related to the Zn concentration in the fertilizer or the rate of application. The high Zn to Cd ratio is presumably responsible for the Cd increase in the soil extracts due to competitive displacement by Zn. Finally, the observed acidification of soils with fertilizer application will also contribute to metal solubilisation.
[Changes of diversity and composition of fungal communities in rhizosphere of Panax ginseng].
Dong, Lin-Lin; Niu, Wei-Hao; Wang, Rui; Xu, Jiang; Zhang, Lian-Juan; Zhang, Jun; Chen, Shi-Lin
2017-02-01
Continuous cropping obstacles resulted in the yield losses of Panax ginseng, and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process, and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method, stated the effects of ginseng cultivation on the micro-ecology, and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils, the fungal diversity of ginseng rhizosphere soils was increased, and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes, Alatospora, Eurotiomycetes, Leotiomycetes, Saccharomycetes, Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson's correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes, Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng, and optimization of fertilization system was an effective method to overcome continuous cropping obstacles. Copyright© by the Chinese Pharmaceutical Association.
Aqueous and gaseous nitrogen losses induced by fertilizer application
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gu, C.; Maggi, F.; Riley, W.J.
2009-01-15
In recent years concern has grown over the contribution of nitrogen (N) fertilizer use to nitrate (NO{sub 3}{sup -}) water pollution and nitrous oxide (N{sub 2}O), nitric oxide (NO), and ammonia (NH{sub 3}) atmospheric pollution. Characterizing soil N effluxes is essential in developing a strategy to mitigate N leaching and emissions to the atmosphere. In this paper, a previously described and tested mechanistic N cycle model (TOUGHREACT-N) was successfully tested against additional observations of soil pH and N{sub 2}O emissions after fertilization and irrigation, and before plant emergence. We used TOUGHREACT-N to explain the significantly different N gas emissions andmore » nitrate leaching rates resulting from the different N fertilizer types, application methods, and soil properties. The N{sub 2}O emissions from NH{sub 4}{sup +}-N fertilizer were higher than from urea and NO{sub 3}{sup -}-N fertilizers in coarse-textured soils. This difference increased with decreases in fertilization application rate and increases in soil buffering capacity. In contrast to methods used to estimate global terrestrial gas emissions, we found strongly non-linear N{sub 2}O emissions as a function of fertilizer application rate and soil calcite content. Speciation of predicted gas N flux into N{sub 2}O and N{sub 2} depended on pH, fertilizer form, and soil properties. Our results highlighted the need to derive emission and leaching factors that account for fertilizer type, application method, and soil properties.« less
NASA Astrophysics Data System (ADS)
Xu, Y. H.; Wang, Z. H.; Xiong, B.; Qiu, X.; Liao, L.; Shun, G. C.; Huang, S. J.; Dong, Z. X.; Liu, X. Y.; Xi, L. J.
2017-08-01
The research is done on the Huangguogan (unique citrus breed in Sichuan, China). The experiment setted 27 groups of “Baoshiling” (self-study compound fertilizer) fertilization treatment to explore the “Baoshiling” different combinations on soil physical and chemical properties of Huangguogan. The results showed that all the combinations had improved the soil of Huangguogan orchard. The combination of A3B2C2 had the best effect. The best Fertilization management measures was “Baoshiling” bud flowering fertilizer 2kg, stable fruit fertilizer 2kg, strong fruit fertilizer 2kg. It could reduce the pH of soil and the bulk density of soil, increase the available nitrogen, available phosphorus, available potassium and urease activity.
K P, Sangeeth; R, Suseela Bhai
2016-05-01
Integrated Plant Nutrition System (IPNS) as a concept and farm management strategy embraces and transcends from single season crop fertilization efforts to planning and management of plant nutrients in crop rotations and farming systems on a long-term basis for enhanced productivity, profitability and sustainability. It is estimated that about two-thirds of the required increase in crop production in developing countries will have to come from yield increases from lands already under cultivation. IPNS enhances soil productivity through a balanced use of soil nutrients, chemical fertilizers, combined with organic sources of plant nutrients, including bio-inoculants and nutrient transfer through agro-forestry systems and has adaptation to farming systems in both irrigated and rainfed agriculture. Horticultural crops, mainly plantation crops, management practices include application of fertilizers and pesticides which become inevitable due to the depletion of soil organic matter and incidence of pests and diseases. The extensive use of chemical fertilizers in these crops deteriorated soil health that in turn affected the productivity. To revitalize soil health and to enhance productivity, it is inexorable to enrich the soil using microorganisms. The lacunae observed here is the lack of exploitation of indigenous microbes having the potential to fix atmospheric nitrogen (N) and to solubilize Phosphorus (P) and Potassium (K). The concept of biofertilizer application appears to be technically simple and financially feasible, but the task of developing biofertilizers with efficient strains in appropriate combinations in a consortia mode is not easier. More than developing consortia, a suitable delivery system to discharge the microbial inoculants warranted much effort. This review focuses on the integrated plant nutrition system incorporating biofertilizer with special emphasis on developing and formulating biofertilizer consortium.
Nogueira, Thiago Assis Rodrigues; Franco, Ademir; He, Zhenli; Braga, Vivian Santoro; Firme, Lucia Pittol; Abreu, Cassio Hamilton
2013-01-15
A field experiment was carried out to study the effect of application rates of sewage sludge and mineral nitrogen and phosphate fertilizers on As, Ba, Cd, Cr, Cu, Ni, Pb, Se, and Zn concentration in soil, cane plant, and first ratoon (residual effect) in a Typic Hapludult soil. To allow an analysis by means of response surface modeling, four rates of sewage sludge (0, 3.6, 7.2 and 10.8 t ha(-1), dry base), of N (0, 30, 60 and 90 kg ha(-1)) and of P(2)O(5) (0, 60, 120 and 180 kg ha(-1)) were applied in randomized block design, in a 4 × 4 × 4 factorial scheme, with confounded degrees of freedom for triple interaction, with two replications. To evaluate the residual effect of the sludge applied to cane plant on the cane ratoon growth, mineral NK fertilizers were applied at the rates of 120 kg ha(-1) N and 140 kg ha(-1) of K(2)O, on all treatments. The application rates of mineral nitrogen and phosphate fertilizers did not affect statistically the heavy metal concentration in the soil and in the sugarcane plants. Sewage sludge application increased As, Cd, Cu, Ni, Pb, and Zn concentrations in soil, but values did not exceed the quality standard established by legislation for agricultural soils. Although the concentrations of metals in the plants were very low, the uptake of heavy metal by sugarcane plants was generally increased by sewage sludge doses. The use of sewage sludge based on N criteria introduces a small amount of heavy metal into the agricultural system, however it poses no hazard to the environment. Copyright © 2012 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Severus Sandor, Mignon; Sandor, Valentina; Mihai Onica, Bogdan; Brad, Traian
2017-04-01
The use of nitrogen inputs to improve agricultural soils fertility is a common practice in arable lands. Depending of nitrogen forms only a part of introduced nitrogen will be effectively used by the crops while another part can be leached from soil with negative impact on the environment. In temperate climate these losses are greater during spring time when rains are frequent and crop plants are in the early growth stage. In a microcosm experiments we simulated this kind of conditions in order to assess nitrogen losses from two different soils (Chernozem, Luvisol) fertilized with mineral (ammonium nitrate) and organic (mustard as green manure, slurry manure and cattle manure) fertilizers. From each microcosms we obtained 100 ml of leachate which was filtered and analyzed from N-NO3 and N-NH4. The leachate was obtained by adding distillate water at the microcosm surface two times during the experiment at a ten days interval. Preliminary results showed that only small quantity of ammonium was leached from fertilized soils, mainly after 20 days of incubation. These amounts were higher in Chernozem soil than in Luvisol and registered the highest amount in cattle manure fertilized soils. In general, the nitrate was leached from soils in high quantities. The highest value was measured in Chernozem soil when cattle manure was used as fertilizer (1200 mg/l) and represents a cumulative amount. For most of the treatments the cumulative loss of nitrate nitrogen was double in Chernozem soil than in Luvisol. The highest quantity of leaching nitrate was measured for both soils in manure fertilized soil.
Zhang, Wei; Liu, Man-Qiang; He, Yuan-Qiu; Fan, Jian-Bo; Chen, Yan
2014-08-01
Soil biota plays a key role in ecosystem functioning of red soil. Based on the long-term inorganic fertilization field experiment (25-year) in an upland red soil, the impacts of different inorganic fertilization managements, including NPK (nitrogen, phosphorus and potassium fertilizers), NPKCaS (NPK plus gypsum fertilizers), NP (nitrogen and phosphorus fertilizers), NK (nitrogen and potassium fertilizers) and PK (phosphorus and potassium fertilizers), on the assemblage of soil nematodes during the growing period of peanut were investigated. Significant differences among the treatments were observed for total nematode abundance, trophic groups and ecological indices (P < 0.01). The total nematode abundance decreased in the order of PK > NPKCaS > NPK > NP > NK. The total number of nematodes was significantly higher in NPKCaS and PK than in NPK, NP and NK except in May. Plant parasitic nematodes were the dominant trophic group in all treatments excepted in NPKCaS, and their proportion ranged between 38% and 65%. The dominant trophic group in NPKCaS was bacterivores and represented 42.1%. Furthermore, the higher values of maturity index, Wasilewska index and structure index in NPKCaS indicated that the combined application of NPK and gypsum could remarkably relieve soil acidification, resulting in a more mature and stable soil food web structure. While, that of the NK had the opposite effect. In conclusion, our study suggested that the application of both gypsum and phosphate is an effective practice to improve soil quality. Moreover, the analysis of nematode assemblage is relevant to reflect the impact of different inorganic fertilizer on the red soil ecosystem.
Tully, Katherine L; Hickman, Jonathan; McKenna, Madeline; Neill, Christopher; Palm, Cheryl A
2016-09-01
Fertilizer applications are poised to increase across sub-Saharan Africa (SSA), but the fate of added nitrogen (N) is largely unknown. We measured vertical distributions and temporal variations of soil inorganic N following fertilizer application in two maize (Zea mays L.)-growing regions of contrasting soil type. Fertilizer trials were established on a clayey soil in Yala, Kenya, and on a sandy soil in Tumbi, Tanzania, with application rates of 0-200 kg N/ha/yr. Soil profiles were collected (0-400 cm) annually (for three years in Yala and two years in Tumbi) to examine changes in inorganic N pools. Topsoils (0-15 cm) were collected every 3-6 weeks to determine how precipitation and fertilizer management influenced plant-available soil N. Fertilizer management altered soil inorganic N, and there were large differences between sites that were consistent with differences in soil texture. Initial soil N pools were larger in Yala than Tumbi (240 vs. 79 kg/ha). Inorganic N pools did not change in Yala (277 kg/ha), but increased fourfold after cultivation and fertilization in Tumbi (371 kg/ha). Intra-annual variability in NO - 3 -N concentrations (3-33 μg/g) in Tumbi topsoils strongly suggested that the sandier soils were prone to high leaching losses. Information on soil inorganic N pools and movement through soil profiles can h vulnerability of SSA croplands to N losses and determine best fertilizer management practices as N application rates increase. A better understanding of the vertical and temporal patterns of soil N pools improves our ability to predict the potential environmental effects of a dramatic increase in fertilizer application rates that will accompany the intensification of African croplands. © 2016 by the Ecological Society of America.
Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare
2014-01-01
Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50–80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies. PMID:24497947
Organic fertilization for soil improvement in a vegetable cropping system
NASA Astrophysics Data System (ADS)
Verhaeghe, Micheline; De Rocker, Erwin; De Reycke, Luc
2016-04-01
Vegetable Research Centre East-Flanders Karreweg 6, 9770 Kruishoutem, Belgium A long term trial for soil improvement by organic fertilization was carried out in Kruishoutem from 2001 till 2010 in a vegetable rotation (carrots - leek - lettuce (2/year) - cauliflower (2/year) - leek - carrots - lettuce (2/year) - cauliflower (2/year) - leek and spinach). The trial compared yearly applications of 30 m²/ha of three types of compost (green compost, vfg-compost and spent mushroom compost) with an untreated object which did not receive any organic fertilization during the trial timescale. The organic fertilization was applied shortly before the cropping season. Looking at the soil quality, effects of organic fertilization manifest rather slow. The first four years after the beginning of the trial, no increase in carbon content of the soil is detectable yet. Although, mineralization of the soil has increased. The effect on the mineralization is mainly visible in crops with a lower N uptake (e.g. carrots) leading to a higher nitrate residue after harvest. Effects on soil structure and compaction occur rather slowly although, during the first two cropping seasons compost applications increase the water retention capacity of the soil. Compost increases the pH of the soil from the first year on till the end of the trial in 2010. Thus, organic fertilization impedes acidification in light sandy soils. Also soil fertility benefits from compost by an increase in K-, Ca- and Mg- content in the soil from the second year on. After 10 years of organic fertilization, yield and quality of spinach were increased significantly (p<0.05) compared to the untreated object. Also leek (2002 and 2009) and lettuce (2003 and 2007) benefit from organic fertilization.
Wu, Jun; Wu, Minjie; Li, Chunping; Yu, Guanghui
2014-01-01
The binding characteristics of organic ligands and minerals in fulvic acids (FAs) with Al are essential for understanding soil C sequestration, remain poorly understood. In this study, Fourier transform infrared (FTIR) spectroscopy combined with two-dimensional correlation spectroscopy (2DCOS) analysis was applied for the first time to explore the binding of Al with organic ligands and minerals in soil FAs. For these analyses, two contrasting treatments were selected from a long-term (i.e., 22-year) fertilization experiment: chemical (NPK) fertilization and swine manure (SM) fertilization. The results showed that the long-term application of organic and inorganic fertilizers to soils had little effect on the compositions of the fluorescent substances and organic ligands in the soil FAs. However, long-term SM fertilization increased the weathered Al and Si concentrations in the soil FAs compared with long-term chemical fertilization. Furthermore, organic ligands in the soil FAs were mainly bound with Al in the NPK treatment, whereas both organic ligands and minerals (Al-O-Si, Si-O) were bound with Al under the M fertilization conditions. Both transmission electron microscopy (TEM) images and X-ray diffraction spectra demonstrated that amorphous and short-range-ordered nanominerals were abundant in the soil FAs from the SM plot in contrast to the soil FAs from the NPK plot. This result illustrates the role nanominerals play in the preservation of soil FAs by during long-term organic fertilization. In summary, the combination of FTIR and 2D correlation spectroscopy is a promising approach for the characterization of the binding capability between soil FAs and Al, and a better understanding FA-Al binding capability will greatly contribute to global C cycling. PMID:25137372
Bi, Qing-Fang; Chen, Qiu-Hui; Yang, Xiao-Ru; Li, Hu; Zheng, Bang-Xiao; Zhou, Wei-Wei; Liu, Xiao-Xia; Dai, Pei-Bin; Li, Ke-Jie; Lin, Xian-Yong
2017-11-07
Soil amended with single biochar or nitrogen (N) fertilizer has frequently been reported to alter soil nitrification process due to its impact on soil properties. However, little is known about the dynamic response of nitrification and ammonia-oxidizers to the combined application of biochar and N fertilizer in intensive vegetable soil. In this study, an incubation experiment was designed to evaluate the effects of biochar and N fertilizer application on soil nitrification, abundance and community shifts of ammonia-oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) in Hangzhou greenhouse vegetable soil. Results showed that single application of biochar had no significant effect on soil net nitrification rates and ammonia-oxidizers. Conversely, the application of only N fertilizer and N fertilizer + biochar significantly increased net nitrification rate and the abundance of AOB rather than AOA, and only AOB abundance was significantly correlated with soil net nitrification rate. Moreover, the combined application of N fertilizer and biochar had greater effect on AOB communities than that of the only N fertilizers, and the relative abundance of 156 bp T-RF (Nitrosospira cluster 3c) decreased but 60 bp T-RF (Nitrosospira cluster 3a and cluster 0) increased to become a single predominant group. Phylogenetic analysis indicated that all the AOB sequences were grouped into Nitrosospira cluster, and most of AOA sequences were clustered within group 1.1b. We concluded that soil nitrification was stimulated by the combined application of N fertilizer and biochar via enhancing the abundance and shifting the community composition of AOB rather than AOA in intensive vegetable soil.
Spectroscopic analyses of soil samples outside Nile Delta of Egypt
NASA Astrophysics Data System (ADS)
Fakhry, Ahmed; Osman, Osama; Ezzat, Hend; Ibrahim, Medhat
2016-11-01
Soil in Egypt, especially around Delta is exposed to various pollutants which are affecting adversely soil fertility and stability. Humic Acids (HA) as a main part of soil organic matter (SOM) represent the heart of the interaction process of inorganic pollutants with soil. Consequently, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonances (NMR) were used to characterize soil, sediment and extracted HA. Resulting data confirmed that the HA was responsible for transporting inorganic pollutants from surface to subsurface reaching the ground water, which may represent a high risk on public health. The transport process is coming as carboxyl in surface soil changed into metal carboxylate then transferred into the carboxyl in bottom soil.
USDA-ARS?s Scientific Manuscript database
Fast pyrolysis of switchgrass (and resultant biochar) can be used for bio-fuel production, soil amendments for fertilizing crops, binding heavy metals, and sequestering environmental biocarbon. To determine the influence of fast pyrolysis-generated switchgrass biochar on survival of foodborne path...
Metal Load of the Crops Depending on Land Use, Land Management and Soil Characteristics
NASA Astrophysics Data System (ADS)
Oeztan, Sezin; Duering, Rolf-Alexander
2010-05-01
The increase of pollutant concentrations in soil and in the food chain became very important in the past few decades. Metals of different toxicities (Cd, Zn, As, Cr, Cu, Pb, Ni, Co, V, Tl) occur in soils as a result of weathering, industrial processes, fertilization and atmospheric deposition. Some of them can be absorbed by the plants due to their mobility. The transfer of metals from soil into the plants can be explained by the physicochemical characteristics of the soil such as pH-value, organic matter and clay content. Badly adapted cultivation of the agricultural soils (declining pH-value, application of unsuitable fertilizers) can enhance the mobility of the metals and by the way increase their concentrations in agricultural products. With this study, a field experiment was established and the aim is to test the relations between available metal concentrations in the soil and metal load of the plants depending on the fertilization techniques. The plants and soil samples of the reference sites were taken, heavy metal contents of the soil samples identified by Microwave Assisted Extraction (MAE) and compared to the Aqua Regia Digestion Method for confirming the methodology. For the determination of the metal content in plants, MAE was executed to the selected plant samples and for that procedure, the samples were digested with HNO3 and H2O2 in the microwave oven. Quantation of the metals in soil and in plants was done by ICP-OES Methodology. The evaluation of the first results confirmed that the metal content of the soil is strongly dependent on the properties of different fertilization variants (N,P,K) used and physicochemical characteristics of the soils. According to the fertilization variants, total metal contents of the soil are increased in the soil samples which have high amounts of N, P, K fertilization. Soils which were enforced with high P fertilization degrees had significantly higher total Cd content. Results on the Cd content of the plant samples also revealed that transition of metals from soil to plants depend heavily on the fertilizer since plant samples and soil samples treated with the same fertilizer showed similar results.
Rashid, Muhammad Imtiaz; Mujawar, Liyakat Hamid; Shahzad, Tanvir; Almeelbi, Talal; Ismail, Iqbal M I; Oves, Mohammad
2016-02-01
Intensive agricultural practices and cultivation of exhaustive crops has deteriorated soil fertility and its quality in agroecosystems. According to an estimate, such practices will convert 30% of the total world cultivated soil into degraded land by 2020. Soil structure and fertility loss are one of the main causes of soil degradation. They are also considered as a major threat to crop production and food security for future generations. Implementing safe and environmental friendly technology would be viable solution for achieving sustainable restoration of degraded soils. Bacterial and fungal inocula have a potential to reinstate the fertility of degraded land through various processes. These microorganisms increase the nutrient bioavailability through nitrogen fixation and mobilization of key nutrients (phosphorus, potassium and iron) to the crop plants while remediate soil structure by improving its aggregation and stability. Success rate of such inocula under field conditions depends on their antagonistic or synergistic interaction with indigenous microbes or their inoculation with organic fertilizers. Co-inoculation of bacteria and fungi with or without organic fertilizer are more beneficial for reinstating the soil fertility and organic matter content than single inoculum. Such factors are of great importance when considering bacteria and fungi inocula for restoration of degraded soils. The overview of presented mechanisms and interactions will help agriculturists in planning sustainable management strategy for reinstating the fertility of degraded soil and assist them in reducing the negative impact of artificial fertilizers on our environment. Copyright © 2015 Elsevier GmbH. All rights reserved.
He, Binghui; Zhong, Zhangcheng
2004-06-01
The study showed that the efficiency of various treatments in improving the height growth of Ginkgo biloba was organic fertilizer plus intercropping > soil preparation by blasting plus intercropping > organic fertilizer > soil preparation by blasting > intercropping, and the height growth increased by 14.5%, 8.6%, 5.7%, 3.2% and 0, respectively. The efficiency of the treatments in improving new shoot growth was organic fertilizer plus intercropping > soil preparation by blasting plus intercropping > intercropping > organic fertilizer > soil preparation by blasting, and the new shoot growth increased by 58.1%, 36.6%, 33.1%, 30.2% and 14.0%, respectively. Soil preparation, organic fertilization and intercropping had no different effect on the number of long shoots, but their effect on the numbers of short shoots and leaves was significantly different. The most efficient treatment in improving the medicine content was organic fertilization plus intercropping. Compared with control, the content of quercetin and rutin in Ginkgo biloba leaves increased by 420% and 220%, respectively.
Anderson, T. Michael; Griffith, Daniel M.; Grace, James B.; Lind, Eric M.; Adler, Peter B.; Biederman, Lori A.; Blumenthal, Dana M.; Daleo, Pedro; Firn, Jennifer; Hagenah, Nicole; Harpole, W. Stanley; MacDougall, Andrew S.; McCulley, Rebecca L.; Prober, Suzanne M.; Risch, Anita C.; Sankaran, Mahesh; Schütz, Martin; Seabloom, Eric W.; Stevens, Carly J.; Sullivan, Lauren; Wragg, Peter; Borer, Elizabeth T.
2018-01-01
Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot‐level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools diverged strongly in response to herbivore exclusion when fertilized; responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing dampened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water‐limited sites.
Anderson, T Michael; Griffith, Daniel M; Grace, James B; Lind, Eric M; Adler, Peter B; Biederman, Lori A; Blumenthal, Dana M; Daleo, Pedro; Firn, Jennifer; Hagenah, Nicole; Harpole, W Stanley; MacDougall, Andrew S; McCulley, Rebecca L; Prober, Suzanne M; Risch, Anita C; Sankaran, Mahesh; Schütz, Martin; Seabloom, Eric W; Stevens, Carly J; Sullivan, Lauren L; Wragg, Peter D; Borer, Elizabeth T
2018-04-01
Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot-level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools diverged strongly in response to herbivore exclusion when fertilized; responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing dampened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water-limited sites. © 2018 by the Ecological Society of America.
Madzaric, Suzana; Ceglie, F G; Depalo, L; Al Bitar, L; Mimiola, G; Tittarelli, F; Burgio, G
2017-11-23
Organic greenhouse (OGH) production is characterized by different systems and agricultural practices with diverse environmental impact. Soil arthropods are widely used as bioindicators of ecological sustainability in open field studies, while there is a lack of research on organic production for protected systems. This study assessed the soil arthropod abundance and diversity over a 2-year crop rotation in three systems of OGH production in the Mediterranean. The systems under assessment differed in soil fertility management: SUBST - a simplified system of organic production, based on an input substitution approach (use of guano and organic liquid fertilizers), AGROCOM - soil fertility mainly based on compost application and agroecological services crops (ASC) cultivation (tailored use of cover crops) as part of crop rotation, and AGROMAN - animal manure and ASC cultivation as part of crop rotation. Monitoring of soil fauna was performed by using pitfall traps and seven taxa were considered: Carabidae, Staphylinidae, Araneae, Opiliones, Isopoda, Myriapoda, and Collembola. Results demonstrated high potential of ASC cultivation as a technique for beneficial soil arthropod conservation in OGH conditions. SUBST system was dominated by Collembola in all crops, while AGROMAN and AGROCOM had more balanced relative abundance of Isopoda, Staphylinidae, and Aranea. Opiliones and Myriapoda were more affected by season, while Carabidae were poorly represented in the whole monitoring period. Despite the fact that all three production systems are in accordance with the European Union regulation on organic farming, findings of this study displayed significant differences among them and confirmed the suitability of soil arthropods as bioindicators in protected systems of organic farming.
Chen, Zhe; Chen, Yuan-yuan; Gao, Ji; Liu, Ru-liang; Yang, Zheng-li; Zhang, Ai-ping
2015-01-01
Agricultural soil has become the largest anthropogenic source of atmospheric nitrous oxide (N20). To estimate the impacts of long-term combined application of organic and inorganic fertilizers on N20 emission in a typical winter wheat-oil sunflower cropping system in the Ningxia irrigation area, we measured N20 fluxes using the static opaque chamber-gas chromatograph method and monitored the seasonal dynamics of related factors. Our results showed that nitrogen addition in the previous crop field significantly stimulated N2O emissions during the following oil-sunflower cultivation, and the mean fluxes of N300-OM, N240-OM1/2, N300 and N240 were (34.16 ± 9.72), (39.69 ±10.70), (27.75 ±9.57) and (26.30 ± 8.52) µg . m-2 . h-1, respectively, which were 4.09, 4.75, 3.32 and 3.15 times of the control groups. The total cumulative N2O emissions of fertilizer treatments in growing season was as high as 796.7 to 1242.5 g . hm-2, which was 2.99 to 4.67 times of the control groups. During the growing season, the rates of N2O emission in each month organic and inorganic fertlizers combined treatments were similar at high levels. N2O emission in chemical fertilizer treatments gradually decreased, and the main period of N2O emission occurred at the beginning of growing season. Taking July for example, N2O emission accounted for 41.3% to 41. 8% of total cumulative amount. The amounts of N20 emission under organic and inorganic fertilizers combined treatments were significantly higher than under chemical fertilizer treatments. The N2O emissions were not significantly different between conventional and optimized applications of nitrogen fertilizer under the same fertilizing method, either between N300-OM and N240-OM1/2, or between N300 and N240. On account of the drought, N2O emission in each treatment was mainly affected by soil moisture. N2O emission had a significant positive correlation with soil ammonium nitrogen content under combined applications of organic and inorganic fertilizers, but was not correlated with soil nitrate nitrogen content under all treatments. This showed that adding organic fertilizer could stimulate the NO2 production via increasing the soil ammonium nitrogen content.
Soil biota response to amendment with biochar as P and K fertilizer
NASA Astrophysics Data System (ADS)
Winding, Anne; Imparato, Valentina; Santos, Susana; Hansen, Veronika; Haugaard-Nielsen, Henrik; Browne, Patrick; Hestbjerg Hansen, Lars; Henning Krogh, Paul; Johansen, Anders
2017-04-01
Thermal gasification converts biomass into a combustible gas at oxygen-poor conditions, the bi-product being biochar which can be used as soil amendment to increase pH, sequester carbon to mitigate climate change, and supply phosphate and potassium to crops; replacing chemical or other alternative organic fertilizers. Amending soil with biochar can support three soil functions: production of food, carbon sequestration, and biodiversity. This was tested in a field experiment with reduced-tillage agricultural management, where the effect of biochar amendment on soil ecosystem services, especially biodiversity and carbon sequestration were studied. The effects on soil microorganisms and fauna (protists and earthworms) were assessed with activity based assays and Next Generation Sequencing (NGS). Crops were alternating oil seed rape and winter wheat, and biochar was added annually for 3 years. The soil was a sandy loam soil with SOM content of ca. 5%. Earthworms and soil were sampled from field plots either left untreated, amended with straw or annually amended with either 6-8 t ha-1 or ca. 1 t ha-1 biochar. Soil was sampled from bulk soil and earthworm drilosphere. Earthworms had a priming effect on protist abundance and basal soil respiration. However, in biochar amended soil the protist abundance decreased in the drilosphere. Culturable bacteria and extracellular enzymatic activities were not significantly affected by earthworms. The abundance of only one earthworm species increased at high compared to low application levels of biochar, while still not differing from controls without biochar. Thus, no harmful effects were detected for earthworms. At the lower biochar amendment, significant changes were observed for the activity of a few selected enzymes related to biochar and also a relative increase in abundance of low abundant microorganisms was seen. At the high doses of biochar the abundance of protists increased compared to control. NGS analysis was more sensitive than activity based functional assays as metagenomics of bacterial communities (16S rDNA) revealed effects of biochar and metagenomics of fungi/protist communities (18S rDNA) revealed effects of biochar and less priming effects of earthworms. Generally, the addition of biochar as soil amendment and alternative fertilizer had limited effect on soil microorganisms and fauna in the tested agricultural soil, and could be a sustainable P and K fertilizer while sequestering carbon to mitigate climate change.
Wang, Fei; Yuan, Ting; Gu, Shou-kuan; Wang, Zheng-yin
2015-04-01
As a new style fertilizer, slow-control release fertilizer had been an important subject in recent years, but few researches were about soil microbial community structure diversity. Phospholipid fatty acid method was used to determined the microbial community structure diversity of acid soil and slight alkaline soil applied with slow-release compound fertilizer (SRF), chemical fertilizer (CF) and common compound fertilizer (CCF) at the 10th, 30th, 60th and 90th day under the constant temperature incubation condition. Results indicated that various bacteria (i. e 13:0, i14:0,14:0, i15:0, a15:0, i16:0, 16:12OH, 16:1w5c,16:0, i17:0, a17:0, cy17:0, 17:02OH, i18:0, 18:0 and cy19:0w8c), two actinomycetes (10Me17:0 and 10Me18:0) and only one fungus (18:1 w9c) were detected in two soils after applying slow-release compound fertilizer and other fertilizers during the whole incubation period. SRF could significantly increase the fungi PLFA content by 8.3% and 6.8% at the early stage (the 10th day and 30th day) compared with CF, as well as significantly increase by 22.7% and 17.1% at the late stage (the 60th day and 90th day) compared with CCF in acid soil. SRF significantly increased bacteria, fungi and gram positive bacteria compared with CF and CCF in incubation period (except at the 30th day) in slight alkaline soil. SRF could significantly improve the ratio of normal saturated fatty acid and monounsaturated fatty acid at the 30th day and 90th days in acid soil compared with no fertilizer (CK), CF and CCF, while as to slight alkaline soil, SRF was significantly greater than that of CK, CF and CCF only at the 60th day. SRF could significantly decrease the ratio of iso PLFA and anteiso PLFA in acid soil (in 30-90 days) and slight alkaline soil (in 10-60 days). For two soils PLFA varieties, contents and ratios of microbial community, slow-release compound fertilizer increased soil microbial PLFA varieties and contents, and decreased the influence to microbial survival environment, especially for the acid soil. Through the research of slow-release compound fertilizer on soil microbial community structure diversity, it could provide a scientific basis for widely application of slow-release compound fertilizer in agricultural production.
Liu, Yi-Ren; Li, Xiang; Yu, Jie; Shen, Qi-Rong; Xu, Yang-Chun
2012-01-01
A pot experiment was conducted to study the effects of combined application of organic and inorganic fertilizers on the nitrogen uptake by rice and the nitrogen supply by soil in a wheat-rice rotation system, and approach the mechanisms for the increased fertilizer nitrogen use efficiency of rice under the combined fertilization from the viewpoint of microbiology. Comparing with applying inorganic fertilizers, combined application of organic and inorganic fertilizers decreased the soil microbial biomass carbon and nitrogen and soil mineral nitrogen contents before tillering stage, but increased them significantly from heading to filling stage. Under the combined fertilization, the dynamics of soil nitrogen supply matched best the dynamics of rice nitrogen uptake and utilization, which promoted the nitrogen accumulation in rice plant and the increase of rice yield and biomass, and increased the fertilizer nitrogen use efficiency of rice significantly. Combined application of inorganic and organic fertilizers also promoted the propagation of soil microbes, and consequently, more mineral nitrogen in soil was immobilized by the microbes at rice early growth stage, and the immobilized nitrogen was gradually released at the mid and late growth stages of rice, being able to better satisfy the nitrogen demand of rice in its various growth and development stages.
Soil and Foliar Guidelines for Phosphorus Fertilization of Loblolly Pine
Carol G. Wells; D.M. Crutchfield; N.M. Berenyi; C.B. Davey
1973-01-01
Several established studies of phosphorus fertilization in 3-year-old plantations of loblolly pine were measured for tree height and sampled for soil tests and needle analysis in order to relate soil and needle content to response to fertilization. Soil tests with the extractant adopted by the North Carolina Soil Testing Laboratories and percentage of P in needles were...
Yu, Hailing; Gao, Qiang; Shao, Zeqiang; Ying, Anning; Sun, Yuyang; Liu, Jingwei; Mao, Wei; Zhang, Bin
2016-01-01
In this study, we examined the influence of different nitrogen (N) application rates (0, 168, 240, 270 and 312 kg N ha-1) on soil properties, maize (Zea mays L.) yields and microbial communities of three types of soils (clay, alluvial and sandy soils). Phospholipid fatty acid analysis was used to characterize soil microbial communities. Results indicated that N fertilization significantly decreased microbial biomass in both clay and sandy soils regardless of application rate. These decreases were more likely a result of soil pH decreases induced by N fertilization, especially in the sandy soils. This is supported by structural equation modeling and redundancy analysis results. Nitrogen fertilization also led to significant changes in soil microbial community composition. However, the change differences were gradually dismissed with increase in N application rate. We also observed that N fertilization increased maize yields to the same level regardless of application rate. This suggests that farmers could apply N fertilizers at a lower rate (i.e. 168 kg N ha-1), which could achieve high maize yield on one hand while maintain soil microbial functions on the other hand. PMID:26992097
Slow release fertilizers in bareroot nurseries
J. G. Iyer; J. Dobrahner; B. Lowery; J. Vandettey
2002-01-01
Maintaining sufficient soil fertility in tree nurseries for good tree growth can be implemented by annually performing soil analyses and following a fertility maintenance program. Percentage recovery by trees of fertilizer applied indicates efficiency of fertilizer use. There is a wide variation in the recovery among the various fertilizer elements. Our research has...
Bouraima, Abdel-Kabirou; He, Binghui; Tian, Taiqiang
2016-03-01
Soil erosion along with soil particles and nutrients losses is detrimental to crop production. We carried out a 5-year (2010 to 2014) study to characterize the soil erosion and nitrogen and phosphorus losses caused by rainfall under different fertilizer application levels in order to provide a theoretical evidence for the agricultural production and coordinate land management to improve ecological environment. The experiment took place under rotation cropping, winter wheat-summer maize, on a 15° slope purple soil in Chongqing (China) within the Three Gorges Region (TGR). Four treatments, control (CK) without fertilizer, combined manure with chemical fertilizer (T1), chemical fertilization (T2), and chemical fertilizer with increasing fertilization (T3), were designed on experimental runoff plots for a long-term observation aiming to study their effects on soil erosion and nutrients losses. The results showed that fertilization reduced surface runoff and nutrient losses as compared to CK. T1, T2, and T3, compared to CK, reduced runoff volume by 35.7, 29.6, and 16.8 %, respectively and sediment yield by 40.5, 20.9, and 49.6 %, respectively. Regression analysis results indicated that there were significant relationships between soil loss and runoff volume in all treatments. The combined manure with chemical fertilizer (T1) treatment highly reduced total nitrogen and total phosphorus losses by 41.2 and 33.33 %, respectively as compared with CK. Through this 5-year experiment, we can conclude that, on the sloping purple soil, the combined application of manure with fertilizer is beneficial for controlling runoff sediments losses and preventing soil erosion.
Dou, Xiaolin; He, Ping; Zhu, Ping; Zhou, Wei
2016-01-01
Effects of different fertilizers on organic carbon (C) storage and turnover of soil fractions remains unclear. We combined soil fractionation with isotope analyses to examine soil organic carbon (SOC) dynamics after 25 years of fertilization. Five types of soil samples including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, N; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into four aggregate sizes (>2000 μm, 2000–250 μm, 250–53 μm, and <53 μm), and three density fractions: free light fraction (LF), intra-aggregate particulate organic matter (iPOM), and mineral-associated organic matter (mSOM). Physical fractionation showed the iPOM fraction of aggregates dominated C storage, averaging 76.87% of SOC storage. Overall, application of N and NPK fertilizers cannot significantly increase the SOC storage but enhanced C in mSOM of aggregates, whereas MNPK fertilizer resulted in the greatest amount of SOC storage (about 5221.5 g C m2) because of the enhanced SOC in LF, iPOM and mSOM of each aggregate. The SNPK fertilizer increased SOC storage in >250 μm aggregates but reduced SOC storage in <250 μm aggregates due to SOC changes in LF and iPOM. PMID:26898121
Dou, Xiaolin; He, Ping; Zhu, Ping; Zhou, Wei
2016-02-22
Effects of different fertilizers on organic carbon (C) storage and turnover of soil fractions remains unclear. We combined soil fractionation with isotope analyses to examine soil organic carbon (SOC) dynamics after 25 years of fertilization. Five types of soil samples including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, N; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into four aggregate sizes (>2000 μm, 2000-250 μm, 250-53 μm, and <53 μm), and three density fractions: free light fraction (LF), intra-aggregate particulate organic matter (iPOM), and mineral-associated organic matter (mSOM). Physical fractionation showed the iPOM fraction of aggregates dominated C storage, averaging 76.87% of SOC storage. Overall, application of N and NPK fertilizers cannot significantly increase the SOC storage but enhanced C in mSOM of aggregates, whereas MNPK fertilizer resulted in the greatest amount of SOC storage (about 5221.5 g C m(2)) because of the enhanced SOC in LF, iPOM and mSOM of each aggregate. The SNPK fertilizer increased SOC storage in >250 μm aggregates but reduced SOC storage in <250 μm aggregates due to SOC changes in LF and iPOM.
NASA Astrophysics Data System (ADS)
Jian, S.; Li, J.; Guo, C.; Hui, D.; Deng, Q.; Yu, C. L.; Dzantor, K. E.; Lane, C.
2017-12-01
Nitrogen (N) fertilizers are widely used to increase bioenergy crop yield but intensive fertilizations on spatial distributions of soil microbial processes in bioenergy croplands remains unknown. To quantify N fertilization effect on spatial heterogeneity of soil microbial biomass carbon (MBC) and N (MBN), we sampled top mineral horizon soils (0-15cm) using a spatially explicit design within two 15-m2 plots under three fertilization treatments in two bioenergy croplands in a three-year long fertilization experiment in Middle Tennessee, USA. The three fertilization treatments were no N input (NN), low N input (LN: 84 kg N ha-1 in urea) and high N input (HN: 168 kg N ha-1 in urea). The two crops were switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.). Results showed that N fertilizations little altered central tendencies of microbial variables but relative to LN, HN significantly increased MBC and MBC:MBN (GG only). HN possessed the greatest within-plot variances except for MBN (GG only). Spatial patterns were generally evident under HN and LN plots and much less so under NN plots. Substantially contrasting spatial variations were also identified between croplands (GG>SG) and among variables (MBN, MBC:MBN > MBC). No significant correlations were identified between soil pH and microbial variables. This study demonstrated that spatial heterogeneity is elevated in microbial biomass of fertilized soils likely by uneven fertilizer application, the nature of soil microbial communities and bioenergy crops. Future researchers should better match sample sizes with the heterogeneity of soil microbial property (i.e. MBN) in bioenergy croplands.
Li, Qingxue; Jia, Zhiqing; Zhu, Yajuan; Wang, Yongsheng; Li, Hong; Yang, Defu; Zhao, Xuebin
2015-01-01
The Gonghe Basin region of the Tibet Plateau is severely affected by desertification. Compared with other desertified land, the main features of this region is windy, cold and short growing season, resulting in relatively difficult for vegetation restoration. In this harsh environment, identification the spatial distribution of soil nutrients and analysis its impact factors after vegetation establishment will be helpful for understanding the ecological relationship between soil and environment. Therefore, in this study, the 12-year-old C. intermedia plantation on sand dunes was selected as the experimental site. Soil samples were collected under and between shrubs on the windward slopes, dune tops and leeward slopes with different soil depth. Then analyzed soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP) and available potassium (AK). The results showed that the spatial heterogeneity of soil nutrients was existed in C. intermedia plantation on sand dunes. (1) Depth was the most important impact factor, soil nutrients were decreased with greater soil depth. One of the possible reasons is that windblown fine materials and litters were accumulated on surface soil, when they were decomposed, more nutrients were aggregated on surface soil. (2) Topography also affected the distribution of soil nutrients, more soil nutrients distributed on windward slopes. The herbaceous coverage were higher and C. intermedia ground diameter were larger on windward slopes, both of them probably related to the high soil nutrients level for windward slopes. (3) Soil “fertile islands” were formed, and the “fertile islands” were more marked on lower soil nutrients level topography positions, while it decreased towards higher soil nutrients level topography positions. The enrichment ratio (E) for TN and AN were higher than other nutrients, most likely because C. intermedia is a leguminous shrub. PMID:25946170
Li, Qingxue; Jia, Zhiqing; Zhu, Yajuan; Wang, Yongsheng; Li, Hong; Yang, Defu; Zhao, Xuebin
2015-01-01
The Gonghe Basin region of the Tibet Plateau is severely affected by desertification. Compared with other desertified land, the main features of this region is windy, cold and short growing season, resulting in relatively difficult for vegetation restoration. In this harsh environment, identification the spatial distribution of soil nutrients and analysis its impact factors after vegetation establishment will be helpful for understanding the ecological relationship between soil and environment. Therefore, in this study, the 12-year-old C. intermedia plantation on sand dunes was selected as the experimental site. Soil samples were collected under and between shrubs on the windward slopes, dune tops and leeward slopes with different soil depth. Then analyzed soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP) and available potassium (AK). The results showed that the spatial heterogeneity of soil nutrients was existed in C. intermedia plantation on sand dunes. (1) Depth was the most important impact factor, soil nutrients were decreased with greater soil depth. One of the possible reasons is that windblown fine materials and litters were accumulated on surface soil, when they were decomposed, more nutrients were aggregated on surface soil. (2) Topography also affected the distribution of soil nutrients, more soil nutrients distributed on windward slopes. The herbaceous coverage were higher and C. intermedia ground diameter were larger on windward slopes, both of them probably related to the high soil nutrients level for windward slopes. (3) Soil "fertile islands" were formed, and the "fertile islands" were more marked on lower soil nutrients level topography positions, while it decreased towards higher soil nutrients level topography positions. The enrichment ratio (E) for TN and AN were higher than other nutrients, most likely because C. intermedia is a leguminous shrub.
Zhang, Xuelin; Wang, Qun; Xu, Jun; Gilliam, Frank S.; Tremblay, Nicolas; Li, Chaohai
2015-01-01
Nitrogen (N) fertilization potentially affects soil N mineralization and leaching, and can enhance NH3 volatilization, thus impacting crop production. A fertilizer experiment with five levels of N addition (0, 79, 147, 215 and 375 kg N ha-1) was performed in 2009 and 2010 in a maize field in Huanghuaihai region, China, where > 300 kg N ha-1 has been routinely applied to soil during maize growth period of 120 days. Responses of net N mineralization, inorganic N flux (0–10cm), NH3 volatilization, and maize yield to N fertilization were measured. During the growth period, net N mineralization and nitrification varied seasonally, with higher rates occurring in August and coinciding with the R1 stage of maize growth. Soil NO3 −-N contributed to more than 60% of inorganic N flux during maize growth. Cumulative NH3 volatilization increased with N additions, with total NH3 volatilization during maize growth accounting for about 4% of added N. Relative to the control, mean maize yield in the fertilizer treatments increased by 17% and 20% in 2009 and 2010, respectively. However, grain yield, aboveground biomass, and plant N accumulation did not increase with added N at levels > 215 kg N ha-1. These results suggest that the current N rate of 300 kg N ha-1 is not only excessive, but also reduces fertilizer efficacy and may contribute to environmental problems such as global warming and eutrophication of ground water and streams. PMID:25635864
Nitrogen transformation in maize soil after application of different organic manures.
Dong, Yu-hong; Ouyang, Zhu; Liu, Shi-liang
2005-01-01
The nitrogen transformation in maize soil after application of different organic manure was studied. The nitrogen mineralization in surface soil, NO3- -N dynamics and distribution in soil profile, and N2O emission were investigated. Eight treatments were laid out randomizing with three replications in 24 plots: maize plantation without fertilizer (CK1), bare soil without maize plantation and fertilization (CK2), swine manure (S1, S2), poultry manure (P1, P2), and cattle manure (C1, C2). Three manures were applied at two application levels (15 t/hm2 and 30 t/hm2). The results indicated that NH+ -N in surface soil showed the same temporal pattern without much variation among different treatments. But NO3- -N in the same layer exhibited large temporal pattern in all treatments, which was mainly due to its easy eluviations of NO3- -N in soil, its transformation to N2O and the influence of precipitation. The distribution of NO3- -N in the soil profile during maize growing season showed the leaching tendency from surface soil to subsoil, which was different among the treatments. The poultry treatments showed the largest leaching tendency. The study also revealed that the emissions of N2O were affected by the application of organic manures in the order of P2 > S2 > C2 > P1 > S1 > Cl > CK1 > CK2. All these results showed that organic manure applications significantly affect nitrogen transformation and distribution in maize soil. Considering N2O emission and NO3- -N leaching, the management of organic manure in the agriculture needs further studies.
USDA-ARS?s Scientific Manuscript database
Soils in the southeastern U.S. Coastal Plain region have meager soil fertility and frequently have compacted subsoil layers (E horizon). Designer biochar has gained global interest as an amendment to improve the fertility, chemical, and physical properties of degraded agricultural soils. We hypothes...
NASA Astrophysics Data System (ADS)
Jin, X.; Filley, T. R.
2017-12-01
Management of crop residues using plastic film mulching (PFM) has the potential to improve soil health by accelerating nutrient cycling and facilitating stable C pool production; however, a key aspect of this process—microbial immobilization of residue C—is poorly understood, especially under PFM when combined with different fertilization treatments. A 360-day in situ 13C-tracing technique was used to analyze the contribution and dynamics of microbial biomass C (MBC) to soil organic C (SOC) after 13C-labelled maize straw residue was applied to micro-plot topsoil in a cultivated maize (Zea mays L.) field under 27-year PFM and four fertilization treatments. Over the course of the experiment, MBC content was significantly (P<0.05) higher in treatments of manure (M) and manure plus nitrogen (MN) compared to the no-fertilization (CK) and nitrogen (N) treatments, regardless of PFM. Compared to no PFM controls, PFM enhanced the decomposition of maize straw during summer (Day 60) in the M and MN treatments, exhibiting increases of 93.0% and 28.6% in straw-derived 13C-MBC and 80.4% and 82.9% in 13C-MBC/13C-SOC, respectively. Overall, both PFM and organic manure treatments improved soil fertility through microbe-mediated incorporation of C derived from newly-added maize straw. Our results indicate that microbial growth and activity are affected by the utilization of different C sources and most dramatically during early seasonal transition.
NASA Technical Reports Server (NTRS)
Daughtry, C. S. T.; Bauer, M. E.; Crecelius, D. W.; Hixson, M. M. (Principal Investigator)
1980-01-01
The effects of available soil moisture, planting date, nitrogen fertilization, and cultivar on reflectance of spring wheat (Triticum aestivum L.) canopies were investigated. Spectral measurements were acquired on eight dates throughout the growing season, along with measurements of crop maturity stage, leaf area index, biomass, plant height, percent soil cover, and soil moisture. Planting date and available soil moisture were the primary agronomic factors which affected reflectance of spring wheat canopies from tillering to maturity. Comparisons of treatments indicated that during the seedling and tillering stages planting date was associated with 36 percent and 85 percent of variation in red and near infrared reflectances, respectively. As the wheat headed and matured, less of the variation in reflectance was associated with planting date and more with available soil moisture. By mid July, soil moisture accounted for 73 percent and 69 percent of the variation in reflectance in red and near infrared bands, respectively. Differences in spectral reflectance among treatments were attributed to changes in leaf area index, biomass, and percent soil cover. Cultivar and N fertilization rate were associated with very little of the variation in the reflectance of these canopies.
Fujita, Yuki; van Bodegom, Peter M.; Witte, Jan-Philip M.
2013-01-01
Soil fertility and nutrient-related plant functional traits are in general only moderately related, hindering the progress in trait-based prediction models of vegetation patterns. Although the relationships may have been obscured by suboptimal choices in how soil fertility is expressed, there has never been a systematic investigation into the suitability of fertility measures. This study, therefore, examined the effect of different soil fertility measures on the strength of fertility–trait relationships in 134 natural plant communities. In particular, for eight plot-mean traits we examined (1) whether different elements (N or P) have contrasting or shared influences, (2) which timescale of fertility measures (e.g. mineralization rates for one or five years) has better predictive power, and (3) if integrated fertility measures explain trait variation better than individual fertility measures. Soil N and P had large mutual effects on leaf nutrient concentrations, whereas they had element-specific effects on traits related to species composition (e.g. Grime's CSR strategy). The timescale of fertility measures only had a minor impact on fertility–trait relationships. Two integrated fertility measures (one reflecting overall fertility, another relative availability of soil N and P) were related significantly to most plant traits, but were not better in explaining trait variation than individual fertility measures. Using all fertility measures together, between-site variations of plant traits were explained only moderately for some traits (e.g. 33% for leaf N concentrations) but largely for others (e.g. 66% for whole-canopy P concentration). The moderate relationships were probably due to complex regulation mechanisms of fertility on traits, rather than to a wrong choice of fertility measures. We identified both mutual (i.e. shared) and divergent (i.e. element-specific and stoichiometric) effects of soil N and P on traits, implying the importance of explicitly considering the roles of different elements to properly interpret fertility–trait relationships. PMID:24391815
Bioorganic Fertilizer Enhances Soil Suppressive Capacity against Bacterial Wilt of Tomato
Liu, Shuangri; Chai, Rushan; Huang, Weiqing; Liu, Xingxing; Tang, Caixian; Zhang, Yongsong
2015-01-01
Tomato bacterial wilt caused by Ralstonia solanacearum is one of the most destructive soil-borne diseases. Many strategies have been taken to improve soil suppressiveness against this destructive disease, but limited success has been achieved. In this study, a novel bioorganic fertilizer revealed a higher suppressive ability against bacterial wilt compared with several soil management methods in the field over four growing seasons from March 2011 to July 2013. The application of the bioorganic fertilizer significantly (P<0.05) reduced disease incidence of tomato and increased fruit yields in four independent trials. The association among the level of disease incidence, soil physicochemical and biological properties was investigated. The soil treated with the bioorganic fertilizer increased soil pH value, electric conductivity, organic carbon, NH4 +-N, NO3 --N and available K content, microbial activities and microbial biomass carbon content, which were positively related with soil suppressiveness. Bacterial and actinomycete populations assessed using classical plate counts were highest, whereas R. solanacearum and fungal populations were lowest in soil applied with the bioorganic fertilizer. Microbial community diversity and richness were assessed using denaturing gel gradient electrophoresis profile analysis. The soil treated with the bioorganic fertilizer exhibited higher bacterial community diversity but lower fungal community diversity. Redundancy analysis showed that bacterial community diversity and richness negatively related with bacterial wilt suppressiveness, while fungal community richness positively correlated with R. solanacearum population. We concluded that the alteration of soil physicochemical and biological properties in soil treated with the bioorganic fertilizer induced the soil suppressiveness against tomato bacterial wilt. PMID:25830639
Kathijotes, Nicholas; Zlatareva, Elena; Marinova, Svetla; Petrova, Vera
2016-09-01
The aim of this study is to establish changes that may occur after a prolonged application of wastewater sludge treated to biosolids, in the 'soil-fertilizer-plant' system. Thirteen experimental plots with different soil types planted with experimental crops were investigated in order to evaluate the suitability of these biosolids as soil conditioners and fertilizers. The biosolids were incorporated in soil starting in 2006 in different quantities (from 6 tons per ha) for various arrays. The rate of application was calculated on the basis of imported nitrogen and was consistent with the characteristics of the sludge, soil diversity, growing crop requirements, and other factors. In 2013 (after 7 years of land use) average soil samples from the same arrays were taken and analyzed. No chemical fertilizer was applied during the experimental period. The results show that the use of sewage biosolids as a soil improver in accordance with local legislation does not pose any serious environmental risks but can maintain and improve soil fertility and crop yield. A slight increase in Cu and Zn in plants was detected, however the content of heavy metals in all soil samples was below maximum allowable limits and no signs of phytotoxicity were observed.
Wei, Xiu-Li; Lei, Ping; Shi, Wei-Yong
2010-08-01
By the method of thermostatic culture, this paper studied the effects of different application rates (0.5, 1.5, and 2.5 ml x kg(-1)) of organic fish protein liquid fertilizer on the enzyme activities and microbial biomass C and N in a silt soil, and the relationships between these parameters and soil nutrient contents. Under the application of the liquid fertilizer, soil pH varied in the range of 7.07-7.31, but had no significant difference from the control. With the increasing application rate of the liquid fertilizer, the activities of soil phosphatase, urease, and protease, as well as the soil biomass C and N, all increased significantly, and the increment was 127, 190 and 196%, 39.81, 78.06 and 173.24%, 56.37, 108.29 and 199.98%, 167, 395 and 474%, and 121, 243 and 406%, respectively, compared with the control. The peak time of the soil urease and protease activities and microbial biomass C and N differed with the fertilization treatments. Soil phosphase, urease, and protease activities and microbial biomass C and N were significantly positively correlated with soil nutrient contents, suggesting that applying organic fish protein liquid fertilizer to silt soil could improve soil microbial growth and enzyme activities, and accordingly, promote the decomposition and transformation of soil organic matter and the release of soil available nutrient elements.
[Effects of long-term fertilization on organic nitrogen fractions in aquic brown soil].
Ren, Jin Feng; Zhou, Hua; Ma, Qiang; Xu, Yong Gang; Jiang, Chun Ming; Pan, Fei Fei; Yu, Wan Tai
2017-05-18
The purpose of present research was to investigate how different fertilization regimes altered soil organic nitrogen fractions and their inter-annual dynamics based on a series of long-term experiment (initiated at 1990), including: CK (non-fertilization); M (recycled pig manure); NPK (chemical fertilizer NPK); NPK + M (recycled pig manure with chemical fertilizer NPK). The results showed that soil organic nitrogen components under the different fertilization treatments presented contrastive patterns from the establishment the experiments to 2015. Generally, acid hydrolysable organic nitrogen content increased year by year. The amino acid nitrogen content under CK and NPK treatments consistently declined, although amino acid nitrogen for M and NPK+M treatments showed a increasing trend. These phenomena were probably ascribed to the utilization of soil amino acids by microbes. From 1990 to 2015, NPK treatment substantially elevated the content of acid-released ammonium nitrogen by 31.1% compared with CK (mean value across the experiment), and for the treatments using organic manure (M and NPK+M), the contents of all fractions of soil organic nitrogen increased. Notably, the increase magnitudes for NPK+M were more dramatic than those of M. These results demonstrated that combined use of organic and inorganic fertilizers could more effectively elevate soil organic nitrogen, subsequently helping to improve the capacity of soil nitrogen supply and enhance the soil fertility.
NASA Astrophysics Data System (ADS)
Marañón-Jiménez, Sara; Serrano-Ortíz, Penelope; Vicente-Vicente, Jose Luis; Chamizo, Sonia; Kowalski, Andrew S.
2017-04-01
Olive (Olea europaea) is the dominant agriculture plantation in Spain and its main product, olive oil, is vital to the economy of Mediterranean countries. Given the extensive surface dedicated to olive plantations, olive groves can potentially sequester large amounts of carbon and contribute to mitigate climate change. Their potential for carbon sequestration will, however, largely depend on the management and irrigation practices in the olive grove. Although soil respiration is the main path of C release from the terrestrial ecosystems to the atmosphere and a suitable indicator of soil health and fertility, the interaction of agricultural management practices with irrigation regimes on soil CO2 fluxes have not been assessed yet. Here we investigate the influence of the presence of herbaceous cover, use of artificial fertilizers and their interaction with the irrigation regime on the CO2 emission from the soil to the atmosphere. For this, the three agricultural management treatments were established in replicated plots in an olive grove in the SE of Spain: presence of herbaceous cover ("H"), exclusion of herbaceous cover by using herbicides ("NH"), and exclusion of herbaceous cover along with addition of artificial fertilizers (0.55 kg m-2 year-1 of N, P, K solid fertilizer in the proportion 20:10:10, "NHF"). Within each management treatment, three irrigation regimes were also implemented in a randomized design: no-irrigation ("NO") or rain fed, full irrigation (224 l week-1 per olive tree, "MAX"), and a 50% restriction (112 l week-1 per olive tree, "MED"). Soil respiration was measured every 2-3 weeks at 1, 3, and 5 meters from each olive tree together with soil temperature and soil moisture in order to account for the spatial and seasonal variability over the year. Soil respiration was higher when herbaceous cover was present compared to the herbaceous exclusion, whereas the addition of fertilizer did not exert any significant effect. Although the different irrigation regimes did affect soil moisture, soil CO2 fluxes remained unaffected by the amount of water added. Soil moisture and temperature were actually reduced by the presence of herbaceous cover during the growing season, which suggests water competition between herbaceous plants and olives with counteracting effects on soil respiration values. Soil respiration showed high spatial heterogeneity, with values decreasing exponentially with the distance from the olive trees. These data highlight the need to account for their spatial and seasonal heterogeneity when estimating the contribution of soil respiration to atmospheric CO2 emissions and the crucial role of the agricultural management on determining the carbon sequestration potential of soil from olive groves.
Wei, Ze-Xiu; Liang, Yin-Li; Inoue, Mitsuhiro; Zhou, Mao-Juan; Huang, Mao-Lin; Gu, Jian-Feng; Wu, Yan
2009-07-01
With cucumber (Cucumis sativus L.) variety Jinyou 1 as test material, a greenhouse experiment was conducted to study the effects of different water and fertilizer supply on the cucumber soil nutrient content, enzyme activity, and microbial diversity. Three water regimes (50%-60%, 70%-80%, and 90%-100% soil relative moisture content) and two fertilization practices (600 kg N x hm(-2) + 420 kg P2O5 x hm(-2) and 420 kg N x hm(-2) + 294 kg P2O5 x hm(-2)) were designed. The increase of water and fertilizer supply benefited the increase of soil available P content and sucrase activity. Increasing fertilization rate increased soil NH(4+)-N content but decreased soil protease activity, and increasing soil relative moisture content decreased the soil NH(4+)-N content and urease activity. Soil microbial diversity had no significant correlations with soil nutrient contents, but significantly positively correlated with soil urease activity and negatively correlated with soil sucrase activity. Among the treatments, the treatment 70%-80% soil relative moisture content + 600 kg N x hm(-2) and 420 kg P2O5 x hm(-2) had the highest soil nutrient contents, soil urease, sucrase, and phosphatase activities, and soil microbial diversity and evenness, being the best in soil potential productivity.
Liu, Yan Ling; Li, Yu; Zhang, Ya Rong; Huang, Xing Cheng; Zhang, Wen An; Jiang, Tai Ming
2017-11-01
A long-term fertilization field experiment was conducted to investigate the effect of nitrogen (N), phosphorus (P), and potassium (K) fertilizer on maize relative yield, yield-increasing effect and the changes of nutrients in yellow soil in Guizhou Province. Five fertilizer combinations were evaluated, including balanced fertilization (NPK) and nutrient deficiency treatments (N, NK, NP, and PK). The maize relative yield, contribution efficiency of N, P, K fertilizer application, sustainability index of soil N, P, K nutrients, and other indicators were measured. The results revealed that the balanced fertilization (NPK) significantly increased maize yield, and the average yield under each treatment ranked as: NPK>NP>NK>PK>CK. The contribution efficiency and agronomic efficiency of N, P, K fertilizer application was N>P>K. The fertilization dependence was ranked as: combined application of N, P and K>N>P>K. But in the lack of P treatment (NK), the maize relative yield significantly decreased at a speed of 1.4% per year, with the contribution efficiency and fertilization dependence of applied P significantly increasing at a speed of 2.3% per year and 1.4% per year, respectively. Over time, the effect of P fertilizer on maize yield gradually became equal to that of N fertilizer. The pH and soil organic matter content were the lowest in the P-lack treatment (NK), while they were higher in the N-lack treatment (PK). The application of chemical P significantly improved the sustainability index of soil P, but the application of chemical N and K did not significantly change the sustainability index of soil N and K nutrients compared to the N- and K-lack treatments, respectively. In summary, the use of balanced fertilizer application is critical for achieving high maize yield in typical yellow soil regions in Guizhou Province. P and N fertilizers are equally important for improving maize yield, and long-term application of unbalanced chemical fertilizer, especially the lack of P, would not benefit the sustainable use of nutrients in yellow soil.
NASA Astrophysics Data System (ADS)
Brad, Traian; Chiriac, Cecilia; Szekeres, Edina; Coman, Cristian; Rudi, Knut; Sandor, Mignon
2017-04-01
Twenty microcosm enclosures containing two types of soil (i.e. a rich Chernozemic and a poorer soil) were fertilized with mineral (NPK-complex) and organic (Gülle, manure and a green fertilizer) materials and placed under dry and wet water regimes. After 10, 20 and 30 days of the experiment, soil samples were analyzed for the structure and composition of microbial communities using next generation sequencing techniques (Illumina) and statistical analysis. The differences between bacteria communities in different soil types, and in different fertilization and hydric treatments were analyzed using quantitative phylogenetic distances and the ANOSIM test. The two types of soil especially selected for the structure of microbial communities, while moisture and the type of fertilizer appeared to have a smaller influence on microbial diversity in microcosms. The alpha-diversity indices (species richness, evenness and phylogenetic diversity) had higher values for the poorer soil compared to the rich Chernozemic soil. For both soil types, the highest bacteria diversity values were obtained after fertilization with manure. The microbial communities in the analyzed soils were complex and dominated by sequences belonging to Actinobacteria, Proteobacteria, Acidobacteria and Firmicutes.
Zhi-Kui, Kou; Zhi-Sheng, Zhang; Jin-Ping, Wang; Ming-Li, Cai; Cou-Gui, Cao
2012-01-01
Quantifying carbon (C) sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT) and no-tillage (NT)] and the application of nitrogen (N) fertilizer (0 and 210 kg N ha−1) on fluxes of CH4 and CO2, and soil organic C (SOC) sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH4 emissions by 13%–66% and SOC by 21%–94% irrespective of soil sampling depths, but had no effect on CO2 emissions in either year. Tillage significantly affected CH4 and CO2 emissions, where NT significantly decreased CH4 emissions by 10%–36% but increased CO2 emissions by 22%–40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%–48% in the 0–5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0–20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered. PMID:22574109
The characteristics of phosphorus adsorption and desorption in gray desert soil of Xinjiang, China
NASA Astrophysics Data System (ADS)
Wang, B.; Sun, J. S.; Liu, H.; Ma, Y. B.
2017-07-01
The characteristics of phosphorus (P) adsorption and desorption in Xinjiang gray desert soil (0 - 200 mm) of China in the long-term fertilization condition is affected by the level of soil P content which studied through an isothermal adsorption and desorption experiments of P. The results stated that within the experimental concentration range, with the increase of the amount of outer-source phosphorus, P adsorption, desorption and desorption rate increased and adsorption rate decreased gradually in different Olsen-P levels of gray desert soil in Xinjiang, China. Olsen-P content is significantly correlated with the P adsorption saturation (DPS) of gray desert soil. The maximum adsorption capacity (Xm ) of the treatments followed an extremely significant decreasing order of CK>NPK≈NPKM>PK≈NPKS. The maximum buffer capacity (MBC) and adsorption constant (K) of the NPK treatment was much higher than NPKM, NPKS, PK and CK treatments. And, MBC value of CK treatment was extremely higher than NPKS and PK, however, the differences between NPKM and CK, NPKS and PK were not significant. The comparison between NPKM, NPKS, PK and CK treatments showed no significant difference in K value, but these four showed significantly lower than NPK treatments. The value of soil easy desorption P (RDP) of NPKS and NPKM was significantly higher than NPK and PK, and the chemical fertilizer with organic fertilizer was a best way to release the phosphorus for Xinjiang agricultural production, China.
Huang, Huagang; Li, Tingqiang; Gupta, D K; He, Zhenli; Yang, Xiao-E; Ni, Bingnan; Li, Mao
2012-01-01
Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. This study assessed the effects of di-hydrogen phosphates (KH2PO4, Ca(H2PO4)2, NaH2PO4 and NH4H2PO4) application at three levels (22, 88 and 352 mg P/kg soil) on Sedum alfredii growth and metal uptake by three consecutive harvests on aged and Zn/Cd combined contaminated paddy soil. The addition of phosphates (P) significantly increased the amount of Zn taken up by S. alfredii due to increased shoot Zn concentration and dry matter yield (DMY) (P < 0.05). The highest phytoextraction of Zn and Cd was observed in KH2PO4 and NH4H2PO4 treatment at 352 mg P/kg soil. The amount of Zn removed by phytoextraction increased in the order of 1st clipping < 2nd clipping < 3rd clipping, and for Cd extraction the order was 2nd clipping < 1st clipping < 3rd clipping. These results indicate that the application of P fertilizers coupled with multiple cuttings can enhance the removal of Zn and Cd from contaminated soils by S. alfredii, thus shortening the time needed for accomplishing remediation goals.
Can Fertilization of Soil Select Less Mutualistic Mycorrhizae?
Johnson, Nancy Collins
1993-11-01
It has been noted previously that nutrient-stressed plants generally release more soluble carbohydrate in root exudates and consequently support more mycorrhizae than plants supplied with ample nutrients. Fertilization may select strains of vesicular-arbuscular mycorrhizal (VAM) fungi that are inferior mutualists if the same characteristics that make a VAM fungus successful in roots with a lowered carbohydrate content also reduce the benefits that the fungus provides a host plant. This two-phase study experimentally tests the hypothesis that fertilizing low-nutrient soil selects VAM fungi that are inferior mutualists. The first phase examines the effects of chemical fertilizers on the species composition of VAM fungal communities in long-term field plots. The second phase measures the effects of VAM fungal assemblages from fertilized and unfertilized plots on big bluestem grass grown in a greenhouse. The field results indicate that 8 yr of fertilization altered the species composition of VAM fungal communities. Relative abundance of Gigaspora gigantea, Gigaspora margarita, Scutellispora calospora, and Glomus occultum decreased while Glomus intraradix increased in response to fertilization. Results from the greenhouse experiment show that big bluestem colonized with VAM fungi from fertilized soil were smaller after 1 mo and produced fewer inflorescences at 3 mo than big bluestem colonized with VAM fungi from unfertilized soil. Fungal structures within big bluestem roots suggest that VAM fungi from fertilized soil exerted a higher net carbon cost on their host than VAM fungi from unfertilized soil. VAM fungi from fertilized soil produced fewer hyphae and arbuscules (and consequently provided their host with less inorganic nutrients from the soil) and produced as many vesicles (and thus provisioned their own storage structures at the same level) as fungi from unfertilized soil. These results support the hypothesis that fertilization selects VAM fungi that are inferior mutualists. © 1993 by the Ecological Society of America.
A GIS-based fuzzy classification for mapping the agricultural soils for N-fertilizers use.
Assimakopoulos, J H; Kalivas, D P; Kollias, V J
2003-06-20
Special attention should be paid to the choice of the proper N-fertilizer, in order to avoid a further acidification and degradation of acid soils and at the same time to improve nitrogen use efficiency and to limit the nitrate pollution of the ground waters. Therefore, the risk of leaching of the fertilizer and of the acidification of the soils must be considered prior to any N-fertilizer application. The application of N-fertilizers to the soil requires a good knowledge of the soil-fertilizer relationship, which those who are planning the fertilization policy and/or applying it might not have. In this study, a fuzzy classification methodology is presented for mapping the agricultural soils according to the kind and the rate of application of N-fertilizer that should be used. The values of pH, clay, sand and carbonates soil variables are estimated at each point of an area by applying geostatistical techniques. Using the pH values three fuzzy sets: "no-risk-acidification"; "low-risk-acidification"; and "high-risk-acidification" are produced and the memberships of each point to the three sets are estimated. Additionally, from the clay and sand values the membership grade to the fuzzy set "risk-of-leaching" is calculated. The parameters and their values, which are used for the construction of the fuzzy sets, are based on the literature, the existing knowledge and the experimentation, of the soil-fertilizer relationships and provide a consistent mechanism for mapping the soils according to the type of N-fertilizers that should be applied and the rate of applications. The maps produced can easily be interpreted and used by non-experts in the application of the fertilization policy at national, local and farm level. The methodology is presented through a case study using data from the Amfilochia area, west Greece.
Artacho, Pamela; Bonomelli, Claudia
2016-05-01
Factors regulating fine-root growth are poorly understood, particularly in fruit tree species. In this context, the effects of N addition on the temporal and spatial distribution of fine-root growth and on the fine-root turnover were assessed in irrigated sweet cherry trees. The influence of other exogenous and endogenous factors was also examined. The rhizotron technique was used to measure the length-based fine-root growth in trees fertilized at two N rates (0 and 60 kg ha(-1)), and the above-ground growth, leaf net assimilation, and air and soil variables were simultaneously monitored. N fertilization exerted a basal effect throughout the season, changing the magnitude, temporal patterns and spatial distribution of fine-root production and mortality. Specifically, N addition enhanced the total fine-root production by increasing rates and extending the production period. On average, N-fertilized trees had a length-based production that was 110-180% higher than in control trees, depending on growing season. Mortality was proportional to production, but turnover rates were inconsistently affected. Root production and mortality was homogeneously distributed in the soil profile of N-fertilized trees while control trees had 70-80% of the total fine-root production and mortality concentrated below 50 cm depth. Root mortality rates were associated with soil temperature and water content. In contrast, root production rates were primarily under endogenous control, specifically through source-sink relationships, which in turn were affected by N supply through changes in leaf photosynthetic level. Therefore, exogenous and endogenous factors interacted to control the fine-root dynamics of irrigated sweet cherry trees. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Artacho, Pamela; Bonomelli, Claudia
2016-01-01
Factors regulating fine-root growth are poorly understood, particularly in fruit tree species. In this context, the effects of N addition on the temporal and spatial distribution of fine-root growth and on the fine-root turnover were assessed in irrigated sweet cherry trees. The influence of other exogenous and endogenous factors was also examined. The rhizotron technique was used to measure the length-based fine-root growth in trees fertilized at two N rates (0 and 60 kg ha−1), and the above-ground growth, leaf net assimilation, and air and soil variables were simultaneously monitored. N fertilization exerted a basal effect throughout the season, changing the magnitude, temporal patterns and spatial distribution of fine-root production and mortality. Specifically, N addition enhanced the total fine-root production by increasing rates and extending the production period. On average, N-fertilized trees had a length-based production that was 110–180% higher than in control trees, depending on growing season. Mortality was proportional to production, but turnover rates were inconsistently affected. Root production and mortality was homogeneously distributed in the soil profile of N-fertilized trees while control trees had 70–80% of the total fine-root production and mortality concentrated below 50 cm depth. Root mortality rates were associated with soil temperature and water content. In contrast, root production rates were primarily under endogenous control, specifically through source–sink relationships, which in turn were affected by N supply through changes in leaf photosynthetic level. Therefore, exogenous and endogenous factors interacted to control the fine-root dynamics of irrigated sweet cherry trees. PMID:26888890
Yagüe, María R; Quílez, Dolores
2010-01-01
The application of pig (Sus scrofa) slurry (PS) is a common fertilization practice that may affect nitrate concentrations and loads in drainage and receiving water bodies. To protect water resources, many agricultural areas are being designated as vulnerable to nitrate contamination, and there is a need for scientific data aiming at reducing nitrate exports from these vulnerable zones by optimizing N fertilization strategies. The objective of this work, conducted in drainage lysimeters in a 4-yr monoculture maize (Zea mays L.) crop, is to assess the effects of four fertilization strategies combining PS (30, 60, 90, and 120 t ha(-1)) and mineral N on yield, changes in soil mineral N, and concentration and mass of nitrate in drainage waters. Grain yield was not affected by treatments in the four experimental years, nor was the soil mineral N at the end of the experiment. Effects of fertilization strategies on nitrate concentration and mass in drainage waters were detected only after 3 yr of repeated PS applications. The mass of nitrate leached over the 4 yr was positively related to the total amount of N applied, either organic or mineral. In year 2003, precipitation in spring reduced N availability for the crop in treatments with rates > or = 60 t PS ha(-1). The N-budget revealed that the transport pathways for 25% of N inputs to the system are unknown. The presowing application of pig slurry at 30 t ha(-1) complemented with mineral N at side-dressing, was the most efficient from an environmental standpoint (4-yr average of 145 kg grain yield kg(-1) N leached).
Lee, Joonhee
2017-01-01
A well-managed chemical nitrogen (N) fertilization practice combined with treated swine slurry (TSS) is necessary to improve sustainability and N use efficiency in rice farming. However, little is known about the fate of N derived from chemical N fertilizer with and without TSS in paddy soil-plant systems. The objectives of this study were (1) to estimate the contribution of applied N fertilizer to N turnover in rice paddy soil with different N fertilization practices that were manipulated by the quantity of treated swine slurry and chemical N fertilizer (i.e., HTSS+LAS, a high amount of TSS with a low amount of ammonium sulfate; LTSS+HAS, a low amount of TSS with a high amount of ammonium sulfate; AS, ammonium sulfate with phosphorus and potassium; C, the control) and (2) to compare the rice response to applied N derived from each N fertilization practice. Rice biomass yield, 15N recovery in both rice grain and stems, soil total N (TN), soil inorganic N, and soil 15N recovery were analyzed. Similar amounts of 15N uptake by rice in the TSS+AS plots were obtained, indicating that the effects of the different quantities of TSS on chemical fertilizer N recovery in rice during the experimental period were not significant. The soil 15N recoveries of HTSS+LAS, LTSS+HAS, and AS in each soil layer were not significantly different. For the HTSS+LAS, LTSS+HAS and AS applications, total 15N recoveries were 42%, 43% and 54%, respectively. Because the effects of reducing the use of chemical N fertilizer were attributed to enhancing soil quality and cost-effectiveness, HTSS+LAS could be an appropriate N fertilization practice for improving the long-term sustainability of paddy soil-plant systems. However, N losses, especially through the coupled nitrification-denitrification process, can diminish the benefits that HTSS+LAS offers. PMID:28339491
Lee, Joonhee; Choi, Hong L
2017-01-01
A well-managed chemical nitrogen (N) fertilization practice combined with treated swine slurry (TSS) is necessary to improve sustainability and N use efficiency in rice farming. However, little is known about the fate of N derived from chemical N fertilizer with and without TSS in paddy soil-plant systems. The objectives of this study were (1) to estimate the contribution of applied N fertilizer to N turnover in rice paddy soil with different N fertilization practices that were manipulated by the quantity of treated swine slurry and chemical N fertilizer (i.e., HTSS+LAS, a high amount of TSS with a low amount of ammonium sulfate; LTSS+HAS, a low amount of TSS with a high amount of ammonium sulfate; AS, ammonium sulfate with phosphorus and potassium; C, the control) and (2) to compare the rice response to applied N derived from each N fertilization practice. Rice biomass yield, 15N recovery in both rice grain and stems, soil total N (TN), soil inorganic N, and soil 15N recovery were analyzed. Similar amounts of 15N uptake by rice in the TSS+AS plots were obtained, indicating that the effects of the different quantities of TSS on chemical fertilizer N recovery in rice during the experimental period were not significant. The soil 15N recoveries of HTSS+LAS, LTSS+HAS, and AS in each soil layer were not significantly different. For the HTSS+LAS, LTSS+HAS and AS applications, total 15N recoveries were 42%, 43% and 54%, respectively. Because the effects of reducing the use of chemical N fertilizer were attributed to enhancing soil quality and cost-effectiveness, HTSS+LAS could be an appropriate N fertilization practice for improving the long-term sustainability of paddy soil-plant systems. However, N losses, especially through the coupled nitrification-denitrification process, can diminish the benefits that HTSS+LAS offers.
Ponderosa pine response to fertilization: influence of brush removal and soil type
Robert F. Powers; Grant D. Jackson
1978-01-01
First-year results of fertilization in a young ponderosa pine plantation on two contrasting soils were analyzed. Trees testing low in foliar nitrogen responded strongly to fertilization where brush had been removed, but failed to respond if brush remained. Height growth was doubled by certain treatment combinations on the less fertile Mariposa soil, but was not...
C. H. Pham; Howard G. Halverson; Gordon M. Heisler
1978-01-01
Red maple (Acer rubrum L.) seedlings were grown in a greenhouse using three treatments: two soil horizons, two soil moisture regimes, and three nutrient levels. Fertilization increased growth under moist conditions on the more fertile topsoil. Under dry conditions, fertilization had no effect on growth in subsoil, and slightly increased growth in...
Pittaway, P A; Melland, A R; Antille, D L; Marchuk, S
2018-05-01
The progressive decline of soil organic matter (SOM) threatens the sustainability of arable cropping worldwide. Residue removal and burning, destruction of protected microsites, and the acceleration of microbial decomposition are key factors. Desorption of SOM by ammonia-based fertilizers from organomineral complexes in soil may also play a role. A urea- and molasses-based liquid fertilizer formulation and a urea-based granular formulation were applied at recommended and district practice rates, respectively, to soil leaching columns, with unfertilized columns used as controls. The chemistry of leachate collected from the columns, filled with two sandy soils differing in recent cropping history, was monitored over eight successive wet-dry drainage events. The pH, electrical conductivity, and concentration and species of N in leachate was compared with the concentration and aromaticity of dissolved organic C (DOC) to indicate if salt solutions derived from the two fertilizers extracted SOM from clay mineral sites. Cation exchange capacity and exchangeable cations in the soil were monitored at the start and end of the trial. Fertilizer application increased DOC in leachate up to 40 times above the control, but reduced aromaticity (specific ultraviolet light absorbance at 253.7 nm). Dissolved organic C was linearly proportional to leachate NH-N concentration. Exchangeable Ca and Mg in soil from fertilized columns at the end of both trials were significantly lower than in unfertilized soil, indicating that ammonium salt solutions derived from the fertilizers extracted cations and variably charged organic matter from soil mineral exchange sites. Desorption of organic matter and divalent cations from organomineral sites by ammonia-based fertilizers may be implicated in soil acidification. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Coucheney, Elsa; Strömgren, Monika; Lerch, Thomas Z; Herrmann, Anke M
2013-01-01
Boreal ecosystems store one-third of global soil organic carbon (SOC) and are particularly sensitive to climate warming and higher nutrient inputs. Thus, a better description of how forest managements such as nutrient fertilization impact soil carbon (C) and its temperature sensitivity is needed to better predict feedbacks between C cycling and climate. The temperature sensitivity of in situ soil C respiration was investigated in a boreal forest, which has received long-term nutrient fertilization (22 years), and compared with the temperature sensitivity of C mineralization measured in the laboratory. We found that the fertilization treatment increased both the response of soil in situ CO2 effluxes to a warming treatment and the temperature sensitivity of C mineralization measured in the laboratory (Q10). These results suggested that soil C may be more sensitive to an increase in temperature in long-term fertilized in comparison with nutrient poor boreal ecosystems. Furthermore, the fertilization treatment modified the SOC content and the microbial community composition, but we found no direct relationship between either SOC or microbial changes and the temperature sensitivity of C mineralization. However, the relation between the soil C:N ratio and the fungal/bacterial ratio was changed in the combined warmed and fertilized treatment compared with the other treatments, which suggest that strong interaction mechanisms may occur between nutrient input and warming in boreal soils. Further research is needed to unravel into more details in how far soil organic matter and microbial community composition changes are responsible for the change in the temperature sensitivity of soil C under increasing mineral N inputs. Such research would help to take into account the effect of fertilization managements on soil C storage in C cycling numerical models. PMID:24455147
Civil-Military Collaboration to Address Adaptation to Climate Change in South America
2011-03-01
drought, water scarcity and soil degradation, intensify land use conflicts (especially in the Andean and Amazon Regions) and trigger environmentally...of the territories , climatic variability, and food scarcity are common problems for many of the countries of the region, which are in dire need to...resource conflicts. Because climate change can further affect such environmental issues as water, forests , soil fertility, hunger, disease, health, and
Energizing marginal soils: A perennial cropping system for Sida hermaphrodita
NASA Astrophysics Data System (ADS)
Nabel, Moritz; Poorter, Hendrik; Temperton, Vicky; Schrey, Silvia D.; Koller, Robert; Schurr, Ulrich; Jablonowski, Nicolai D.
2017-04-01
As a way to avoid land use conflicts, the use of marginal soils for the production of plant biomass can be a sustainable alternative to conventional biomass production (e.g. maize). However, new cropping strategies have to be found that meet the challenge of crop production under marginal soil conditions. We aim for increased soil fertility by the use of the perennial crop Sida hermaphrodita in combination with organic fertilization and legume intercropping to produce substantial biomass yield. We present results of a three-year outdoor mesocosm experiment testing the perennial energy crop Sida hermaphrodita grown on a marginal model substrate (sand) with four kinds of fertilization (Digestate broadcast, Digestate Depot, mineral NPK and unfertilized control) in combination with legume intercropping. After three years, organic fertilization (via biogas digestate) compared to mineral fertilization (NPK), reduced the nitrate concentration in leachate and increased the soil carbon content. Biomass yields of Sida were 25% higher when fertilized organically, compared to mineral fertilizer. In general, digestate broadcast application reduced root growth and the wettability of the sandy substrate. However, when digestate was applied locally as depot to the rhizosphere, root growth increased and the wettability of the sandy substrate was preserved. Depot fertilization increased biomass yield by 10% compared to digestate broadcast fertilization. We intercropped Sida with various legumes (Trifolium repens, Trifolium pratense, Melilotus spp. and Medicago sativa) to enable biological nitrogen fixation and make the cropping system independent from synthetically produced fertilizers. We could show that Medicago sativa grown on marginal substrate fixed large amounts of N, especially when fertilized organically, whereas mineral fertilization suppressed biological nitrogen fixation. We conclude that the perennial energy crop Sida in combination with organic fertilization has great potential to increase the soil fertility of marginal substrates and produce substantial biomass yields.
Is leaf dry matter content a better predictor of soil fertility than specific leaf area?
Hodgson, J. G.; Montserrat-Martí, G.; Charles, M.; Jones, G.; Wilson, P.; Shipley, B.; Sharafi, M.; Cerabolini, B. E. L.; Cornelissen, J. H. C.; Band, S. R.; Bogard, A.; Castro-Díez, P.; Guerrero-Campo, J.; Palmer, C.; Pérez-Rontomé, M. C.; Carter, G.; Hynd, A.; Romo-Díez, A.; de Torres Espuny, L.; Royo Pla, F.
2011-01-01
Background and Aims Specific leaf area (SLA), a key element of the ‘worldwide leaf economics spectrum’, is the preferred ‘soft’ plant trait for assessing soil fertility. SLA is a function of leaf dry matter content (LDMC) and leaf thickness (LT). The first, LDMC, defines leaf construction costs and can be used instead of SLA. However, LT identifies shade at its lowest extreme and succulence at its highest, and is not related to soil fertility. Why then is SLA more frequently used as a predictor of soil fertility than LDMC? Methods SLA, LDMC and LT were measured and leaf density (LD) estimated for almost 2000 species, and the capacity of LD to predict LDMC was examined, as was the relative contribution of LDMC and LT to the expression of SLA. Subsequently, the relationships between SLA, LDMC and LT with respect to soil fertility and shade were described. Key Results Although LD is strongly related to LDMC, and LDMC and LT each contribute equally to the expression of SLA, the exact relationships differ between ecological groupings. LDMC predicts leaf nitrogen content and soil fertility but, because LT primarily varies with light intensity, SLA increases in response to both increased shade and increased fertility. Conclusions Gradients of soil fertility are frequently also gradients of biomass accumulation with reduced irradiance lower in the canopy. Therefore, SLA, which includes both fertility and shade components, may often discriminate better between communities or treatments than LDMC. However, LDMC should always be the preferred trait for assessing gradients of soil fertility uncoupled from shade. Nevertheless, because leaves multitask, individual leaf traits do not necessarily exhibit exact functional equivalence between species. In consequence, rather than using a single stand-alone predictor, multivariate analyses using several leaf traits is recommended. PMID:21948627
Is leaf dry matter content a better predictor of soil fertility than specific leaf area?
Hodgson, J G; Montserrat-Martí, G; Charles, M; Jones, G; Wilson, P; Shipley, B; Sharafi, M; Cerabolini, B E L; Cornelissen, J H C; Band, S R; Bogard, A; Castro-Díez, P; Guerrero-Campo, J; Palmer, C; Pérez-Rontomé, M C; Carter, G; Hynd, A; Romo-Díez, A; de Torres Espuny, L; Royo Pla, F
2011-11-01
Specific leaf area (SLA), a key element of the 'worldwide leaf economics spectrum', is the preferred 'soft' plant trait for assessing soil fertility. SLA is a function of leaf dry matter content (LDMC) and leaf thickness (LT). The first, LDMC, defines leaf construction costs and can be used instead of SLA. However, LT identifies shade at its lowest extreme and succulence at its highest, and is not related to soil fertility. Why then is SLA more frequently used as a predictor of soil fertility than LDMC? SLA, LDMC and LT were measured and leaf density (LD) estimated for almost 2000 species, and the capacity of LD to predict LDMC was examined, as was the relative contribution of LDMC and LT to the expression of SLA. Subsequently, the relationships between SLA, LDMC and LT with respect to soil fertility and shade were described. Although LD is strongly related to LDMC, and LDMC and LT each contribute equally to the expression of SLA, the exact relationships differ between ecological groupings. LDMC predicts leaf nitrogen content and soil fertility but, because LT primarily varies with light intensity, SLA increases in response to both increased shade and increased fertility. Gradients of soil fertility are frequently also gradients of biomass accumulation with reduced irradiance lower in the canopy. Therefore, SLA, which includes both fertility and shade components, may often discriminate better between communities or treatments than LDMC. However, LDMC should always be the preferred trait for assessing gradients of soil fertility uncoupled from shade. Nevertheless, because leaves multitask, individual leaf traits do not necessarily exhibit exact functional equivalence between species. In consequence, rather than using a single stand-alone predictor, multivariate analyses using several leaf traits is recommended.
Lee, Chia-Hsing; Huang, Hsuan-Han; Syu, Chien-Hui; Lin, Tzu-Huei; Lee, Dar-Yuan
2014-07-15
Silicon (Si) was shown to be able to reduce arsenic (As) uptake by rice in hydroponic culture or in low As soils using high Si application rates. However, the effect of Si application on As uptake of rice grown in As-contaminated soils using Si fertilizer recommendation rate has not been investigated. In this study, the effect of Si application using Si fertilizer recommendation rate on As release and phytotoxicity in soils with different properties and contents of As was examined. The results show that the concentrations of As in soil solutions increased after Si applications due to competitive adsorption between As and Si on soil solids and the Si concentrations in soil solutions were also elevated to beneficial levels for rice growth. The rice seedlings accumulated more As and its growth was inhibited by Si application in As contaminated/spiked soils. The results indicate that there is an initial aggravation in As toxicity before the beneficial effects of Si fertilizing to rice were revealed when Si application based on fertilizer recommendation rate to As-contaminated paddy soils. Therefore, for As-contaminated paddy soils with high levels of As, the application of Si fertilizer could result in increasing As phytotoxicity and uptake by rice. Copyright © 2014 Elsevier B.V. All rights reserved.
Diversity of inland valleys and opportunities for agricultural development in Sierra Leone.
Dossou-Yovo, Elliott Ronald; Baggie, Idriss; Djagba, Justin Fagnombo; Zwart, Sander Jaap
2017-01-01
Inland valleys are becoming increasingly important agricultural production areas for rural households in sub-Saharan Africa due to their relative high and secure water availability and soil fertility. In addition, inland valleys are important as water buffer and biodiversity hot spots and they provide local communities with forest, forage, and fishing resources. As different inland-valley ecosystem functions may conflict with agricultural objectives, indiscriminate development should be avoided. This study aims to analyze the diversity of inland valleys in Sierra Leone and to develop guidelines for more precise interventions. Land use, biophysical and socio-economic data were analyzed on 257 inland valleys using spatial and multivariate techniques. Five cluster groups of inland valleys were identified: (i) semi-permanently flooded with high soil organic carbon (4.2%) and moderate available phosphorus (10.2 ppm), mostly under natural vegetation; (ii) semi-permanently flooded with low soil organic carbon (1.5%) and very low available phosphorus (3.1 ppm), abandoned by farmers; (iii) seasonally flooded with moderate soil organic carbon (3.1%) and low available phosphorus (8.3 ppm), used for rainfed rice and off-season vegetables produced without fertilizer application for household consumption and market; (iv) well drained with moderate soil organic carbon (3.8%) and moderate available phosphorus (10.0 ppm), used for rainfed rice and off-season vegetables produced with fertilizer application for household consumption and market; and (v) well drained with moderate soil organic carbon (3.6%) and moderate available phosphorus (11 ppm), used for household consumption without fertilizer application. Soil organic carbon, available phosphorus, hydrological regime, physical accessibility and market opportunity were the major factors affecting agricultural intensification of inland valleys. Opening up the areas in which inland valleys occur through improved roads and markets, and better water control through drainage infrastructures along with an integrated nutrient management would promote the sustainable agricultural use of inland valleys.
Sun, Jia Un; Fu, Qing Xia; Gu, Jie; Wang, Xiao Juan; Gao, Hua
2016-03-01
A field experiment was conducted to compare the effects of three fertilizer managements (bio-organic fertilizer, traditional organic fertilizer and chemical fertilizer) and a no-fertilizer control on soil enzyme activities and microbial community functional diversity in a kiwifruit orchard. The results showed that the soil invertase and FDA hydrolase activities in the bio-organic fertilizer treatment were 12.2%-129.4% and 18.8%-87.4% higher than those in the no-fertilizer control during kiwifruit growth period, respectively. The application of bio-organic fertilizer also increased soil urease and acid phosphatase activities at the expanding stage and maturity stage. The Biolog results suggested that bio-organic fertilizer treatment improved the average well color development (AWCD) and increased the species diversity, richness and evenness. The relative ratios of six groups of carbon sources by microbes were changed to some extent after the application of bio-organic fertilizer. Compared with the no-fertilizer control, bio-organic fertilizer application decreased the capacity of microbes in using amino acids, but enhanced the utilization of polyphenols and polyamines. The principal components analysis demonstrated that the differentiation of microbial community was mainly in utilization of carbohydrates, amino acids and carboxylic acids.
NASA Astrophysics Data System (ADS)
Tiemann, Lisa; Grandy, Stuart; Hartter, Joel
2014-05-01
Soil is the keystone in building sustainable agricultural systems, but increased demand for these soil services has led to soil degradation, particularly in sub-Saharan Africa. In Uganda, where population growth rates are 9th highest in the world, increasing pressure on soil resources and potential losses of SOM are particularly concerning because there is virtually no use of fertilizers or other inputs on farms. In addition, smallholder farmers in Uganda are placing greater emphasis on resource-intensive cash crops like maize, and thereby straining soil resources. In this study we investigate the relationships between land use decisions and soil fertility to better understand declines in soil fertility and how they might be slowed near Kibale National Park (KNP), Uganda, a global biodiversity hotspot. Within 2.5 km of the KNP border, we conducted household surveys and collected soil samples in 160 farms along a 20 km north-south transect. We also collected soils from inside KNP, adjacent to farms we visited, to serve as controls. Cultural differences in land use, such as greater residue removal and a lower likelihood of legumes in rotation with the Bakiga, likely led to the greater declines in SOM and soil fertility we observed in Bakiga compared to Batooro maize fields. We also found that households in areas of high soil fertility are more reliant on maize sales. Surprisingly, these same areas have also seen relatively smaller declines in total SOM, but do show larger relative declines in nutrients (e.g. N, P and K) when compared to the adjacent KNP soils. We found lower depletion of nutrients and overall higher soil fertility measures and more stability of SOM in banana fields compared to maize fields, which is due to transferring maize crop residues to banana plantations as well as no-till practices in banana fields. Our work reveals that complex interactions between edaphic soil properties, land use management, cultural background, perceptions of soil fertility and SOM dynamics will constrain the region's capacity to meet the demands of rapid population growth.
Zhao, Lijuan; Whan, Xiaozeng; Wang, Shouyu; Liu, Hongxiang; Li, Haibo; Miao, Shujie; Ang, Feng
2006-05-01
A long-term experiment was conducted on a black soil of Northeast China to study the effects of applying chemical fertilizers and recycled organic manure (ROM) on the changes of soil organic carbon and its fractions. The results showed that from 1985 to 2004, soil total organic carbon (TOC) decreased by 7.83% in control,4.56% in N application, 1.61% in N + P application, and 5.56% in ROM application, but increased by 0.33% in N + P + K application. Comparing with single application of ROM, its application with chemical fertilizers, i. e., N + ROM, N + P + ROM, and N + P + K + ROM, increased the TOC concentration by 0.35%, 1.05% and 0.64%, respectively. The readily oxidized carbon (ROC) in fertilization treatments was increased by 8.64% to approximately 28.4%, and the increment was higher in treatments of chemical fertilizers plus ROM than in treatments of chemical fertilizers. The ROC was significantly correlated with soil TOC (Y = 14.192X + 23.9, R2 = 0.802) and stalk yields (Y = 19032X - 7950.6, R2 = 0.759). Light fraction organic carbon (LF-C) had the same trends with ROC. After 20 years fertilization, the organic carbon in soil humic acid and fulvic acid was decreased by 1.64% to approximately 26.23% and 2.33% to approximately 28.68%, respectively, but in treatments of chemical fertilizers plus ROM, the decreasing trend was slowed down.
Effect of land management on soil properties in flood irrigated citrus orchards in Eastern Spain
NASA Astrophysics Data System (ADS)
Morugán-Coronado, A.; García-Orenes, F.; Cerdà, A.
2015-01-01
Agricultural land management greatly affects soil properties. Microbial soil communities are the most sensitive and rapid indicators of perturbations in land use and soil enzyme activities are sensitive biological indicators of the effects of soil management practices. Citrus orchards frequently have degraded soils and this paper evaluates how land management in citrus orchards can improve soil quality. A field experiment was performed in an orchard of orange trees (Citrus Sinensis) in the Alcoleja Experimental Station (Eastern Spain) with clay-loam agricultural soils to assess the long-term effects of herbicides with inorganic fertilizers (H), intensive ploughing and inorganic fertilizers (P) and organic farming (O) on the soil microbial properties, and to study the relationship between them. Nine soil samples were taken from each agricultural management plot. In all the samples the basal soil respiration, soil microbial biomass carbon, water holding capacity, electrical conductivity, soil organic matter, total nitrogen, available phosphorus, available potassium, aggregate stability, cation exchange capacity, pH, texture, macronutrients (Na, Ca and Mg), micronutrients (Fe, Mn, Zn and Cu), calcium carbonate equivalent, calcium carbonate content of limestone and enzimatic activities (urease, dehydrogenase, β-glucosidase and acid phosphatase) were determined. The results showed a substantial level of differentiation in the microbial properties, which were highly associated with soil organic matter content. The management practices including herbicides and intensive ploughing had similar results on microbial soil properties. O management contributed to an increase in the soil biology quality, aggregate stability and organic matter content.
Madejón, P; Xiong, J; Cabrera, F; Madejón, E
2014-11-01
The use of fast growing trees could be an alternative in trace element contaminated soils to stabilize these elements and improve soil quality. In this study we investigate the effect of Paulownia fortunei growth on trace element contaminated soils amended with two organic composts under semi-field conditions for a period of 18 months. The experiment was carried out in containers filled with tree different soils, two contaminated soils (neutral AZ and acid V) and a non contaminated soil, NC. Three treatments per soil were established: two organic amendments (alperujo compost, AC, and biosolid compost, BC) and a control without amendment addition. We study parameters related with fertility and contamination in soils and plants. Paulownia growth and amendments increased pH in acid soils whereas no effect of these factors was observed in neutral soils. The plant and the amendments also increased organic matter and consequently, soil fertility. Positive results were also found in soils that were only affected by plant growth (without amendment). A general improvement of "soil biochemical quality" was detected over time and treatments, confirming the positive effect of amendments plus paulownia. Even in contaminated soils, except for Cu and Zn, trace element concentrations in leaves were in the normal range for plants. Results of this mid-term study showed that Paulownia fortunei is a promising species for phytoremediation of trace element polluted soils. Copyright © 2014 Elsevier Ltd. All rights reserved.
Data of heavy metals in soil and groundwater at Kiwi gardens of Amlash in Guilan Province, Iran.
Naghipour, Dariush; Ashrafi, Seyed Davoud; Taghavi, Kamran
2018-06-01
Data on this paper describe the concentrations of arsenic, cadmium, copper, nickel, lead and zinc in the surface soils and groundwater's of Kiwi gardens and its relation to chemical fertilizers in Amlash city, Guilan Province, in Iran. The results of this study showed that the average concentration of heavy metals in groundwater and soils of the studied areas was less than the national standards of Iran for irrigation water, Dutch MPA for soils (except Cu and Ni) and Canadian MAC for inorganic fertilizers. Considering that after fertilizing to soils used in gardening, the concentration of heavy metals in groundwater and soil can be increased significantly, so that chemical fertilizers can be considered as an effective factor in increasing the amount of heavy metals in water and soil. The results of this research can be used by who concern about water and soil quality related to fertilizing and also can be used by Rural Water and Wastewater Company and Ministry of Jahad Agriculture of Iran.
Liu, J; Zhang, F
2000-06-01
The effects of long-term applying fertilizer P and manure on the pools of soil total P and inorganic P and the crop yield in rotation of winter wheat-summer maize-->spring maize were studied. The results showed that the pool of soil total P and inorganic P were increased by applying fertilizer P and manure, and the phosphorus mostly accumulated in soil was inorganic P. The critical amounts of fertilizer P (P2O5) for balancing soil P were 94.7 kg.hm-2 to winter wheat-summer maize and 51.5 kg.hm-2 to spring maize. Based on regression equations, the application rates of fertilizer P (P2O5) for economic optimum and highest yields were 135.8 and 149.8 kg.hm-2 to winter wheat-summer maize, and 88.6 and 95.9 kg.hm-2 to spring maize, respectively.
Soil and solid poultry waste nutrient management and water quality.
Chapman, S L
1996-07-01
Concerns about the impacts of nitrogen, phosphorus, and pathogens on surface and ground water quality has forced the poultry industry to implement voluntary waste management guidelines for use by growers. In some states, animal waste guidelines are being enforced by regulatory agencies. Strategies that growers may use to properly dispose of poultry waste include: 1) local land application as a fertilizer; 2) offsite marketing for use as a fertilizer or soil amendment, feed additive, or energy source; and 3) chemical additives that will immobilize nitrogen and phosphorus in the manure or litter. If properly followed, these and other innovative strategies should be adequate to protect surface and ground water quality without adversely affecting the economics of poultry production.
NASA Astrophysics Data System (ADS)
Fornara, Dario A.; Wasson, Elizabeth-Anne; Christie, Peter; Watson, Catherine J.
2016-09-01
Sustainable grassland intensification aims to increase plant yields while maintaining the ability of soil to act as a sink rather than sources of atmospheric CO2. High biomass yields from managed grasslands, however, can be only maintained through long-term nutrient fertilization, which can significantly affect soil carbon (C) storage and cycling. Key questions remain about (1) how long-term inorganic vs. organic fertilization influences soil C stocks, and (2) how soil C gains (or losses) contribute to the long-term C balance of managed grasslands. Using 43 years of data from a permanent grassland experiment, we show that soils not only act as significant C sinks but have not yet reached C saturation. Even unfertilized control soils showed C sequestration rates of 0.35 Mg C ha-1 yr-1 (i.e. 35 g C m-2 yr-1; 0-15 cm depth) between 1970 and 2013. High application rates of liquid manure (i.e. cattle slurry) further increased soil C sequestration to 0.86 Mg C ha-1 yr-1 (i.e. 86 g C m-2 yr-1) and a key cause of this C accrual was greater C inputs from cattle slurry. However, average coefficients of slurry-C retention in soils suggest that 85 % of C added yearly through liquid manure is lost possibly via CO2 fluxes and organic C leaching. Inorganically fertilized soils (i.e. NPK) had the lowest C-gain efficiency (i.e. unit of C gained per unit of N added) and lowest C sequestration (similar to control soils). Soils receiving cattle slurry showed higher C-gain and N-retention efficiencies compared to soils receiving NPK or pig slurry. We estimate that net rates of CO2-sequestration in the top 15 cm of the soil can offset 9-25 % of GHG (greenhouse gas) emissions from intensive management. However, because of multiple GHG sources associated with livestock farming, the net C balance of these grasslands remains positive (9-12 Mg CO2-equivalent ha-1 yr-1), thus contributing to climate change. Further C-gain efficiencies (e.g. reduced enteric fermentation and use of feed concentrates, better nutrient management) are required to make grassland intensification more sustainable.
Effect of fertilizer application on NO and N2O fluxes from agricultural fields
NASA Astrophysics Data System (ADS)
Harrison, Roy M.; Yamulki, Sirwan; Goulding, K. W. T.; Webster, C. P.
1995-12-01
Losses of fertilizer as NO and N2O were studied at Broadbalk field, Rothamsted Experimental Station in England, on which subplots have been subject to differing constant levels of fertilizer application for many years. Fluxes of NO and N2O were measured using open- and closed-chamber techniques, respectively. Fluxes from unfertilized soil ranged from 0.3 to 4.8 ng N m-2 s-1 for NO and 0.23 to 3.0 ng N m-2 s-1 for N2O. The corresponding fluxes from the plot with the highest fertilizer application (92 kg N ha-1 yr-1 as NH4NO3) ranged from 0.5 to 64 ng N m-2 s-1 for NO and 0.4 to 240 ng N m-2 s-1 for N2O. Application of increasing amounts of fertilizer substantially enhanced emission rates of both NO and N2O. However, the amount of increase was controlled by competition between the crop and the microorganisms for the available soil nutrients, and loss of N2O to the atmosphere increased sharply at superoptimal levels of fertilizer application. The fertilizer-derived NO and N2O emissions represented approximately 90% of the total emission of these gases during the 25-day sampling period after fertilizer application. The results suggest that while increasing the amount of fertilizer increases both NO and N2O fluxes simultaneously, the NO/N2O emission ratio decreases. Results from laboratory experiments showed that the magnitude of the fertilizer loss as N2O was strongly affected by the form of the applied fertilizer.
Cynthia D. Huebner; Jim Steinman; Todd F. Hutchinson; Todd E. Ristau; Alejandro A. Royo
2014-01-01
Background and aims. A soil fertility gradient, ranging from infertile to highly fertile soils, may define whether or not a plant will establish and spread at a site. We evaluated whether or not such a fertility gradient exists for Rosa multiflora Thunb., a nonnative invasive shrub, and Kalmia latifolia L., a...
Long-Term Responses of Understory Vegetation on a Highly Erosive Louisiana Soil to Fertilization
James D. Haywood; Ronald E. Thill
1995-01-01
Responses of vegetation on highly eroded Kisatchie soils to a broadcast application of 600 lb/acre of 16-30-l 3 granular fertilizer were monitored for 12 years. Understory woody and herbaceous vegetation responded to fertilization immediately, and thus the soil surface was protected from erosion sooner in the fertilized area than in the two unfertilized areas. After 1...
Zielinski, R.A.; Asher-Bolinder, S.; Meier, A.L.; Johnson, C.A.; Szabo, B. J.
1997-01-01
Drainage from heavily cultivated soils may be contaminated with U that is leached from the soil or added as a trace constituent of PO4-based commercial fertilizer. The effect of decades-long application of U-rich fertilizer on the U concentration of irrigation drainage was investigated in a small (14.2 km2) drainage basin in southeastern Colorado. The basin was chosen because previous reports indicated locally anomalous concentrations of dissolved NO3(6-36 mg l-1) and dissolved U (61 ??g l-1) at the mouth of the only stream. Results of this study indicated minimal impact of fertilizer-U compared to natural U leached from the local soils. Detailed sampling of the stream along a 6 mile (9.7 km) reach through heavily cultivated lands indicated marked decoupling of the buildup of dissolved NO3 and U. Dissolved U increased markedly in the upstream half of the reach and correlated positively with increases in Na, Mg, SO4, B and Li derived from leaching of surrounding shaley soils. In contrast, major increases in dissolved NO3 occurred farther downstream where stream water was heavily impacted by ground water return from extensively fertilized fields. Nitrogen isotopic measurements confirmed that dissolved NO3 originated from fertilizer and soil organic N (crop waste). Uranium isotopic measurements of variably uraniferous waters showed little evidence of contamination with fertilizer-derived U of isotopically distinct 234U/238U alpha activity ratio (A.R. = 1.0). Leaching experiments using local alkaline soil, irrigation water and U-rich fertilizer confirmed the ready leachability of soil-bound U and the comparative immobility of U added with liquid fertilizer. Relatively insoluble precipitates containing Ca-P-U were formed by mixing liquid fertilizer with water containing abundant dissolved Ca. In the local soils soluble Ca is provided by dissolution of abundant gypsum. Similar studies are needed elsewhere because the mobility of fertilizer-derived U is dependent on fertilizer type, porewater chemistry and soil properties (pH, moisture, mineralogy, texture).
Wang, Yongjie; Dang, Fei; Evans, R. Douglas; Zhong, Huan; Zhao, Jiating; Zhou, Dongmei
2016-01-01
Methylmercury (MeHg) accumulation in rice has great implications for human health. Here, effects of selenium (Se) on MeHg availability to rice are explored by growing rice under soil or foliar fertilization with Se. Results indicate that soil amendment with Se could reduce MeHg levels in soil and grain (maximally 73%). In contrast, foliar fertilization with Se enhanced plant Se levels (3–12 folds) without affecting grain MeHg concentrations. This evidence, along with the distinct distribution of MeHg and Se within the plant, demonstrate for the first time that Se-induced reduction in soil MeHg levels (i.e., MeHg-Se antagonism in soil) rather than MeHg-Se interactions within the plant might be the key process triggering the decreased grain MeHg levels under Se amendment. The reduction in soil MeHg concentrations could be mainly attributed to the formation of Hg-Se complexes (detected by TEM-EDX and XANES) and thus reduced microbial MeHg production. Moreover, selenite and selenate were equally effective in reducing soil MeHg concentrations, possibly because of rapid changes in Se speciation. The dominant role of Se-induced reduction in soil MeHg levels, which has been largely underestimated previously, together with the possible mechanisms advance our mechanistic understanding about MeHg dynamics in soil-rice systems. PMID:26778218
NASA Astrophysics Data System (ADS)
Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes
2017-04-01
Plant litter decomposition is a global ecosystem process, with a crucial role in carbon and nutrient cycling. The majority of litter processing occurs in terrestrial systems, but an important fraction also takes place in inland waters. Among environmental factors, pH impacts the litter decomposition through its selective influence on microbial decomposers. Fungal communities are less affected by pH than bacteria, possibly owing to a wider pH tolerance by this group. On the other hand, bacterial pH optima are constrained to a narrower range of pH values. The microbial decomposition of litter is universally nutrient limited; but few comparisons exist between terrestrial and aquatic systems. We investigated the microbial colonisation and decomposition of plant litter along a fertility gradient, which varied in both pH and N availability in both soil and adjacent water. To do this we installed litterbags with birch (Betula pendula) in streams and corresponding soils in adjacent riparian areas in a boreal system, in Krycklan, Sweden. During the four months covering the ice-free growth season we monitored the successional dynamics of fungal (acetate incorporation into ergosterol) and bacterial growth (thymidine incorporation), microbial respiration in leaf litter, and quantitative and qualitative changes in litter over time. We observed that bacterial growth rates were initially higher in litter decomposing in streams than those in soils, but differences between terrestrial and aquatic bacterial production converged towards the end of the experiment. In litter bags installed in soils, bacterial growth was lower at sites with more acidic pH and lower N availability, while aquatic bacteria were relatively unaffected by the fertility level. Fungal growth rates were two-fold higher for litter decomposing in streams than in soils. In aquatic systems, fungal growth was initially lower in low fertility sites, but differences gradually disappeared over the time course. Fungal growth rates measured on litter-bags in soils were relatively stable over time, with unclear links to fertility. Microbial respiration rates were highest in litterbags buried in soils, and only initially negatively affected by pH. There was a large decrease in litter mass loss initially in aquatic systems. Subsequently the rates of loss stabilized to similar values to those in terrestrial systems, to finally be exceeded by the rates of loss in terrestrial systems. In conclusion, initial decomposition of litter appeared to be N-limited in aquatic systems, which was associated with a fungal dominance. In contrast, litter decomposition in terrestrial systems appeared to be lower in acidic sites, which coincided with lower growth rates of bacteria. Litter degradation was initially faster in aquatic systems, but overall mass-loss over the full time course was higher in terrestrial systems.
Fertilizer and Mulch Improves Yellow-Poplar Growth on Exposed harsells Subsoils
John K. Francis
1977-01-01
Fertilizing and mulching of eroded Hartsells soil increased height and diameter of yellow-poplars. To see if chemical infertility of exposed Hartsells subsoils limits yellow-poplar growth and to test fertilizer and mulch as remedial agents, seedlings were planted on undisturbed soil, soil with the topsoil removed, and soil with the topsoil removed but mulched with leaf...
Wu, Jiasen; Huang, Jianqin; Liu, Dan; Li, Jianwu; Zhang, Jinchi; Wang, Hailong
2014-01-01
Chinese hickory (Carya cathayensis), a popular nut food tree species, is mainly distributed in southeastern China. A field study was carried out to investigate the effect of long-term intensive management on fertility of soils under a C. cathayensis forest. Results showed that after 26 years' intensive management, the soil organic carbon (SOC) content of the A and B horizons reduced by 19% and 14%, respectively. The reduced components of SOC are mainly the alkyl C and O-alkyl C, whereas the aromatic C and carbonyl C remain unchanged. The reduction of active organic matter could result in degradation of soil fertility. The pH value of soil in the A horizon had dropped by 0.7 units on average. The concentrations of the major nutrients also showed a decreasing trend. On average the concentrations of total nitrogen (N), phosphorus (P), and potassium (K) of tested soils dropped by 21.8%, 7.6%, and 13.6%, respectively, in the A horizon. To sustain the soil fertility and C. cathayensis production, it is recommended that more organic fertilizers (manures) should be used together with chemical fertilizers. Lime should also be applied to reduce soil acidity. PMID:24558339
Wu, Jiasen; Huang, Jianqin; Liu, Dan; Li, Jianwu; Zhang, Jinchi; Wang, Hailong
2014-01-01
Chinese hickory (Carya cathayensis), a popular nut food tree species, is mainly distributed in southeastern China. A field study was carried out to investigate the effect of long-term intensive management on fertility of soils under a C. cathayensis forest. Results showed that after 26 years' intensive management, the soil organic carbon (SOC) content of the A and B horizons reduced by 19% and 14%, respectively. The reduced components of SOC are mainly the alkyl C and O-alkyl C, whereas the aromatic C and carbonyl C remain unchanged. The reduction of active organic matter could result in degradation of soil fertility. The pH value of soil in the A horizon had dropped by 0.7 units on average. The concentrations of the major nutrients also showed a decreasing trend. On average the concentrations of total nitrogen (N), phosphorus (P), and potassium (K) of tested soils dropped by 21.8%, 7.6%, and 13.6%, respectively, in the A horizon. To sustain the soil fertility and C. cathayensis production, it is recommended that more organic fertilizers (manures) should be used together with chemical fertilizers. Lime should also be applied to reduce soil acidity.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Long, T.M.
1995-09-01
In general, C3 annual plants respond positively in terms of growth, reproduction and biomass accrued when grown under elevated levels of atmospheric carbon dioxide. However, most studies documenting this response have been conducted in growth chambers where plants can be reared under conditions free form environmental stressors such as nutrient and water constraints, UV exposure and damage from pests. During the 1993 fieldseason, I grew 200 individuals of Solanum ptycanthum in an array of 10 outdoor, open-topped CO2 enclosures (5 @ 700 ppm CO2) at the University of Michigan Biological Station in Pellston, MI. Half of the plants were grownmore » in a 50;50 mix of native C-horizon soil and topsoil (low fertility); the other half were grown in 100% topsoil (high-fertility). Plants were censused throughout the growing season for flower and fruit production, growth rate and degree of infestation of aphids. Fertility and CO2 both significantly affected production of flowers and fruits, but only fertility was significantly related to vegetative growth. Aphid infestation varied significantly among enclosures, but was not related to CO2 or fertility.« less
Soil fertility assessment in the 3 PG model using site index in the southeastern United States
Santosh Subedi; Thomas R. Fox
2016-01-01
Soil fertility is one of the most important, yet least understood aspects of forest ecosystems. Study of soil fertility in forest ecosystems is complicated by the complex relationship between soil properties and stand productivity and immense variability in properties and characteristics of soils within relatively small geographic areas. Furthermore, the deep rooting...
Fertilizer-derived uranium and sulfur in rangeland soil and runoff: A case study in central Florida
Zielinski, R.A.; Orem, W.H.; Simmons, K.R.; Bohlen, P.J.
2006-01-01
Fertilizer applications to rangeland and pastures in central Florida have potential impact on the nutrient-sensitive ecosystems of Lake Okeechobee and the Northern Everglades. To investigate the effects of fertilizer applications, three soil profiles from variably managed and improved rangeland, and four samples of surface runoff from both fertilized and unfertilized pasture were collected. In addition to determining nutrient concentrations, isotopic analyses of uranium (U) and sulfur (S) were performed to provide isotopic evidence for U derived from historically applied phosphate (P)-bearing fertilizer ( 234 U 238U activity ratio =1.0 ?? 0.05), and Sderived from recently applied ammonium sulfate fertilizer(??34 S=3.5permil).The distribution and mobility of fertilizer-derived U in these samples is considered to be analogous to that of fertilizer-derived phosphate.Variations of U concentrations and 234 U/238 U activity ratios in soils indicate contribution of fertilizer-derived U in the upper portions of the fertilized soil (15-}34 percent of total U). The U isotope data for runoff from the fertilized field also are consistent with some contribution from fertilizer-derived U. Parallel investigations of S showed no consistent chemical or isotopic evidence for significant fertilizer-derived sulfate in rangeland soil or runoff. Relatively abundant and isotopically variable S present in the local environment hinders detection of fertilizer-derived sulfate. The results indicate a continuing slow-release of fertilizer-derived U and, by inference, P, to the P-sensitive ecosystem, and a relatively rapid release of sulfate of possible natural origin. ?? Springer 2006.
Speciation And Distribution Of Phosphorus In A Fertilized Soil: A Synchrotron-Based Investigation
Phosphorus availability is often a limiting factor for crop production around the world. The efficiency of P fertilizers in calcareous soils is limited by reactions that decrease P availability; however, fluid fertilizers have recently been shown, in highly calcareous soils of s...
Metagenomic analysis of soil and freshwater from zoo agricultural area with organic fertilization
Meneghine, Aylan K.; Nielsen, Shaun; Thomas, Torsten; Carareto Alves, Lucia Maria
2017-01-01
Microbial communities drive biogeochemical cycles in agricultural areas by decomposing organic materials and converting essential nutrients. Organic amendments improve soil quality by increasing the load of essential nutrients and enhancing the productivity. Additionally, fresh water used for irrigation can affect soil quality of agricultural soils, mainly due to the presence of microbial contaminants and pathogens. In this study, we investigated how microbial communities in irrigation water might contribute to the microbial diversity and function of soil. Whole-metagenomic sequencing approaches were used to investigate the taxonomic and the functional profiles of microbial communities present in fresh water used for irrigation, and in soil from a vegetable crop, which received fertilization with organic compost made from animal carcasses. The taxonomic analysis revealed that the most abundant genera were Polynucleobacter (~8% relative abundance) and Bacillus (~10%) in fresh water and soil from the vegetable crop, respectively. Low abundance (0.38%) of cyanobacterial groups were identified. Based on functional gene prediction, denitrification appears to be an important process in the soil community analysed here. Conversely, genes for nitrogen fixation were abundant in freshwater, indicating that the N-fixation plays a crucial role in this particular ecosystem. Moreover, pathogenicity islands, antibiotic resistance and potential virulence related genes were identified in both samples, but no toxigenic genes were detected. This study provides a better understanding of the community structure of an area under strong agricultural activity with regular irrigation and fertilization with an organic compost made from animal carcasses. Additionally, the use of a metagenomic approach to investigate fresh water quality proved to be a relevant method to evaluate its use in an agricultural ecosystem. PMID:29267397
Jiang, Yuji; Jin, Chen; Sun, Bo
2014-10-01
Nitrification plays a central role in global nitrogen cycle, which is affected by interaction between soil microfauna and microorganisms. The impact of synchronized changes in nematodes and ammonia oxidizers within aggregate fractions on nitrification was investigated in an acid soil under 10-year manure application. Nematodes, ammonia oxidizers and potential nitrification activity (PNA) were examined in three soil aggregate fractions under four fertilization regimes. Pyrosequencing data revealed that the dominant bacterial amoA operational taxonomic units (OTUs) were related to Nitrosospira species, while archaeal OTUs were affiliated with Nitrososphaera and Nitrosotalea species. PNA was more strongly correlated with ammonia-oxidizing bacteria (AOB) abundance than ammonia-oxidizing archaea (AOA) abundance, although AOA were dominant in the acid soil. Plant parasites had a negative effect on AOB abundance; however, bacterivores stimulated AOB abundance and contributed more to PNA than plant parasites. Aggregate fractions exerted significant impacts on AOA abundance and AOB community composition. Total carbon content strongly affected the abundance and composition of AOA community, while soil pH primarily affected that of AOB community. Soil variables explained 62.7% and 58.1% variations, and nematode variables explained 11.7% and 19.5% variations in the AOA and AOB community composition respectively. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.
Novara, Agata; Pisciotta, Antonino; Minacapilli, Mario; Maltese, Antonino; Capodici, Fulvio; Cerdà, Artemi; Gristina, Luciano
2018-05-01
Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60cm depth. Soil was sampled every 10cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the pole height method which allowed mapping of the soil redistribution. The vigor of vegetation, expressed as Normalized Difference Vegetation Index (NDVI), derived from high-resolution satellite multispectral data, was compared with measured pruning weight. Results confirmed that soil erosion, sediment redistribution and SOC across the slope was strongly affected by topographic features, slope and curvature. The erosion rate was 16Mgha -1 y -1 since the time of planting (6years). SOC redistribution was strongly correlated with the detachment or deposition areas as highlighted by pole height measurements. The off-farm SOC loss over six years amounted to 1.2MgCha -1 . SUVA 254 values, which indicate hydrophobic material rich in aromatic constituents of WEOC, decreased significantly along the slope, demonstrating that WEOC in the detachment site is more stable in comparison to deposition sites. The plant vigor was strongly correlated with WEOC constituents. Results demonstrated that high resolution passive remote sensing data combined with soil and plant analyses can survey areas with contrasting SOC, soil fertility, soil erosion and plant vigor. This will allow monitoring of soil erosion and degradation risk areas and support decision-makers in developing measures for friendly environmental management. Copyright © 2017 Elsevier B.V. All rights reserved.
Zhang, Kai; Zheng, Hua; Chen, Falin; Li, Ruida; Yang, Miao; Ouyang, Zhiyun; Lan, Jun; Xiang, Xuewu
2017-01-01
Nitrogen (N) fertilization is necessary to sustain productivity in eucalypt plantations, but it can increase the risk of greenhouse gas emissions. However, the response of soil greenhouse gas emissions to N fertilization might be influenced by soil characteristics, which is of great significance for accurately assessing greenhouse gas budgets and scientific fertilization in plantations. We conducted a two-year N fertilization experiment (control [CK], low N [LN], middle N [MN] and high N [HN] fertilization) in two eucalypt plantations with different soil characteristics (higher and lower soil organic carbon sites [HSOC and LSOC]) in Guangxi, China, and assessed soil–atmosphere greenhouse gas exchanges. The annual mean fluxes of soil CO2, CH4, and N2O were separately 153–266 mg m-2 h-1, -55 –-40 μg m-2 h-1, and 11–95 μg m-2 h-1, with CO2 and N2O emissions showing significant seasonal variations. N fertilization significantly increased soil CO2 and N2O emissions and decreased CH4 uptake at both sites. There were significant interactions of N fertilization and SOC level on soil CO2 and N2O emissions. At the LSOC site, the annual mean flux of soil CO2 emission was only significantly higher than the CK treatment in the HN treatment, but, at the HSOC site, the annual mean flux of soil CO2 emission was significantly higher for both the LN (or MN) and HN treatments in comparison to the CK treatment. Under the CK and LN treatments, the annual mean flux of N2O emission was not significantly different between HSOC and LSOC sites, but under the HN treatment, it was significantly higher in the HSOC site than in the LSOC site. Correlation analysis showed that changes in soil CO2 and N2O emissions were significantly related to soil dissolved organic carbon, ammonia, nitrate and pH. Our results suggested significant interactions of N fertilization and soil characteristics existed in soil–atmosphere greenhouse gas exchanges, which should be considered in assessing greenhouse gas budgets and scientific fertilization strategies in eucalypt plantations. PMID:28192496
Häring, Volker; Manka'abusi, Delphine; Akoto-Danso, Edmund K; Werner, Steffen; Atiah, Kofi; Steiner, Christoph; Lompo, Désiré J P; Adiku, Samuel; Buerkert, Andreas; Marschner, Bernd
2017-09-06
In large areas of sub-Saharan Africa crop production must cope with low soil fertility. To increase soil fertility, the application of biochar (charred biomass) has been suggested. In urban areas, untreated waste water is widely used for irrigation because it is a nutrient-rich year-round water source. Uncertainty exists regarding the interactions between soil properties, biochar, waste water and fertilization over time. The aims of this study were to determine these interactions in two typical sandy, soil organic carbon (SOC) and nutrient depleted soils under urban vegetable production in Tamale (Ghana) and Ouagadougou (Burkina Faso) over two years. The addition of biochar at 2 kg m -2 made from rice husks and corn cobs initially doubled SOC stocks but SOC losses of 35% occurred thereafter. Both biochar types had no effect on soil pH, phosphorous availability and effective cation exchange capacity (CEC) but rice husk biochar retained nitrogen (N). Irrigation with domestic waste water increased soil pH and exchangeable sodium over time. Inorganic fertilization alone acidified soils, increased available phosphorous and decreased base saturation. Organic fertilization increased SOC, N and CEC. The results from both locations demonstrate that the effects of biochar and waste water were less pronounced than reported elsewhere.
Barbosa, Eduardo R M; Tomlinson, Kyle W; Carvalheiro, Luísa G; Kirkman, Kevin; de Bie, Steven; Prins, Herbert H T; van Langevelde, Frank
2014-01-01
Changes in land use may lead to increased soil nutrient levels in many ecosystems (e.g. due to intensification of agricultural fertilizer use). Plant species differ widely in their response to differences in soil nutrients, and for savannas it is uncertain how this nutrient enrichment will affect plant community dynamics. We set up a large controlled short-term experiment in a semi-arid savanna to test how water supply (even water supply vs. natural rainfall) and nutrient availability (no fertilisation vs. fertilisation) affects seedlings' above-ground biomass production and leaf-nutrient concentrations (N, P and K) of broad-leafed and fine-leafed tree species. Contrary to expectations, neither changes in water supply nor changes in soil nutrient level affected biomass production of the studied species. By contrast, leaf-nutrient concentration did change significantly. Under regular water supply, soil nutrient addition increased the leaf phosphorus concentration of both fine-leafed and broad-leafed species. However, under uneven water supply, leaf nitrogen and phosphorus concentration declined with soil nutrient supply, this effect being more accentuated in broad-leafed species. Leaf potassium concentration of broad-leafed species was lower when growing under constant water supply, especially when no NPK fertilizer was applied. We found that changes in environmental factors can affect leaf quality, indicating a potential interactive effect between land-use changes and environmental changes on savanna vegetation: under more uneven rainfall patterns within the growing season, leaf quality of tree seedlings for a number of species can change as a response to changes in nutrient levels, even if overall plant biomass does not change. Such changes might affect herbivore pressure on trees and thus savanna plant community dynamics. Although longer term experiments would be essential to test such potential effects of eutrophication via changes in leaf nutrient concentration, our findings provide important insights that can help guide management plans that aim to preserve savanna biodiversity.
NASA Astrophysics Data System (ADS)
Hamilton, S. K.; McGill, B.
2017-12-01
The top meter of the earth's soil contains about twice the amount of carbon than the atmosphere. Agricultural management practices influence whether a cropland soil is a net carbon source or sink. These practices affect both organic and inorganic carbon cycling although the vast majority of studies examine the former. We will present results from several rarely-compared carbon fluxes: carbon dioxide emissions and sequestration from lime (calcium carbonate) weathering, dissolved gases emitted from groundwater-fed irrigation, dissolved organic carbon (DOC) leaching to groundwater, and soil organic matter storage. These were compared in a corn-soybean-wheat rotation under no-till management across a nitrogen fertilizer gradient where half of the replicated blocks are irrigated with groundwater. DOC and liming fluxes are also estimated from a complementary study in neighboring plots comparing a gradient of management practices from conventional to biologically-based annuals and perennials. These studies were conducted at the Kellogg Biological Station Long Term Ecological Research site in Michigan where previous work estimated that carbon dioxide emissions from liming accounted for about one quarter of the total global warming impact (GWI) from no-till systems—our work refines that figure. We will present a first time look at the GWI of gases dissolved in groundwater that are emitted when the water equilibrates with the atmosphere. We will explore whether nitrogen fertilizer and irrigation increase soil organic carbon sequestration by producing greater crop biomass and residues or if they enhance microbial activity, increasing decomposition of organic matter. These results are critical for more accurately estimating how intensive agricultural practices affect the carbon balance of cropping systems.
Fernández, José M; Nieto, M Aurora; López-de-Sá, Esther G; Gascó, Gabriel; Méndez, Ana; Plaza, César
2014-06-01
Semi-arid soils cover a significant area of Earth's land surface and typically contain large amounts of inorganic C. Determining the effects of biochar additions on CO2 emissions from semi-arid soils is therefore essential for evaluating the potential of biochar as a climate change mitigation strategy. Here, we measured the CO2 that evolved from semi-arid calcareous soils amended with biochar at rates of 0 and 20tha(-1) in a full factorial combination with three different fertilizers (mineral fertilizer, municipal solid waste compost, and sewage sludge) applied at four rates (equivalent to 0, 75, 150, and 225kg potentially available Nha(-1)) during 182 days of aerobic incubation. A double exponential model, which describes cumulative CO2 emissions from two active soil C compartments with different turnover rates (one relatively stable and the other more labile), was found to fit very well all the experimental datasets. In general, the organic fertilizers increased the size and decomposition rate of the stable and labile soil C pools. In contrast, biochar addition had no effects on any of the double exponential model parameters and did not interact with the effects ascribed to the type and rate of fertilizer. After 182 days of incubation, soil organic and microbial biomass C contents tended to increase with increasing the application rates of organic fertilizer, especially of compost, whereas increasing the rate of mineral fertilizer tended to suppress microbial biomass. Biochar was found to increase both organic and inorganic C contents in soil and not to interact with the effects of type and rate of fertilizer on C fractions. As a whole, our results suggest that the use of biochar as enhancer of semi-arid soils, either alone or combined with mineral and organic fertilizers, is unlikely to increase abiotic and biotic soil CO2 emissions. Copyright © 2014 Elsevier B.V. All rights reserved.
Perchlorate in Turfgrass Systems, Suffolk County, Long Island, NY
NASA Astrophysics Data System (ADS)
Munster, J. E.; Hanson, G. N.; Jackson, W. A.
2007-12-01
Perchlorate concentrations in precipitation, grass clippings, and soil water were analyzed at nine turfgrass sites in Suffolk County, NY. The samples were collected monthly between June, 2006 and January, 2007. The soil water was collected from suction lysimeters at 100 cm depth. Four of these sites were treated with chemical fertilizer, three with organic fertilizer and two were not fertilized. Concentrations of ClO4 in grass clippings and soil water, at the sites treated with chemical fertilizer or not treated with fertilizer, are found to increase when spikes of ClO4 concentrations in precipitation are observed. We believe that the spikes in perchlorate in precipitation collected shortly after the Fourth of July are due to firework displays. The concentration of ClO4 in soil water are 1 to 3 times higher than the maximum perchlorate concentrations in precipitation, with maximum soil water concentrations ranging from 0.5 to 3.0 ppb. At the sites treated with organic fertilizer, grass clippings and soil water ClO4 concentrations increase after the fertilizer application in May. The organic fertilizer that was applied has nine mg ClO4 per kg (9,000 ppb). Soil water concentrations at the sites treated with organic fertilizer increase 100 to 300 times the maximum ClO4 concentration observed in precipitation, with maximum soil water concentrations ranging from 120 to 625 ppb. The increase in ClO4 concentrations in the soil water cannot be explained by evaporation alone since the Cl to ClO4 ratios decrease in the soil water relative to precipitation. This decrease in the Cl to ClO4 ratio suggests another source of perchlorate besides precipitation. We postulate that this additional source is associated with the decomposition of mulched grass left after mowing. Grass takes only a few weeks to decompose after mulching, thus providing a continuous source of perchlorate throughout the mowing season. The Cl to ClO4 ratio of the grass is unknown.
Shen, Fei; Zhu, Tong-bin; Teng, Ming-jiao; Chen, Yue; Liu, Man-qiang; Hu, Feng; Li, Hui-xin
2016-02-01
In this study, we investigated the effects of two strains of probiotic bacteria (Bacillus megaterium BM and Bacillus amyloliquefaciens BA) combined with chemical fertilizers and vermicompost on the soil property, the yield and quality of tomato. The results showed that under the same nutrient level, vermicompost significantly increased the yield, soluble sugar and protein contents of fruit, the soil pH and available phosphorus when compared with chemical fertilizers. Vermicompost combined with probiotics not only increased the tomato yield, soluble sugar, protein and vitamin C contents, sugar/acid ratio of fruit, and reduced the organic acid and nitrate nitrogen contents of fruit, also increased the soil pH and nitrate nitrogen content, and reduced soil electric conductivity when compared with vermicompost treatment. This improved efficiency was better than that by chemical fertilizers combined with probiotics. For BA and BM applied with chemical fertilizers or vermicompost, both stains had no significant effect on tomato quality. When co-applied with vermicompost, BA and BM showed significant difference in tomato yield. High soil available phosphorus content was determined when BM was combined with chemical fertilizers, while high soil available potassium content was obtained when BA was combined with vermicompost. Our results suggested that probiotics and vermicompost could be used as alternatives of chemical fertilizers in tomato production and soil fertility improvement.
Inorganic fertilizers after broiler litter amendment reduce surplus nutrients in orchardgrass soils
USDA-ARS?s Scientific Manuscript database
The common producer practice to dispose of broiler litter at high rates to forage crops allow excessive accumulation of soil nutrients. A remediation study was developed to examine if inorganic fertilizer application over the residual fertility of broiler litter would reduce surplus soil nutrients i...
USDA-ARS?s Scientific Manuscript database
Nitrogen fertilization of forage grasses is critical for optimizing biomass and utilization of manure soil nutrients. Field studies were conducted in 2007-09 to determine the effects of spring N fertilization on amelioration of high soil P when cool-season, annual ryegrass (Lolium multiflorum L.) is...
[Soils salinity content of greenhouse in Shanghai suburb].
Yao, Chun-Xia; Chen, Zhen-Lou; Xu, Shi-Yuan
2007-06-01
Salinity content and characteristic of farmland soil in Shanghai suburb was studied. Result indicates that soils in greenhouse in Shanghai suburb are partially salted. Soils of suburb where melons or vegetables grow in Shanghai city, 88.52% soil is non-salted while 10.37% mildly salted, 0.74% obviously salted and 0.37% badly salted. Anions component of salt salinity in soil are mainly SO4(2-), Cl-, NO3(-) and cations component are mainly Ca2+, Na+, Mg2+, K+. These ions are mostly from fertilizer auxiliary component or fertilizer transformation component besides some original deposition in soil. The formation of soil secondary salted in greenhouse cultivation in suburbs of Shanghai has a close relationship with improper fertilization or employing too much fertilizer. Soil salinity is different with different cultivation mode and utilization time. From high to low, sequence of soil salinity content in 0 - 20 cm cultivation layer of different crop mode is greenhouse vegetable soil, melon soil, vegetable melon rotation soil and hypaethral vegetable soil respectively. In the same region, salinity in greenhouse soil continually increases and accumulates from underlayer to surface along with more utilization years.
Qiutong, Xu; Mingkui, Zhang
2017-08-01
Vegetable production in China is suffering increasingly heavy metal damages from various pollution sources including agricultural, industrial and other activities. It is of practical significance to understand the effects of human activities on the accumulation and exchangeability of soil heavy metals in vegetable fields. In this study, seventy-two arable layer samples of vegetable soils were collected from the Shaoxing coastal plain, a representative region of the coastal plain of eastern Zhejiang province, China for characterizing the effects of fertilization methods on accumulation and exchangeable heavy metals in soils (Exchangeable heavy metals in the soil samples were extracted by 0.01molL -1 CaCl 2 ). The different origins of heavy metals in the vegetable soils were investigated by multivariate statistical techniques, including principal component analysis (PCA) and cluster analysis (CA). Marked increases were noted for soil heavy metals due to long-term manure or chemical fertilizer application. Three significant components were extracted by PCA, explaining 78.86% of total variance. Mn, Co, Ni, Fe, and Al were associated in lithogenic components, while an anthropogenic origin was identified for Cu, Cr, Pb, Zn, Cd, Hg. However, As level was due to the geochemical background and was not linked to soil management. The results obtained by cluster analysis elucidated individual relationships between metals and agreed with PCA. Cu, Cr, Pb, and Zn in the soils that were mainly associated with the application of chemical fertilizers, organic manures or other activities regarding soil management. Although the origin of Cd, Hg, and As was also attributed to soil management, other sources like vehicle exhaust or aerial depositions were not discarded as possible contributors. Soil amended with organic fertilizer contained more Cu, Pb, Zn and Cr; whereas the soil amended with chemical fertilizer had more Cd. Application of fertilizers also had significant effect on the concentrations of exchangeable heavy metals. Higher mean concentrations of exchangeable Cd and Pb were found in the soils amended with chemical fertilizers, while those of exchangeable Cu and Zn were found in the soils amended with organic fertilizers. Copyright © 2017 Elsevier Inc. All rights reserved.
Peng, Xingxing; Guo, Zheng; Zhang, Yujiao; Li, Jun
2017-07-14
The Loess Plateau, China, is the world's largest apple-producing region, and over 80% of the orchards are in rainfed (dryland) areas. Desiccation of the deep soil layer under dryland apple orchards is the main stressor of apple production in this region. Fertilization is a factor that causes soil desiccation in dryland apple orchards. Given its applicability and precision validations, the Environmental Policy Integrated Climate (EPIC) model was used to simulate the dynamics of fruit yield and deep soil desiccation in apple orchards under six fertilization treatments. During the 45 years of study, the annual fruit yield under the fertilization treatments initially increased and then decreased in a fluctuating manner, and the average fruit yields were 24.42, 27.27, 28.69, 29.63, 30.49 and 29.43 t/ha in these respective fertilization treatments. As fertilization increased, yield of the apple orchards increased first and then declined,desiccation of the soil layers occurred earlier and extended deeper, and the average annual water consumption, over-consumption and water use efficiency increased as fertilization increased. In terms of apple yields, sustainable soil water use, and economic benefits, the most appropriate fertilization rate for drylands in Luochuan is 360-480 kg/ha N and 180-240 kg/ha P.
[Effects of long-term fertilization on enzyme activities in black soil of Northeast China].
Wang, Shu-Qi; Han, Xiao-Zeng; Qiao, Yun-Fa; Wang, Shou-Yu
2008-03-01
In this paper, black soil samples at the depths of 0-20 cm and 20-40 cm were collected from the Hailun Agricultural Ecology Station of Chinese Academy of Sciences to study the effects of long-term fertilization on their urease, invertase, phosphatase and catalase activities and total C and N contents. The results showed that long-term application of chemical fertilizers and organic manure increased the activities of urease, invertase and phosphatase in 0-20 cm and 20-40 cm soil layers in different degree, and the combined application of them increased the activities of the three enzymes significantly, with an increment of 43.6%-113.2%, 25.9%-79.5% and 14.7%-134.4% in 0-20 cm soil layer and 56.1%-127.2%, 14.5%-113.8% and 16.2%-207.2% in 20-40 cm soil layer, respectively. However, long-term application of chemical fertilizers without organic manure had little effects on catalase activity. The activities of urease, invertase and phosphatase decreased with increasing soil depth. Long-term application of N fertilizer increased urease activity, and P fertilization had obvious positive effect on phosphatase activity. Long-term fertilization also had obvious effects on the soil total C and N contents and C/N ratio.
Reynolds, R.; Phillips, S.; Duniway, M.; Belnap, J.
2003-01-01
Sources of desert soil fertility include parent material weathering, aeolian deposition, and on-site C and N biotic fixation. While parent materials provide many soil nutrients, aeolian deposition can provide up to 75% of plant-essential nutrients including N, P, K, Mg, Na, Mn, Cu, and Fe. Soil surface biota are often sticky, and help retain wind-deposited nutrients, as well as providing much of the N inputs. Carbon inputs are from both plants and soil surface biota. Most desert soils are protected by cyanobacterial-lichen-moss soil crusts, chemical crusts and/or desert pavement. Experimental disturbances applied in US deserts show disruption of soil surfaces result in decreased N and C inputs from soil biota by up to 100%. The ability to glue aeolian deposits in place is compromised, and underlying soils are exposed to erosion. The ability to withstand wind increases with biological and physical soil crust development. While most undisturbed sites show little sediment production, disturbance by vehicles or livestock produce up to 36 times more sediment production, with soil movement initiated at wind velocities well below commonly-occurring wind speeds. Soil fines and flora are often concentrated in the top 3 mm of the soil surface. Winds across disturbed areas can quickly remove this material from the soil surface, thereby potentially removing much of current and future soil fertility. Thus, disturbances of desert soil surfaces can both reduce fertility inputs and accelerate fertility losses.
Land Degradation is The Instinctive Source of Poverty in Rural Areas of Pakistan
NASA Astrophysics Data System (ADS)
Qiu, L. L.; Koondhar, M. A.; Liu, Y. Y.; Zeng, W. Z.
2017-10-01
This review paper focused on the correlation between land degradation and poverty. Pakistan is an agricultural country and agriculture is the backbone of Pakistan`s economy. For the rapid growth of population food security should be under guarantee as well as the food production. In that farmers overused agrarian inputs, such as fertilizer, pesticide and water, environment and farmers were affected from the perspective of contamination and disease increase respectively. Due to over-exploitation of fertilizer and irrigation, ground water was contaminated, soil fertility weakening,salinity increasing and waterlogged. Consequently, soil was hard to be cultivated. In Pakistan 70% of people live in rural areas who are directly or indirectly involved in agriculture. As a result of land degradation farmers can not gain much benefit from agricultural activities and they are also unable to feed their children. Many of them became criminals, therefore, poverty deepened day after day. In order to alleviate poverty, Pakistan government should subsidize farmers on environmentally friendly inputs and; government should also open agricultural training schools to engage farmers in modern methods of cultivation, and provide modern technologies with subsidy rate. When the farmers are aware of how to increase the fertility of soil by employing modern methods, they can gain higher production, and obvious higher production is critical for living a better life and reducing poverty.
Changes in fungal communities along a boreal forest soil fertility gradient.
Sterkenburg, Erica; Bahr, Adam; Brandström Durling, Mikael; Clemmensen, Karina E; Lindahl, Björn D
2015-09-01
Boreal forests harbour diverse fungal communities with decisive roles in decomposition and plant nutrition. Although changes in boreal plant communities along gradients in soil acidity and nitrogen (N) availability are well described, less is known about how fungal taxonomic and functional groups respond to soil fertility factors. We analysed fungal communities in humus and litter from 25 Swedish old-growth forests, ranging from N-rich Picea abies stands to acidic and N-poor Pinus sylvestris stands. 454-pyrosequencing of ITS2 amplicons was used to analyse community composition, and biomass was estimated by ergosterol analysis. Fungal community composition was significantly related to soil fertility at the levels of species, genera/orders and functional groups. Ascomycetes dominated in less fertile forests, whereas basidiomycetes increased in abundance in more fertile forests, both in litter and humus. The relative abundance of mycorrhizal fungi in the humus layer remained high even in the most fertile soils. Tolerance to acidity and nitrogen deficiency seems to be of greater importance than plant carbon (C) allocation patterns in determining responses of fungal communities to soil fertility, in old-growth boreal forests. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
JPRS Report, Near East and South Asia.
1989-03-15
65 percent of the land in the Arab world is very much affected by desertification. The detailed study on Arab countries in West Asia, which was...turned out that more than half the pasture land in Tunisia has been affected by severe desertification, and it became clear that a similar portion...cultivated have affected the land. The soil became salty or alkaline, and vast areas of fertile land were saturated with water. In recent years
NASA Astrophysics Data System (ADS)
Yang, J.; Luedtke, C.; Akers, K.; McGuire, M.; Aubrey, D. P.; Teskey, R. O.
2014-12-01
Soil CO2 efflux (RS) is an important component of forest ecosystem carbon budgets and net ecosystem CO2 exchange, but little is known about how RS and its components respond to decreasing soil moisture and changes in soil fertility. The experiment design was a 2 X 2 factorial combination of fertilization (2 levels) and precipitation (throughfall exclusion, 2 levels) replicated in four blocks. We measured RS along with soil temperature (Ts) and soil moisture (WS) from 2012 to 2014 in a loblolly pine plantation in Washington, GA. The autotrophic (RA) and heterotrophic (RH) components of soil CO2 efflux were separated using trenched plots. Our objectives were to (1) quantify impacts of throughfall exclusion and fertilization on RS and its components (RA, RH).and (2) determine soil CO2efflux and its components individually response to environmental factors and biological factors in throughfall exclusion and fertilization treatments. Annual mean RS was 2.11, 1.73, 2.09 and 1.92 for treatments of control, fertilization, throughfall exclusion and combination of fertilization and throughfall exclusion, respectively, from 2012 to 2013. The apparent Q10 for RS was 2.26, 2.25, 2.12 and 2.35 in the four treatments, respectively. There were no significant differences in RS among treatments except between the Ws treatments. However, there was slight reduction in RS and RA in fertilization and the fertilization plus throughfall exclusion treatment. In all treaments, Ts explained more than 80% of variation in RS. The contribution of CO2-derived from ectomycorrhizal hyphae was less than 15%. RS and RH was better predicted by TS in the dormant season than the growing season, indicating that additional factors such as root growth and photosynthesis became more important contributors to RS during the growing season. Fertilization slightly decreased RS mainly from a decrease in RH. Throughfall exclusion increased the contribution of RA to RS. We concluded that soil moisture had more effect on RS and its components than changes in fertility.
Ma, Mingchao; Jiang, Xin; Wang, Qingfeng; Ongena, Marc; Wei, Dan; Ding, Jianli; Guan, Dawei; Cao, Fengming; Zhao, Baisuo; Li, Jun
2018-03-23
How fungi respond to long-term fertilization in Chinese Mollisols as sensitive indicators of soil fertility has received limited attention. To broaden our knowledge, we used high-throughput pyrosequencing and quantitative PCR to explore the response of soil fungal community to long-term chemical and organic fertilization strategies. Soils were collected in a 35-year field experiment with four treatments: no fertilizer, chemical phosphorus, and potassium fertilizer (PK), chemical phosphorus, potassium, and nitrogen fertilizer (NPK), and chemical phosphorus and potassium fertilizer plus manure (MPK). All fertilization differently changed soil properties and fungal community. The MPK application benefited soil acidification alleviation and organic matter accumulation, as well as soybean yield. Moreover, the community richness indices (Chao1 and ACE) were higher under the MPK regimes, indicating the resilience of microbial diversity and stability. With regards to fungal community composition, the phylum Ascomycota was dominant in all samples, followed by Zygomycota, Basidiomycota, Chytridiomycota, and Glomeromycota. At each taxonomic level, the community composition dramatically differed under different fertilization strategies, leading to different soil quality. The NPK application caused a loss of Leotiomycetes but an increase in Eurotiomycetes, which might reduce the plant-fungal symbioses and increase nitrogen losses and greenhouse gas emissions. According to the linear discriminant analysis (LDA) coupled with effect size (LDA score > 3.0), the NPK application significantly increased the abundances of fungal taxa with known pathogenic traits, such as order Chaetothyriales, family Chaetothyriaceae and Pleosporaceae, and genera Corynespora, Bipolaris, and Cyphellophora. In contrast, these fungi were detected at low levels under the MPK regime. Soil organic matter and pH were the two most important contributors to fungal community composition. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
Ren, Tao; Wang, Jingguo; Chen, Qing; Zhang, Fusuo; Lu, Shuchang
2014-01-01
With the goal of improving N fertilizer management to maximize soil organic carbon (SOC) storage and minimize N losses in high-intensity cropping system, a 6-years greenhouse vegetable experiment was conducted from 2004 to 2010 in Shouguang, northern China. Treatment tested the effects of organic manure and N fertilizer on SOC, total N (TN) pool and annual apparent N losses. The results demonstrated that SOC and TN concentrations in the 0-10cm soil layer decreased significantly without organic manure and mineral N applications, primarily because of the decomposition of stable C. Increasing C inputs through wheat straw and chicken manure incorporation couldn't increase SOC pools over the 4 year duration of the experiment. In contrast to the organic manure treatment, the SOC and TN pools were not increased with the combination of organic manure and N fertilizer. However, the soil labile carbon fractions increased significantly when both chicken manure and N fertilizer were applied together. Additionally, lower optimized N fertilizer inputs did not decrease SOC and TN accumulation compared with conventional N applications. Despite the annual apparent N losses for the optimized N treatment were significantly lower than that for the conventional N treatment, the unchanged SOC over the past 6 years might limit N storage in the soil and more surplus N were lost to the environment. Consequently, optimized N fertilizer inputs according to root-zone N management did not influence the accumulation of SOC and TN in soil; but beneficial in reducing apparent N losses. N fertilizer management in a greenhouse cropping system should not only identify how to reduce N fertilizer input but should also be more attentive to improving soil fertility with better management of organic manure. PMID:24830463
Fertilizer usage and cadmium in soils, crops and food.
Dharma-Wardana, M W C
2018-06-23
Phosphate fertilizers were first implicated by Schroeder and Balassa (Science 140(3568):819-820, 1963) for increasing the Cd concentration in cultivated soils and crops. This suggestion has become a part of the accepted paradigm on soil toxicity. Consequently, stringent fertilizer control programs to monitor Cd have been launched. Attempts to link Cd toxicity and fertilizers to chronic diseases, sometimes with good evidence, but mostly on less certain data are frequent. A re-assessment of this "accepted" paradigm is timely, given the larger body of data available today. The data show that both the input and output of Cd per hectare from fertilizers are negligibly small compared to the total amount of Cd/hectare usually present in the soil itself. Calculations based on current agricultural practices are used to show that it will take centuries to double the ambient soil Cd level, even after neglecting leaching and other removal effects. The concern of long-term agriculture should be the depletion of available phosphate fertilizers, rather than the negligible contamination of the soil by trace metals from fertilizer inputs. This conclusion is confirmed by showing that the claimed correlations between fertilizer input and Cd accumulation in crops are not robust. Alternative scenarios that explain the data are presented. Thus, soil acidulation on fertilizer loading and the effect of Mg, Zn and F ions contained in fertilizers are considered using recent [Formula: see text], [Formula: see text] and [Formula: see text] ion-association theories. The protective role of ions like Zn, Se, Fe is emphasized, and the question of Cd toxicity in the presence of other ions is considered. These help to clarify difficulties in the standard point of view. This analysis does not modify the accepted views on Cd contamination by airborne delivery, smoking, and industrial activity, or algal blooms caused by phosphates.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dai, Zhongmin; Su, Weiqin; Chen, Huaihai
Long-term Elevated nitrogen (N) input from anthropogenic sources may cause soil acidification and decrease crop yield, yet the response of the belowground microbial community to long-term N input and the input of N combined with phosphorus (P) and potassium (K) is still poorly understood. Here, we explored the effect of long-term N and NPK fertilization on soil bacterial diversity and community composition using meta-analysis of a global dataset. Nitrogen fertilization decreased soil pH, and increased soil organic carbon (C) and available N contents. Bacterial taxonomic diversity was decreased by N fertilization alone, but was increased by NPK fertilization. The effectmore » of N fertilization on bacterial diversity depends on soil texture and water management, but independent of crop type or N application rate. Both soil pH and organic C content were positively related to changes in bacterial diversity under N fertilization, while soil organic C was the dominant factor determining changes in bacterial diversity under NPK fertilization. Microbial biomass C decreased with decreasing bacterial diversity under long-term N fertilization. Nitrogen fertilization increased the relative abundance of copiotrophic bacteria (i.e. Proteobacteria and Actinobacteria), but reduced the abundance of oligotrophic taxa (i.e. Acidobacteria), consistent with the general life history strategy theory for bacteria. The relative abundance of Proteobacteria was also increased by NPK fertilization. The positive correlation between N application rate and the relative abundance of Actinobacteria indicates that increased N availability favored the growth of Actinobacteria. This first global analysis of long-term N and NPK fertilization effect on bacterial diversity and community composition suggests that N input decreases bacterial diversity but favors the growth of copiotrophic bacteria, providing a reference for nutrient management strategies for maintaining belowground microbial diversity in agro-ecosystems worldwide.« less
Dai, Zhongmin; Su, Weiqin; Chen, Huaihai; ...
2018-04-25
Long-term Elevated nitrogen (N) input from anthropogenic sources may cause soil acidification and decrease crop yield, yet the response of the belowground microbial community to long-term N input and the input of N combined with phosphorus (P) and potassium (K) is still poorly understood. Here, we explored the effect of long-term N and NPK fertilization on soil bacterial diversity and community composition using meta-analysis of a global dataset. Nitrogen fertilization decreased soil pH, and increased soil organic carbon (C) and available N contents. Bacterial taxonomic diversity was decreased by N fertilization alone, but was increased by NPK fertilization. The effectmore » of N fertilization on bacterial diversity depends on soil texture and water management, but independent of crop type or N application rate. Both soil pH and organic C content were positively related to changes in bacterial diversity under N fertilization, while soil organic C was the dominant factor determining changes in bacterial diversity under NPK fertilization. Microbial biomass C decreased with decreasing bacterial diversity under long-term N fertilization. Nitrogen fertilization increased the relative abundance of copiotrophic bacteria (i.e. Proteobacteria and Actinobacteria), but reduced the abundance of oligotrophic taxa (i.e. Acidobacteria), consistent with the general life history strategy theory for bacteria. The relative abundance of Proteobacteria was also increased by NPK fertilization. The positive correlation between N application rate and the relative abundance of Actinobacteria indicates that increased N availability favored the growth of Actinobacteria. This first global analysis of long-term N and NPK fertilization effect on bacterial diversity and community composition suggests that N input decreases bacterial diversity but favors the growth of copiotrophic bacteria, providing a reference for nutrient management strategies for maintaining belowground microbial diversity in agro-ecosystems worldwide.« less
Huang, Min; Zhou, Xuefeng; Xie, Xiaobing; Zhao, Chunrong; Chen, Jiana; Cao, Fangbo; Zou, Yingbin
2016-01-01
The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot-1 (equivalent to the recommended field rate of 150 kg ha-1) to 0.44 g pot-1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk.
Huang, Min; Zhou, Xuefeng; Xie, Xiaobing; Zhao, Chunrong; Chen, Jiana; Cao, Fangbo; Zou, Yingbin
2016-01-01
The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot–1 (equivalent to the recommended field rate of 150 kg ha–1) to 0.44 g pot–1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk. PMID:27880837
NASA Astrophysics Data System (ADS)
Bracho, R. G.; Vogel, J.; Jokela, E. J.; Cucinella, J.; Noormets, A.; Laviner, M. A.; Gonzalez-Benecke, C. A.; Samuelson, L. J.; Markewitz, D.; Will, R.; Meek, C.; Seiler, J.; Strahm, B. D.; McElligott, K.; Martin, T.
2016-12-01
Planted loblolly pine covers over 11 million hectares in the southeastern United States. Occurring across a range of climatic conditions, these pine plantations are critical for the regional economy and offset a significant fraction of anthropogenic CO2 emissions. Loblolly pine productivity has been enhanced through genetic improvement and intensive silviculture. However, climate projections forecast higher air temperature and more variable precipitation patterns for the region. A critical question is how silvicultural practices will interact with projected climate change to affect loblolly pine carbon balance. A fertilization by throughfall reduction experiment was established in the spring of 2012 at four loblolly pine plantations at the margins of the natural range of the specie (Florida FL, Georgia GA, Oklahoma OK and Virginia VA). Net primary productivity (NPP) was estimated from repeated tree inventories and net ecosystem productivity (NEP) as the difference between NPP and heterotrophic respiration (RH). Soil respiration (RS) and RH were measured simultaneously several times during the experiment. Throughfall reduction significantly decreased surface soil water content at all sites. After four years of treatment, fertilization increased NPP at all sites and throughfall reduction had a negative effect on NPP at the GA and OK sites. The combination fertilization x throughfall reduction did not have a significant effect on NPP. RS and RH were, in general negatively affected by fertilization and throughfall reduction with differential responses between sites, leading to significant NEP increases under fertilization, while throughfall reduction increased NEP at FL and VA due to no effect on NPP and negative effect on RS. Fertilization offset the negative effect of throughfall reduction on NEP in the fertilization x throughfall reduction treatment. All sites were significant carbon sinks, accumulating from 3.5 to 24 Mg C ha-1 in a 3 year period under a range of climatic conditions, age and treatments.
Fierer, Noah; Lauber, Christian L; Ramirez, Kelly S; Zaneveld, Jesse; Bradford, Mark A; Knight, Rob
2012-05-01
Terrestrial ecosystems are receiving elevated inputs of nitrogen (N) from anthropogenic sources and understanding how these increases in N availability affect soil microbial communities is critical for predicting the associated effects on belowground ecosystems. We used a suite of approaches to analyze the structure and functional characteristics of soil microbial communities from replicated plots in two long-term N fertilization experiments located in contrasting systems. Pyrosequencing-based analyses of 16S rRNA genes revealed no significant effects of N fertilization on bacterial diversity, but significant effects on community composition at both sites; copiotrophic taxa (including members of the Proteobacteria and Bacteroidetes phyla) typically increased in relative abundance in the high N plots, with oligotrophic taxa (mainly Acidobacteria) exhibiting the opposite pattern. Consistent with the phylogenetic shifts under N fertilization, shotgun metagenomic sequencing revealed increases in the relative abundances of genes associated with DNA/RNA replication, electron transport and protein metabolism, increases that could be resolved even with the shallow shotgun metagenomic sequencing conducted here (average of 75 000 reads per sample). We also observed shifts in the catabolic capabilities of the communities across the N gradients that were significantly correlated with the phylogenetic and metagenomic responses, indicating possible linkages between the structure and functioning of soil microbial communities. Overall, our results suggest that N fertilization may, directly or indirectly, induce a shift in the predominant microbial life-history strategies, favoring a more active, copiotrophic microbial community, a pattern that parallels the often observed replacement of K-selected with r-selected plant species with elevated N.
Conversion of Grazed Pastures to Energy Cane as a Biofuel Feedstock Alters Soil GHG Fluxes
NASA Astrophysics Data System (ADS)
Gomez-Casanovas, N.; DeLucia, N.; Bernacchi, C.; DeLucia, E. H.
2013-12-01
Changes in land use profoundly affect climate through variations in soil Greenhouse Gas (GHG) exchange. The need for alternative energies is accelerating land use change as marginal land or managed ecosystems are being converted to highly productive second-generation bioenergy crops such as energy cane (Saccharum spp. L). Although the deployment of energy cane is a promising strategy to meet global bioenergy industry demands, few studies have investigated soil GHG fluxes in these crops and sub-tropical low-intensity grazing pasture (bahiagrass, Paspalum notatum L., as forage for cattle, Bos taurus L.) with which they are competing for land. Here, we showed that soil N2O fluxes in bioenergy crops were higher (>250%) than those observed in pastures following fertilization when soil moisture and temperature were high. In the absence of recent fertilization, the N2O source strength in energy cane and pasture sites was similar. Under drier and cooler soil conditions, both pastures and bioenergy crops were weak sources of N2O even when energy cane plots were recently fertilized. Soils on grazed pastures were sources of CH4 during the wet season but became sinks under drier, colder conditions. Energy cane plantations were weak sources of CH4 over a complete wet-dry seasonal cycle. The heterotrophic component of soil respiration was larger (139-155%) in pastures than in energy cane crops, suggesting lower decomposition of SOC in bioenergy crops. In terms of global warming potential, grazed pastures were stronger (120-150%) soil GHG emitters than energy cane crops over a complete wet-dry seasonal cycle. Moreover, pastures became a substantial source of GHG emitters when including estimates of CH4 flux from cattle. Our results suggest that the conversion of pasture to energy cane will be beneficial in relation to GHGs emitted from soils and cattle. Improved understanding of land use impact on soil GHG dynamics will provide valuable information for decision makers debating sustainable bioenergy policies.
Zhou, Minghua; Zhu, Bo; Wang, Shijie; Zhu, Xinyu; Vereecken, Harry; Brüggemann, Nicolas
2017-10-01
Animal manure application as organic fertilizer does not only sustain agricultural productivity and increase soil organic carbon (SOC) stocks, but also affects soil nitrogen cycling and nitrous oxide (N 2 O) emissions. However, given that the sign and magnitude of manure effects on soil N 2 O emissions is uncertain, the net climatic impact of manure application in arable land is unknown. Here, we performed a global meta-analysis using field experimental data published in peer-reviewed journals prior to December 2015. In this meta-analysis, we quantified the responses of N 2 O emissions to manure application relative to synthetic N fertilizer application from individual studies and analyzed manure characteristics, experimental duration, climate, and soil properties as explanatory factors. Manure application significantly increased N 2 O emissions by an average 32.7% (95% confidence interval: 5.1-58.2%) compared to application of synthetic N fertilizer alone. The significant stimulation of N 2 O emissions occurred following cattle and poultry manure applications, subsurface manure application, and raw manure application. Furthermore, the significant stimulatory effects on N 2 O emissions were also observed for warm temperate climate, acid soils (pH < 6.5), and soil texture classes of sandy loam and clay loam. Average direct N 2 O emission factors (EFs) of 1.87% and 0.24% were estimated for upland soils and rice paddy soils receiving manure application, respectively. Although manure application increased SOC stocks, our study suggested that the benefit of increasing SOC stocks as GHG sinks could be largely offset by stimulation of soil N 2 O emissions and aggravated by CH 4 emissions if, particularly for rice paddy soils, the stimulation of CH 4 emissions by manure application was taken into account. © 2017 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Cavoski, Ivana; Chami, Ziad Al; Jarrar, Mohammad; Dumontet, Stefano; Mondelli, Donato
2014-05-01
In organic farming, plant production depends almost exclusively on nutrient deriving from the decomposition of exogenous organic matter in soil which is able to provide significant quantities of several important nutrients for the plant growth. However, in the soil the timing and amount of mineralization often does not coincide with crop nutritional need, making in-season fertilization necessary. The Regulation (EC) No 889/2008 on organic farming standards recognizes these needs and allows the use of a limited range fertilizers and soil conditioners (inputs) in order to meet nutritional needs of the plants and to achieve short term economically viable yield. Short-term open field experiment was conducted at the Mediterranean Agronomic Institute of Bari (MAIB) located in Apulia region (Southern Italy) in order study the effects of different fertilization scenarios based on equilibrated nutritional requirement on tomato (Lycopersicon esculentum Mill, cv. San Marzano) production efficiency and soil chemical properties. In soil dressing phase, three months before planting, biochar (BCH), organic fertilizers (OF), combined treatment (BCH+OF), cattle manure and vineyard wood compost (MVC), dairy wastes industry and vineyard wood compost (DVC) and unamended soil as control (CON) were established. In the pre-crop phase, organic and/or mineral fertilizers were incorporated into the previous treatments except CON and BCH in order to achieve balanced N, P and K application rates for tomato plants. Different fertilization scenarios significantly increased the yields over CON and BCH treatments, maintaining fruits quality. In short period of time, most of the soil parameters remained invariable, only available phosphorus significantly increased in the treatments which received organic fertilizers maybe due to the slight reduction in soil pH. However, such results are not surprising, if we consider the quantity of amendments and fertilizers applied in the experiment, as well as a short term study. Future research needs to address the scope for increasing nutrient use efficiency and monitoring of soil nutrient pools in long term studies. Keywords: organic farming, fertility management, tomato crop, Biochar
A meta-analysis of fertilizer-induced soil NO and combined NO+N2 O emissions.
Liu, Shuwei; Lin, Feng; Wu, Shuang; Ji, Cheng; Sun, Yi; Jin, Yaguo; Li, Shuqing; Li, Zhaofu; Zou, Jianwen
2017-06-01
Soils are among the important sources of atmospheric nitric oxide (NO) and nitrous oxide (N 2 O), acting as a critical role in atmospheric chemistry. Updated data derived from 114 peer-reviewed publications with 520 field measurements were synthesized using meta-analysis procedure to examine the N fertilizer-induced soil NO and the combined NO+N 2 O emissions across global soils. Besides factors identified in earlier reviews, additional factors responsible for NO fluxes were fertilizer type, soil C/N ratio, crop residue incorporation, tillage, atmospheric carbon dioxide concentration, drought and biomass burning. When averaged across all measurements, soil NO-N fluxes were estimated to be 4.06 kg ha -1 yr -1 , with the greatest (9.75 kg ha -1 yr -1 ) in vegetable croplands and the lowest (0.11 kg ha -1 yr -1 ) in rice paddies. Soil NO emissions were more enhanced by synthetic N fertilizer (+38%), relative to organic (+20%) or mixed N (+18%) sources. Compared with synthetic N fertilizer alone, synthetic N fertilizer combined with nitrification inhibitors substantially reduced soil NO emissions by 81%. The global mean direct emission factors of N fertilizer for NO (EF NO ) and combined NO+N 2 O (EF c ) were estimated to be 1.16% and 2.58%, with 95% confidence intervals of 0.71-1.61% and 1.81-3.35%, respectively. Forests had the greatest EF NO (2.39%). Within the croplands, the EF NO (1.71%) and EF c (4.13%) were the greatest in vegetable cropping fields. Among different chemical N fertilizer varieties, ammonium nitrate had the greatest EF NO (2.93%) and EF c (5.97%). Some options such as organic instead of synthetic N fertilizer, decreasing N fertilizer input rate, nitrification inhibitor and low irrigation frequency could be adopted to mitigate soil NO emissions. More field measurements over multiyears are highly needed to minimize the estimate uncertainties and mitigate soil NO emissions, particularly in forests and vegetable croplands. © 2016 John Wiley & Sons Ltd.
Xu, Bingcheng; Xu, Weizhou; Wang, Zhi; Chen, Zhifei; Palta, Jairo A; Chen, Yinglong
2018-01-01
Water and fertilizers affect the nitrogen (N) and phosphorus (P) acquisition and allocation among organs in dominant species in natural vegetation on the semiarid Loess Plateau. This study aimed to clarify the N and P accumulation and N:P ratio at organ and plant level of a local legume species mixed with a grass species under varying water and fertilizer supplies, and thus to fully understand the requirements and balance of nutrient elements in response to growth conditions change of native species. The N and P concentration in the organ (leaf, stem, and root) and plant level of Lespedeza davurica (C 3 legume), were examined when intercropped with Bothriochloa ischaemum (C 4 grass). The two species were grown outdoors in pots under 80, 60, and 40% of soil water field capacity (FC), -NP, +N, +P, and +NP supply and the grass:legume mixture ratios of 2:10, 4:8, 6:6, 8:4, 10:2, and 12:0. The three set of treatments were under a randomized complete block design. Intercropping with B. ischaemum did not affect N concentrations in leaf, stem and root of L. davurica , but reduced P concentration in each organ under P fertilization. Only leaf N concentration in L. davurica showed decreasing trend as soil water content decreased under all fertilization and mixture proportion treatments. Stems had the lowest, while roots had the highest N and P concentration. As the mixture proportion of L. davurica decreased under P fertilization, P concentration in leaf and root also decreased. The N concentration in L. davurica at the whole plant level was 11.1-17.2%. P fertilization improved P concentration, while decreased N:P ratio in L. davurica . The N:P ratios were less than 14.0 under +P and +NP treatments. Our results implied that exogenous N and P fertilizer application may change the N:P stoichiometry and influence the balance between nutrients and organs of native dominant species in natural grassland, and P element should be paid more attention when considering rehabilitating degraded grassland via fertilization application in semiarid Loess Plateau region.
NASA Astrophysics Data System (ADS)
de Winter, H.
2012-04-01
The scientific branch of soil science was worldwide firmly established at the beginning of the 20th century. In this period, it developed strongly in various countries. During the thirties, interest in soil science and its subfields (plant nutrition, soil hydrology, soil microbiology,...) grew even more strongly, which can be demonstrated by the rapid growth of 'soil research institutions' all over the world. In Belgium, it was professor priest Joseph Baeyens (1885-1990) who established the first chair of 'Soil Science' in 1935 at the Catholic University of Leuven. He can be considered as a Belgian pioneer in soil fertility research. After having done prospective soil research in the Belgian Congo, the Belgium government supported him to start the same study for Belgian soils. This innovative soil fertility research was done at the Soil Science Institute of the University of Leuven, which was established and lead by Joseph Baeyens himself. His goal was to determine the fertility norms of the Belgian farmlands. After this large-scale study was done, the fertility norms and associated fertilizer needs could be presented to farmers all over the country. The overall goal was to increase crop production and to minimize fertilizer costs. When Baeyens started to spread his knowledge to the farmers, it would not take long before the demand for his knowledge grew significantly. This lead in 1946 to the erection of the Soil Service of Belgium: an independent laboratory and research institution, analyzing soil samples in order to customize fertilizer recommendations for farmers. This paper discusses the establishment and-development of the SSB. It covers the period between 1930 and 1950. Following questions will be addressed: How unique was the development of SSB on a national and international level? How did research take shape at the SSB? How did the SSB obtain its place in the Belgian agricultural network? What was the role of the government ? And finally, how did the institution generate and disperse scientific knowledge to the farmers?
NASA Astrophysics Data System (ADS)
Dossou-Yovo, E.; Brueggemann, N.; Naab, J.; Huat, J.; Ampofo, E.; Ago, E.; Agbossou, E.
2015-12-01
To explore effective ways to decrease soil CO2 emission and increase grain yield, field experiments were conducted on two upland rice soils (Lixisols and Gleyic Luvisols) in northern Benin in West Africa. The treatments were two tillage systems (no-tillage, and manual tillage), two rice straw managements (no rice straw, and rice straw mulch at 3 Mg ha-1) and three nitrogen fertilizers levels (no nitrogen, recommended level of nitrogen: 60 kg ha-1, and high level of nitrogen: 120 kg ha-1). Potassium and phosphorus fertilizers were applied to be non-limiting at 40 kg K2O ha-1 and 40 kg P2O5 ha-1. Four replications of the twelve treatment combinations were arranged in a randomized complete block design. Soil CO2 emission, soil moisture and soil temperature were measured at 5 cm depth in 6 to 10 days intervals during the rainy season and every two weeks during the dry season. Soil moisture was the main factor explaining the seasonal variability of soil CO2 emission. Much larger soil CO2 emissions were found in rainy than dry season. No-tillage planting significantly reduced soil CO2 emissions compared with manual tillage. Higher soil CO2 emissions were recorded in the mulched treatments. Soil CO2 emissions were higher in fertilized treatments compared with non fertilized treatments. Rice biomass and yield were not significantly different as a function of tillage systems. On the contrary, rice biomass and yield significantly increased with application of rice straw mulch and nitrogen fertilizer. The highest response of rice yield to nitrogen fertilizer addition was obtained for 60 kg N ha-1 in combination with 3 Mg ha-1 of rice straw for the two tillage systems. Soil CO2 emission per unit grain yield was lower under no-tillage, rice straw mulch and nitrogen fertilizer treatments. No-tillage combined with rice straw mulch and 60 kg N ha-1 could be used by smallholder farmers to achieve higher grain yield and lower soil CO2 emission in upland rice fields in northern Benin.
Hippler, Franz Walter Rieger; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Boaretto, Antonio Enedi; Abreu-Junior, Cassio Hamilton; Mattos, Dirceu
2015-01-01
The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay) that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff) and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays. PMID:25751056
Huang, Qingqing; Yu, Yao; Wan, Yanan; Wang, Qi; Luo, Zhang; Qiao, Yuhui; Su, Dechun; Li, Huafen
2018-06-01
A four-year field trial was conducted in a rice paddy in southern China to determine the effects of continuous phosphate fertilizer, pig manure, chicken manure, and sewage sludge application on soil Cd accumulation in soil and Cd uptake by rice. The results showed that continuous application of fertilizers with higher Cd levels caused Cd to accumulate and redistribute in various soil fractions. In turn, these effects influenced Cd bioavailability in rice plants. After four years of phosphate fertilizer, pig manure, chicken manure, and sewage sludge application, the annual soil Cd accumulation rates were 0.007-0.032 mg kg -1 , 0.005-0.022 mg kg -1 , 0.002-0.013 mg kg -1 , and 0.032-0.087 mg kg -1 , respectively. Relative to the control, the pig- and chicken manure treatments significantly increased soil pH and reduced DTPA-extractable Cd (DTPA-Cd) and the exchangeable Cd fraction (Exc-Cd). In contrast, sewage sludge application significantly increased DTPA-Cd and Cd in all soil fractions. Phosphate fertilization had no significant effect on soil pH, DTPA-Cd, or Exc-Cd. Pearson's correlation coefficients showed that the rice grain Cd levels varied directly with DTPA-Cd, and Exc-Cd but inversely with soil pH. Pig- or chicken manure decreased rice grain Cd content, but sewage sludge increased both soil Cd availability and rice grain Cd uptake. Application of phosphate fertilizer had no significant effect on rice grain Cd content. The continuous use of organic- or phosphate fertilizer with elevated Cd content at high application rates may induce soil Cd accumulation and influence rice grain Cd accumulation. Copyright © 2018 Elsevier Ltd. All rights reserved.
Hippler, Franz Walter Rieger; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Boaretto, Antonio Enedi; Abreu-Junior, Cassio Hamilton; Mattos, Dirceu
2015-01-01
The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay) that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff) and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays.
González, M E; Cea, M; Medina, J; González, A; Diez, M C; Cartes, P; Monreal, C; Navia, R
2015-02-01
Biochar constitutes a promising support material for the formulation of controlled-release fertilizers (CRFs). In this study we evaluated the effect of different polymeric materials as encapsulating agents to control nitrogen (N) leaching from biochar based CRFs. Nitrogen impregnation onto biochar was performed in a batch reactor using urea as N source. The resulting product was encapsulated by using sodium alginate (SA), cellulose acetate (CA) and ethyl cellulose (EC). Leaching potential was studied in planted and unplanted soil columns, monitoring nitrate, nitrite, ammonium and urea concentrations. After 90 days, plants were removed from the soil columns and plant yield was evaluated. It was observed that the ammonium concentration in leachates presented a maximum concentration for all treatments at day 22. The highest concentration of N in the leachates was the nitrate form. The crop yield was negatively affected by all developed CRFs using biochar compared with the traditional fertilization. Copyright © 2014 Elsevier B.V. All rights reserved.
Sulfur and Zinc Availability from Co-granulated Zn-Enriched Elemental Sulfur Fertilizers.
Mattiello, Edson M; da Silva, Rodrigo C; Degryse, Fien; Baird, Roslyn; Gupta, Vadakattu V S R; McLaughlin, Michael J
2017-02-15
Acidification by oxidation of elemental sulfur (ES) can solubilize ZnO, providing slow release of both sulfur (S) and zinc (Zn) in soil. For this study, a new granular fertilizer with ES and ZnO was produced and evaluated. The effect of incorporating microorganisms or a carbon source in the granule was also evaluated. Four granulated ES-Zn fertilizers with and without S-oxidizing microorganisms, a commercial ES pastille, ZnSO 4 , and ZnO were applied to the center of Petri dishes containing two contrasting pH soils. Soil pH, CaCl 2 -extractable S and Zn, and remaining ES were evaluated at 30 and 60 days in two soil sections (0-5 and 5-9 mm from the fertilizer application site). A visualization test was performed to evaluate Zn diffusion over time. A significant pH decrease was observed in the acidic soil for all ES-Zn fertilizer treatments and in the alkaline soil for the Acidithiobacillus thiooxidans-inoculated treatment only. In agreement with Zn visualization tests, extractable-Zn concentrations were higher from the point of application in the acidic (62.9 mg dm -3 ) compared to the alkaline soil (5.5 mg dm -3 ). Elemental S oxidation was greater in the acidic soil (20.9%) than slightly alkaline soil (12%). The ES-Zn granular fertilizers increased S and Zn concentrations in soil and can provide a strategically slow release of nutrients to the soil.
2016-01-01
Mulching and nitrogen are critical drivers of crop production for smallholders of the Loess Plateau in China. The purpose of this study was to investigate the effect of mulching and nitrogen fertilizer on the soil water content, soil nitrate-N content and vertical distribution in maize root-zone. The experiment was conducted over two consecutive years and used randomly assigned field plots with three replicates. The six treatments consisted of no fertilizer without plastic film (CK), plastic film mulching with no basal fertilizer and no top dressing (MN0), basal fertilizer with no top dressing and no mulching (BN1), plastic film mulching and basal fertilizer with no top dressing (MN1), basal fertilizer and top dressing with no mulching (BN2) and plastic film mulching with basal fertilizer and top dressing (MN2). In the top soil layers, the soil water content was a little high in the plastic film mulching than that without mulching. The mean soil water content from 0 to 40 cm without mulching were 3.35% lower than those measured in the corresponding mulching treatments in 31 days after sowing in 2012. The mulching treatment increased the soil nitrate-N content was observed in the 0–40-cm soil layers. The results indicate that high contents of soil nitrate-N were mainly distributed at 0–20-cm at 31 days after sowing in 2012, and the soil nitrate-N concentration in the MN2 treatment was 1.58 times higher than that did not receive fertilizer. The MN2 treatment greatly increased the soil nitrate-N content in the upper layer of soil (0–40-cm), and the mean soil nitrate-N content was increased nearly 50 mg kg−1 at 105 days after sowing compared with CK treatment in 2012. The soil nitrate-N leaching amount in MN1 treatment was 28.61% and 39.14% lower than BN1 treatment, and the mulch effect attained to 42.55% and 65.27% in MN2 lower than BN2 in both years. The yield increased with an increase in the basal fertilizer, top dressing and plastic film mulching, and the grain yield increase ranged from 31.41% to 83.61% in two consecutive years. The MN1 and MN2 treatment is recommended because it increased the grain yield and improved the fertilizer use efficiency, compared with the no-mulching treatment. PMID:27560826
Wang, Lei; Li, Jing; Yang, Fang; E, Yaoyao; Raza, Waseem; Huang, Qiwei; Shen, Qirong
2017-02-01
Application of bioorganic fertilizers has been reported to improve crop yields and change soil bacterial community structure; however, little work has been done in apple orchard soils where the biological properties of the soils are being degraded due to long-term application of chemical fertilizers. In this study, we used Illumina-based sequencing approach to characterize the bacterial community in the 0-60-cm soil profile under different fertilizer regimes in the Loess Plateau. The experiment includes three treatments: (1) control without fertilization (CK); (2) application of chemical fertilizer (CF); and (3) application of bioorganic fertilizer and organic-inorganic mixed fertilizer (BOF). The results showed that the treatment BOF increased the apple yields by 114 and 67 % compared to the CK and CF treatments, respectively. The treatment BOF also increased the soil organic matter (SOM) by 22 and 16 % compared to the CK and CF treatments, respectively. The Illumina-based sequencing showed that Acidobacteria and Proteobacteria were the predominant phyla and Alphaproteobacteria and Gammaproteobacteria were the most abundant classes in the soil profile. The bacterial richness for ACE was increased after the addition of BOF. Compared to CK and CF treatments, BOF-treated soil revealed higher abundance of Proteobacteria, Alphaproteobacteria and Gammaproteobacteria, Rhizobiales, and Xanthomonadales while Acidobacteria, Gp7, Gp17, and Sphaerobacter were found in lower abundance throughout the soil profile. Bacterial community structure varied with soil depth under different fertilizer treatments, e.g., the bacterial richness, diversity, and the relative abundance of Verruccomicrobia, Candidatus Brocadiales, and Skermanella were decreased with the soil depth in all three treatments. Permutational multivariate analysis showed that the fertilizer regime was the major factor than soil depth in the variations of the bacterial community composition. Two groups, Lysobacter and Rhodospirillaceae, were found to be the significantly increased by the BOF addition and the genus Lysobacter may identify members of this group effective in biological control-based plant disease management and the members of family Rhodospirillaceae had an important role in fixing molecular nitrogen. These results strengthen the understanding of responses to the BOF and possible interactions within bacterial communities in soil that can be associated with disease suppression and the accumulation of carbon and nitrogen. The increase of apple yields after the application of BOF might be attributed to the fact that the application of BOF increased SOM, and soil total nitrogen, and changed the bacterial community by enriching Rhodospirillaceae, Alphaprotreobateria, and Proteobacteria.
Wang, Xiukang; Xing, Yingying
2016-01-01
Mulching and nitrogen are critical drivers of crop production for smallholders of the Loess Plateau in China. The purpose of this study was to investigate the effect of mulching and nitrogen fertilizer on the soil water content, soil nitrate-N content and vertical distribution in maize root-zone. The experiment was conducted over two consecutive years and used randomly assigned field plots with three replicates. The six treatments consisted of no fertilizer without plastic film (CK), plastic film mulching with no basal fertilizer and no top dressing (MN0), basal fertilizer with no top dressing and no mulching (BN1), plastic film mulching and basal fertilizer with no top dressing (MN1), basal fertilizer and top dressing with no mulching (BN2) and plastic film mulching with basal fertilizer and top dressing (MN2). In the top soil layers, the soil water content was a little high in the plastic film mulching than that without mulching. The mean soil water content from 0 to 40 cm without mulching were 3.35% lower than those measured in the corresponding mulching treatments in 31 days after sowing in 2012. The mulching treatment increased the soil nitrate-N content was observed in the 0-40-cm soil layers. The results indicate that high contents of soil nitrate-N were mainly distributed at 0-20-cm at 31 days after sowing in 2012, and the soil nitrate-N concentration in the MN2 treatment was 1.58 times higher than that did not receive fertilizer. The MN2 treatment greatly increased the soil nitrate-N content in the upper layer of soil (0-40-cm), and the mean soil nitrate-N content was increased nearly 50 mg kg-1 at 105 days after sowing compared with CK treatment in 2012. The soil nitrate-N leaching amount in MN1 treatment was 28.61% and 39.14% lower than BN1 treatment, and the mulch effect attained to 42.55% and 65.27% in MN2 lower than BN2 in both years. The yield increased with an increase in the basal fertilizer, top dressing and plastic film mulching, and the grain yield increase ranged from 31.41% to 83.61% in two consecutive years. The MN1 and MN2 treatment is recommended because it increased the grain yield and improved the fertilizer use efficiency, compared with the no-mulching treatment.
Zhang, Yaojun; Lin, Feng; Jin, Yaguo; Wang, Xiaofei; Liu, Shuwei; Zou, Jianwen
2016-01-01
It is of great concern worldwide that active nitrogenous gases in the global nitrogen cycle contribute to regional and global-scale environmental issues. Nitrous oxide (N2O) and nitric oxide (NO) are generally interrelated in soil nitrogen biogeochemical cycles, while few studies have simultaneously examined these two gases emission from typical croplands. Field experiments were conducted to measure N2O and NO fluxes in response to chemical N fertilizer application in annual greenhouse vegetable cropping systems in southeast China. Annual N2O and NO fluxes averaged 52.05 and 14.87 μg N m−2 h−1 for the controls without N fertilizer inputs, respectively. Both N2O and NO emissions linearly increased with N fertilizer application. The emission factors of N fertilizer for N2O and NO were estimated to be 1.43% and 1.15%, with an annual background emission of 5.07 kg N2O-N ha−1 and 1.58 kg NO-N ha−1, respectively. The NO-N/N2O-N ratio was significantly affected by cropping type and fertilizer application, and NO would exceed N2O emissions when soil moisture is below 54% WFPS. Overall, local conventional input rate of chemical N fertilizer could be partially reduced to attain high yield of vegetable and low N2O and NO emissions in greenhouse vegetable cropping systems in China. PMID:26848094
Zhang, Yaojun; Lin, Feng; Jin, Yaguo; Wang, Xiaofei; Liu, Shuwei; Zou, Jianwen
2016-02-05
It is of great concern worldwide that active nitrogenous gases in the global nitrogen cycle contribute to regional and global-scale environmental issues. Nitrous oxide (N2O) and nitric oxide (NO) are generally interrelated in soil nitrogen biogeochemical cycles, while few studies have simultaneously examined these two gases emission from typical croplands. Field experiments were conducted to measure N2O and NO fluxes in response to chemical N fertilizer application in annual greenhouse vegetable cropping systems in southeast China. Annual N2O and NO fluxes averaged 52.05 and 14.87 μg N m(-2) h(-1) for the controls without N fertilizer inputs, respectively. Both N2O and NO emissions linearly increased with N fertilizer application. The emission factors of N fertilizer for N2O and NO were estimated to be 1.43% and 1.15%, with an annual background emission of 5.07 kg N2O-N ha(-1) and 1.58 kg NO-N ha(-1), respectively. The NO-N/N2O-N ratio was significantly affected by cropping type and fertilizer application, and NO would exceed N2O emissions when soil moisture is below 54% WFPS. Overall, local conventional input rate of chemical N fertilizer could be partially reduced to attain high yield of vegetable and low N2O and NO emissions in greenhouse vegetable cropping systems in China.
Lü, Shaoyu; Feng, Chen; Gao, Chunmei; Wang, Xinggang; Xu, Xiubin; Bai, Xiao; Gao, Nannan; Liu, Mingzhu
2016-06-22
Fertilizer is one of the most important elements of modern agriculture. However, conventional fertilizer, when applied to crops, is vulnerable to losses through volatilization, leaching, nitrification, or other means. Such a loss limits crop yields and pollutes the environment. In an effort to enhance nutrient use efficiency and reduce environmental pollution, an environmental smart fertilizer was reported in the current study. Poly(aspartic acid) and a degradable macro-cross-linker based on l-aspartic acid were synthesized and introduced into the fertilizer as a superabsorbent to improve the fertilizer degradability and soil moisture-retention capacity. Sustained release behavior of the fertilizer was achieved in soil. Cumulative release of nitrogen and phosphorus was 79.8% and 64.4% after 30 days, respectively. The water-holding and water-retention capacities of soil with the superabsorbent are obviously higher than those of the control soil without superabsorbent. For the sample of 200 g of soil with 1.5 g of superabsorbent, the water-holding capacity is 81.8%, and the water-retention capacity remains 22.6% after 23 days. All of the current results in this study indicated that the as-prepared fertilizer has a promising application in sustainable modern agriculture.
Zn uptake behavior of rice genotypes and its implication on grain Zn biofortification
Johnson-Beebout, Sarah E.; Goloran, Johnvie Bayang; Rubianes, Francis H. C.; Jacob, Jack D. C.; Castillo, Oliver B.
2016-01-01
Understanding Zn uptake dynamics is critical to rice grain Zn biofortification. Here we examined soil Zn availability and Zn uptake pathways as affected by genotype (high-grain Zn varieties IR69428 and IR68144), Zn fertilization and water management in two pot experiments. Results showed significant interactions (P < 0.05) between genotypes and Zn fertilization on DTPA (diethylenetriaminepentaacetic acid)-extractable soil Zn from early tillering to flowering. DTPA-extractable Zn in soils grown with IR69428 was positively correlated with stem (r = 0.78, P < 0.01), flagleaf (r = 0.60, P < 0.01) and grain (r = 0.67, P < 0.01) Zn concentrations, suggesting improved soil Zn availability and continued soil Zn uptake by IR69428 even at maturity. Conversely for IR68144, DTPA-extractable Zn was positively correlated only with leaf Zn uptake (r = 0.60, P < 0.01) at active tillering, indicating dependence on remobilization for grain Zn loading. Furthermore, the highest grain Zn concentration (P < 0.05) was produced by a combination of IR69428 and Zn fertilization applied at panicle initiation (38.5 μg g−1) compared with other treatments (P < 0.05). The results highlight that Zn uptake behavior of a rice genotype determines the fate of Zn from the soil to the grain. This has implications on overcoming Zn translocation barriers between vegetative parts and grains, and achieving grain Zn biofortification targets (30.0 μg g−1). PMID:27910900
Ahmed, Osumanu H; Ahmad, Husni M H; Musa, Hanafi M; Rahim, Anuar A; Rastan, Syed Omar S
2005-01-21
In Malaysia, pineapples are grown on peat soils, but most K fertilizer recommendations do not take into account K loss through leaching. The objective of this study was to determine applied K use efficiency under a conventionally recommended fertilization regime in pineapple cultivation with residues removal. Results showed that K recovery from applied K fertilizer in pineapple cultivation on tropical peat soil was low, estimated at 28%. At a depth of 0-10 cm, there was a sharp decrease of soil total K, exchangeable K, and soil solution K days after planting (DAP) for plots with K fertilizer. This decline continued until the end of the study. Soil total, exchangeable, and solution K at the end of the study were generally lower than prior values before the study. There was no significant accumulation of K at depths of 10-25 and 25-45 cm. However, K concentrations throughout the study period were generally lower or equal to their initial status in the soil indicating leaching of the applied K and partly explained the low K recovery. Potassium losses through leaching in pineapple cultivation on tropical peat soils need to be considered in fertilizer recommendations for efficient recovery of applied K.
Makita, Naoki; Hirano, Yasuhiro; Sugimoto, Takanobu; Tanikawa, Toko; Ishii, Hiroaki
2015-12-01
Soil N fertility has an effect on belowground C allocation, but the physiological and morphological responses of individual fine root segments to variations in N availability under field conditions are still unclear. In this study, the direction and magnitude of the physiological and morphological function of fine roots in response to variable in situ soil N fertility in a forest site were determined. We measured the specific root respiration (Rr) rate, N concentration and morphology of fine root segments with 1-3 branching orders in a 100-year-old coniferous forest of Chamaecyparis obtusa. Higher soil N fertility induced higher Rr rates, root N concentration, and specific root length (SRL), and lower root tissue density (RTD). In all fertility levels, the Rr rates were significantly correlated positively with root N and SRL and negatively with RTD. The regression slopes of respiration with root N and RTD were significantly higher along the soil N fertility gradient. Although no differences in the slopes of Rr and SRL relationship were found across the levels, there were significant shifts in the intercept along the common slope. These results suggest that a contrasting pattern in intraspecific relationships between specific Rr and N, RTD, and SRL exists among soils with different N fertility. Consequently, substantial increases in soil N fertility would exert positive effects on organ-scale root performance by covarying the Rr, root N, and morphology for their potential nutrient and water uptake.
NASA Astrophysics Data System (ADS)
De Graaff, M. A.; Jastrow, J. D.
2017-12-01
Ethanol production from second generation biofuel feedstocks, including the perennial grasses switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii) has expanded rapidly, with the aim to reduce greenhouse gas emissions. However, land conversion for bioenergy production releases carbon (C) stored in soil to the atmosphere as CO2, and creates a C debt in ecosystems. If biofuels are to aid in curbing atmospheric CO2 concentrations, it is important that this initial C debt be repaid rapidly. A variety of management approaches aimed at increasing NPP and soil C input may be used to accelerate the repayment of soil C. We conducted a long-term field experiment located at the Fermilab National Environmental Research Park in IL, that compares a variety of approaches for perennial feedstock production following conversion of an old-field dominated by C3 grasses to a grassland dominated by C4 perennial grasses. Treatments included a variety of big bluestem and switchgrass cultivars grown in monoculture, diversity manipulated at both the species- and cultivar level, and nitrogen (N) applied at two levels (0 and 67 kg/ha). Previous results from this experiment indicated that four years following initiation of this experiment, only choice of plant species significantly affected the rate of bulk soil C-debt repayment. Here we quantified how nine years of fertilization, plant species, and inter- and intra-specific diversity treatments affect soil C accumulation. To increase our detection of changes in soil C and our mechanistic understanding of the processes that drive C accumulation in this experiment, we used the natural abundance C isotope ratio technique to estimate the contribution and fate of root-derived C to soil organic matter pools. Additionally, we evaluated how the different management approaches affected the ecological sustainability of bioenergy production, by quantifying impacts of the treatments on soil micro-and meso fauna abundance and diversity. Our results will improve our understanding of how alternative management approaches in lignocellulosic biofuel cropping systems regulate soil C sequestration, and the processes that influence it.
Belnap, Jayne
2003-01-01
Cyanobacteria and cyanolichens dominate most desert soil surfaces as the major component of biological soil crusts (BSC). BSCs contribute to soil fertility in many ways. BSC can increase weathering of parent materials by up to 100 times. Soil surface biota are often sticky, and help retain dust falling on the soil surface; this dust provides many plant-essential nutrients including N, P, K, Mg, Na, Mn, Cu, and Fe. BSCs also provide roughened soil surfaces that slow water runoff and aid in retaining seeds and organic matter. They provide inputs of newly-fixed carbon and nitrogen to soils. They are essential in stabilizing soil surfaces by linking soil particles together with filamentous sheaths, enabling soils to resist both water and wind erosion. These same sheaths are important in keeping soil nutrients from becoming bound into plant-unavailable forms. Experimental disturbances applied in US deserts show soil surface impacts decrease N and C inputs from soil biota by up to 100%. The ability to hold aeolian deposits in place is compromised, and underlying soils are exposed to erosion. While most undisturbed sites show little sediment production, disturbance by vehicles or livestock produces up to 36 times more sediment production, with soil movement initiated at wind velocities well below commonly-occurring wind speeds. Winds across disturbed areas can quickly remove this material from the soil surface, thereby potentially removing much of current and future soil fertility. Thus, reduction in the cover of cyanophytes in desert soils can both reduce fertility inputs and accelerate fertility losses.
NASA Astrophysics Data System (ADS)
Bhattarai, Hem Raj; Virkajärvi, Perttu; -Yli Pirilä, Pasi; Maljanen, Marja
2017-04-01
There is no doubt that nitrogen (N) fertilization has crucial role in increasing food production. However, in parallel it can cause severe impact in environment such as eutrophication, surface/groundwater pollution via nitrate (NO3-) leaching and emissions of N trace gases. Fertilization increases the emissions of nitrous oxide (N2O) which is 260 stronger greenhouse gas than carbon dioxide (CO2). It also enhances the emissions of nitric oxide (NO); an oxidized and very reactive form of nitrogen which can fluctuate the ozone (O3) concentration in atmosphere and cause acidification. The effects of N- fertilization on the emission of N2O and NO from agricultural soil are well known. However, the effects of N fertilization on nitrous acid (HONO) emissions are unknown. Few studies have shown that HONO is emitted from soil but they lack to interlink fertilization and HONO emission. HONO accounts for 17-34 % of hydroxyl (OH-) radical production? in the atmosphere, OH- radicals have vital role in atmospheric chemistry; they can cause photochemical smog, form O3, oxidize volatile organic compounds and also atmospheric methane (CH4). We formulated hypothesis that N fertilization will increase the HONO emissions as it does for N2O and NO. To study this, we took soil samples from agricultural soil receiving different amount of N-fertilizer (0, 250 and 450 kg ha-1) in eastern Finland. HONO emissions were measured by dynamic chamber technique connected with LOPAP (Quma Elektronik & Analytik GmbH), NO by NOx analyzer (Thermo scientific) and static chamber technique and gas chromatograph was used for N2O gas sampling and analysis. Several soil parameters were also measured to establish the relationship between the soil properties, fertilization rate and HONO emission. This study is important because eventually it will open up more questions regarding the forms of N loss from soils and impact of fertilization on atmospheric chemistry.
Quinoa Seed Quality Response to Sodium Chloride and Sodium Sulfate Salinity
Wu, Geyang; Peterson, Adam J.; Morris, Craig F.; Murphy, Kevin M.
2016-01-01
Quinoa (Chenopodium quinoa Willd.) is an Andean crop with an edible seed that both contains high protein content and provides high quality protein with a balanced amino acid profile in embryonic tissues. Quinoa is a halophyte adapted to harsh environments with highly saline soil. In this study, four quinoa varieties were grown under six salinity treatments and two levels of fertilization, and then evaluated for quinoa seed quality characteristics, including protein content, seed hardness, and seed density. Concentrations of 8, 16, and 32 dS m-1 of NaCl and Na2SO4, were applied to the soil medium across low (1 g N, 0.29 g P, 0.29 g K per pot) and high (3 g N, 0.85 g P, 0.86 g K per pot) fertilizer treatments. Seed protein content differed across soil salinity treatments, varieties, and fertilization levels. Protein content of quinoa grown under salinized soil ranged from 13.0 to 16.7%, comparable to that from non-saline conditions. NaCl and Na2SO4 exhibited different impacts on protein content. Whereas the different concentrations of NaCl did not show differential effects on protein content, the seed from 32 dS m-1 Na2SO4 contained the highest protein content. Seed hardness differed among varieties, and was moderately influenced by salinity level (P = 0.09). Seed density was affected significantly by variety and Na2SO4 concentration, but was unaffected by NaCl concentration. The samples from 8 dS m-1 Na2SO4 soil had lower density (0.66 g/cm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4, 0.74 and 0.72g/cm3, respectively. This paper identifies changes in critical seed quality traits of quinoa as influenced by soil salinity and fertility, and offers insights into variety response and choice across different abiotic stresses in the field environment. PMID:27375648
Luo, Xuesong; Han, Shun; Lai, Songsong; Huang, Qiaoyun; Chen, Wenli
2017-04-01
Nitrospira are the most widespread and well known nitrite-oxidizing bacteria (NOB) and putatively key nitrite-oxidizers in acidic ecosystems. Nevertheless, their ecology in agriculture soils has not been well studied. To understand the impact of straw incorporation on soil Nitrospira-like bacterial community, a cloned library analysis of the nitrite oxidoreductase gene-nxrB was performed for a long-term rapeseed-rice rotation system. In this study, most members of the Nitrospira-like NOB in the paddy soils from the Wuxue field experiment station were phylogenetically related with Nitrospira lineages II. The Shannon diversity index possessed a decrease trend in the straw applied soils. The relative abundances of 16 OTUs (accounting 72% of the total OTUs, including 11 unique OTUs and 5 shared OTUs) were different between in the straw applied and control soils. These data suggested a selection effect from the long-term straw fertilization. Canonical correspondence analysis data showed that a centralized group of Nitrospira-like NOB OTUs in the community was partly explained by the soil ammonium, nitrate, available phosphorus, and the available potassium. This could suggest that straw fertilization led to the soil Nitrospira-like NOB community shift, which was correlated with the change of available nutrients in the bulk soil. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Kudrevatykh, Irina; Ivashchenko, Kristina; Ananyeva, Nadezhda
2016-04-01
Inflow of pollutants in terrestrial ecosystems nowadays increases dramatically, that might be led to disturbance of natural biogeochemical cycles and landscapes structure. Production of nitrogen fertilizers is one of the air pollution sources, namely by nitrogen compounds (NH4+, NO3-, NO2-). Air pollution by nitrogen compounds of terrestrial ecosystems might be affected on soil biochemical properties, which results increasing mineral nitrogen content in soil, changing soil P/N and Al/Ca ratios, and, finally, the deterioration of soil microbial community functioning. The research is focused on the assessment of anthropogenic emission of nitrogen compounds on soil properties of grassland ecosystems in European Russia. Soil samples (Voronic Chernozem Pachic, upper 10 cm mineral layer, totally 10) were taken from grassland ecosystem: near (5-10 m) nitrogen fertilizer factory (NFF), and far from it (20-30 km, served as a control) in Tula region. In soil samples the NH4+ and NO3- (Kudeyarov's photocolorimetric method), P, Ca, Al (X-ray fluorescence method) contents were measured. Soil microbial biomass carbon (Cmic) was analyzed by substrate-induced respiration method. Soil microbial respiration (MR) was assessed by CO2 rate production. Soil microbial metabolic quotient (qCO2) was calculated as MR/Cmic ratio. Near NFF the soil ammonium and nitrate nitrogen contents were a strongly varied, variation coefficient (CV) was 42 and 86This study was supported by Russian Foundation of Basic Research Grant No. 14-04-00098, 15-44-03220, 15-04-00915.
Qiao, Jianmin; Yu, Deyong; Wu, Jianguo
2018-02-01
Agricultural ecosystem management needs to ensure food production and minimize soil erosion and nitrogen (N) leaching under climate change and increasingly intensive human activity. Thus, the mechanisms through which climatic and management factors affect crop production, soil erosion, and N leaching must be understood in order to ensure food security and sustainable agricultural development. In this study, we adopted the GIS-based Environmental Policy Integrated Climate (EPIC) model to simulate crop production, soil erosion, and N leaching, and used a partial least squares regression model to evaluate the contributions of climate variables (solar radiation, precipitation, wind speed, relative humidity, and maximum and minimum temperature) and management factors (irrigation, fertilization, and crop cultivation area) on agricultural ecosystem services (AES) in the agro-pastoral transitional zone (APTZ) of northern China. The results indicated that crop production and N leaching markedly increased, whereas soil erosion declined from 1980 to 2010 in the APTZ. Management factors had larger effects on the AES than climate change. Among the climatic variables, daily minimum temperature was the most important contributor to the variations in ecosystem services of wheat, maize, and rice. Spatial changes in the cultivated area most affected crop production, soil erosion, and N leaching for majority of the cultivated areas of the three crops, except for the wheat-cultivated area, where the dominant factor for N leaching was fertilization. Although a tradeoff existed between crop production and negative environmental effects, compromises were possible. These findings provide new insights into the effects of climatic and management factors on AES, and have practical implications for improving crop production while minimizing negative environmental impacts. Copyright © 2017 Elsevier B.V. All rights reserved.
The Impact of Soil Sampling Errors on Variable Rate Fertilization
DOE Office of Scientific and Technical Information (OSTI.GOV)
R. L. Hoskinson; R C. Rope; L G. Blackwood
2004-07-01
Variable rate fertilization of an agricultural field is done taking into account spatial variability in the soil’s characteristics. Most often, spatial variability in the soil’s fertility is the primary characteristic used to determine the differences in fertilizers applied from one point to the next. For several years the Idaho National Engineering and Environmental Laboratory (INEEL) has been developing a Decision Support System for Agriculture (DSS4Ag) to determine the economically optimum recipe of various fertilizers to apply at each site in a field, based on existing soil fertility at the site, predicted yield of the crop that would result (and amore » predicted harvest-time market price), and the current costs and compositions of the fertilizers to be applied. Typically, soil is sampled at selected points within a field, the soil samples are analyzed in a lab, and the lab-measured soil fertility of the point samples is used for spatial interpolation, in some statistical manner, to determine the soil fertility at all other points in the field. Then a decision tool determines the fertilizers to apply at each point. Our research was conducted to measure the impact on the variable rate fertilization recipe caused by variability in the measurement of the soil’s fertility at the sampling points. The variability could be laboratory analytical errors or errors from variation in the sample collection method. The results show that for many of the fertility parameters, laboratory measurement error variance exceeds the estimated variability of the fertility measure across grid locations. These errors resulted in DSS4Ag fertilizer recipe recommended application rates that differed by up to 138 pounds of urea per acre, with half the field differing by more than 57 pounds of urea per acre. For potash the difference in application rate was up to 895 pounds per acre and over half the field differed by more than 242 pounds of potash per acre. Urea and potash differences accounted for almost 87% of the cost difference. The sum of these differences could result in a $34 per acre cost difference for the fertilization. Because of these differences, better analysis or better sampling methods may need to be done, or more samples collected, to ensure that the soil measurements are truly representative of the field’s spatial variability.« less
Liu, Mohan; Sun, Jian; Li, Yang; Xiao, Yan
2017-01-01
This study aimed to explore whether nitrogen availability could influence mycorrhizal function and their associations with host plants in Cd-contaminated acidic soils or not. A greenhouse pot experiment was conducted to assess the effects of mycorrhizal inoculation (non-mycorrhizal inoculation (NM), Glomus aggregatum (Ga), G. tortuosum (Gt) and G. versiforme (Gv)) and inorganic N amendment on the growth, nutrient and Cd uptake of Medicago sativa grown in Cd-contaminated acidic soils (10 mg Cd kg -1 soil). AMF inoculations significantly increased the shoot and total biomass and decreased the shoot Cd concentration in comparison to plants uninoculated. N addition increased markedly concentration and content of N and decreased those of P in plants at all inoculation treatments. Shoot K, Na and Mg concentration in plants inoculated with Ga and Gv were decreased by N addition, whereas shoot K, Na, Ca and Mg concentration in plants inoculated with Gt were not negatively affected. It was observed that N addition only increased mycorrhizal colonization, shoot biomass, shoot K, Ca and Mg content of plants inoculated with Gt. Irrespective of N addition, plants with Gt inoculation got the maximum shoot and root P concentration and content, as well as P/Cd concentration molar ratio among all inoculation treatment. Neither AMF nor N fertilizer contributed to the decrease of soil exchangeable Cd and increase of soil pH. These results suggested that N fertilizer only elevated plant performance of alfalfa with Gt inoculation grown in acidic soil, by diluting Cd concentration and alleviating of nutrient deficiency, especially P. Copyright © 2016 Elsevier Ltd. All rights reserved.
Long-term fate of nitrate fertilizer in agricultural soils.
Sebilo, Mathieu; Mayer, Bernhard; Nicolardot, Bernard; Pinay, Gilles; Mariotti, André
2013-11-05
Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere-hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three-decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere. We found that 61-65% of the applied fertilizers N were taken up by plants, whereas 12-15% of the labeled fertilizer N were still residing in the soil organic matter more than a quarter century after tracer application. Between 8-12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of (15)N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils.
Long-term fate of nitrate fertilizer in agricultural soils
Sebilo, Mathieu; Mayer, Bernhard; Nicolardot, Bernard; Pinay, Gilles; Mariotti, André
2013-01-01
Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere–hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three–decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere. We found that 61–65% of the applied fertilizers N were taken up by plants, whereas 12–15% of the labeled fertilizer N were still residing in the soil organic matter more than a quarter century after tracer application. Between 8–12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of 15N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils. PMID:24145428
Evidence for Different Reaction Pathways for Liquid and Granular Micronutrients in a Calcareous Soil
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hettiarachchi, Ganga M.; McLaughlin, Mike J.; Scheckel, Kirk G.
2008-06-16
The benefits of Mn and Zn fluid fertilizers over conventional granular products in calcareous sandy loam soils have been agronomically demonstrated. We hypothesized that the differences in the effectiveness between granular and fluid Mn and Zn fertilizers is due to different Mn and Zn reaction processes in and around fertilizer granules and fluid fertilizer bands. We used a combination of several synchrotron-based x-ray techniques, namely, spatially resolved micro-x-ray fluorescence (?-XRF), micro-x-ray absorption near edge structure spectroscopy (?-XANES), and bulk-XANES and -extended x-ray absorption fine structure (EXAFS) spectroscopy, along with several laboratory-based x-ray techniques to speciate different fertilizer-derived Mn and Znmore » species in highly calcareous soils to understand the chemistry underlying the observed differential behavior of fluid and granular micronutrient forms. Micro-XRF mapping of soil-fertilizer reactions zones indicated that the mobility of Mn and Zn from liquid fertilizer was greater than that observed for equivalent granular sources of these micronutrients in soil. After application of these micronutrient fertilizers to soil, Mn and Zn from liquid fertilizers were found to remain in comparatively more soluble solid forms, such as hydrated Mn phosphate-like, Mn calcite-like, adsorbed Zn-like, and Zn silicate-like phases, whereas Mn and Zn from equivalent granular sources tended to transform into comparatively less soluble solid forms such as Mn oxide-like, Mn carbonate-like, and Zn phosphate-like phases.« less
Speciation and Distribution of Phosphorus in a Fertilized Soil: A Synchrotron-Based Investigation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lombi, E.; Scheckel, K.G.; Armstrong, R.D.
2008-06-09
Phosphorus availability is often a limiting factor for crop production around the world. The efficiency of P fertilizers in calcareous soils is limited by reactions that decrease P availability; however, fluid fertilizers have recently been shown, in highly calcareous soils of southern Australia, to be more efficient for crop (wheat [Triticum aestivum L.]) P nutrition than granular products. To elucidate the mechanisms responsible for this differential response, an isotopic dilution technique (E value) coupled with a synchrotron-based spectroscopic investigation were used to assess the reaction products of a granular (monoammonium phosphate, MAP) and a fluid P (technical-grade monoammonium phosphate, TG-MAP)more » fertilizer in a highly calcareous soil. The isotopic exchangeability of P from the fluid fertilizer, measured with the E-value technique, was higher than that of the granular product. The spatially resolved spectroscopic investigation, performed using nano x-ray fluorescence and nano x-ray absorption near-edge structure (n-XANES), showed that P is heterogeneously distributed in soil and that, at least in this highly calcareous soil, it is invariably associated with Ca rather than Fe at the nanoscale. 'Bulk' XANES spectroscopy revealed that, in the soil surrounding fertilizer granules, P precipitation in the form of octacalcium phosphate and apatite-like compounds is the dominant mechanism responsible for decreases in P exchangeability. This process was less prominent when the fluid P fertilizer was applied to the soil.« less
Anthropogenic impact on the presence of L. monocytogenes in soil, fruits, and vegetables.
Szymczak, Barbara; Szymczak, Mariusz; Sawicki, Wojciech; Dąbrowski, Waldemar
2014-01-01
The aim of this study was to determine the prevalence of Listeria sp. and Listeria monocytogenes in soil samples with reference to type of fertilizers (natural and artificial) and distance from places intensively exploited by men, as well as to determine the relationship between the presence of L. monocytogenes in the soil and in fruits and vegetables. The examined 1,000 soil samples originated from 15 different areas, whilst 140 samples of fruits and 210 samples of vegetables were collected from those areas. L. monocytogenes was isolated only from 5.5 % of all soil samples coming exclusively from meadows intensively grazed by cattle (27.8 %) and areas near food processing plants (25 %) and wild animal forests (24 %). Listeria sp. and L. monocytogenes were not present on artificially fertilized areas and wastelands. L. monocytogenes was detected in 10 % of samples of strawberry, 15 % of potato samples, and 5 % of parsley samples. Our data indicate that Listeria spp. and particularly L. monocytogenes were found in the soil from (1) arable lands fertilized with manure, (2) pasture (the land fertilized with feces of domestic animals), and (3) forests (again, the land fertilized with feces of animals, not domestic but wild). The bacteria were not detected in the soil samples collected at (1) artificially fertilized arable lands and (2) wastelands (the lands that were not fertilized with manure or animal feces). Moreover, a correlation was determined in the presence of L. monocytogenes between soil samples and samples of the examined fruits and vegetables.
Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping
2015-01-01
Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration.
A Comparison of Soil Test Kits for Use in the Secondary Classroom
ERIC Educational Resources Information Center
Yusten, Jason; Gerber, D. Timothy; Beck, Judy
2003-01-01
Because soils provide water, minerals, and a medium to anchor the roots of plants, measuring the basic physical/chemical components of soils is important to maintaining healthy garden plants and agricultural crops. Historically, soil analysis has been practiced to determine fertilizer and lime applications, soil fertility, and soil improvement…
NASA Astrophysics Data System (ADS)
Lakew, Walle; Baartman, Jantiene; Ritsema, Coen
2016-04-01
There has been little effort to systematically document the experiences and perceptions of farmers on soil erosion and soil and water conservation (SWC) even though a wealth of SWC knowledge and information exists, and there is a great demand to access it. Sustainable Land Management (SLM) has largely evolved through local traditional practices than being adopted on basis of scientific evidence. This research aimed to document the experiences of farmers on soil erosion and conservation, and to increase awareness and participation of the local community in SWC. Participatory stakeholders' workshops were undertaken at local level focused on experiences and perceptions of farmers. The workshops included group discussion and field monitoring of sheet erosion indicators, profiles of rills and gullies and impacts of SWC strategies. Systematic descriptions of the status of soil erosion, soil fertility and yield were used to assess the performances of SWC strategies. Results show that farmers were aware of the harmful effects of ongoing soil erosion and impacts of mitigation strategies on their farms. Sheet erosion was found to be the most damaging form of erosion while rill damage was critical on cereal cultivated farms on steep slopes. Farmers perceived that the desired impacts of SWC practices were attained in general: runoff and soil loss rates decreased, while soil fertility and production increased. The performance of SWC measures were found to be highly affected by the design quality and management strategies on the farm. Comparatively graded stone-faced soil bunds revealed maximum desired impacts and were liked by farmers whereas all level bunds caused water logging and traditional ditches begun incising and affected production of cereals. Bund maintenance practices were low and also distracted the stability of bunds. This calls for further improvement of design of SWC technologies and their maintenance. Further research should integrate the local knowledge for assessment of soil erosion and SWC strategies.
Yin, Chang; Fan, Fenliang; Song, Alin; Cui, Peiyuan; Li, Tingqiang; Liang, Yongchao
2015-07-01
Preferable inorganic fertilization over the last decades has led to fertility degradation of black soil in Northeast China. However, how fertilization regimes impact denitrification and its related bacterial community in this soil type is still unclear. Here, taking advantage of a suit of molecular ecological tools in combination of assaying the potential denitrification (DP), we explored the variation of activity, community structure, and abundance of nirS and nirK denitrifiers under four different fertilization regimes, namely no fertilization control (N0M0), organic pig manure (N0M1), inorganic fertilization (N1M0), and combination of inorganic fertilizer and pig manure (N1M1). The results indicated that organic fertilization increased DP, but inorganic fertilization had no impacts. The increase of DP was mirrored by the shift of nirS denitrifiers' community structure but not by that of nirK denitrifiers'. Furthermore, the change of DP coincided with the variation of abundances of both denitrifiers. Shifts of community structure and abundance of nirS and nirK denitrifiers were correlated with the change of soil pH, total nitrogen (TN), organic matter (OM), C:P, total phosphorus (TP), and available phosphorus (Olsen P). Our results suggest that the change of DP under these four fertilization regimes was closely related to the shift of denitrifying bacteria communities resulting from the variation of properties in the black soil tested.
[Effects of fertilizing regime and planting age on soil calcium decline in Luochuan apple orchards].
Li, Peng; Li, Chun Yue; Wang, Yi Quan; Jiao, Cai Qiang
2017-05-18
This study was conducted to assess the effects of fertilizing regime and orchard planting age on soil calcium contents and stocks in the apple orchards on the Loess Plateau. The apple orchards in Luochuan County, one of the best regions for apple plantation in the world, were selec-ted in this study. The contents of calcium carbonate,water-soluble calcium and exchangeable cal-cium at 0-100 cm soil layer under different fertilizing regimes and various planting ages were mea-sured, their stocks were calculated and their variation features were analyzed. The results showed that soil in the apple orchards in the study region was characterized by the decline in calcium contents. The decline was more serious in apple orchards with long-term application of chemical fertili-zer than in those with combined application of chemical fertilizer and farmyard manure. The average contents of calcium carbonate, water-soluble calcium and exchangeable calcium at 0-100 cm soil layer in apple orchards with long-term application of chemical fertilizer decreased by 38.8%, 25.4% and 5.6% respectively than those in the apple orchards with long-term application of both chemical fertilizer and farmyard manure. The stocks of calcium carbonate, water-soluble calcium and exchangeable calcium decreased by 36.4%, 26.0% and 4.3%, respectively. The decline of soil cal-cium was aggravated with the increase of orchard planting age. The contents of calcium carbonate, water-soluble calcium and exchangeable calcium at 0-100 cm soil layer in orchards of more than 25 years of planting age decreased by 48.8%, 69.4% and 39.5% respectively, compared with orchards of less than 10 years of planting age, and the stocks decreased by 40.8%, 64.1% and 33.0%, respectively. These results indicated that either long-term application of chemical fertilizer or long-term plantation of apple trees obviously depleted soil calcium carbonate, water-soluble calcium and exchangeable calcium. Therefore, it was recommended that application of chemical fertilizer and farmyard manure should be combined to mitigate soil calcium decline, and calcium management should be strengthened in apple orchards of more than 25 years of planting age. The fertilizing regime was a driving factor of soil calcium decline which had a significant temporal (orchard planting age) and spatial (soil depth) effect.