40 CFR 52.1837 - Original identification of plan section.

Code of Federal Regulations, 2013 CFR

2013-07-01

... deterioration of air quality (PSD) regulations to incorporate the nitrogen dioxide (NO2) increments and to make... permitting of new PSD sources, PSD major modifications, and sources to be located in nonattainment areas. (23... changes in the Federal PSD permitting regulations for utility pollution control projects, PM-10 increments...

40 CFR 52.1837 - Original identification of plan section.

Code of Federal Regulations, 2010 CFR

2010-07-01

... deterioration of air quality (PSD) regulations to incorporate the nitrogen dioxide (NO2) increments and to make... permitting of new PSD sources, PSD major modifications, and sources to be located in nonattainment areas. (23... changes in the Federal PSD permitting regulations for utility pollution control projects, PM-10 increments...

Effects of Elevated CO2 on Plant Chemistry, Growth, Yield of Resistant Soybean, and Feeding of a Target Lepidoptera Pest, Spodoptera litura (Lepidoptera: Noctuidae).

PubMed

Yifei, Zhang; Yang, Dai; Guijun, Wan; Bin, Liu; Guangnan, Xing; Fajun, Chen

2018-04-25

Atmospheric CO2 level arising is an indisputable fact in the future climate change, as predicted, it could influence crops and their herbivorous insect pests. The growth and development, reproduction, and consumption of Spodoptera litura (F.) (Lepidoptera: Noctuidae) fed on resistant (cv. Lamar) and susceptible (cv. JLNMH) soybean grown under elevated (732.1 ± 9.99 μl/liter) and ambient (373.6 ± 9.21 μl/liter) CO2 were examined in open-top chambers from 2013 to 2015. Elevated CO2 promoted the above- and belowground-biomass accumulation and increased the root/shoot ratio of two soybean cultivars, and increased the seeds' yield for Lamar. Moreover, elevated CO2 significantly reduced the larval and pupal weight, prolonged the larval and pupal life span, and increased the feeding amount and excretion amount of two soybean cultivars. Significantly lower foliar nitrogen content and higher foliar sugar content and C/N ratio were observed in the sampled foliage of resistant and susceptible soybean cultivars grown under elevated CO2, which brought negative effects on the growth of S. litura, with the increment of foliar sugar content and C/N ratio were greater in the resistant soybean in contrast to the susceptible soybean. Furthermore, the increment of larval consumption was less than 50%, and the larval life span was prolonged more obvious of the larvae fed on resistant soybean compared with susceptible soybean under elevated CO2. It speculated that the future climatic change of atmospheric CO2 level arising would likely cause the increase of the soybean yield and the intake of S. litura, but the resistant soybean would improve the resistance of the target Lepidoptera pest, S. litura.

[Interactive impact of water and nitrogen on yield, quality of watermelon and use of water and nitrogen in gravel-mulched field].

PubMed

Du, Shao-ping; Ma, Zhong-ming; Xue, Liang

2015-12-01

In order to develop the optimal coupling model of water and nitrogen of watermelon under limited irrigation in gravel-mulched field, a field experiment with split-plot design was conducted to study the effects of supplementary irrigation volume, nitrogen fertilization, and their interactions on the growth, yield, quality and water and nitrogen use efficiency of watermelon with 4 supplementary irrigation levels (W: 0, 35, 70, and 105 m³ · hm⁻²) in main plots and 3 nitrogen fertilization levels (N: 0, 120, and 200 kg N · hm⁻²) in sub-plots. The results showed that the photosynthetic rate, yield, and water and nitrogen use efficiency of watermelon increased with the increasing supplementary irrigation, but the nitrogen partial productivity and nitrogen use efficiency decreased with increasing nitrogen fertilization level. The photosynthetic rate and quality indicators increased with increasing nitrogen fertilization level as the nitrogen rate changed from 0 to 120 kg N · hm⁻², but no further significant increase as the nitrogen rate exceeded 120 kg · hm⁻². The interactive effects between water and nitrogen was significant for yield and water and nitrogen use efficiency of watermelon, supplementary irrigation volume was a key factor for the increase yield compared with the nitrogen fertilizer, and the yield reached the highest for the W₇₀N₂₀₀ and W₁₀₅ N₁₂₀ treatments, for which the yield increased by 42.4% and 40.4% compared to CK. Water use efficiency (WUE) was improved by supplementary irrigation and nitrogen rate, the WUE of all nitrogen fertilizer treatments were more than 26 kg · m⁻³ under supplemental irrigation levels 70 m³ · hm⁻² and 105 m³ · hm⁻². The nitrogen partial productivity and nitrogen use efficiency reached the highest in the treatment of W₁₀₅N₁₂₀. It was considered that under the experimental condition, 105 m³ · hm⁻² of supplementary irrigation plus 120 kg · hm⁻² of nitrogen fertilization was the optimal combination of obtaining the high yield and high efficiency.

[Effects of postponed basal nitrogen application with reduced nitrogen rate on grain yield and nitrogen use efficiency of south winter wheat].

PubMed

Zhang, Lei; Shao, Yu Hang; Gu, Shi Lu; Hu, Hang; Zhang, Wei Wei; Tian, Zhong Wei; Jiang, Dong; Dai, Ting Bo

2016-12-01

Excessive nitrogen (N) fertilizer application has led to a reduction of nitrogen use efficiency and environmental problems. It was of great significance for high-yield and high-efficiency cultivation to reduce N fertilizer application with modified application strategies. A two-year field experiment was conducted to study effects of different N application rates at basal and seedling application stages on grain yield and nitrogen use efficiency. Taking the conventional nitrogen application practice (240 kg N·hm -2 with application at basal, jointing, and booting stages at ratios of 5:3:2, respectively) as control, a field trial was conducted at different N application rates (240, 180 and 150 kg N·hm -2 , N 240 , N 180 and N 150 , respectively) and different application times [basal (L 0 ), fourth (L 4 ) and sixth leaf stage (L 6 )] to investigate the effects on grain yield and nitrogen use efficiency. The results indicated that grain yield decreased along with reducing the N application rate, but it had no significant difference between N 240 and N 180 while decreased significantly under N 150 . Nitrogen agronomy and recovery efficiency were all highest under N 180 . Among different N application stages, grain yield and nitrogen use efficiency were highest under L 4 . N 180 L 4 had no signifi-cant difference with control in grain yield, but its nitrogen use efficiency was significantly higher. The leaf area index, flag leaf photosynthesis rate, leaf nitrogen content, activity of nitrogen reductase and glutamine synthase in flag leaf, dry matter and N accumulation after jointing of N 180 L 4 had no significant difference with control. In an overall view, postponing basal N fertilizer application at reduced nitrogen rate could maintain high yield and improve nitrogen use efficiency through improving photosynthetic production capacity and promoting nitrogen uptake and assimilation.

Prediction of Enzyme Mutant Activity Using Computational Mutagenesis and Incremental Transduction

PubMed Central

Basit, Nada; Wechsler, Harry

2011-01-01

Wet laboratory mutagenesis to determine enzyme activity changes is expensive and time consuming. This paper expands on standard one-shot learning by proposing an incremental transductive method (T2bRF) for the prediction of enzyme mutant activity during mutagenesis using Delaunay tessellation and 4-body statistical potentials for representation. Incremental learning is in tune with both eScience and actual experimentation, as it accounts for cumulative annotation effects of enzyme mutant activity over time. The experimental results reported, using cross-validation, show that overall the incremental transductive method proposed, using random forest as base classifier, yields better results compared to one-shot learning methods. T2bRF is shown to yield 90% on T4 and LAC (and 86% on HIV-1). This is significantly better than state-of-the-art competing methods, whose performance yield is at 80% or less using the same datasets. PMID:22007208

Growing C4 perennial grass for bioenergy using a new Agro-BGC ecosystem model

NASA Astrophysics Data System (ADS)

di Vittorio, A. V.; Anderson, R. S.; Miller, N. L.; Running, S. W.

2009-12-01

Accurate, spatially gridded estimates of bioenergy crop yields require 1) biophysically accurate crop growth models and 2) careful parameterization of unavailable inputs to these models. To meet the first requirement we have added the capacity to simulate C4 perennial grass as a bioenergy crop to the Biome-BGC ecosystem model. This new model, hereafter referred to as Agro-BGC, includes enzyme driven C4 photosynthesis, individual live and dead leaf, stem, and root carbon/nitrogen pools, separate senescence and litter fall processes, fruit growth, optional annual seeding, flood irrigation, a growing degree day phenology with a killing frost option, and a disturbance handler that effectively simulates fertilization, harvest, fire, and incremental irrigation. There are four Agro-BGC vegetation parameters that are unavailable for Panicum virgatum (switchgrass), and to meet the second requirement we have optimized the model across multiple calibration sites to obtain representative values for these parameters. We have verified simulated switchgrass yields against observations at three non-calibration sites in IL. Agro-BGC simulates switchgrass growth and yield at harvest very well at a single site. Our results suggest that a multi-site optimization scheme would be adequate for producing regional-scale estimates of bioenergy crop yields on high spatial resolution grids.

Derivative Analysis of AVIRIS Data for Crop Stress Detection

NASA Technical Reports Server (NTRS)

Estep, Lee; Carter, Gregory A.; Berglund, Judith

2003-01-01

Low-altitude Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) hyperspectral imagery of a cornfield in Nebraska was used to determine whether derivative analysis methods provided enhanced plant stress detection compared with narrow-band ratios. The field was divided into 20 plots representing 4 replicates each of 5 nitrogen (N) fertilization treatments that ranged from 0 to 200 kg N/ha in 50 kg/ha increments. The imagery yielded a 3 m ground pixel size for 224 spectral bands. Derivative analysis provided no advantage in stress detection compared with the performance of narrow-band indices derived from the literature. This result was attributed to a high leaf area index at the time of overflight (LAI approx. equal to 5 to 6t) and the high signal-to-noise character of the narrow AVIRIS bands.

Polygonum sachalinense alters the balance between capacities of regeneration and carboxylation of ribulose-1,5-bisphosphate in response to growth CO2 increment but not the nitrogen allocation within the photosynthetic apparatus.

PubMed

Akita, Risako; Kamiyama, Chiho; Hikosaka, Kouki

2012-12-01

The limiting step of photosynthesis changes depending on CO(2) concentration and, in theory, photosynthetic nitrogen use efficiency at a respective CO(2) concentration is maximized if nitrogen is redistributed from non-limiting to limiting processes. It has been shown that some plants increase the capacity of ribulose-1,5-bisphoshate (RuBP) regeneration (evaluated as J(max) ) relative to the RuBP carboxylation capacity (evaluated as V(cmax) ) at elevated CO(2) , which is in accord with the theory. However, there is no study that tests whether this change is accompanied by redistribution of nitrogen in the photosynthetic apparatus. We raised a perennial plant, Polygonum sachalinense, at two nutrient availabilities under two CO(2) concentrations. The J(max) to V(cmax) ratio significantly changed with CO(2) increment but the nitrogen allocation among the photosynthetic apparatus did not respond to growth CO(2) . Enzymes involved in RuBP regeneration might be more activated at elevated CO(2) , leading to the higher J(max) to V(cmax) ratio. Our result suggests that nitrogen partitioning is not responsive to elevated CO(2) even in species that alters the balance between RuBP regeneration and carboxylation. Nitrogen partitioning seems to be conservative against changes in growth CO(2) concentration. Copyright © Physiologia Plantarum 2012.

Response of thinned White fir stands to fertilization with nitrogen plus sulphur.

Treesearch

P.H. Cochran

1991-01-01

A single application of 200 pounds nitrogen (N) plus 33 pounds of sulphur (S) per acre to white fir (Abies concolor (Gord. & Glen.) Lindl.) increased periodic annual increments of basal area and volume by 1.7 ft2acre-1year-1 and 43 to 68 ft3acre

Strengthening of Fe3Al Aluminides by One or Two Solute Elements

NASA Astrophysics Data System (ADS)

Kratochvíl, Petr; Daniš, Stanislav; Minárik, Peter; Pešička, Josef; Král, Robert

2017-09-01

The compressive yield stress of Fe-26Al with additives Ti (0.5 to 4 at. pct), Cr (0.5 to 8 at. pct), Mo (0.5 to 4 at. pct), and V (0.5 to 8 at. pct) at 1073 K (800 °C) has been determined. The effect of the concentration of diverse solutes on the yield stress at 1073 K (800 °C) was compared, and the additivity of the effects of solutes was tested. The effects in iron aluminides with two solutes (V and Ti, Ti and Cr, V and Cr) are compared with those of a single solute V, Ti, and Cr. It is found that the additivity of yield stress increments is valid only for lower solute concentrations. When the amount of the solute atoms increases, the yield stress increment is substantially higher than the sum of the yield stress increments of single solutes. This behavior is related to the high-temperature order in iron aluminides.

Concentrations, loads, and yields of total phosphorus, total nitrogen, and suspended sediment and bacteria concentrations in the Wister Lake Basin, Oklahoma and Arkansas, 2011-13

USGS Publications Warehouse

Buck, Stephanie D.

2014-01-01

The Poteau Valley Improvement Authority uses Wister Lake in southeastern Oklahoma as a public water supply. Total phosphorus, total nitrogen, and suspended sediments from agricultural runoff and discharges from wastewater treatment plants and other sources have degraded water quality in the lake. As lake-water quality has degraded, water-treatment cost, chemical usage, and sludge production have increased for the Poteau Valley Improvement Authority. The U.S. Geological Survey (USGS), in cooperation with the Poteau Valley Improvement Authority, investigated and summarized concentrations of total phosphorus, total nitrogen, suspended sediment, and bacteria (Escherichia coli and Enterococcus sp.) in surface water flowing to Wister Lake. Estimates of total phosphorus, total nitrogen, and suspended sediment loads, yields, and flow-weighted mean concentrations of total phosphorus and total nitrogen concentrations were made for the Wister Lake Basin for a 3-year period from October 2010 through September 2013. Data from water samples collected at fixed time increments during base-flow conditions and during runoff conditions at the Poteau River at Loving, Okla. (USGS station 07247015), the Poteau River near Heavener, Okla. (USGS station 07247350), and the Fourche Maline near Leflore, Okla. (USGS station 07247650), water-quality stations were used to evaluate water quality over the range of streamflows in the basin. These data also were collected to estimate annual constituent loads and yields by using regression models. At the Poteau River stations, total phosphorus, total nitrogen, and suspended sediment concentrations in surface-water samples were significantly larger in samples collected during runoff conditions than in samples collected during base-flow conditions. At the Fourche Maline station, in contrast, concentrations of these constituents in water samples collected during runoff conditions were not significantly larger than concentrations during base-flow conditions. Flow-weighted mean total phosphorus concentrations at all three stations from 2011 to 2013 were several times larger than the Oklahoma State Standard for Scenic Rivers (0.037 milligrams per liter [mg/L]), with the largest flow-weighted phosphorus concentrations typically being measured at the Poteau River at Loving, Okla., station. Flow-weighted mean total nitrogen concentrations did not vary substantially between the Poteau River stations and the Fourche Maline near Leflore, Okla., station. At all of the sampled water-quality stations, bacteria (Escherichia coli and Enterococcus sp.) concentrations were substantially larger in water samples collected during runoff conditions than in water samples collected during base-flow conditions from 2011 to 2013. Estimated annual loads of total phosphorus, total nitrogen, and suspended sediment in the Poteau River stations during runoff conditions ranged from 82 to 98 percent of the total annual loads of those constituents. Estimated annual loads of total phosphorus, total nitrogen, and suspended sediment in the Fourche Maline during runoff conditions ranged from 86 to nearly 100 percent of the total annual loads. Estimated seasonal total phosphorus loads generally were smallest during base-flow and runoff conditions in autumn. Estimated seasonal total phosphorus loads during base-flow conditions tended to be largest in winter and during runoff conditions tended to be largest in the spring. Estimated seasonal total nitrogen loads tended to be smallest in autumn during base-flow and runoff conditions and largest in winter during runoff conditions. Estimated seasonal suspended sediment loads tended to be smallest during base-flow conditions in the summer and smallest during runoff conditions in the autumn. The largest estimated seasonal suspended sediment loads during runoff conditions typically were in the spring. The estimated mean annual total phosphorus yield was largest at the Poteau River at Loving, Okla., water-quality station. The estimated mean annual total phosphorus yield was largest during base flow at the Poteau River at Loving, Okla., water-quality station and at both of the Poteau River water-quality stations during runoff conditions. The estimated mean annual total nitrogen yields were largest at the Poteau River water-quality stations. Estimated mean annual total nitrogen yields were largest during base-flow and runoff conditions at the Poteau River at Loving, Okla., water-quality station. The estimated mean annual suspended sediment yield was largest at the Poteau River near Heavener, Okla., water-quality station during base-flow and runoff conditions. Flow-weighted mean concentrations indicated that total phosphorus inputs from the Poteau River Basin in the Wister Lake Basin were larger than from the Fourche Maline Basin. Flow-weighted mean concentrations of total nitrogen did not vary spatially in a consistent manner. The Poteau River and the Fourche Maline contributed estimated annual total phosphorus loads of 137 to 278 tons per year (tons/yr) to Wister Lake. Between 89 and 95 percent of the annual total phosphorus loads were transported to Wister Lake during runoff conditions. The Poteau River and the Fourche Maline contributed estimated annual total nitrogen loads of 657 to 1,294 tons/yr, with 86 to 94 percent of the annual total nitrogen loads being transported to Wister Lake during runoff conditions. The Poteau River and the Fourche Maline contributed estimated annual total suspended sediment loads of 110,919 to 234,637 tons/yr, with 94 to 99 percent of the annual suspended sediment loads being transported to Wister Lake during runoff conditions. Most of the total phosphorus and suspended sediment were delivered to Wister Lake during runoff conditions in the spring. The majority of the total nitrogen was delivered to Wister Lake during runoff conditions in winter.

Effect of nitrogen levels and nitrogen ratios on lodging resistance and yield potential of winter wheat (Triticum aestivum L.)

PubMed Central

Wang, Hui; Yi, Yuan; Ding, Jinfeng; Zhu, Min; Li, Chunyan; Guo, Wenshan; Feng, Chaonian; Zhu, Xinkai

2017-01-01

Lodging is one of the constraints that limit wheat yields and quality due to the unexpected bending or breaking stems on wheat (Triticum aestivum L.) production worldwide. In addition to choosing lodging resistance varieties, husbandry practices also have a significant effect on lodging. Nitrogen management is one of the most common and efficient methods. A field experiment with Yangmai 20 as research material (a widely-used variety) was conducted to study the effects of different nitrogen levels and ratios on culm morphological, anatomical characters and chemical components and to explore the nitrogen application techniques for lodging tolerance and high yield. Results showed that some index of basal internodes, such as stem wall thickness, filling degree, lignin content, cellulose content, water-soluble carbohydrate (WSC) and WSC/N ratio, were positively and significantly correlated with culm lodging-resistant index (CLRI). As the increase of nitrogen level and basal nitrogen ratio, the basal internodes became slender and fragile with the thick stem wall, while filling degree, chemical components and the strength of the stem decreased gradually, which significantly increased the lodging risk. The response of grain yield to nitrogen doses was quadratic and grain yield reached the highest at the nitrogen ratio of 50%:10%:20%:20% (the ratio of nitrogen amount applied before sowing, at tillering stage, jointing stage and booting stage respectively, abbreviated as 5:1:2:2). These results suggested that for Yangmai 20, the planting density of 180×104ha-1, nitrogen level of 225 kg ha-1, and the ratio of 5: 1: 2: 2 effectively increased lodging resistance and grain yield. This combination of planting density and nitrogen level and ratio could effectively relieve the contradiction between high-yielding and anti-lodging. PMID:29117250

Effect of nitrogen levels and nitrogen ratios on lodging resistance and yield potential of winter wheat (Triticum aestivum L.).

PubMed

Zhang, Mingwei; Wang, Hui; Yi, Yuan; Ding, Jinfeng; Zhu, Min; Li, Chunyan; Guo, Wenshan; Feng, Chaonian; Zhu, Xinkai

2017-01-01

Lodging is one of the constraints that limit wheat yields and quality due to the unexpected bending or breaking stems on wheat (Triticum aestivum L.) production worldwide. In addition to choosing lodging resistance varieties, husbandry practices also have a significant effect on lodging. Nitrogen management is one of the most common and efficient methods. A field experiment with Yangmai 20 as research material (a widely-used variety) was conducted to study the effects of different nitrogen levels and ratios on culm morphological, anatomical characters and chemical components and to explore the nitrogen application techniques for lodging tolerance and high yield. Results showed that some index of basal internodes, such as stem wall thickness, filling degree, lignin content, cellulose content, water-soluble carbohydrate (WSC) and WSC/N ratio, were positively and significantly correlated with culm lodging-resistant index (CLRI). As the increase of nitrogen level and basal nitrogen ratio, the basal internodes became slender and fragile with the thick stem wall, while filling degree, chemical components and the strength of the stem decreased gradually, which significantly increased the lodging risk. The response of grain yield to nitrogen doses was quadratic and grain yield reached the highest at the nitrogen ratio of 50%:10%:20%:20% (the ratio of nitrogen amount applied before sowing, at tillering stage, jointing stage and booting stage respectively, abbreviated as 5:1:2:2). These results suggested that for Yangmai 20, the planting density of 180×104ha-1, nitrogen level of 225 kg ha-1, and the ratio of 5: 1: 2: 2 effectively increased lodging resistance and grain yield. This combination of planting density and nitrogen level and ratio could effectively relieve the contradiction between high-yielding and anti-lodging.

[Effects of nitrogen application rates and straw returning on nutrient balance and grain yield of late sowing wheat in rice-wheat rotation].

PubMed

Zhang, Shan; Shi, Zu-liang; Yang, Si-jun; Gu, Ke-jun; Dai, Ting-bo; Wang, Fei; Li, Xiang; Sun, Ren-hua

2015-09-01

Field experiments were conducted to study the effects of nitrogen application rates and straw returning on grain yield, nutrient accumulation, nutrient release from straw and nutrient balance in late sowing wheat. The results showed that straw returning together with appropriate application of nitrogen fertilizer improved the grain yield. Dry matter, nitrogen, phosphorus and potassium accumulation increased significantly as the nitrogen application rate increased. At the same nitrogen application rate (270 kg N · hm(-2)), the dry matter, phosphorus and potassium accumulation of the treatment with straw returning were higher than that without straw returning, but the nitrogen accumulation was lower. Higher-rate nitrogen application promoted straw decomposition and nutrient release, and decreased the proportion of the nutrient released from straw after jointing. The dry matter, phosphorus and potassium release from straw showed a reverse 'N' type change with the wheat growing, while nitrogen release showed a 'V' type change. The nutrient surplus increased significantly with the nitrogen application rate. At the nitrogen application rate for the highest grain yield, nitrogen and potassium were surplus significantly, and phosphorus input could keep balance. It could be concluded that as to late sowing wheat with straw returning, applying nitrogen at 257 kg · hm(-2) and reducing potassium fertilizer application could improve grain yield and reduce nutrients loss.

A novel air pollution index based on the relative risk of daily mortality associated with short-term exposure to common air pollutants

NASA Astrophysics Data System (ADS)

Cairncross, Eugene K.; John, Juanette; Zunckel, Mark

Communication of the complex relationship between air pollutant exposure and ill health is essential to an air pollution information system. We propose a novel air pollution index (API) system based on the relative risk of the well-established increased daily mortality associated with short-term exposure to common air pollutants: particulate matter (PM 10, PM 2.5), sulphur dioxide, ozone, nitrogen dioxide and carbon monoxide. To construct our index system, the total incremental daily mortality risk of exposure to these pollutants was associated with an index value ranging from 0 to 10. The index scale is linear with respect to incremental risk. The index is open ended, although, for convenience, an index of 10 is assigned for exposures yielding indices ⩾10. To illustrate the application of this API system, a set of published relative risk factors are used to calculate sub-index values for each pollutant, in the range of air pollutant concentrations commonly experienced in urban areas. To account for the reality of ubiquitous simultaneous exposure to a mixture of the common air pollutants, the final API is the sum of the normalised values of the individual indices for PM 10, PM 2.5, sulphur dioxide, ozone, nitrogen dioxide and carbon monoxide. This establishes a self-consistent index system where a given index value corresponds to the same daily mortality risk associated with the combined exposure to the common air pollutants. To facilitate health-risk communication, index values are colour coded and associated with broad health-risk descriptors. The utility of the proposed API is illustrated by applying it to monitored ambient concentration data for the City of Cape Town, South Africa.

[Effects of nitrogen and irrigation water application on yield, water and nitrogen utilization and soil nitrate nitrogen accumulation in summer cotton].

PubMed

Si, Zhuan Yun; Gao, Yang; Shen, Xiao Jun; Liu, Hao; Gong, Xue Wen; Duan, Ai Wang

2017-12-01

A field experiment was carried out to study the effects of nitrogen and irrigation water application on growth, yield, and water and nitrogen use efficiency of summer cotton, and to develop the optimal water and nitrogen management model for suitable yield and less nitrogen loss in summer cotton field in the Huang-Huai region. Two experimental factors were arranged in a split plot design. The main plots were used for arranging nitrogen factor which consisted of five nitrogen fertilizer le-vels(0, 60, 120, 180, 240 kg·hm -2 , referred as N 0 , N 1 , N 2 , N 3 , N 4 ), and the subplots for irrigation factor which consisted of three irrigation quota levels (30, 22.5, 15 mm, referred as I 1 , I 2 , I 3 ). There were 15 treatments with three replications. Water was applied with drip irrigation system. Experimental results showed that both irrigation and nitrogen fertilization promoted cotton growth and yield obviously, but nitrogen fertilizer showed more important effects than irrigation and was the main factor of regulating growth and yield of summer cotton in the experimental region. With the increase of nitrogen fertilization rate and irrigation amount, the dry mater accumulation of reproductive organs, the above-ground biomass at the flowering-bolling stage and seed cotton yield increased gradually, reached peak values at nitrogen fertilization rate of 180 kg·hm -2 and decreased slowly with the nitrogen fertilization rate further increased. The maximum yield of 4016 kg·hm -2 was observed in the treatment of N 3 I 1 . Increasing nitrogen fertilizer amount would improve significantly total N absorption of shoots and N content of stem and leaf, but decrease nitrogen partial factor productivity. The maximum irrigation-water use efficiency of 5.40 kg·m -3 and field water use efficiency of 1.24 kg·m -3 were found in the treatments of N 3 I 3 and N 3 I 1 , respectively. With increasing nitrogen fertilization amount, soil NO 3 - -N content increased and the main soil NO 3 - -N accumulation layer moved downward. By comprehensively considering above-ground biomass, seed cotton yield, water and nitrogen uptake and utilization, and soil NO 3 - -N accumulation in the soil profile, the treatment N 3 I 1 could be recommended as the optimal water and nitrogen application pattern for summer cotton production in the experimental region.

[Effects of nitrogen fertilizer application rate on nitrogen use efficiency and grain yield and quality of different rice varieties].

PubMed

Cong, Xi Han; Shi, Fu Zhi; Ruan, Xin Min; Luo, Yu Xiang; Ma, Ting Chen; Luo, Zhi Xiang

2017-04-18

To provide scientific basis for reasonable application of nitrogen and create varieties with high N use-efficiency, an experiment was carried out to study the effects of nitrogen fertilizer application rate on grain yield, N use rate and quality of different rice varieties. Four different genotypic rice varieties, Nipponbare, N70, N178 and OM052 were used as tested material and three levels of nitrogen application rate (0, 120, 270 kg·hm -2 ) were conducted. Urea as nitrogen source was applied as basal (70%) and panicle (30%) fertilizer. The results showed that nitrogen fertilizer could raise yield mainly because of the increased effective panicles and filled grains per panicle. When the N application rate was 120 and 270 kg·hm -2 , OM052 had the largest grain yield among four varieties, being 41.1% and 76.8% higher, respectively compared with control. Difference in grain yield among four varieties was due to the difference of nitrogen use efficiency. Under 120 and 270 kg·hm -2 nitrogen levels, Nipponbare had the lowest grain yield and N agronomic efficiency (NAE, 40.90 g·g -1 and 18.56 g·g -1 ), which was a variety with low N use-efficiency. On the contrary, OM052 had the highest grain yield and NAE (145.9 g·g -1 and 81.24 g·g -1 ), was a variety with high N use-efficiency. N fertilizer application increased the amylose content and protein content, lengthened gel consistency, reduced chalky kernel, chalkiness, and alkali digestion value. With the increase of N fertilizer application, hot paste viscosity, peak viscosity, consistence viscosity and breakdown viscosity were decreased gradually, and setback viscosity was increased. Correlation analysis showed that the yield and yield components had more significant correlations with appearance quality, cooking and eating quality under low N level. This study confirmed that OM052 was a double high variety with extremely high N agronomic efficiency and yield. Reasonable application of nitrogen fertilizer could significantly increase effective panicles and filled grains per panicle, improve rice quality, and ensure high yield and superior quality simultaneously.

A Numerical Process Control Method for Circular-Tube Hydroforming Prediction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Kenneth I.; Nguyen, Ba Nghiep; Davies, Richard W.

2004-03-01

This paper describes the development of a solution control method that tracks the stresses, strains and mechanical behavior of a tube during hydroforming to estimate the proper axial feed (end-feed) and internal pressure loads through time. The analysis uses the deformation theory of plasticity and Hill?s criterion to describe the plastic flow. Before yielding, the pressure and end-feed increments are estimated based on the initial tube geometry, elastic properties and yield stress. After yielding, the pressure increment is calculated based on the tube geometry at the previous solution increment and the current hoop stress increment. The end-feed increment is computedmore » from the increment of the axial plastic strain. Limiting conditions such as column buckling (of long tubes), local axi-symmetric wrinkling of shorter tubes, and bursting due to localized wall thinning are considered. The process control method has been implemented in the Marc finite element code. Hydroforming simulations using this process control method were conducted to predict the load histories for controlled expansion of 6061-T4 aluminum tubes within a conical die shape and under free hydroforming conditions. The predicted loading paths were transferred to the hydroforming equipment to form the conical and free-formed tube shapes. The model predictions and experimental results are compared for deformed shape, strains and the extent of forming at rupture.« less

[Effects of fertilizer application on water consumption characteristics and yield of potato cultured under ridge-furrow and whole filed plastic mulching in rain-fed area.

PubMed

Yu, Xian Feng; Zhang, Xu Cheng; Wang, Hong Li; Ma, Yi Fan; Hou, Hui Zhi; Fang, Yan Jie

2016-03-01

Chemical fertilizer reduction and organic manure substitution are the useful methods to increase potato water-and nutrient use efficiency, which is cultured under ridge-furrow and whole soil surface mulched by plastic film in semiarid rain-fed area. A 4-year field experiment was carried out from 2011 to 2014 with three treatments: 1) traditional chemical fertilizer application (F), 2) chemical nitrogen fertilizer reduced by 25% and dressing at flowering stage (DF), and 3) chemical nitrogen fertilizer reduced by 50% and organic manure substitution (OF). The soil moisture and potato yield were investigated, and seasonal water consumption, water use efficiency (WUE) were calculated to study the regulations of different nutrient management methods on potato water use process, as well as its effects on potato tuber yield and WUE. The results showed that soil water storage in potato flowering stage was the highest under DF treatment, but there were no significant difference among these three treatments. The depth of soil water depletion in DF and OF showed an increasing trend at post-flowering stage. Potato water consumption decreased significantly at pre-flowering stage, but increased by 36.2%, 23.2%, 24.8% and 19.0% respectively at post-flowering stage in 2011-2014 under DF treatment, as compared with those under F treatment. OF treatment increased potato water consumption by 20.7% and 16.3% than that under F treatment at post-flowering stage from 2011 to 2012, respectively, but exerted no significant effect at pre-flowering stage. Compared with F, DF increased potato tuber yield averagely by 2595.1 kg·hm -2 from 2012 to 2014 and significantly increased the WUE by 14.4% and 6.3% in 2013 and 2014, respectively; OF significantly increased potato tuber yield averagely by 2945 kg·hm -2 tuber yield in 4 experimental years and WUE was significantly higher than that under F from 2012 to 2014. It was indicated that both DF and OF could regulate water consumption between pre-flowering and post-flowering stages, and increase potato tuber yield and WUE. OF showed more significant effects than DF on the increment of tuber yield and WUE.

[Effects of nitrogen application levels on yield and active composition content of Desmodium styracifolium].

PubMed

Zhou, Jiamin; Yin, Xiaohong; Chen, Chaojun; Huang, Min; Peng, Fuyuan; Zhu, Xiaoqi

2010-06-01

To find out the optimal nitrogen application level of Desmodium styracifolium. A field experiment using randomized block design was carried out to study the effects of 5 nitrogen application levels (150, 187.5, 225.0, 262.5 and 300.0 kg x hm(-2)) on yield and active component content of D. styracifolium. Nitrogen application could increase the yield and contents of polysaccharide, total flavonoides and total saponins of D. styracifolium. However, the enhancing extent of the active component content and the yield were not always significant with the increase of nitrogen level. In which, the yield were not significantly different among the nitrogen application levels of 225.0, 262.5, 300.0 kg x hm(-2) the polysaccharide content was no significantly difference among the nitrogen application levels of 225.0, 262. 5 and 300.0 kg x hm(-2), the total flavonoides content under the nitrogen level of 300.0 kg x hm(-2) was significantly lower than that of 150.0 kg hm(-2) (P < 0.01), and the total saponins content under the nitrogen level of 300.0 kg x hm(-2) was no significant difference compared with that of 262.5 kg x hm(-2). The optimal nitrogen application level of D. styracifolium was 225.0-262.5 kg x hm(-2).

Incremental Reactivity Effects on Secondary Organic Aerosol Formation in Urban Atmospheres with and without Biogenic Influence

NASA Astrophysics Data System (ADS)

Kacarab, Mary; Li, Lijie; Carter, William P. L.; Cocker, David R., III

2016-04-01

Two different surrogate mixtures of anthropogenic and biogenic volatile organic compounds (VOCs) were developed to study secondary organic aerosol (SOA) formation at atmospheric reactivities similar to urban regions with varying biogenic influence levels. Environmental chamber simulations were designed to enable the study of the incremental aerosol formation from select anthropogenic (m-Xylene, 1,2,4-Trimethylbenzene, and 1-Methylnaphthalene) and biogenic (α-pinene) precursors under the chemical reactivity set by the two different surrogate mixtures. The surrogate reactive organic gas (ROG) mixtures were based on that used to develop the maximum incremental reactivity (MIR) factors for evaluation of O3 forming potential. Multiple incremental aerosol formation experiments were performed in the University of California Riverside (UCR) College of Engineering Center for Environmental Research and Technology (CE-CERT) dual 90m3 environmental chambers. Incremental aerosol yields were determined for each of the VOCs studied and compared to yields found from single precursor studies. Aerosol physical properties of density, volatility, and hygroscopicity were monitored throughout experiments. Bulk elemental chemical composition from high-resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) data will also be presented. Incremental yields and SOA chemical and physical characteristics will be compared with data from previous single VOC studies conducted for these aerosol precursors following traditional VOC/NOx chamber experiments. Evaluation of the incremental effects of VOCs on SOA formation and properties are paramount in evaluating how to best extrapolate environmental chamber observations to the ambient atmosphere and provides useful insights into current SOA formation models. Further, the comparison of incremental SOA from VOCs in varying surrogate urban atmospheres (with and without strong biogenic influence) allows for a unique perspective on the impacts different compounds have on aerosol formation in different urban regions.

Genetic variations in ARE1 mediate grain yield by modulating nitrogen utilization in rice.

PubMed

Wang, Qing; Nian, Jinqiang; Xie, Xianzhi; Yu, Hong; Zhang, Jian; Bai, Jiaoteng; Dong, Guojun; Hu, Jiang; Bai, Bo; Chen, Lichao; Xie, Qingjun; Feng, Jian; Yang, Xiaolu; Peng, Juli; Chen, Fan; Qian, Qian; Li, Jiayang; Zuo, Jianru

2018-02-21

In crops, nitrogen directly determines productivity and biomass. However, the improvement of nitrogen utilization efficiency (NUE) is still a major challenge in modern agriculture. Here, we report the characterization of are1, a genetic suppressor of a rice fd-gogat mutant defective in nitrogen assimilation. ARE1 is a highly conserved gene, encoding a chloroplast-localized protein. Loss-of-function mutations in ARE1 cause delayed senescence and result in 10-20% grain yield increases, hence enhance NUE under nitrogen-limiting conditions. Analysis of a panel of 2155 rice varieties reveals that 18% indica and 48% aus accessions carry small insertions in the ARE1 promoter, which result in a reduction in ARE1 expression and an increase in grain yield under nitrogen-limiting conditions. We propose that ARE1 is a key mediator of NUE and represents a promising target for breeding high-yield cultivars under nitrogen-limiting condition.

[Effects of nitrogen application rate on potassium uptake and utilization of direct-seeded cotton after wheat harvest].

PubMed

Zhang, Guo Wei; Yang, Chang Qin; Liu, Rui Xian; Zhang, Lei; Ni, Wan Chao

2016-10-01

By using cotton cultivar CCRI-50 as material, field experiments were conducted in the summer seasons of 2013 and 2014 at the experimental station of Jiangsu Academy of Agricultural Sciences (Nanjing, China) to study the effects of different nitrogen application rates (0, 60, 120, 150, 180 and 240 kg N·hm -2 ) on the potassium uptake and utilization of the cotton plant that was direct-seeded after wheat harvest. Data suggested that the elevated nitrogen application rates increased the cotton potassium uptake of all growth stages, and the largest increment was observed at the peak flowering-boll opening stage. Nitrogen application also changed the uptake percentage of potassium uptake of each stage, i.e., the percentage of potassium uptake decreased in the stage from seedling to peak flowering, while increased in the stage from peak flowering to boll maturing. In addition, the elevated nitrogen applications reduced the decreasing rate of nitrogen concentration in upper fruiting branches, but promoted the decreasing rate in middle and low fruiting branches at later growth stages. As the nitrogen application rate increased, the marginal effect of potassium uptake (promoted amount of potassium uptake due to 1 kg increase of N application) increased first and then decreased, and the lint production efficiency of potassium descended steadily. In cotton plants that were direct-seeded after wheat harvest, potassium and biomass were mainly accumulated in the lower and middle fruiting branches. At the 150 and 180 kg N·hm -2 application levels, much more potassium was allocated to the reproductive organs and the characters and the eigenvalues of simulated curves of potassium concentration and total potassium accumulation were more optimized than those at the higher or the lower N application levels. At the high nitrogen application (more than 180 kg N·hm -2 ) level, the marginal effect of potassium uptake and lint production efficiency decreased, and at the lower nitrogen application (less than 150 kg N·hm -2 ) level, lint yield was lower due to the decrease of economic coefficient of biomass and potassium in the middle and low fruiting branches.

Regional variation in growth response of Coastal Douglas-fir to nitrogen fertilizer in the Pacific Northwest.

Treesearch

C.E. Peterson; J.W. Hazard

1990-01-01

Hypothesis testing for differences in growth responses among physiographic strata, thinning levels, and fertilizer dosage levels resulted in a set of empirical models for predicting volume increment response of even aged coastal Douglas-fir to nitrogen fertilizer. Absolute and percent responses are estimated for stands both thinned and unthinned, as a function of...

Rate and yield relationships in the production of xanthan gum by batch fermentations using complex and chemically defined growth media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinches, A.; Pallent, L.J.

1986-10-01

Rate and yield information relating to biomass and product formation and to nitrogen, glucose and oxygen consumption are described for xanthan gum batch fermentations in which both chemically defined (glutamate nitrogen) and complex (peptone nitrogen) media are employed. Simple growth and product models are used for data interpretation. For both nitrogen sources, rate and yield parameter estimates are shown to be independent of initial nitrogen concentrations. For stationary phases, specific rates of gum production are shown to be independent of nitrogen source but dependent on initial nitrogen concentration. The latter is modeled empirically and suggests caution in applying simple productmore » models to xanthan gum fermentations. 13 references.« less

Corn yield and economic return with nitrogen applied through drip tubing

USDA-ARS?s Scientific Manuscript database

A two year project was established to determine corn (Zea mays, L) yield response to subsurface (SSDI) and surface (SDI) drip irrigation systems at various nitrogen fertilizer rates. Nitrogen was applied through the drip system at two nitrogen levels in three split applications. Supplemental dry N ...

Efficacy of Rice Insecticide Seed Treatments at Selected Nitrogen Rates for Control of the Rice Water Weevil (Coleoptera: Curculionidae).

PubMed

Everett, Mallory; Lorenz, Gus; Slaton, Nathan; Hardke, Jarrod

2015-08-01

Seed-applied insecticides are the standard control method used in the United States to minimize rice water weevil (Lissorhoptrus oryzophilus Kuschel) injury to rice (Oryza sativa L.) roots, and often results in greater yields than rice that receives no seed-applied insecticide. Yield increases from seed-applied insecticides often occur even when insect pressure is low and should not cause yield loss. The research objective was to evaluate the effect of urea-nitrogen rate and seed-applied insecticide on number of rice water weevil larvae, nitrogen uptake, and rice grain yield. Six trials were conducted at the Pine Tree Research Station (PTRS) and the Rice Research Extension Center (RREC) to examine the response of rice plants receiving different insecticide-seed treatments and urea-nitrogen rate combinations. Insecticide-seed treatments included label rates of clothianidin, thiamethoxam, and a no-insecticide (fungicide only) control, in combination with season-total nitrogen rates of 0, 50, 100, 150, and 200 kg urea-nitrogen/ha. Rice seed that was treated with clothianidin or thiamethoxam generally had equal numbers of rice water weevil larvae, which were significantly fewer compared with rice that received no insecticide with an equivalent urea-nitrogen rate. Nitrogen uptake at panicle differentiation was not affected by insecticide-seed treatments at four of six sites and usually increased positively and linearly as urea-nitrogen rate increased. As urea-nitrogen rate increased, grain yield increased either linearly or nonlinearly. Averaged across urea-nitrogen rates, both insecticide seed treatments had similar yields that were 4 to 7% greater than the grain yields of rice that received no insecticide at four of the five harvested sites. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Coupling effects of periodic rewatering after drought stress and nitrogen fertilizer on growth and water and nitrogen productivity of Coffea arabica].

PubMed

Hao, Kun; Liu, Xiao Gang; Zhang, Yan; Han, Zhi Hui; Yu, Ning; Yang, Qi Liang; Liu, Yan Wei

2017-12-01

The effects of periodic rewatering after drought stress and nitrogen fertilizer on growth, yield, photosynthetic characteristics of leaves and water and nitrogen productivity of Coffea arabica (Katim P7963) were studied under different nitrogen application levels in 2.5 consecutive years. Irrigation (periodic rewatering after drought stress) and nitrogen were designed as two factors, with four modes of irrigation, namely, full irrigation (I F-F : 100%ET 0 +100%ET 0 , ET 0 was reference crop evapotranspiration), rewatering after light drought stress (I L-F : 80%ET 0 +100%ET 0 ), rewatering after moderate drought stress (I M-F : 60%ET 0 +100%ET 0 ) and rewatering after severe drought stress (I S-F : 40%ET 0 +100%ET 0 ), and three levels of nitrogen, namely, high nitrogen (N H : 750 kg N·hm -2 each time), middle nitrogen (N M : 500 kg N·hm -2 each time), low nitrogen (N L : 250 kg N·hm -2 each time), and nitrogen was equally applied for 4 times. The results showed that irrigation and nitrogen had significant effect on plant height, stem diameter, yield and water and nitrogen productivity of C. arabica, and plant height and stem diameter showed S-curve with the day ordinal number, and leaf photosynthesis decreased significantly under drought stress but most photosynthesis index recovered somewhat after rewatering. Compared with I F-F , I L-F increased dry bean yield by 6.9%, while I M-F and I S-F decreased dry bean yield by 15.2% and 38.5%, respectively; I L-F and I M-F increased water use efficiency by 18.8% and 6.0%, respectively, while I S-F decreased water use efficiency by 12.1%; I L-F increased nitrogen partial productivity by 6.1%, while I M-F and I S-F decreased nitrogen partial productivity by 14.0% and 36.0%, respectively. Compared with N H , N M increased dry bean yield and water use efficiency by 20.9% and 19.3%, while N L decreased dry bean yield and water use efficiency by 42.4% and 41.9%, respectively; N M and N L increased nitrogen partial productivity by 81.4% and 72.9%, respectively. Compared with I F-F N H , I L-F N M increased dry bean yield, water use efficiency and nitrogen partial productivity by 37.6%, 52.9% and 106.4%, respectively. Regression analysis showed that the yield of dry bean was the maximum (2362 kg·hm -2 ) when the irrigation amount was 318 mm and the nitrogen application amount was 583 kg·hm -2 ; the water use efficiency was the maximum (0.78 kg·m -3 ) when the irrigationamount was 295 mm and the nitrogen application amount was 584 kg·hm -2 , that's to say when yield of dry bean and water use efficiency reach the maximum value at the same time, the combination was the closest to I L-F N M . Therefore, the best combination of water and nitrogen model for C. arabica was I L-F N M .

Genetic basis of nitrogen use efficiency and yield stability across environments in winter rapeseed.

PubMed

Bouchet, Anne-Sophie; Laperche, Anne; Bissuel-Belaygue, Christine; Baron, Cécile; Morice, Jérôme; Rousseau-Gueutin, Mathieu; Dheu, Jean-Eric; George, Pierre; Pinochet, Xavier; Foubert, Thomas; Maes, Olivier; Dugué, Damien; Guinot, Florent; Nesi, Nathalie

2016-09-15

Nitrogen use efficiency is an important breeding trait that can be modified to improve the sustainability of many crop species used in agriculture. Rapeseed is a major oil crop with low nitrogen use efficiency, making its production highly dependent on nitrogen input. This complex trait is suspected to be sensitive to genotype × environment interactions, especially genotype × nitrogen interactions. Therefore, phenotyping diverse rapeseed populations under a dense network of trials is a powerful approach to study nitrogen use efficiency in this crop. The present study aimed to determine the quantitative trait loci (QTL) associated with yield in winter oilseed rape and to assess the stability of these regions under contrasting nitrogen conditions for the purpose of increasing nitrogen use efficiency. Genome-wide association studies and linkage analyses were performed on two diversity sets and two doubled-haploid populations. These populations were densely genotyped, and yield-related traits were scored in a multi-environment design including seven French locations, six growing seasons (2009 to 2014) and two nitrogen nutrition levels (optimal versus limited). Very few genotype × nitrogen interactions were detected, and a large proportion of the QTL were stable across nitrogen nutrition conditions. In contrast, strong genotype × trial interactions in which most of the QTL were specific to a single trial were found. To obtain further insight into the QTL × environment interactions, genetic analyses of ecovalence were performed to identify the genomic regions contributing to the genotype × nitrogen and genotype × trial interactions. Fifty-one critical genomic regions contributing to the additive genetic control of yield-associated traits were identified, and the structural organization of these regions in the genome was investigated. Our results demonstrated that the effect of the trial was greater than the effect of nitrogen nutrition levels on seed yield-related traits under our experimental conditions. Nevertheless, critical genomic regions associated with yield that were stable across environments were identified in rapeseed.

40 CFR 52.320 - Identification of plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) regulations to incorporate the nitrogen dioxide (NO2) increments. (i) Incorporation by reference. (A... Gasoline Transfer at Bulk Plants-Vapor Balance System), and D (Test Procedures for Annual Pressure/Vacuum...

Effects of starter nitrogen fertilizer on soybean root activity, leaf photosynthesis and grain yield

PubMed Central

Gai, Zhijia; Zhang, Jingtao; Li, Caifeng

2017-01-01

The objective of this study was to examine the impact of starter nitrogen fertilizer on soybean root activity, leaf photosynthesis, grain yield and their relationship. To achieve this objective, field experiments were conducted in 2013 and 2014, using a randomized complete block design, with three replications. Nitrogen was applied at planting at rates of 0, 25, 50, and 75 kg N ha-1. In both years, starter nitrogen fertilizer benefited root activity, leaf photosynthesis, and consequently its yield. Statistically significant correlation was found among root activity, leaf photosynthetic rate, and grain yield at the developmental stage. The application of N25, N50, and N75 increased grain yield by 1.28%, 2.47%, and 1.58% in 2013 and by 0.62%, 2.77%, and 2.06% in 2014 compared to the N0 treatment. Maximum grain yield of 3238.91 kg ha-1 in 2013 and 3086.87 kg ha-1 in 2014 were recorded for N50 treatment. Grain yield was greater for 2013 than 2014, possibly due to more favorable environmental conditions. This research indicated that applying nitrogen as starter is necessary to increase soybean yield in Sangjiang River Plain in China. PMID:28388620

[Effects of grafting and nitrogen fertilization on melon yield and nitrogen uptake and utilization].

PubMed

Xue, Liang; Ma, Zhong Ming; DU, Shao Ping

2017-06-18

A split-field design experiment was carried out using two main methods of cultivation (grafting and self-rooted cultivation) and subplots with different nitrogen application levels (0, 120, 240, and 360 kg N·hm -2 ) to investigate the effects of cultivation method and nitrogen application levels on the yield and quality of melons, nitrogen transfer, nitrogen distribution, and nitrogen utilization rate. The results showed that melons produced by grafting cultivation had a 7.3% increase in yield and a 0.16%-3.28% decrease in soluble solid content, compared to those produced by self-rooted cultivation. The amount of nitrogen accumulated in melons grafted in the early growth phase was lower than that in self-rooted melons, and higher after fruiting. During harvest, nitrogen accumulation amount in grafted melon plants was 5.2% higher than that in self-rooted plants and nitrogen accumulation amount in fruits was 10.3% higher. Grafting cultivation increased the amount of nitrogen transfer from plants to fruits by 20.9% compared to self-rooted cultivation. Nitrogen distribution in fruits was >80% in grafted melons, whereas that in self-rooted melons was <80%. Under the same level of nitrogen fertilization, melons cultivated by grafting showed 1.3%-4.2% increase in nitrogen absorption and utilization rate, 2.73-5.56 kg·kg -1 increase in nitrogen agronomic efficiency, and 7.39-16.18 kg·kg -1 increase in nitrogen physiological efficiency, compared to self-rooted cultivation. On the basis of the combined perspective of commercial melon yield, and nitrogen absorption and utilization rate, an applied nitrogen amount of 240 kg·hm -2 is most suitable for graf-ting cultivation in this region.

Estimated nitrogen loads from selected tributaries in Connecticut draining to Long Island Sound, 1999–2009

USGS Publications Warehouse

Mullaney, John R.; Schwarz, Gregory E.

2013-01-01

The total nitrogen load to Long Island Sound from Connecticut and contributing areas to the north was estimated for October 1998 to September 2009. Discrete measurements of total nitrogen concentrations and continuous flow data from 37 water-quality monitoring stations in the Long Island Sound watershed were used to compute total annual nitrogen yields and loads. Total annual computed yields and basin characteristics were used to develop a generalized-least squares regression model for use in estimating the total nitrogen yields from unmonitored areas in coastal and central Connecticut. Significant variables in the regression included the percentage of developed land, percentage of row crops, point-source nitrogen yields from wastewater-treatment facilities, and annual mean streamflow. Computed annual median total nitrogen yields at individual monitoring stations ranged from less than 2,000 pounds per square mile in mostly forested basins (typically less than 10 percent developed land) to more than 13,000 pounds per square mile in urban basins (greater than 40 percent developed) with wastewater-treatment facilities and in one agricultural basin. Medians of computed total annual nitrogen yields for water years 1999–2009 at most stations were similar to those previously computed for water years 1988–98. However, computed medians of annual yields at several stations, including the Naugatuck River, Quinnipiac River, and Hockanum River, were lower than during 1988–98. Nitrogen yields estimated for 26 unmonitored areas downstream from monitoring stations ranged from less than 2,000 pounds per square mile to 34,000 pounds per square mile. Computed annual total nitrogen loads at the farthest downstream monitoring stations were combined with the corresponding estimates for the downstream unmonitored areas for a combined estimate of the total nitrogen load from the entire study area. Resulting combined total nitrogen loads ranged from 38 to 68 million pounds per year during water years 1999–2009. Total annual loads from the monitored basins represent 63 to 74 percent of the total load. Computed annual nitrogen loads from four stations near the Massachusetts border with Connecticut represent 52 to 54 percent of the total nitrogen load during water years 2008–9, the only years with data for all the border sites. During the latter part of the 1999–2009 study period, total nitrogen loads to Long Island Sound from the study area appeared to increase slightly. The apparent increase in loads may be due to higher than normal streamflows, which consequently increased nonpoint nitrogen loads during the study, offsetting major reductions of nitrogen from wastewater-treatment facilities. Nitrogen loads from wastewater treatment facilities declined as much as 2.3 million pounds per year in areas of Connecticut upstream from the monitoring stations and as much as 5.8 million pounds per year in unmonitored areas downstream in coastal and central Connecticut.

[Characteristics of dry matter production and nitrogen accumulation in barley genotypes with high nitrogen utilization efficiency].

PubMed

Huang, Yi; Li, Ting-Xuan; Zhang, Xi-Zhou; Ji, Lin

2014-07-01

A pot experiment was conducted under low (125 mg x kg-1) and normal (250 mg x kg(-1)) nitrogen treatments. The nitrogen uptake and utilization efficiency of 22 barley cultivars were investigated, and the characteristics of dry matter production and nitrogen accumulation in barley were analyzed. The results showed that nitrogen uptake and utilization efficiency were different for barley under two nitrogen levels. The maximal values of grain yield, nitrogen utilization efficiency for grain and nitrogen harvest index were 2.87, 2.91 and 2.47 times as those of the lowest under the low nitrogen treatment. Grain yield and nitrogen utilization efficiency for grain and nitrogen harvest index of barley genotype with high nitrogen utilization efficiency were significantly greater than low nitrogen utilization efficiency, and the parameters of high nitrogen utilization efficiency genotype were 82.1%, 61.5% and 50.5% higher than low nitrogen utilization efficiency genotype under the low nitrogen treatment. Dry matter mass and nitrogen utilization of high nitrogen utilization efficiency was significantly higher than those of low nitrogen utilization efficiency. A peak of dry matter mass of high nitrogen utilization efficiency occurred during jointing to heading stage, while that of nitrogen accumulation appeared before jointing. Under the low nitrogen treatment, dry matter mass of DH61 and DH121+ was 34.4% and 38.3%, and nitrogen accumulation was 54. 8% and 58.0% higher than DH80, respectively. Dry matter mass and nitrogen accumulation seriously affected yield before jointing stage, and the contribution rates were 47.9% and 54.7% respectively under the low nitrogen treatment. The effect of dry matter and nitrogen accumulation on nitrogen utilization efficiency for grain was the largest during heading to mature stages, followed by sowing to jointing stages, with the contribution rate being 29.5% and 48.7%, 29.0% and 15.8%, respectively. In conclusion, barley genotype with high nitrogen utilization efficiency had a strong ability of dry matter production and nitrogen accumulation. It could synergistically improve yield and nitrogen utilization efficiency by enhancing the ability of nitrogen uptake and dry matter formation before jointing stage in barley.

Response of a 110-year-old Douglas-fir stand to urea and ammonium nitrate fertilization

Treesearch

Constance A. Harrington; Richard E. Miller

1979-01-01

Basal area response to 150 pounds of nitrogen per acre applied as urea or ammonium nitrate was monitored on 1/5-acre plots for 4 years in a recently thinned, 110-year-old, site II, Douglas-fir stand. Nitrogen fertilization significantly increased growth. Basal area increment was increased 59 percent over the controls by ammonium nitrate and 37 percent by urea. The...

New Estimates of Land Use Intensity of Potential Bioethanol Production in the U.S.A.

NASA Astrophysics Data System (ADS)

Kheshgi, H. S.; Song, Y.; Torkamani, S.; Jain, A. K.

2016-12-01

We estimate potential bioethanol land use intensity (the inverse of potential bioethanol yield per hectare) across the United States by modeling crop yields and conversion to bioethanol (via a fermentation pathway), based on crop field studies and conversion technology analyses. We apply the process-based land surface model, the Integrated Science Assessment model (ISAM), to estimate the potential yield of four crops - corn, Miscanthus, and two variants of switchgrass (Cave-in-Rock and Alamo) - across the U.S.A. landscape for the 14-year period from 1999 through 2012, for the case with fertilizer application but without irrigation. We estimate bioethanol yield based on recent experience for corn bioethanol production from corn kernel, and current cellulosic bioethanol process design specifications under the assumption of the maximum practical harvest fraction for the energy grasses (Miscanthus and switchgrasses) and a moderate (30%) harvest fraction of corn stover. We find that each of four crops included has regions where that crop is estimated to have the lowest land use intensity (highest potential bioethanol yield per hectare). We find that minimizing potential land use intensity by including both corn and the energy grasses only improves incrementally to that of corn (using both harvested kernel and stover for bioethanol). Bioethanol land use intensity is one fundamental factor influencing the desirability of biofuels, but is not the only one; others factors include economics, competition with food production and land use, water and climate, nitrogen runoff, life-cycle emissions, and the pace of crop and technology improvement into the future.

QTL and QTL x environment effects on agronomic and nitrogen acquisition traits in rice.

PubMed

Senthilvel, Senapathy; Vinod, Kunnummal Kurungara; Malarvizhi, Palaniappan; Maheswaran, Marappa

2008-09-01

Agricultural environments deteriorate due to excess nitrogen application. Breeding for low nitrogen responsive genotypes can reduce soil nitrogen input. Rice genotypes respond variably to soil available nitrogen. The present study attempted quantification of genotype x nitrogen level interaction and mapping of quantitative trait loci (QTLs) associated with nitrogen use efficiency (NUE) and other associated agronomic traits. Twelve parameters were observed across a set of 82 double haploid (DH) lines derived from IR64/Azucena. Three nitrogen regimes namely, native (0 kg/ha; no nitrogen applied), optimum (100 kg/ha) and high (200 kg/ha) replicated thrice were the environments. The parents and DH lines were significantly varying for all traits under different nitrogen regimes. All traits except plant height recorded significant genotype x environment interaction. Individual plant yield was positively correlated with nitrogen use efficiency and nitrogen uptake. Sixteen QTLs were detected by composite interval mapping. Eleven QTLs showed significant QTL x environment interactions. On chromosome 3, seven QTLs were detected associated with nitrogen use, plant yield and associated traits. A QTL region between markers RZ678, RZ574 and RZ284 was associated with nitrogen use and yield. This chromosomal region was enriched with expressed gene sequences of known key nitrogen assimilation genes.

Pesticides reduce symbiotic efficiency of nitrogen-fixing rhizobia and host plants

PubMed Central

Fox, Jennifer E.; Gulledge, Jay; Engelhaupt, Erika; Burow, Matthew E.; McLachlan, John A.

2007-01-01

Unprecedented agricultural intensification and increased crop yield will be necessary to feed the burgeoning world population, whose global food demand is projected to double in the next 50 years. Although grain production has doubled in the past four decades, largely because of the widespread use of synthetic nitrogenous fertilizers, pesticides, and irrigation promoted by the “Green Revolution,” this rate of increased agricultural output is unsustainable because of declining crop yields and environmental impacts of modern agricultural practices. The last 20 years have seen diminishing returns in crop yield in response to increased application of fertilizers, which cannot be completely explained by current ecological models. A common strategy to reduce dependence on nitrogenous fertilizers is the production of leguminous crops, which fix atmospheric nitrogen via symbiosis with nitrogen-fixing rhizobia bacteria, in rotation with nonleguminous crops. Here we show previously undescribed in vivo evidence that a subset of organochlorine pesticides, agrichemicals, and environmental contaminants induces a symbiotic phenotype of inhibited or delayed recruitment of rhizobia bacteria to host plant roots, fewer root nodules produced, lower rates of nitrogenase activity, and a reduction in overall plant yield at time of harvest. The environmental consequences of synthetic chemicals compromising symbiotic nitrogen fixation are increased dependence on synthetic nitrogenous fertilizer, reduced soil fertility, and unsustainable long-term crop yields. PMID:17548832

Nitrogen, phosphorus, and potassium effects on biomass yield and flavonoid content of American Skullcap (Scutellaria Lateriflora)

USDA-ARS?s Scientific Manuscript database

Information on optimum dosage of nitrogen (N), phosphorus (P) and potassium (K) fertilizer for high dry matter yield and flavonoid yield of American Skullcap is lacking. Greenhouse experiments were conducted to determine the effects of N, P and K fertilizer on biomass yield and flavonoid content of...

Plutons: Simmer between 350° and 500°C for 10 million years, then serve cold (Invited)

NASA Astrophysics Data System (ADS)

Coleman, D. S.; Davis, J.

2009-12-01

The growing recognition that continental plutons are assembled incrementally over millions of years requires reexamination of the thermal histories of intrusive rocks. With the exception of the suggestion that pluton magma chambers can be revitalized by mafic input at their deepest structural levels, most aspects of modern pluton petrology are built on the underlying assumption that silicic plutons intrude as discrete thermal packages that undergo subsequent monotonic decay back to a steady-state geothermal gradient. The recognition that homogeneous silicic plutons are constructed over timescales too great to be single events necessitates rethinking pluton intrusion mechanisms, textures, thermochronology, chemical evolution and links to volcanic rocks. Three-dimensional thermal modeling of sheeted (horizontal and vertical) incremental pluton assembly (using HEAT3D by Wohletz, 2007) yields several results that are largely independent of intrusive geometry and may help understand bothersome field and laboratory results from plutonic rocks. 1) All increments cool quickly below hornblende closure temperature. However, late increments are emplaced into walls warmed by earlier increments, and they cycle between hornblende and biotite closure temperatures, a range in which fluid-rich melts are likely to be present. These conditions persist until the increments are far from the region of new magma flux, or the addition of increments stops. These observations are supported by Ar thermochronology and may explain why heterogeneous early marginal intrusive phases often grade into younger homogeneous interior map units. 2) Early increments become the contact metamorphic wall rocks of later increments. This observation suggests that much of the contact metamorphism associated with a given volume of plutonic rock is “lost” via textural modification of early increments during intrusion of later increments. Johnson and Glazner (CMP, in press) argue that mappable variations in pluton texture can result from textural modification during thermal cycling associated with incremental assembly. 3) The thermal structure of the model pluton evolves toward roughly spheroidal isotherms even though the pluton is assembled from thin tabular sheets. The zone of melt-bearing rock and the shape of intrapluton contact metamorphic isograds bear little resemblance to the increments from which the pluton was built. Consequently, pluton contacts mapped by variations in texture that reflect the thermal cycling inherent to incremental assembly will inevitably be “blob” or diapir-like, but will yield little insight into magma intrusion geometry. 4) Although models yield large regions of melt-bearing rock, the melt fraction is low and the melt-bearing volume at any time is small compared to the total volume of the pluton. This observation raises doubts about the connections between zoned silicic plutons and large ignimbrite eruptions.

Recent Genetic Gains in Nitrogen Use Efficiency in Oilseed Rape

PubMed Central

Stahl, Andreas; Pfeifer, Mara; Frisch, Matthias; Wittkop, Benjamin; Snowdon, Rod J.

2017-01-01

Nitrogen is essential for plant growth, and N fertilization allows farmers to obtain high yields and produce sufficient agricultural commodities. On the other hand, nitrogen losses potentially cause adverse effects to ecosystems and to human health. Increasing nitrogen use efficiency (NUE) is vital to solve the conflict between productivity, to secure the demand of a growing world population, and the protection of the environment. To ensure this, genetic improvement is considered to be a paramount aspect toward ecofriendly crop production. Winter oilseed rape (Brassica napus L.) is the second most important oilseed crop in the world and is cultivated in many regions across the temperate zones. To our knowledge, this study reports the most comprehensive field-based data generated to date for an empirical evaluation of genetic improvement in winter oilseed rape varieties under two divergent nitrogen fertilization levels (NFLs). A collection of 30 elite varieties registered between 1989 and 2014, including hybrids and open pollinated varieties, was tested in a 2-year experiment in 10 environments across Germany for changes in seed yield and seed quality traits. Furthermore, NUE was calculated. We observed a highly significant genetics-driven increase in seed yield per-se and, thus, increased NUE at both NFLs. On average, seed yield from modern open-pollinated varieties and modern hybrids was higher than from old open-pollinated varieties and old hybrids. The annual yield progress across all tested varieties was ~35 kg ha−1 year−1 at low nitrogen and 45 kg ha−1 year−1 under high nitrogen fertilization. Furthermore, in modern varieties an increased oil concentration and decreased protein concentration was observed. Despite, the significant effects of nitrogen fertilization, a surprisingly low average seed yield gap of 180 kg N ha−1 was noted between high and low nitrogen fertilization. Due to contrary effects of N fertilization on seed yield per-se and seed oil concentration an oil yield of 2.04 t ha−1 was measured at both N levels. Collectively, the data reveal that genetic improvement through modern breeding techniques in conjunction with reduced N fertilizer inputs has a tremendous potential to increase NUE of oilseed rape. PMID:28638399

Computing wheat nitrogen requirements from grain yield and protein maps

USDA-ARS?s Scientific Manuscript database

Optical protein sensors and mass-flow yield monitors provide the opportunity to continuously measure grain quality and quantity during harvesting. This chapter illustrates how yield monitor and grain protein measurements may provide useful postharvest information for evaluating water or nitrogen (N)...

Computing wheat nitrogen requirements from grain yield and protein maps

USDA-ARS?s Scientific Manuscript database

Optical protein sensors and mass-flow yield monitors provide the opportunity to continuously measure grain quality and quantity during harvesting. This chapter illustrates how yield monitor and grain protein measurements may provide useful post-harvest information for evaluating water or nitrogen (...

Effects of reduced nitrogen inputs on crop yield and nitrogen use efficiency in a long-term maize-soybean relay strip intercropping system.

PubMed

Chen, Ping; Du, Qing; Liu, Xiaoming; Zhou, Li; Hussain, Sajad; Lei, Lu; Song, Chun; Wang, Xiaochun; Liu, Weiguo; Yang, Feng; Shu, Kai; Liu, Jiang; Du, Junbo; Yang, Wenyu; Yong, Taiwen

2017-01-01

The blind pursuit of high yields via increased fertilizer inputs increases the environmental costs. Relay intercropping has advantages for yield, but a strategy for N management is urgently required to decrease N inputs without yield loss in maize-soybean relay intercropping systems (IMS). Experiments were conducted with three levels of N and three planting patterns, and dry matter accumulation, nitrogen uptake, nitrogen use efficiency (NUE), competition ratio (CR), system productivity index (SPI), land equivalent ratio (LER), and crop root distribution were investigated. Our results showed that the CR of soybean was greater than 1, and that the change in root distribution in space and time resulted in an interspecific facilitation in IMS. The maximum yield of maize under monoculture maize (MM) occurred with conventional nitrogen (CN), whereas under IMS, the maximum yield occurred with reduced nitrogen (RN). The yield of monoculture soybean (MS) and of soybean in IMS both reached a maximum under RN. The LER of IMS varied from 1.85 to 2.36, and the SPI peaked under RN. Additionally, the NUE of IMS increased by 103.7% under RN compared with that under CN. In conclusion, the separation of the root ecological niche contributed to a positive interspecific facilitation, which increased the land productivity. Thus, maize-soybean relay intercropping with reduced N input provides a very useful approach to increase land productivity and avert environmental pollution.

Including climate variability in determination of the optimum rate of N fertilizer application using a crop model: A case study for rainfed corn in eastern Canada

NASA Astrophysics Data System (ADS)

Mesbah, M.; Pattey, E.; Jégo, G.; Geng, X.; Tremblay, N.; Didier, A.

2017-12-01

Identifying optimum nitrogen (N) application rate is essential for increasing agricultural production while limiting potential environmental contaminations caused by release of reactive N, especially for high demand N crops such as corn. The central question of N management is then how the optimum N rate is affected by climate variability for given soil. The experimental determination of optimum N rates involve the analyses of variance on the mean value of crop yield response to various N application rates used by factorial plot based experiments for a few years in several regions. This traditional approach has limitations to capture 1) the non-linear response of yield to N application rates due to large incremental N rates (often more than 40 kg N ha-1) and 2) the ecophysiological response of the crop to climate variability because of limited numbers of growing seasons considered. Modeling on the other hand, does not have such limitations and hence we use a crop model and propose a model-based methodology called Finding NEMO (N Ecophysiologically Modelled Optimum) to identify the optimum N rates for variable agro-climatic conditions and given soil properties. The performance of the methodology is illustrated using the STICS crop model adapted for rainfed corn in the Mixedwood Plains ecozone of eastern Canada (42.3oN 83oW-46.8oN 71oW) where more than 90% of Canadian corn is produced. The simulations were performed using small increment of preplant N application rate (10 kg N ha -1), long time series of daily climatic data (48 to 61 years) for 5 regions along the ecozone, and three contrasting soils per region. The results show that N recommendations should be region and soil specific. Soils with lower available water capacity required more N compared to soil with higher available water capacity. When N rates were at their ecophysiologically optimum level, 10 to 17 kg increase in dry yield could be achieved by adding 1 kg N. Expected yield also affected the optimum N rates for the region and soil. For instance, the probability to achieve a yield of 9.2 t ha-1 at 15% grain moisture on a loamy soil varied from 0 to 73% along the ecozone. For this level of expected yield, the recommended N rates ranged from 64 to 155 kg ha-1, which are relatively less than current provincial recommendations in Ontario and Quebec (120-170 kg ha-1).

[Effects of nitrogen management on yield, quality, nitrogen accumulation and its transportation of watermelon in gravel-mulched field].

PubMed

Ma, Zhong-ming; Du, Shao-ping; Xue, Liang

2015-11-01

The effects of nitrogen management on yield, quality, nitrogen and dry matter accumulation and transportation of watermelon in sand field were studied based on a field experiment. The results showed that too low or too high basal nitrogen fertilzation was unfavorable to seedling growth of watermelon in sand field, and no nitrogen application at vine extension or fruiting stages limited the formation of 'source' or 'sink'. At the same nitrogen rate, compared with the traditional T1 treatment (30% basal N fertilizer + 70% N fertilizer in vine extension), the nitrogen and dry matter accumulation of vegetative organs of T4 treatment (30% basal N fertilizer + 30% N fertilizer in vine extension + 40% N fertilizer in fruiting) and T6 treatment (100% basal N fertilizer + NAM) were reduced significantly, but the nitrogen and dry matter accumulation of fruit were increased significantly in the flushing period. The nitrogen transportation ratio and nitrogen contribution ratio of T4 were 33.6% and 12.0%, respectively. Compared to T1, the nitrogen harvest index, nitrogen fertilizer partial factor productivity and nitrogen fertilizer recovery efficiency of T4 and T6 treatments increased by 14.1% and 12.7%, 11.6% and 12.5%, 5.3% and 8.7%, respectively, and yield of watermelon increased by 11.6% and 12.5%, the soluble sugar, effective acid, the ratio of sugar and acid, Vc content increased by 16.5% and 11.7%, 4.5% and 2.8%, 19.4% and 13.4%, 35.6% and 19.0%, respectively. Therefore, T4 and T6 treatments were the optimal nitrogen fertilizer management mode which could not only achieve high yield and quality but also obtain high nitrogen fertilizer use efficiency in sand field. T6 treatment was the best nitrogen fertilizer management mode considering reduction of fertilizing labor intensity and extending service time of gravel-mulched field.

Effects of Elevated CO2 and Temperature on Yield and Fruit Quality of Strawberry (Fragaria × ananassa Duch.) at Two Levels of Nitrogen Application

PubMed Central

Sun, Peng; Mantri, Nitin; Lou, Heqiang; Hu, Ya; Sun, Dan; Zhu, Yueqing; Dong, Tingting; Lu, Hongfei

2012-01-01

We investigated if elevated CO2 could alleviate the negative effect of high temperature on fruit yield of strawberry (Fragaria × ananassa Duch. cv. Toyonoka) at different levels of nitrogen and also tested the combined effects of CO2, temperature and nitrogen on fruit quality of plants cultivated in controlled growth chambers. Results show that elevated CO2 and high temperature caused a further 12% and 35% decrease in fruit yield at low and high nitrogen, respectively. The fewer inflorescences and smaller umbel size during flower induction caused the reduction of fruit yield at elevated CO2 and high temperature. Interestingly, nitrogen application has no beneficial effect on fruit yield, and this may be because of decreased sucrose export to the shoot apical meristem at floral transition. Moreover, elevated CO2 increased the levels of dry matter-content, fructose, glucose, total sugar and sweetness index per dry matter, but decreased fruit nitrogen content, total antioxidant capacity and all antioxidant compounds per dry matter in strawberry fruit. The reduction of fruit nitrogen content and antioxidant activity was mainly caused by the dilution effect of accumulated non-structural carbohydrates sourced from the increased net photosynthetic rate at elevated CO2. Thus, the quality of strawberry fruit would increase because of the increased sweetness and the similar amount of fruit nitrogen content, antioxidant activity per fresh matter at elevated CO2. Overall, we found that elevated CO2 improved the production of strawberry (including yield and quality) at low temperature, but decreased it at high temperature. The dramatic fluctuation in strawberry yield between low and high temperature at elevated CO2 implies that more attention should be paid to the process of flower induction under climate change, especially in fruits that require winter chilling for reproductive growth. PMID:22911728

Initial yield to depth relation for water wells drilled into crystalline bedrock - Pinardville quadrangle, New Hampshire

USGS Publications Warehouse

Drew, L.J.; Schuenemeyer, J.H.; Amstrong, T.R.; Sutphin, D.M.

2001-01-01

A model is proposed to explain the statistical relations between the mean initial water well yields from eight time increments from 1984 to 1998 for wells drilled into the crystalline bedrock aquifer system in the Pinardville area of southern New Hampshire and the type of bedrock, mean well depth, and mean well elevation. Statistical analyses show that the mean total yield of drilling increments is positively correlated with mean total well depth and mean well elevation. In addition, the mean total well yield varies with rock type from a minimum of 46.9 L/min (12.4 gpm) in the Damon Pond granite to a maximum of 74.5 L/min (19.7 gpm) in the Permian pegmatite and granite unit. Across the eight drilling increments that comprise 211 wells each, the percentages of very low-yield wells (1.9 L/min [0.5 gpm] or less) and high-yield wells (151.4 L/min [40 gpm] or more) increased, and those of intermediate-yield wells decreased. As housing development progressed during the 1984 to 1998 interval, the mean depth of the wells and their elevations increased, and the mix of percentages of the bedrock types drilled changed markedly. The proposed model uses a feed-forward mechanism to explain the interaction between the increasing mean elevation, mean well depth, and percentages of very low-yielding wells and the mean well yield. The increasing percentages of very low-yielding wells through time and the economics of the housing market may control the system that forces the mean well depths, percentages of high-yield wells, and mean well yields to increase. The reason for the increasing percentages of very low-yield wells is uncertain, but the explanation is believed to involve the complex structural geology and tectonic history of the Pinardville quadrangle.

12 years of intensive management increases soil carbon stocks in Loblolly pine and Sweetgum stands

NASA Astrophysics Data System (ADS)

Sanchez, F. G.; Samuelson, L.; Johnsen, K.

2009-12-01

To achieve and maintain productivity goals, forest managers rely on intensive management strategies. These strategies have resulted in considerable gains in forest productivity. However, the impacts of these strategies on belowground carbon dynamics is less clear. Carbon dynamics are influenced by a multitude of factors including soil moisture, nutrient status, net primary productivity and carbon allocation patterns. In this study, we describe the impact of four management strategies on soil carbon and nitrogen stocks in 12-year-old loblolly pine and sweetgum plantations. The management strategies are: (1) complete understory control, (2) complete understory control + drip irrigation, (3) complete understory control + drip irrigation and fertilization and (4) complete understory control + drip irrigation and fertilization and pest control. These management strategies were replicated on 3 blocks in a randomized complete block design. After 12 years, soil carbon stocks increased with increasing management intensity for both tree species. This effect was consistent throughout the depth increments measured (0-10, 10-20, 20-30 cm). Alternatively, no significant effect was detected for soil nitrogen at any depth increment. Sweetgum had higher soil carbon and nitrogen stocks at each depth increment than loblolly pine. There was a greater difference in nitrogen stocks than carbon stocks between the two species resulting in lower soil C:N ratios in the sweetgum stands. These observations may be due to differences in net primary productivity, rooting structure and carbon allocation patterns of sweetgum compared with loblolly pine. To determine the relative stability of the carbon and nitrogen stocks for the different treatments and tree species, we sequentially fractionated the soil samples into six fractions of differing stability. Although soil carbon stocks for both species increased with management intensity, there was no detectable difference in the soil carbon fractions based on management intensity. Additionally, there was no difference between soil carbon fractions based on tree species. These observations suggest that although external inputs (i.e., moisture, carbon and nutrients) increase soil carbon stocks, they do not alter soil carbon stabilization mechanisms at these sites.

Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields.

PubMed

Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping; Zhao, Xing; Ye, Xinyi

2016-09-15

The application rate of nitrogen fertilizer was believed to dramatically influence greenhouse gas (GHG) emissions from paddy fields. Thus, providing a suitable nitrogen fertilization rate to ensure rice yields, reducing GHG emissions and exploring emission behavior are important issues for field management. In this paper, a two year experiment with six rates (0, 75, 150, 225, 300, 375kgN/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) flux and their cumulative global warming potential (GWP) from paddy fields in Hangzhou, Zhejiang in 2013 and 2014. The results indicated that the GWP and rice yields increased with an increasing application rate of nitrogen fertilizer. Emission peaks of CH4 mainly appeared at the vegetative phase, and emission peaks of CO2, and N2O mainly appeared at reproductive phase of rice growth. The CO2 flux was significantly correlated with soil temperature, while the CH4 flux was influenced by logging water remaining period and N2O flux was significantly associated with nitrogen application rates. This study showed that 225kgN/ha was a suitable nitrogen fertilizer rate to minimize GHG emissions with low yield-scaled emissions of 3.69 (in 2013) and 2.23 (in 2014) kg CO2-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89t/ha in paddy fields. Copyright © 2016 Elsevier B.V. All rights reserved.

GIS-modeled indicators of traffic-related air pollutants and adverse pulmonary health among children in El Paso, Texas.

PubMed

Svendsen, Erik R; Gonzales, Melissa; Mukerjee, Shaibal; Smith, Luther; Ross, Mary; Walsh, Debra; Rhoney, Scott; Andrews, Gina; Ozkaynak, Halûk; Neas, Lucas M

2012-10-01

Investigators examined 5,654 children enrolled in the El Paso, Texas, public school district by questionnaire in 2001. Exposure measurements were first collected in the late fall of 1999. School-level and residence-level exposures to traffic-related air pollutants were estimated using a land use regression model. For 1,529 children with spirometry, overall geographic information system (GIS)-modeled residential levels of traffic-related ambient air pollution (calibrated to a 10-ppb increment in nitrogen dioxide levels) were associated with a 2.4% decrement in forced vital capacity (95% confidence interval (CI): -4.0, -0.7) after adjustment for demographic, anthropomorphic, and socioeconomic factors and spirometer/technician effects. After adjustment for these potential covariates, overall GIS-modeled residential levels of traffic-related ambient air pollution (calibrated to a 10-ppb increment in nitrogen dioxide levels) were associated with pulmonary function levels below 85% of those predicted for both forced vital capacity (odds ratio (OR) = 3.10, 95% CI: 1.65, 5.78) and forced expiratory volume in 1 second (OR = 2.35, 95% CI: 1.38, 4.01). For children attending schools at elevations above 1,170 m, a 10-ppb increment in modeled nitrogen dioxide levels was associated with current asthma (OR = 1.56, 95% CI: 1.08, 2.50) after adjustment for demographic, socioeconomic, and parental factors and random school effects. These results are consistent with previous studies in Europe and California that found adverse health outcomes in children associated with modeled traffic-related air pollutants.

Improvement of crop yield in dry environments: benchmarks, levels of organisation and the role of nitrogen.

PubMed

Sadras, V O; Richards, R A

2014-05-01

Crop yield in dry environments can be improved with complementary approaches including selecting for yield in the target environments, selecting for yield potential, and using indirect, trait- or genomic-based methods. This paper (i) outlines the achievements of direct selection for yield in improving drought adaptation, (ii) discusses the limitations of indirect approaches in the context of levels of organization, and (iii) emphasizes trade-offs and synergies between nitrogen nutrition and drought adaptation. Selection for yield in the water- and nitrogen-scarce environments of Australia improved wheat yield per unit transpiration at a rate of 0.12kg ha(-1) mm(-1) yr(-1); for indirect methods to be justified, they must return superior rates of improvement, achieve the same rate at lower cost or provide other cost-effective benefits, such as expanding the genetic basis for selection. Slow improvement of crop adaptation to water stress using indirect methods is partially related to issues of scale. Traits are thus classified into three broad groups: those that generally scale up from low levels of organization to the crop level (e.g. herbicide resistance), those that do not (e.g. grain yield), and traits that might scale up provided they are considered in a integrated manner with scientifically sound scaling assumptions, appropriate growing conditions, and screening techniques (e.g. stay green). Predicting the scalability of traits may help to set priorities in the investment of research efforts. Primary productivity in arid and semi-arid environments is simultaneously limited by water and nitrogen, but few attempts are made to target adaptation to water and nitrogen stress simultaneously. Case studies in wheat and soybean highlight biological links between improved nitrogen nutrition and drought adaptation.

[Nitrogen status diagnosis and yield prediction of spring maize after green manure incorporation by using a digital camera].

PubMed

Bai, Jin-Shun; Cao, Wei-Dong; Xiong, Jing; Zeng, Nao-Hua; Shimizu, Katshyoshi; Rui, Yu-Kui

2013-12-01

In order to explore the feasibility of using the image processing technology to diagnose the nitrogen status and to predict the maize yield, a field experiment with different nitrogen rates with green manure incorporation was conducted. Maize canopy digital images over a range of growth stages were captured by digital camera. Maize nitrogen status and the relationships between image color indices derived by digital camera for maize at different growth stages and maize nitrogen status indicators were analyzed. These digital camera sourced image color indices at different growth stages for maize were also regressed with maize grain yield at maturity. The results showed that the plant nitrogen status for maize was improved by green manure application. The leaf chlorophyll content (SPAD value), aboveground biomass and nitrogen uptake for green manure treatments at different maize growth stages were all higher than that for chemical fertilization treatments. The correlations between spectral indices with plant nitrogen indicators for maize affected by green manure application were weaker than that affected by chemical fertilization. And the correlation coefficients for green manure application were ranged with the maize growth stages changes. The best spectral indices for diagnosis of plant nitrogen status after green manure incorporation were normalized blue value (B/(R+G+B)) at 12-leaf (V12) stage and normalized red value (R/(R+G+B)) at grain-filling (R4) stage individually. The coefficients of determination based on linear regression were 0. 45 and 0. 46 for B/(R+G+B) at V12 stage and R/(R+G+B) at R4 stage respectively, acting as a predictor of maize yield response to nitrogen affected by green manure incorporation. Our findings suggested that digital image technique could be a potential tool for in-season prediction of the nitrogen status and grain yield for maize after green manure incorporation when the suitable growth stages and spectral indices for diagnosis were selected.

Nitrification inhibitors mitigated reactive gaseous nitrogen intensity in intensive vegetable soils from China.

PubMed

Fan, Changhua; Li, Bo; Xiong, Zhengqin

2018-01-15

Nitrification inhibitors, a promising tool for reducing nitrous oxide (N 2 O) losses and promoting nitrogen use efficiency by slowing nitrification, have gained extensive attention worldwide. However, there have been few attempts to explore the broad responses of multiple reactive gaseous nitrogen emissions of N 2 O, nitric oxide (NO) and ammonia (NH 3 ) and vegetable yield to nitrification inhibitor applications across intensive vegetable soils in China. A greenhouse pot experiment with five consecutive vegetable crops was performed to assess the efficacies of two nitrification inhibitors, namely, nitrapyrin and dicyandiamide on reactive gaseous nitrogen emissions, vegetable yield and reactive gaseous nitrogen intensity in four typical vegetable soils representing the intensive vegetable cropping systems across mainland China: an Acrisol from Hunan Province, an Anthrosol from Shanxi Province, a Cambisol from Shandong Province and a Phaeozem from Heilongjiang Province. The results showed soil type had significant influences on reactive gaseous nitrogen intensity, with reactive gaseous nitrogen emissions and yield mainly driven by soil factors: pH, nitrate, C:N ratio, cation exchange capacity and microbial biomass carbon. The highest reactive gaseous nitrogen emissions and reactive gaseous nitrogen intensity were in Acrisol while the highest vegetable yield occurred in Phaeozem. Nitrification inhibitor applications decreased N 2 O and NO emissions by 1.8-61.0% and 0.8-79.5%, respectively, but promoted NH 3 volatilization by 3.2-44.6% across all soils. Furthermore, significant positive correlations were observed between inhibited N 2 O+NO and stimulated NH 3 emissions with nitrification inhibitor additions across all soils, indicating that reduced nitrification posed the threat of NH 3 losses. Additionally, reactive gaseous nitrogen intensity was significantly reduced in the Anthrosol and Cambisol due to the reduced reactive gaseous nitrogen emissions and increased yield, respectively. Our findings highlight the benefits of nitrification inhibitors for integrating environment and agronomy in intensive vegetable ecosystems in China. Copyright © 2017. Published by Elsevier B.V.

Effects of different nitrogen reduction modes on yield of spring maize and nitrate - N residue in soils of the southern Loess Plateau

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.

Quantifying long-term responses of crop yield and nitrate leaching in an intensive farmland using agro-eco-environmental model.

PubMed

Sun, Mei; Huo, Zailin; Zheng, Yanxia; Dai, Xiaoqin; Feng, Shaoyuan; Mao, Xiaomin

2018-02-01

Quantitatively ascertaining and analyzing long-term responses of crop yield and nitrate leaching on varying irrigation and fertilization treatments are focal points for guaranteeing crop yield and reducing nitrogen loss. The calibrated agricultural-hydrological RZWQM2 model was used to explore the long-term (2003-2013) transport processes of water and nitrogen and the nitrate leaching amount into groundwater in summer maize and winter wheat rotation field in typical intensive plant area in the North China Plain, Daxing district of Beijing. Simulation results showed that application rates of irrigation and nitrogen fertilizer have couple effects on crop yields and nitrogen leaching of root zone. When both the irrigation and fertilizer for summer maize and winter wheat were 400mm and 400kgNha -1 , respectively, nitrate leaching into groundwater accounted for 47.9% of application amount of nitrogen fertilizer. When application amount of irrigation is 200mm and fertilization is 200kgNha -1 , NUPE (nitrogen uptake efficiency), NUE (nitrogen use efficiency), NPFP (nitrogen partial factor productivity), and W pi (irrigation water productive efficiency) were in general higher than that under other irrigation and fertilization condition (irrigation from 104-400mm, fertilizer 104-400kgNha -1 ). Irrigation bigger than 200mm could shorten the response time of nitrate leaching in deeper soil layer in different irrigation treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Nutrient mass balance and trends, Mobile River Basin, Alabama, Georgia, and Mississippi

USGS Publications Warehouse

Harned, D.A.; Atkins, J.B.; Harvill, J.S.

2004-01-01

A nutrient mass balance - accounting for nutrient inputs from atmospheric deposition, fertilizer, crop nitrogen fixation, and point source effluents; and nutrient outputs, including crop harvest and storage - was calculated for 18 subbasins in the Mobile River Basin, and trends (1970 to 1997) were evaluated as part of the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program. Agricultural nonpoint nitrogen and phosphorus sources and urban nonpoint nitrogen sources are the most important factors associated with nutrients in this system. More than 30 percent of nitrogen yield in two basins and phosphorus yield in eight basins can be attributed to urban point source nutrient inputs. The total nitrogen yield (1.3 tons per square mile per year) for the Tombigbee River, which drains a greater percentage of agricultural (row crop) land use, was larger than the total nitrogen yield (0.99 tons per square mile per year) for the Alabama River. Decreasing trends of total nitrogen concentrations in the Tombigbee and Alabama Rivers indicate that a reduction occurred from 1975 to 1997 in the nitrogen contributions to Mobile Bay from the Mobile River. Nitrogen concentrations also decreased (1980 to 1995) in the Black Warrior River, one of the major tributaries to the Tombigbee River. Total phosphorus concentrations increased from 1970 to 1996 at three urban influenced sites on the Etowah River in Georgia. Multiple regression analysis indicates a distinct association between water quality in the streams of the Mobile River drainage basin and agricultural activities in the basin.

Continuously pumping and reactivating gas pump

DOEpatents

Batzer, T.H.; Call, W.R.

Apparatus for continuous pumping using cycling cryopumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels that alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independant pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

Continuously pumping and reactivating gas pump

DOEpatents

Batzer, Thomas H.; Call, Wayne R.

1984-01-01

Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

Hydrothermal liquefaction pathways for low-nitrogen biocrude from wet algae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanzella, Francis; Lim, Jin-Ping

Our SRI International (SRI) team has developed a new two-step hydrothermal liquefaction (HTL) process to convert wet algal biomass into biocrude oil. The first step in the process (low-temperature HTL or HTL1) yields crude oil but, most importantly, it selectively dissolves nitrogen-containing compounds in the aqueous phase. Once the oil and the aqueous phase are separated, the low-nitrogen soft solids left behind can be taken to the second step (high-temperature HTL or HTL2) for full conversion to biocrude. HTL2 will hence yield low-nitrogen biocrude, which can be hydro-processed to yield transportation fuels. The expected high carbon yield and low nitrogenmore » content can lead to a transportation fuel from algae that avoids two problems common to existing algae-to-fuel processes: (1) poisoning of the hydro-processing catalyst; and (2) inefficient conversion of algae-to-liquid fuels. The process we studied would yield a new route to strategic energy production from domestic sources.« less

[Effects of nitrogen application level on soil nitrate accumulation and ammonia volatilization in high-yielding wheat field].

PubMed

Wang, Dong; Yu, Zhenwen; Yu, Wenming; Shi, Yu; Zhou, Zhongxin

2006-09-01

The study showed that during the period from sowing to pre-wintering, the soil nitrate in high-yielding wheat field moved down to deeper layers, and accumulated in the layers below 140 cm. An application rate of 96-168 kg N x hm(-2) increased the nitrate content in 0-60 cm soil layer and the wheat grain yield and its protein content, and decreased the proportion of apparent N loss to applied N and the ammonia volatilization loss from basal nitrogen. Applying 240 kg N x hm(-2) promoted the downward movement of soil nitrate and its accumulation in deeper layers, increased the proportion of apparent N loss to applied N and the ammonia volatilization loss from basal nitrogen, had no significant effect on the protein content of wheat grain, but decreased the grain yield. The appropriate application rate of nitrogen on high-yielding wheat field was 132-204 kg N x hm(-2).

[Further reduction of nitrogen fertilizer application in paddy field under green manuring of Taihu Area, China].

PubMed

Zhao, Dong; Yan, Ting-mei; Qiao, Jun; Yang, Lin-zhang; Tang, Fang; Song, Yun-fei

2015-06-01

This study focused on the nitrogen loss via runoff, change of nitrogen in different forms in surface water in paddy field, and grain yield, through further reduction of nitrogen fertilizer application rate under green manuring without basal dressing. Results showed that with 150 kg · hm(-2) inorganic N fertilizer input after return of green manure to soil, no basal dressing could not only sharply reduce N concentration in surface water and decrease 17.2% of N loss, but also increase 2.8% of grain yield in comparison with basal dressing. It was a worthwhile farming method that inorganic nitrogen fertilizer was not used for basal dressing but for topdressing after return of green ma- nure to soil in Taihu Area. However, the grain yield would decrease if the rate of topdressing nitro- gen was excessively reduced or increased. After all, it was feasible to realize harmonization of grain yield and environmental benefits in Taihu Area, with 133 kg · hm(-2) inorganic N fertilizer input after return of green manure to soil as well as no application of basal dressing, which could greatly reduce N fertilizer input and N loss as well as ensure rice yield.

Comparison of X-Ray Micro-Tomography Measurements of Densities and Porosity to Traditional Techniques for Carbon-Carbon Composites

DTIC Science & Technology

2009-02-26

equation, nitrogen , argon, and krypton are employed while for the D-R equation CO2 is usually used . With the adsorption techniques, certain assumption...structure to characterize it. Lastly, other liquids are used in a density gradient column [73-75] employing a sink-float technique in an attempt to...least 147 incremental intrusion pressures to 275 kPa, using nitrogen gas as the displacing medium. The sample is then loaded into the high-pressure

Freebies for Investors--Precise Incremental Yield Value

ERIC Educational Resources Information Center

Michelson, Irving

1977-01-01

Competition for savings dollars has led to free gift bonus offers as incentive for new deposits. A concise new formula presented here permits calculation of the total yield using an inexpensive minicomputer. Yield is expressed in terms of interest rate, effective discount value of gift bonus, and period of deposit. (Author/MA)

Optimization of cellulase production by Penicillium sp.

PubMed

Prasanna, H N; Ramanjaneyulu, G; Rajasekhar Reddy, B

2016-12-01

The production of cellulolytic enzymes (β-exoglucanase, β-endoglucanase and β-glucosidase) by Penicillium sp. on three different media in liquid shake culture conditions was compared. The organism exhibited relatively highest activity of endoglucanase among three enzymes measured at 7-day interval during the course of its growth on Czapek-Dox medium supplemented with 0.5 % (w/v) cellulose. Cellulose at 0.5 %, lactose at 0.5 %, sawdust at 0.5 %, yeast extract at 0.2 % as a nitrogen source, pH 5.0 and 30 °C temperature were found to be optimal for growth and cellulase production by Penicillium sp. Yields of Fpase, CMCase and β-glucosidase, attained on optimized medium with Penicillium sp. were 8.7, 25 and 9.52 U/ml, respectively with increment of 9.2, 5.9 and 43.8-folds over titers of the respective enzyme on unoptimised medium. Cellulase of the fungal culture with the ratio of β-glucosidase to Fpase greater than one will hold potential for biotechnological applications.

Winter wheat: A model for the simulation of growth and yield in winter wheat

NASA Technical Reports Server (NTRS)

Baker, D. N.; Smika, D. E.; Black, A. L.; Willis, W. O.; Bauer, A. (Principal Investigator)

1981-01-01

The basic ideas and constructs for a general physical/physiological process level winter wheat simulation model are documented. It is a materials balance model which calculates daily increments of photosynthate production and respiratory losses in the crop canopy. The partitioning of the resulting dry matter to the active growing tissues in the plant each day, transpiration and the uptake of nitrogen from the soil profile are simulated. It incorporates the RHIZOS model which simulates, in two dimensions, the movement of water, roots, and soluble nutrients through the soil profile. It records the time of initiation of each of the plant organs. These phenological events are calculated from temperature functions with delays resulting from physiological stress. Stress is defined mathematically as an imbalance in the metabolite supply; demand ratio. Physiological stress is also the basis for the calculation of rates of tiller and floret abortion. Thus, tillering and head differentiation are modeled as the resulants of the two processes, morphogenesis and abortion, which may be occurring simulaneously.

Concentrations, fluxes, and yields of nitrogen, phosphorus, and suspended sediment in the Illinois River basin, 1996-2000

USGS Publications Warehouse

Terrio, Paul J.

2006-01-01

Concentrations, spatial and temporal variations, and fluxes of nitrogen, phosphorus, and suspended sediment were determined for 16 streams in the Illinois River Basin, Illinois from October 1996 through September 2000. Water samples were collected through the National Water-Quality Assessment's Lower Illinois River Basin (LIRB) and Upper Illinois River Basin (UIRB) Study Units on a monthly to weekly frequency from watersheds representing predominantly agricultural and urban land, as well as areas of mixed land-use. Streams in agricultural watersheds had high concentrations and fluxes of nitrate nitrogen, whereas streams in predominantly urban watersheds had high concentrations (above background levels) of ammonia nitrogen, organic nitrogen, and phosphorus. Median concentrations of nitrate nitrogen and total phosphorus were similar at the two Illinois River sampling stations (Illinois River at Ottawa, Ill. and Illinois River at Valley City, Ill.) that represented the downstream points of the UIRB and LIRB Study Units, respectively, and integrated multiple land-use areas. Concentrations of nitrogen were typically highest in the spring and lowest in the fall in agricultural watersheds, but highest in the winter in urban watersheds. Phosphorus concentrations in urban watersheds were highest in the fall and winter, but there was minimal seasonal variation in phosphorus concentrations in agricultural watersheds. Concentrations of nitrate and total nitrogen were affected primarily by non-point sources and hydrologic factors such as streamflow, storm intensity, watershed configuration, and soil permeability, whereas concentrations of phosphorus were affected largely by point-source contributions that typically have little seasonal variation. Seasonal variation in hydrologic conditions was an important factor for seasonal variation in nutrient concentration. Fluxes and yields of nitrogen and phosphorus forms varied substantially throughout the Illinois River Basin, and yields of specific nutrient forms were determined primarily by upstream land uses. Yields of nitrate nitrogen were highest in predominantly agricultural watersheds, whereas yields of phosphorus and ammonia nitrogen were highest in urban watersheds with wastewater effluent contributions. Yields of both total nitrogen and total phosphorus were similar at the two Illinois River stations representing the integrated UIRB and LIRB Study Units. Concentrations of suspended sediment ranged from 1 to 3,110 milligrams per liter (mg/L), with median concentrations generally higher in the UIRB. Suspended-sediment concentrations were highest and most variable in the LaMoine River Basin. The median concentration of suspended sediment in the Illinois River at Valley City, Ill. (155 mg/L) was twice as high as that at Ottawa, Ill. (80 mg/L). Fluxes of suspended sediment generally corresponded to watershed size and yields from agricultural watersheds were larger than yields from urban watersheds. The flux in the Illinois River at Valley City, Ill. (4,880,000 tons per year) was approximately four times the flux in the Illinois River at Ottawa, Ill. (1,060,000 tons per year).

Reducing Soil CO2 Emission and Improving Upland Rice Yield with no-Tillage, Straw Mulch and Nitrogen Fertilization in Northern Benin

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.

A series of inorganic solid nitrogen sources for the synthesis of metal nitride clusterfullerenes: the dependence of production yield on the oxidation state of nitrogen and counter ion.

PubMed

Liu, Fupin; Guan, Jian; Wei, Tao; Wang, Song; Jiao, Mingzhi; Yang, Shangfeng

2013-04-01

A series of nitrogen-containing inorganic solid compounds with variable oxidation states of nitrogen and counter ions have been successfully applied as new inorganic solid nitrogen sources toward the synthesis of Sc-based metal nitride clusterfullerenes (Sc-NCFs), including ammonium salts [(NH4)xH(3-x)PO4 (x = 0-2), (NH4)2SO4, (NH4)2CO3, NH4X (X = F, Cl), NH4SCN], thiocyanate (KSCN), nitrates (Cu(NO3)2, NaNO3), and nitrite (NaNO2). Among them, ammonium phosphates ((NH4)xH(3-x)PO4, x = 1-3) and ammonium thiocyanate (NH4SCN) are revealed to behave as better nitrogen sources than others, and the highest yield of Sc-NCFs is achieved when NH4SCN was used as a nitrogen source. The optimum molar ratio of Sc2O3:(NH4)3PO4·3H2O:C and Sc2O3:NH4SCN:C has been determined to be 1:2:15 and 1:3:15, respectively. The thermal decomposition products of these 12 inorganic compounds have been discussed in order to understand their different performances toward the synthesis of Sc-NCFs, and accordingly the dependence of the production yield of Sc-NCFs on the oxidation state of nitrogen and counter ion is interpreted. The yield of Sc3N@C80 (I(h) + D(5h)) per gram Sc2O3 by using the N2-based group of nitrogen sources (thiocyanate, nitrates, and nitrite) is overall much lower than those by using gaseous N2 and NH4SCN, indicating the strong dependence of the yield of Sc-NCFs on the oxidation state of nitrogen, which is attributed to the "in-situ" redox reaction taking place for the N2-based group of nitrogen sources during discharging. For NH3-based group of nitrogen sources (ammonium salts) which exhibits a (-3) oxidation states of nitrogen, their performance as nitrogen sources is found to be sensitively dependent on the anion, and this is understood by considering their difference on the thermal stability and/or decomposition rate. Contrarily, for the N2-based group of nitrogen sources, the formation of Sc-NCFs is independent to both the oxidation state of nitrogen (+3 or +5) and the cation.

Methane production by anaerobic digestion of Bermuda grass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klass, D.L.; Ghosh, S.

1981-01-01

Bermuda grass (Cynodon dactylon) is one of the high-yield warm-season grasses that has been suggested as a promising raw material for conversion to methane. Experimental work performed with laboratory digesters to study the anaerobic digestion of Coastal Bermuda grass harvested in Louisiana and having a C/N ratio of 24 is described. Methane yields of about 1.9 SCF/lb of volatile solids (VS) added were observed under conventional mesophilic high-rate conditions. When supplemental nitrogen additions were made, the methane yields increased. This observation along with the compositional data compiled on the grass used in this work indicated that the nitrogen content ofmore » the unsupplemented grass was insufficient to sustain high-rate digestion at the higher yield level. However, as the C/N ratio was reduced by addition of ammonium chloride, the methane yield continually increased up to 3.5 SCF/lb added at the lowest C/N ratio examined (6.3) even after relatively high concentrations of ammonium nitrogen were measured in the effluent. It appears that the added nutrient had a stimulatory effect on methane production above the point where nitrogen was not limiting. Thermophilic digestion with supplemental nitrogen additions afforded methane yields of about 2.7 SCF/lb VS added. Carbon and energy balances were calculated and the relative biodegradabilities of the organics were estimated. It was concluded from this work that Coastal Bermuda grass can be converted to high-methane gas under conventional anaerobic digestion conditions. The performance of the particular lot of grass studied was substantially improved by supplemental nitrogen additions. (Refs. 12).« less

Enhancing crop yield with the use of N-based fertilizers co-applied with plant hormones or growth regulators.

PubMed

Zaman, Mohammad; Kurepin, Leonid V; Catto, Warwick; Pharis, Richard P

2015-07-01

Crop yield, vegetative or reproductive, depends on access to an adequate supply of essential mineral nutrients. At the same time, a crop plant's growth and development, and thus yield, also depend on in situ production of plant hormones. Thus optimizing mineral nutrition and providing supplemental hormones are two mechanisms for gaining appreciable yield increases. Optimizing the mineral nutrient supply is a common and accepted agricultural practice, but the co-application of nitrogen-based fertilizers with plant hormones or plant growth regulators is relatively uncommon. Our review discusses possible uses of plant hormones (gibberellins, auxins, cytokinins, abscisic acid and ethylene) and specific growth regulators (glycine betaine and polyamines) to enhance and optimize crop yield when co-applied with nitrogen-based fertilizers. We conclude that use of growth-active gibberellins, together with a nitrogen-based fertilizer, can result in appreciable and significant additive increases in shoot dry biomass of crops, including forage crops growing under low-temperature conditions. There may also be a potential for use of an auxin or cytokinin, together with a nitrogen-based fertilizer, for obtaining additive increases in dry shoot biomass and/or reproductive yield. Further research, though, is needed to determine the potential of co-application of nitrogen-based fertilizers with abscisic acid, ethylene and other growth regulators. © 2014 Society of Chemical Industry.

Energy and conservation benefits from managed prairie biomass

USGS Publications Warehouse

Jungers, Jacob M.; Trost, Jared J.; Lehman, Clarence L.; Tilman, David; Booth, Elaine

2011-01-01

Marginally productive land, such as that enrolled in the Conservation Reserve Program (CRP), may provide acreage and economic incentives for cellulosic energy production. Improving the yields from these lands will help establish a biomass producer?s position in the marketplace. The effects of water and nitrogen on biomass yields were investigated in both a plot-scale experiment and a broad-scale survey of CRP lands. The plot-scale experiment demonstrated that irrigation improved mixed-species prairie biomass yields more than nitrogen fertilizer on coarse-textured, marginally productive soils. Experimental plots amended with both irrigation and moderate (but not high) nitrogen produced more biomass than other treatment combinations, but this trend was not statistically significant. The survey of biomass yields on CRP lands across four Midwestern States indicates that yields are better correlated with June rainfall than any other individual month. Applying nutrient-enriched water such as agricultural runoff could benefit prairie yields if applied at appropriate times.

Examination of Treatment Methods for Cyanide Wastes.

DTIC Science & Technology

1979-05-15

industry,is alkaline chlorination. This process oxidizes cyanide to cyanate followed by complete decomposition yielding carbon dioxide and nitrogen or...decomposition yielding carbon dioxide and nitrogen, or ammonium salts depending on final treatment methods. The major oxidizing agents that have been...2H20 (X represents a cation.) 29 NADC-78198-60 This liberates carbon dioxide and nitrogen gas as end products. Possible acid hydrolysis has been

Changes in nitrogen budget and potential risk to the environment over 20years (1990-2010) in the agroecosystems of the Haihe Basin, China.

PubMed

Zheng, Mengmeng; Zheng, Hua; Wu, Yingxia; Xiao, Yi; Du, Yihua; Xu, Weihua; Lu, Fei; Wang, Xiaoke; Ouyang, Zhiyun

2015-02-01

The nitrogen balance can serve as an indicator of the risk to the environment of nitrogen loss from agricultural land. To investigate the temporal and spatial changes in agricultural nitrogen application and its potential threat to the environment of the Haihe Basin in China, we used a database of county-level agricultural statistics to calculate agricultural nitrogen input, output, surplus intensity, and use efficiency. Chemical fertilizer nitrogen input increased by 51.7% from 1990 to 2000 and by 37.2% from 2000 to 2010, concomitant with increasing crop yields. Simultaneously, the nitrogen surplus intensity increased by 53.5% from 1990 to 2000 and by 16.5% from 2000 to 2010, presenting a continuously increased environmental risk. Nitrogen use efficiency decreased from 0.46 in 1990 to 0.42 in 2000 and remained constant at 0.42 in 2010, partly due to fertilizer composition and type improvement. This level indicates that more than half of nitrogen inputs are lost in agroecosystems. Our results suggest that although the improvement in fertilizer composition and types has partially offset the decrease in nitrogen use efficiency, the environmental risk has still increased gradually over the past 20 years, along with the increase in crop yields and nitrogen application. It is important to achieve a better nitrogen balance through more effective management to significantly reduce the environmental risk, decrease nitrogen surplus intensity, and increase nitrogen use efficiency without sacrificing crop yields. Copyright © 2014. Published by Elsevier B.V.

[Effect of biopesticide Pythium oligandrum broth on gummy stem blight in cucumber seedlings, animal health and plant growth].

PubMed

Geng, Mingming; Jia, Ruilian; Sui, Zongming; Huang, Jianguo

2016-07-04

Biopesticides are safe and environment friendly. We evaluated the biocontrol effect of Pythium oligandrum broth (POB) and its toxicity to animals and plant growth. Animal, antagonist, pot, and field experiments with mice, Mycosphaerella melonis, and cucumber seedlings were carried out to study animal toxicity, control of gummy stem blight, plant growth, fruit yield and quality with POB produced from self-isolated P. oligandrum CQ2010. Mouse showed normal weight, appearances, performances and no pathogenic changes in organs and tissues with a large amount of POB supplied by lavage. The inhibition rate of POB against M. melonis was 51.95%, similar to thiophanate methy (800 times dilution) but much higher than chlorothalonil (200 times dilution). Malondialdehyde concentration was reduced whereas activities of peroxidase and superoxide dismutase were stimulated in seedling leaves irrespective of POB supplied before and after pathogenic inoculation. POB also decreased the pathogenic incidence and disease index with relative control efficacy from 54.8% to 64.1%. Thus, POB could alleviate cell membrane damage caused by pathogenic microbes, stimulate physiological reactions related to disease defense, and increase disease-resistant abilities of plants. Moreover, POB increased chlorophyll content, root activity, and uptake of nitrogen, phosphorus and potassium, resulting in growth acceleration, fruit yield increment, and quality improvement. POB is safe to animals and could control gummy stem blight of cucumber seedlings, promote plant growth, increase fruit yield, and improve the qualities.

Incremental yield of dysplasia detection in Barrett's esophagus using volumetric laser endomicroscopy with and without laser marking compared with a standardized random biopsy protocol.

PubMed

Alshelleh, Mohammad; Inamdar, Sumant; McKinley, Matthew; Stewart, Molly; Novak, Jeffrey S; Greenberg, Ronald E; Sultan, Keith; Devito, Bethany; Cheung, Mary; Cerulli, Maurice A; Miller, Larry S; Sejpal, Divyesh V; Vegesna, Anil K; Trindade, Arvind J

2018-02-02

Volumetric laser endomicroscopy (VLE) is a new wide-field advanced imaging technology for Barrett's esophagus (BE). No data exist on incremental yield of dysplasia detection. Our aim is to report the incremental yield of dysplasia detection in BE using VLE. This is a retrospective study from a prospectively maintained database from 2011 to 2017 comparing the dysplasia yield of 4 different surveillance strategies in an academic BE tertiary care referral center. The groups were (1) random biopsies (RB), (2) Seattle protocol random biopsies (SP), (3) VLE without laser marking (VLE), and (4) VLE with laser marking (VLEL). A total of 448 consecutive patients (79 RB, 95 SP, 168 VLE, and 106 VLEL) met the inclusion criteria. After adjusting for visible lesions, the total dysplasia yield was 5.7%, 19.6%, 24.8%, and 33.7%, respectively. When compared with just the SP group, the VLEL group had statistically higher rates of overall dysplasia yield (19.6% vs 33.7%, P = .03; odds ratio, 2.1, P = .03). Both the VLEL and VLE groups had statistically significant differences in neoplasia (high-grade dysplasia and intramucosal cancer) detection compared with the SP group (14% vs 1%, P = .001 and 11% vs 1%, P = .003). A surveillance strategy involving VLEL led to a statistically significant higher yield of dysplasia and neoplasia detection compared with a standard random biopsy protocol. These results support the use of VLEL for surveillance in BE in academic centers. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Regulation Effects of Water and Nitrogen on the Source-Sink Relationship in Potato during the Tuber Bulking Stage

PubMed Central

Li, Wenting; Xiong, Binglin; Wang, Shiwen; Deng, Xiping; Yin, Lina; Li, Hongbing

2016-01-01

The source-sink relationship determines crop yield, and it is largely regulated by water and nutrients in agricultural production. This has been widely investigated in cereals, but fewer studies have been conducted in root and tuber crops such as potato (Solanum tuberosum L.). The objective of this study was to investigate the source-sink relationship in potato and the regulation of water and nitrogen on the source-sink relationship during the tuber bulking stage. A pot experiment using virus-free plantlets of the Atlantic potato cultivar was conducted, using three water levels (50%, 70% and 90% of field capacity) and three nitrogen levels (0, 0.2, 0.4 g N∙kg−1 soil). The results showed that, under all water and nitrogen levels, plant source capacity were small at the end of the experiment, since photosynthetic activity in leaves were low and non-structural reserves in underground stems were completely remobilized. While at this time, there were very big differences in maximum and minimum tuber number and tuber weight, indicating that the sink tuber still had a large potential capacity to take in assimilates. These results suggest that the source-supplied assimilates were not sufficient enough to meet the demands of sink growth. Thus, we concluded that, unlike cereals, potato yield is more likely to be source-limited than sink-limited during the tuber bulking stage. Water and nitrogen are two key factors in potato production management. Our results showed that water level, nitrogen level and the interaction between water and nitrogen influence potato yield mainly through affecting source capacity via the net photosynthetic rate, total leaf area and leaf life span. Well-watered, sufficient nitrogen and well-watered combined with sufficient nitrogen increased yield mainly by enhancing the source capacity. Therefore, this suggests that increasing source capacity is more crucial to improve potato yield. PMID:26752657

Increasing anthropogenic nitrogen inputs and riverine DIN exports from the Changjiang River basin under changing human pressures

NASA Astrophysics Data System (ADS)

Yan, Weijin; Mayorga, Emilio; Li, Xinyan; Seitzinger, Sybil P.; Bouwman, A. F.

2010-12-01

In this paper, we estimate the inputs of nitrogen (N) and exports of dissolved inorganic nitrogen (DIN) from the Changjiang River to the estuary for the period 1970-2003, by using the global NEWS-DIN model. Modeled DIN yields range from 260 kg N km-2 yr-1 in 1970 to 895 kg N km-2 yr-1 in 2003, with an increasing trend. The study demonstrated a varied contribution of different N inputs to river DIN yields during the period 1970-2003. Chemical fertilizer and manure together contributed about half of the river DIN yields, while atmospheric N deposition contributed an average of 21% of DIN yields in the period 1970-2003. Biological N fixation contributed 40% of DIN yields in 1970, but substantially decreased to 13% in 2003. Point sewage N input also showed a decreasing trend in contribution to DIN yields, with an average of 8% over the whole period. We also discuss possible future trajectories of DIN export based on the Global NEWS implementation of the Millennium Ecosystem Assessment scenarios. Our result indicates that anthropogenically enhanced N inputs dominate and will continue to dominate river DIN yields under changing human pressures in the basin. Therefore, nitrogen pollution is and will continue to be a great challenge to China.

Assessing variable rate nitrogen fertilizer strategies within an extensively instrument field site using the MicroBasin model

NASA Astrophysics Data System (ADS)

Ward, N. K.; Maureira, F.; Yourek, M. A.; Brooks, E. S.; Stockle, C. O.

2014-12-01

The current use of synthetic nitrogen fertilizers in agriculture has many negative environmental and economic costs, necessitating improved nitrogen management. In the highly heterogeneous landscape of the Palouse region in eastern Washington and northern Idaho, crop nitrogen needs vary widely within a field. Site-specific nitrogen management is a promising strategy to reduce excess nitrogen lost to the environment while maintaining current yields by matching crop needs with inputs. This study used in-situ hydrologic, nutrient, and crop yield data from a heavily instrumented field site in the high precipitation zone of the wheat-producing Palouse region to assess the performance of the MicroBasin model. MicroBasin is a high-resolution watershed-scale ecohydrologic model with nutrient cycling and cropping algorithms based on the CropSyst model. Detailed soil mapping conducted at the site was used to parameterize the model and the model outputs were evaluated with observed measurements. The calibrated MicroBasin model was then used to evaluate the impact of various nitrogen management strategies on crop yield and nitrate losses. The strategies include uniform application as well as delineating the field into multiple zones of varying nitrogen fertilizer rates to optimize nitrogen use efficiency. We present how coupled modeling and in-situ data sets can inform agricultural management and policy to encourage improved nitrogen management.

Tracking historical increases in nitrogen-driven crop production possibilities

NASA Astrophysics Data System (ADS)

Mueller, N. D.; Lassaletta, L.; Billen, G.; Garnier, J.; Gerber, J. S.

2015-12-01

The environmental costs of nitrogen use have prompted a focus on improving the efficiency of nitrogen use in the global food system, the primary source of nitrogen pollution. Typical approaches to improving agricultural nitrogen use efficiency include more targeted field-level use (timing, placement, and rate) and modification of the crop mix. However, global efficiency gains can also be achieved by improving the spatial allocation of nitrogen between regions or countries, due to consistent diminishing returns at high nitrogen use. This concept is examined by constructing a tradeoff frontier (or production possibilities frontier) describing global crop protein yield as a function of applied nitrogen from all sources, given optimal spatial allocation. Yearly variation in country-level input-output nitrogen budgets are utilized to parameterize country-specific hyperbolic yield-response models. Response functions are further characterized for three ~15-year eras beginning in 1961, and series of calculations uses these curves to simulate optimal spatial allocation in each era and determine the frontier. The analyses reveal that excess nitrogen (in recent years) could be reduced by ~40% given optimal spatial allocation. Over time, we find that gains in yield potential and in-country nitrogen use efficiency have led to increases in the global nitrogen production possibilities frontier. However, this promising shift has been accompanied by an actual spatial distribution of nitrogen use that has become less optimal, in an absolute sense, relative to the frontier. We conclude that examination of global production possibilities is a promising approach to understanding production constraints and efficiency opportunities in the global food system.

Effects of ditch-buried straw return on water percolation, nitrogen leaching and crop yields in a rice-wheat rotation system.

PubMed

Yang, Haishui; Xu, Mingmin; Koide, Roger T; Liu, Qian; Dai, Yajun; Liu, Ling; Bian, Xinmin

2016-03-15

Crop residue management and nitrogen loss are two important environmental problems in the rice-wheat rotation system in China. This study investigated the effects of burial of straw on water percolation, nitrogen loss by leaching, crop growth and yield. Greenhouse mesocosm experiments were conducted over the course of three simulated cropping seasons in a rice1-wheat-rice2 rotation. Greater amounts of straw resulted in more water percolation, irrespective of crop season. Burial at 20 and 35 cm significantly reduced, but burial at 50 cm increased nitrogen leaching. Straw at 500 kg ha(-1) reduced, but at 1000 kg ha(-1) and at 1500 kg ha(-1) straw increased nitrogen leaching in three consecutive crop rotations. In addition, straw at 500 kg ha(-1) buried at 35 cm significantly increased yield and its components for both crops. This study suggests that N losses via leaching from the rice-wheat rotation may be reduced by the burial of the appropriate amount of straw at the appropriate depth. Greater amounts of buried straw, however, may promote nitrogen leaching and negatively affect crop growth and yields. Complementary field experiments must be performed to make specific agronomic recommendations. © 2015 Society of Chemical Industry.

Optimal tree increment models for the Northeastern United Statesq

Treesearch

Don C. Bragg

2003-01-01

used the potential relative increment (PRI) methodology to develop optimal tree diameter growth models for the Northeastern United States. Thirty species from the Eastwide Forest Inventory Database yielded 69,676 individuals, which were then reduced to fast-growing subsets for PRI analysis. For instance, only 14 individuals from the greater than 6,300-tree eastern...

Optimal Tree Increment Models for the Northeastern United States

Treesearch

Don C. Bragg

2005-01-01

I used the potential relative increment (PRI) methodology to develop optimal tree diameter growth models for the Northeastern United States. Thirty species from the Eastwide Forest Inventory Database yielded 69,676 individuals, which were then reduced to fast-growing subsets for PRI analysis. For instance, only 14 individuals from the greater than 6,300-tree eastern...

Nitrogen and harvest impact on warm-season grasses biomass yield

USDA-ARS?s Scientific Manuscript database

Perennial warm-season grasses have drawn interest as bioenergy feedstocks due to their high productivity with minimal amounts of inputs while producing multiple environmental benefits. Nitrogen (N) fertility and harvest timing are critical management practices when optimizing biomass yield of these ...

Improving yield potential in crops under elevated CO2: Integrating the photosynthetic and nitrogen utilization efficiencies

PubMed Central

Kant, Surya; Seneweera, Saman; Rodin, Joakim; Materne, Michael; Burch, David; Rothstein, Steven J.; Spangenberg, German

2012-01-01

Increasing crop productivity to meet burgeoning human food demand is challenging under changing environmental conditions. Since industrial revolution atmospheric CO2 levels have linearly increased. Developing crop varieties with increased utilization of CO2 for photosynthesis is an urgent requirement to cope with the irreversible rise of atmospheric CO2 and achieve higher food production. The primary effects of elevated CO2 levels in most crop plants, particularly C3 plants, include increased biomass accumulation, although initial stimulation of net photosynthesis rate is only temporal and plants fail to sustain the maximal stimulation, a phenomenon known as photosynthesis acclimation. Despite this acclimation, grain yield is known to marginally increase under elevated CO2. The yield potential of C3 crops is limited by their capacity to exploit sufficient carbon. The “C fertilization” through elevated CO2 levels could potentially be used for substantial yield increase. Rubisco is the rate-limiting enzyme in photosynthesis and its activity is largely affected by atmospheric CO2 and nitrogen availability. In addition, maintenance of the C/N ratio is pivotal for various growth and development processes in plants governing yield and seed quality. For maximizing the benefits of elevated CO2, raising plant nitrogen pools will be necessary as part of maintaining an optimal C/N balance. In this review, we discuss potential causes for the stagnation in yield increases under elevated CO2 levels and explore possibilities to overcome this limitation by improved photosynthetic capacity and enhanced nitrogen use efficiency. Opportunities of engineering nitrogen uptake, assimilatory, and responsive genes are also discussed that could ensure optimal nitrogen allocation toward expanding source and sink tissues. This might avert photosynthetic acclimation partially or completely and drive for improved crop production under elevated CO2 levels. PMID:22833749

Improving yield potential in crops under elevated CO(2): Integrating the photosynthetic and nitrogen utilization efficiencies.

PubMed

Kant, Surya; Seneweera, Saman; Rodin, Joakim; Materne, Michael; Burch, David; Rothstein, Steven J; Spangenberg, German

2012-01-01

Increasing crop productivity to meet burgeoning human food demand is challenging under changing environmental conditions. Since industrial revolution atmospheric CO(2) levels have linearly increased. Developing crop varieties with increased utilization of CO(2) for photosynthesis is an urgent requirement to cope with the irreversible rise of atmospheric CO(2) and achieve higher food production. The primary effects of elevated CO(2) levels in most crop plants, particularly C(3) plants, include increased biomass accumulation, although initial stimulation of net photosynthesis rate is only temporal and plants fail to sustain the maximal stimulation, a phenomenon known as photosynthesis acclimation. Despite this acclimation, grain yield is known to marginally increase under elevated CO(2). The yield potential of C(3) crops is limited by their capacity to exploit sufficient carbon. The "C fertilization" through elevated CO(2) levels could potentially be used for substantial yield increase. Rubisco is the rate-limiting enzyme in photosynthesis and its activity is largely affected by atmospheric CO(2) and nitrogen availability. In addition, maintenance of the C/N ratio is pivotal for various growth and development processes in plants governing yield and seed quality. For maximizing the benefits of elevated CO(2), raising plant nitrogen pools will be necessary as part of maintaining an optimal C/N balance. In this review, we discuss potential causes for the stagnation in yield increases under elevated CO(2) levels and explore possibilities to overcome this limitation by improved photosynthetic capacity and enhanced nitrogen use efficiency. Opportunities of engineering nitrogen uptake, assimilatory, and responsive genes are also discussed that could ensure optimal nitrogen allocation toward expanding source and sink tissues. This might avert photosynthetic acclimation partially or completely and drive for improved crop production under elevated CO(2) levels.

The anaerobic potentially mineralizable nitrogen test as a tool for nitrogen management in the Midwest

USDA-ARS?s Scientific Manuscript database

The anaerobic potentially mineralizable nitrogen (PMNan) test is a tool that can improve estimations of mineralizable nitrogen (N) and enhance nitrogen use efficiency. This tool may also help improve predictions of N uptake, grain yield, and the economic optimum nitrogen rate (EONR) of corn (Zea ma...

40 CFR 52.200 - Original identification of plan section.

Code of Federal Regulations, 2012 CFR

2012-07-01

... plan to incorporate Federal Prevention of Significant Deterioration (PSD) Regulations 40 CFR 52.21 by... Plan for Prevention of Significant Deterioration (PSD) of Air Quality Supplement Arkansas Plan of Implementation for Air Pollution Control (PSD nitrogen dioxide increments), as adopted on May 25, 1990, by the...

40 CFR 52.200 - Original identification of plan section.

Code of Federal Regulations, 2014 CFR

2014-07-01

... plan to incorporate Federal Prevention of Significant Deterioration (PSD) Regulations 40 CFR 52.21 by... Plan for Prevention of Significant Deterioration (PSD) of Air Quality Supplement Arkansas Plan of Implementation for Air Pollution Control (PSD nitrogen dioxide increments), as adopted on May 25, 1990, by the...

40 CFR 52.200 - Original identification of plan section.

Code of Federal Regulations, 2013 CFR

2013-07-01

... plan to incorporate Federal Prevention of Significant Deterioration (PSD) Regulations 40 CFR 52.21 by... Plan for Prevention of Significant Deterioration (PSD) of Air Quality Supplement Arkansas Plan of Implementation for Air Pollution Control (PSD nitrogen dioxide increments), as adopted on May 25, 1990, by the...

CARIBIAM: constrained Association Rules using Interactive Biological IncrementAl Mining.

PubMed

Rahal, Imad; Rahhal, Riad; Wang, Baoying; Perrizo, William

2008-01-01

This paper analyses annotated genome data by applying a very central data-mining technique known as Association Rule Mining (ARM) with the aim of discovering rules and hypotheses capable of yielding deeper insights into this type of data. In the literature, ARM has been noted for producing an overwhelming number of rules. This work proposes a new technique capable of using domain knowledge in the form of queries in order to efficiently mine only the subset of the associations that are of interest to investigators in an incremental and interactive manner.

Accumulated Expression Level of Cytosolic Glutamine Synthetase 1 Gene (OsGS1;1 or OsGS1;2) Alter Plant Development and the Carbon-Nitrogen Metabolic Status in Rice

PubMed Central

Bao, Aili; Zhao, Zhuqing; Ding, Guangda; Shi, Lei; Xu, Fangsen; Cai, Hongmei

2014-01-01

Maintaining an appropriate balance of carbon to nitrogen metabolism is essential for rice growth and yield. Glutamine synthetase is a key enzyme for ammonium assimilation. In this study, we systematically analyzed the growth phenotype, carbon-nitrogen metabolic status and gene expression profiles in GS1;1-, GS1;2-overexpressing rice and wildtype plants. Our results revealed that the GS1;1-, GS1;2-overexpressing plants exhibited a poor plant growth phenotype and yield and decreased carbon/nitrogen ratio in the stem caused by the accumulation of nitrogen in the stem. In addition, the leaf SPAD value and photosynthetic parameters, soluble proteins and carbohydrates varied greatly in the GS1;1-, GS1;2-overexpressing plants. Furthermore, metabolite profile and gene expression analysis demonstrated significant changes in individual sugars, organic acids and free amino acids, and gene expression patterns in GS1;1-, GS1;2-overexpressing plants, which also indicated the distinct roles that these two GS1 genes played in rice nitrogen metabolism, particularly when sufficient nitrogen was applied in the environment. Thus, the unbalanced carbon-nitrogen metabolic status and poor ability of nitrogen transportation from stem to leaf in GS1;1-, GS1;2-overexpressing plants may explain the poor growth and yield. PMID:24743556

Increasing water productivity, nitrogen economy, and grain yield of rice by water saving irrigation and fertilizer-N management.

PubMed

Aziz, Omar; Hussain, Saddam; Rizwan, Muhammad; Riaz, Muhammad; Bashir, Saqib; Lin, Lirong; Mehmood, Sajid; Imran, Muhammad; Yaseen, Rizwan; Lu, Guoan

2018-06-01

The looming water resources worldwide necessitate the development of water-saving technologies in rice production. An open greenhouse experiment was conducted on rice during the summer season of 2016 at Huazhong Agricultural University, Wuhan, China, in order to study the influence of irrigation methods and nitrogen (N) inputs on water productivity, N economy, and grain yield of rice. Two irrigation methods, viz. conventional irrigation (CI) and "thin-shallow-moist-dry" irrigation (TSMDI), and three levels of nitrogen, viz. 0 kg N ha -1 (N 0 ), 90 kg N ha -1 (N 1 ), and 180 kg N ha -1 (N 2 ), were examined with three replications. Study data indicated that no significant water by nitrogen interaction on grain yield, biomass, water productivity, N uptake, NUE, and fertilizer N balance was observed. Results revealed that TSMDI method showed significantly higher water productivity and irrigation water applications were reduced by 17.49% in TSMDI compared to CI. Thus, TSMDI enhanced root growth and offered significantly greater water saving along with getting more grain yield compared to CI. Nitrogen tracer ( 15 N) technique accurately assessed the absorption and distribution of added N in the soil crop environment and divulge higher nitrogen use efficiency (NUE) influenced by TSMDI. At the same N inputs, the TSMDI was the optimal method to minimize nitrogen leaching loss by decreasing water leakage about 18.63%, which are beneficial for the ecological environment.

[Influences of micro-irrigation and subsoiling before planting on enzyme activity in soil rhizosphere and summer maize yield.

PubMed

Zhang, Ming Zhi; Niu, Wen Quan; Xu, Jian; Li, Yuan

2016-06-01

In order to explore the influences of micro-irrigation and subsoiling before planting on enzyme activity in soil rhizosphere and summer maize yield, an orthogonal experiment was carried out with three factors of micro-irrigation method, irrigation depth, and subsoiling depth. The factor of irrigation method included surface drip irrigation, subsurface drip irrigation, and moistube-irrigation; three levels of irrigation depth were obtained by controlling the lower limit of soil water content to 50%, 65%, and 80% of field holding capacity, respectively; and three depths of deep subsoiling were 20, 40, and 60 cm. The results showed that the activities of catalase and urease increased first and then decreased, while the activity of phosphatase followed an opposite trend in the growth season of summer maize. Compared with surface drip irrigation and moistube-irrigation, subsurface drip irrigation increased the average soil moisture of 0-80 cm layer by 6.3% and 1.8% in the growth season, respectively. Subsurface drip irrigation could significantly increase soil urease activity, roots volume, and yield of summer maize. With the increase of irrigation level, soil phosphatase activity decreased first and then increased, while urease activity and yield increased first and then decreased. The average soil moisture and root volume all increased in the growth season of summer maize. The increments of yield and root volume from subsoiling of 40 to 20 cm were greater than those from 60 to 40 cm. The highest enzyme activity was obtained with the treatment of subsoiling of 40 cm. In terms of improving water resource use efficiency, nitrogen use efficiency, and crop yield, the best management strategy of summer maize was the combination of subsurface drip irrigation, controlling the lower limit of soil water content to 65% of field holding capacity, and 40 cm subsoiling before planting.

Methane production by anaerobic digestion of Bermuda grass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klass, D.L.; Ghosh, S.

1979-01-01

Bermuda grass (Cynodon dactylon) is one of the high-yield warm-season grasses that has been suggested as a promising raw material for conversion to methane. Experimental work performed with laboratory digesters to study the anaerobic digestion of Coastal Bermuda grass harvested in Louisiana and having a C/N ratio of 24 is described. Methane yields of about 1.9 SCF/lb of volatile solids( VS) added were observed under conventional mesophilic high-rate conditions. When supplemental nitrogen additions were made, the yields increased up to 3.5 SCF/lb of VS added indicating that the nitrogen content of the grass examined was insufficient to sustain high-rate digestionmore » at the higher yield level. Thermophilic digestion with supplemental nitrogen additions afforded methane yields of about 2.7 SCF/lb VS added. Carbon and energy balances were calculated and the relative biodegradabilities of the organics were estimated.« less

Oxygen quenching in a LAB based liquid scintillator and the nitrogen bubbling model

NASA Astrophysics Data System (ADS)

Xiao, Hua-Lin; Deng, Jing-Shan; Wang, Nai-Yan

2010-05-01

The oxygen quenching effect in a Linear Alkl Benzene (LAB) based liquid scintillator (LAB as the solvent, 3 g/L 2, 5 diphe-nyloxazole (PPO) as the fluor and 15 mg/L p-bis-(o-methylstyryl)-benzene (bis-MSB) as the λ-shifter) is studied by measuring the light yield as a function of the nitrogen bubbling time. It is shown that the light yield of the fully purged liquid scintillator is increased by 11% at room temperature and the room atmospheric pressure. A simple nitrogen bubbling model is proposed to describe the relationship between the relative light yield (oxygen quenching factor) and the bubbling time.

Corn grain yield and nutrient uptake from application of enhanced-efficiency nitrogen fertilizers

USDA-ARS?s Scientific Manuscript database

Increasing demand for food and agricultural products directly impact the use of chemical fertilizers particularly nitrogen (N). This study examined corn grain yield and nutrient uptake resulting from applications of different N fertilizer sources, urea (U), urea-ammonium nitrate (UAN), ammonium nitr...

[Effects of nitrogen application on canopy vertical structure, grain-leaf ratio and economic benefit of winter wheat under drip irrigation.

PubMed

Zhang, Na; Xu, Wen Xiu; Li, Lan Hai; Wu, Ni Ping; Wu, Pei Jie; Cheng, Xue Feng

2016-08-01

To optimize the fertilization rate of winter wheat under drip irrigation in Xinjiang region, a field investigation was carried out to assess effects of nitrogen (N) applications on canopy vertical structure, grain-leaf ratio, yield and economic benefit of winter wheat. Four rates of nitrogen application, 0 kg·hm -2 (N 0 ), 104 kg·hm -2 (N 1 ), 173 kg·hm -2 (N 2 ) and 242 kg·hm -2 (N 3 ) were set in a randomized block experimental design. Meantime, leaf and stem morphological characters, canopy temperature and humidity in flowering stage, grain-leaf area ratio, yield and yield components, economic benefits of winter wheat were observed under different treatments. The results showed that the leaf length and width at different positions of wheat under the nitrogen fertilization treatments were significantly higher than that without nitrogen fertilization (P<0.05), and plant height ranged from 65.57 to 81.58 cm. With an increasing rate of nitrogen fertilization, both leafarea index and stem diameter presented a trend of first increasing and then decreasing, and reached the maximum under N 2 treatment, which was 5.48 and 0.49 cm, respectively. Diurnal variation of canopy temperature and humidity were "convex" and "concave" shape, followed an order of N 0 >N 1 >N 2 >N 3 in temperature, but reversely in canopy humidity. The duration of high temperature higher than 35 ℃ were shorten 1 hour to 3.5 hours as the nitrogen application level increased, and there was significant difference between N 1 and N 3 on grain-leaf ratio. Yield and economic be-nefit decreased initially and then increased with increasing nitrogen application. Yield and economic benefit of treatment N 2 were 32.8% and 77.7% higher than those of treatment N 0 , 12.6% and 5.4% higher than those of treatment N 1 , and 5.2% and 4.2% higher than those of treatment N 3 , respectively. These results indicated that nitrogen application at about 173 kg·hm -2 could be recommended as the optimum rate for winter wheat, which had good leaf and plant morphology, appropriate canopy temperature and humidity, high yield and economic efficiency in the experiment area.

Simulation on Change Law of Runoff, Sediment and Non-point Source Nitrogen and Phosphorus Discharge under Different Land uses Based on SWAT Model: A Case Study of Er hai Lake Small Watershed

NASA Astrophysics Data System (ADS)

Tong, Xiao Xia; Lai Cui, Yuan; Chen, Man Yu; Hu, Bo; Xu, Wen Sheng

2018-05-01

The Er yuan watershed of Er hai district is chosen as the research area, the law of runoff and sediment and non-point source nitrogen and phosphorus discharges under different land uses during 2001 to 2014 are simulated based on SWAT model. Results of simulation indicate that the order of total runoff yield of different land use type from high to low is grassland, paddy fields, dry land. Specifically, the order of surface runoff yield from high to low is paddy fields, dry land, grassland, the order of lateral runoff yield from high to low is paddy fields, dry land, grassland, the order of groundwater runoff yield from high to low is grassland, paddy fields, dry land. The orders of sediment and nitrogen and phosphorus yield per unit area of different land use type are the same, grassland> paddy fields> dry land. It can be seen, nitrogen and phosphorus discharges from paddy fields and dry land are the main sources of agricultural non-point pollution of the irrigated area. Therefore, reasonable field management measures which can decrease the discharge of nitrogen and phosphorus of paddy fields and dry land are the key to agricultural non-point source pollution prevention and control.

Gene Expression Biomarkers Provide Sensitive Indicators of in Planta Nitrogen Status in Maize[W][OA

PubMed Central

Yang, Xiaofeng S.; Wu, Jingrui; Ziegler, Todd E.; Yang, Xiao; Zayed, Adel; Rajani, M.S.; Zhou, Dafeng; Basra, Amarjit S.; Schachtman, Daniel P.; Peng, Mingsheng; Armstrong, Charles L.; Caldo, Rico A.; Morrell, James A.; Lacy, Michelle; Staub, Jeffrey M.

2011-01-01

Over the last several decades, increased agricultural production has been driven by improved agronomic practices and a dramatic increase in the use of nitrogen-containing fertilizers to maximize the yield potential of crops. To reduce input costs and to minimize the potential environmental impacts of nitrogen fertilizer that has been used to optimize yield, an increased understanding of the molecular responses to nitrogen under field conditions is critical for our ability to further improve agricultural sustainability. Using maize (Zea mays) as a model, we have characterized the transcriptional response of plants grown under limiting and sufficient nitrogen conditions and during the recovery of nitrogen-starved plants. We show that a large percentage (approximately 7%) of the maize transcriptome is nitrogen responsive, similar to previous observations in other plant species. Furthermore, we have used statistical approaches to identify a small set of genes whose expression profiles can quantitatively assess the response of plants to varying nitrogen conditions. Using a composite gene expression scoring system, this single set of biomarker genes can accurately assess nitrogen responses independently of genotype, developmental stage, tissue type, or environment, including in plants grown under controlled environments or in the field. Importantly, the biomarker composite expression response is much more rapid and quantitative than phenotypic observations. Consequently, we have successfully used these biomarkers to monitor nitrogen status in real-time assays of field-grown maize plants under typical production conditions. Our results suggest that biomarkers have the potential to be used as agronomic tools to monitor and optimize nitrogen fertilizer usage to help achieve maximal crop yields. PMID:21980173

Gene expression biomarkers provide sensitive indicators of in planta nitrogen status in maize.

PubMed

Yang, Xiaofeng S; Wu, Jingrui; Ziegler, Todd E; Yang, Xiao; Zayed, Adel; Rajani, M S; Zhou, Dafeng; Basra, Amarjit S; Schachtman, Daniel P; Peng, Mingsheng; Armstrong, Charles L; Caldo, Rico A; Morrell, James A; Lacy, Michelle; Staub, Jeffrey M

2011-12-01

Over the last several decades, increased agricultural production has been driven by improved agronomic practices and a dramatic increase in the use of nitrogen-containing fertilizers to maximize the yield potential of crops. To reduce input costs and to minimize the potential environmental impacts of nitrogen fertilizer that has been used to optimize yield, an increased understanding of the molecular responses to nitrogen under field conditions is critical for our ability to further improve agricultural sustainability. Using maize (Zea mays) as a model, we have characterized the transcriptional response of plants grown under limiting and sufficient nitrogen conditions and during the recovery of nitrogen-starved plants. We show that a large percentage (approximately 7%) of the maize transcriptome is nitrogen responsive, similar to previous observations in other plant species. Furthermore, we have used statistical approaches to identify a small set of genes whose expression profiles can quantitatively assess the response of plants to varying nitrogen conditions. Using a composite gene expression scoring system, this single set of biomarker genes can accurately assess nitrogen responses independently of genotype, developmental stage, tissue type, or environment, including in plants grown under controlled environments or in the field. Importantly, the biomarker composite expression response is much more rapid and quantitative than phenotypic observations. Consequently, we have successfully used these biomarkers to monitor nitrogen status in real-time assays of field-grown maize plants under typical production conditions. Our results suggest that biomarkers have the potential to be used as agronomic tools to monitor and optimize nitrogen fertilizer usage to help achieve maximal crop yields.

Nutrient concentrations and loads in the northeastern United States - Status and trends, 1975-2003

USGS Publications Warehouse

Trench, Elaine C. Todd; Moore, Richard B.; Ahearn, Elizabeth A.; Mullaney, John R.; Hickman, R. Edward; Schwarz, Gregory E.

2012-01-01

The U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) began regional studies in 2003 to synthesize information on nutrient concentrations, trends, stream loads, and sources. In the northeastern United States, a study area that extends from Maine to central Virginia, nutrient data were evaluated for 130 USGS water-quality monitoring stations. Nutrient data were analyzed for trends in flow-adjusted concentrations, modeled instream (non-flow-adjusted) concentrations, and stream loads for 32 stations with 22 to 29 years of water-quality and daily mean streamflow record during 1975-2003 (termed the long-term period), and for 46 stations during 1993-2003 (termed the recent period), by using a coupled statistical model of streamflow and water quality developed by the USGS. Recent trends in flow-adjusted concentrations of one or more nutrients also were analyzed for 90 stations by using Tobit regression. Annual stream nutrient loads were estimated, and annual nutrient yields were calculated, for 47 stations for the long-term and recent periods, and for 37 additional stations that did not have a complete streamflow and water-quality record for 1993-2003. Nutrient yield information was incorporated for 9 drainage basins evaluated in a national NAWQA study, for a total of 93 stations evaluated for nutrient yields. Long-term downward trends in flow-adjusted concentrations of total nitrogen and total phosphorus (18 and 19 of 32 stations, respectively) indicate regional improvements in nutrient-related water-quality conditions. Most of the recent trends detected for total phosphorus were upward (17 of 83 stations), indicating possible reversals to the long-term improvements. Concentrations of nutrients in many streams persist at levels that are likely to affect aquatic habitat adversely and promote freshwater or coastal eutrophication. Recent trends for modeled instream concentrations, and modeled reference concentrations, were evaluated relative to ecoregion-based nutrient criteria proposed by the U.S. Environmental Protection Agency. Instream concentrations of total nitrogen and total phosphorus persist at levels higher than proposed criteria at more than one-third and about one-half, respectively, of the 46 stations analyzed. Long-term trends in nutrient loads were primarily downward, with downward trends in total nitrogen and total phosphorus loads detected at 12 and 17 of 32 stations, respectively. Upward trends were rare, with one upward trend for total nitrogen loads and none for total phosphorus. Trends in loads of nitrite-plus-nitrate nitrogen included 7 upward and 8 downward trends among 32 stations. Downward trends in loads of ammonia nitrogen and total Kjeldahl nitrogen were detected at all six stations evaluated. Long-term downward trends detected in four of the five largest drainage basins evaluated include: total nitrogen loads for the Connecticut, Delaware, and James Rivers; total Kjeldahl nitrogen and ammonia nitrogen loads for the Susquehanna River; ammonia nitrogen and nitrite-plus-nitrate nitrogen loads for the James River; and total phosphorus loads for the Connecticut and Delaware Rivers. No trends in load were detected for the Potomac River. Nutrient yields were evaluated relative to the extent of land development in 93 drainage basins. The undeveloped land-use category included forested drainage basins with undeveloped land ranging from 75 to 100 percent of basin area. Median total nitrogen yields for the 27 undeveloped drainage basins evaluated, including 9 basins evaluated in a national NAWQA study, ranged from 290 to 4,800 pounds per square mile per year (lb/mi2/yr). Total nitrogen yields even in the most pristine drainage basins may be elevated relative to natural conditions, because of high rates of atmospheric deposition of nitrogen in parts of the northeastern United States. Median total phosphorus yields ranged from 12 to 330 lb/mi2/yr for the 26 undeveloped basins evaluated. The undeveloped category includes some large drainage basins with point-source discharges and small percentages of developed land; in these basins, streamflow from undeveloped headwater areas dilutes streamflow in more urbanized reaches, and dampens but does not eliminate the point-source "signal" of higher nutrient loads. Median total nitrogen yields generally do not exceed 1,700 lb/mi2/yr, and median total phosphorus yields generally do not exceed 100 lb/mi2/yr, in the drainage basins that are least affected by human land-use and waste-disposal practices. Agricultural and urban land use has increased nutrient yields substantially relative to undeveloped drainage basins. Median total nitrogen yields for 24 agricultural basins ranged from 1,700 to 26,000 lb/mi2/yr, and median total phosphorus yields ranged from 94 to 1,000 lb/mi2/yr. The maximum estimated total nitrogen and total phosphorus yields, 32,000 and 16,000 lb/mi2/yr, respectively, for all stations in the region were in small (less than 50 square miles (mi2)) agricultural drainage basins. Median total nitrogen yields ranged from 1,400 to 17,000 lb/mi2/yr in 26 urbanized drainage basins, and median total phosphorus yields ranged from 43 to 1,900 lb/mi2/yr. Urbanized drainage basins with the highest nutrient yields are generally small (less than 300 mi2) and are drained by streams that receive major point-source discharges. Instream nutrient loads were evaluated relative to loads from point-source discharges in four drainage basins: the Quinebaug River Basin in Connecticut, Massachusetts, and Rhode Island; the Raritan River Basin in New Jersey; the Patuxent River Basin in Maryland; and the James River Basin in Virginia. Long-term downward trends in nutrient loads, coupled with similar trends in flow-adjusted nutrient concentrations, indicate long-term reductions in the delivery of most nutrients to these streams. However, the absence of recent downward trends in load for most nutrients, coupled with instream concentrations that exceed proposed nutrient criteria in several of these waste-receiving streams, indicates that challenges remain in reducing delivery of nutrients to streams from point sources. During dry years, the total nutrient load from point sources in some of the drainage basins approached or equaled the nutrient load transported by the stream.

Nitrogen fertilization effects on sorghum forage yield and quality

USDA-ARS?s Scientific Manuscript database

The study objective was to determine the effect of nitrogen fertilization on yield and quality of photoperiod sensitive (PS) and non-PS forage sorghum, sorghum-sudangrass, and sudangrass compared to corn. This study was a randomized complete block design with treatments arranged in a 4 x 8 factorial...

Tillage and Composting Strategies to Maximize Potentially Mineralizable Nitrogen in Maize-based Cropping Systems

USDA-ARS?s Scientific Manuscript database

Cereal crop yields vary drastically between developed and developing nations. In developing nations, a lack of synthetic nitrogen (N) fertilizer often limits yields. Low-cost soil management strategies that increase biologically available soil organic matter can reduce farmer reliance on synthetic N...

Stover removal effects on continuous corn yield and nitrogen use efficiency under irrigation

USDA-ARS?s Scientific Manuscript database

Corn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a primary feedstock for cellulosic biofuels. Limited information is available on corn residue removal effects on grain yield under different nitrogen (N) fertilizer rates, irrigation rates and amelioration pr...

Corn response to nitrogen management under fully-irrigated vs. water-stressed conditions

USDA-ARS?s Scientific Manuscript database

Characterizing corn grain yield response to nitrogen (N) fertilizer rate is critical for maximizing profits, optimizing N use efficiency and minimizing environmental impacts. Although a large data base of yield response to N has been compiled for highly productive soils in the upper Midwest U.S., f...

Increased tree carbon storage in response to nitrogen deposition in the US

NASA Astrophysics Data System (ADS)

Quinn Thomas, R.; Canham, Charles D.; Weathers, Kathleen C.; Goodale, Christine L.

2010-01-01

Human activities have greatly accelerated emissions of both carbon dioxide and biologically reactive nitrogen to the atmosphere. As nitrogen availability often limits forest productivity, it has long been expected that anthropogenic nitrogen deposition could stimulate carbon sequestration in forests. However, spatially extensive evidence for deposition-induced stimulation of forest growth has been lacking, and quantitative estimates from models and plot-level studies are controversial. Here, we use forest inventory data to examine the impact of nitrogen deposition on tree growth, survival and carbon storage across the northeastern and north-central USA during the 1980s and 1990s. We show a range of growth and mortality responses to nitrogen deposition among the region's 24 most common tree species. Nitrogen deposition (which ranged from 3 to 11kgha-1yr-1) enhanced the growth of 11 species and decreased the growth of 3 species. Nitrogen deposition enhanced growth of all tree species with arbuscular mycorrhizal fungi associations. In the absence of disturbances that reduced carbon stocks by more than 50%, above-ground biomass increment increased by 61kg of carbon per kg of nitrogen deposited, amounting to a 40% enhancement over pre-industrial conditions. Extrapolating to the globe, we estimate that nitrogen deposition could increase tree carbon storage by 0.31Pg carbon yr-1.

Reduced Height (Rht) Alleles Affect Wheat Grain Quality

PubMed Central

Casebow, Richard; Hadley, Caroline; Uppal, Rajneet; Addisu, Molla; Loddo, Stefano; Kowalski, Ania; Griffiths, Simon; Gooding, Mike

2016-01-01

The effects of dwarfing alleles (reduced height, Rht) in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c) as well as those that retained GA-sensitivity (rht(tall), Rht8, Rht8 + Ppd-D1a, Rht12). Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0–450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (P<0.05) reduced grain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN) was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there was the strongest evidence for a direct pleiotropic effect of GA-insensitivity, rather than an effect consequential to yield and/or height. PMID:27196288

Reduced Height (Rht) Alleles Affect Wheat Grain Quality.

PubMed

Casebow, Richard; Hadley, Caroline; Uppal, Rajneet; Addisu, Molla; Loddo, Stefano; Kowalski, Ania; Griffiths, Simon; Gooding, Mike

2016-01-01

The effects of dwarfing alleles (reduced height, Rht) in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c) as well as those that retained GA-sensitivity (rht(tall), Rht8, Rht8 + Ppd-D1a, Rht12). Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0-450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (P<0.05) reduced grain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN) was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there was the strongest evidence for a direct pleiotropic effect of GA-insensitivity, rather than an effect consequential to yield and/or height.

Climate sensitivity of DSSAT under different agriculture practice scenarios in China

NASA Astrophysics Data System (ADS)

Xia, L.; Robock, A.

2014-12-01

Crop yields are sensitive to both agricultural practice and climate changes. Under different agricultural practice scenarios, crop yield may have different climate sensitivities. Since it is important to understand how future climate changes affect agriculture productivity and what the potential adaptation strategies would be to compensate for possible negative impacts on crop production, we performed experiments to study climate sensitivity under different agricultural practice scenarios for rice, maize and wheat in the top four production provinces in China using the Decision Support System for Agrotechnology Transfer (DSSAT) crop model. The agricultural practice scenarios include four categories: different amounts of nitrogen fertilizer or no nitrogen stress; irrigation turned on or off, or no water stress; all possible seeds in the DSSAT cultivar data base; and different planting dates. For the climate sensitivity test, the control climate is from 1998 to 2007, and we individually modify four climate variables: daily maximum and minimum temperature by +2 °C and -2 °C, daily precipitation by +20% and -20%, and daily solar radiation by + 20% and -20%. With more nitrogen fertilizer applied, crops are more sensitive to temperature changes as well as precipitation changes because of their release from nitrogen limitation. With irrigation turned on, crop yield sensitivity to temperature decreases in most of the regions depending on the amount of the local precipitation, since more water is available and soil temperature varies less with higher soil moisture. Those results indicate that there could be possible agriculture adaptation strategies under certain future climate scenarios. For example, increasing nitrogen fertilizer usage by a certain amount might compensate for the negative impact on crop yield from climate changes. However, since crops are more sensitive to climate changes when there is more nitrogen fertilizer applied, if the climate changes are unfavorable to crop yields, increasing nitrogen fertilizer usage at certain levels might enhance the negative climate change impact. Enhanced nitrogen fertilizer use might have additional negative impacts on climate because of nitrogen emissions to the atmosphere, but those effects were not studied here.

Interaction of potato production systems and the environment: a case of waste water irrigation in central Washington.

PubMed

Wang, H Holly; Tan, Tih Koon; Schotzko, R Thomas

2007-02-01

Potato production and processing are very important activities in the agricultural economy of the Pacific Northwest. Part of the reason for the development of this industry has been the availability of water for both growing and processing. A great amount of water is used in processing potato products, such as frozen French fries, and the waste water is a pollutant because it contains high levels of nitrate and other nutrients. Using this waste water to irrigate the fields can be a suitable disposal method. Field application will reduce potato fertilizer costs, but it can also cause underground water contamination if over-applied to the field. In this econometric study, we used field data associated with current waste water applications in central Washington to examine the yield response as well as the soil nitrogen content response to waste water applications. Our results from the production model show that both water and nitrogen positively affect crop yields at the current levels of application, but potassium has been over applied. This implies that replacing some waste water with fresh water and nitrogen fertilizer will increase production. The environmental model results show that applying more nitrogen to the soil leads to more movement below the root zone. The results also suggest that higher crop yields lead to less nitrogen in the soil, and applying more water increases crop yields, which can reduce the nitrogen left in the soil. Therefore, relative to the current practice, waste water application rates should be reduced and supplemented with fresh water to enhance nitrogen use by plants and reduce residual nitrogen in the soil.

Impacts of Farmers' Knowledge Increase on Farm Profit and Watershed Water Quality

NASA Astrophysics Data System (ADS)

Ding, D.; Bennett, D. A.

2013-12-01

This study explores the impact that an increase in real-time data might have on farmers' nitrogen management, on-farm profit, and watershed water quality in the Midwestern US. In this study, an agent-based model (ABM) is used to simulate farmers' decisions about nitrogen application rate and timing in corn fields. SWAT (soil-water assessment tool) is used to generate a database that characterizes the response of corn yields to nitrogen fertilizer application and the dynamics of nitrogen loss under different scenarios of rainfall events. The database simulates a scenario where farmers would receive real-time feedback about the fate and impact of nitrogen applied to their fields from in-situ sensors. The ability to transform these data into optimal actions is simulated at multiple levels for farmer agents. In a baseline scenario, the farmer agent is only aware of the yield potential of the land field and single values of N rates for achieving the yield potential and is not aware of N loss from farm fields. Knowledge increase is represented by greater accuracy in predicting rainfall events, and the increase of the number of discrete points in a field-specific quadratic curve that captures crop yield response to various levels of nitrogen perceived by farmer agents. In addition, agents perceive N loss from farm fields at increased temporal resolutions. Correspondingly, agents make adjustments to the rate of N application for crops and the timing of fertilizer application given the rainfall events predictions. Farmers' decisions simulated by the ABM are input into SWAT to model nitrogen concentration in impacted streams. Farm profit statistics and watershed-level nitrogen loads are compared among different scenarios of knowledge increase. The hypothesis that the increase of farmers' knowledge benefits both farm profits and watershed water quality is tested through the comparison.

Worldwide Organic Soil Carbon and Nitrogen Data (1986) (NDP-018)

DOE Data Explorer

Zinke, P. J. [Univ. of California, Berkeley, CA (United States); Stangenberger, A. G. [Univ. of California, Berkeley, CA (United States); Post, W. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Emanuel, W. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Olson, J. S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Millemann, R. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boden, T. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

1986-01-01

This data base was begun with the collection and analysis of soil samples from California. Additional data came from soil surveys of Italy, Greece, Iran, Thailand, Vietnam, various tropical Amazonian areas, and U.S. forests and from the soil-survey literature. The analyzed samples were collected at uniform soil-depth increments and included bulk-density determinations. The data on each sample are soil profile number; soil profile carbon content; soil profile nitrogen content; sampling site latitude and longitude; site elevation; profile literature reference source; and soil profile codes for Holdridge life zone, Olson ecosystem type, and parent material. These data may be used to estimate the size of the soil organic carbon and nitrogen pools at equilibrium with natural soil-forming factors.

Effects of low nitrogen supply on tomato (Solanum lycopersicum) fruit yield and quality with special emphasis on sugars, acids, ascorbate, carotenoids, and phenolic compounds.

PubMed

Bénard, Camille; Gautier, Hélène; Bourgaud, Frédéric; Grasselly, Dominique; Navez, Brigitte; Caris-Veyrat, Catherine; Weiss, Marie; Génard, Michel

2009-05-27

The objective of this study was to determine the impact of lowering nitrogen supply from 12 to 6 or 4 mM NO(3)(-) on tomato fruit yield and quality during the growing season. Lowering nitrogen supply had a low impact on fruit commercial yield (-7.5%), but it reduced plant vegetative growth and increased fruit dry matter content, improving consequently fruit quality. Fruit quality was improved due to lower acid (10-16%) and increased soluble sugar content (5-17%). The content of some phenolic compounds (rutin, a caffeic acid glycoside, and a caffeic acid derivate) and total ascorbic acid tended to be higher in fruit with the lowest nitrogen supply, but differences were significant in only a few cases (trusses). With regard to carotenoids, data did not show significant and univocal differences related to different levels of nitrogen supply. Thus, reducing nitrogen fertilization limited environmental pollution, on the one hand, and may improve, on the other hand, both growers' profits, by limiting nitrogen inputs, and fruit quality for consumers, by increasing tomato sugars content. It was concluded that primary and secondary metabolites could be affected as a result of a specific response to low nitrogen, combined with a lower degree of vegetative development, increasing fruit irradiance, and therefore modifying fruit composition.

Orchard nitrogen management: Which nitrogen source is best?

USDA-ARS?s Scientific Manuscript database

Suboptimal management of nitrogen fertility in pecan orchards leads to a loss of nutmeat yield and quality, but also a waste of natural resources and money. This article reviews several basic guiding principles useful to orchard managers when developing nitrogen management strategies, and determini...

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.

Nutrient recycle from defatted microalgae (Aurantiochytrium) with hydrothermal treatment for microalgae cultivation.

PubMed

Aida, Taku Michael; Maruta, Ryouma; Tanabe, Yuuhiko; Oshima, Minori; Nonaka, Toshiyuki; Kujiraoka, Hiroki; Kumagai, Yasuaki; Ota, Masaki; Suzuki, Iwane; Watanabe, Makoto M; Inomata, Hiroshi; Smith, Richard L

2017-03-01

Defatted heterotrophic microalgae (Aurantiochytrium limacinum SR21) was treated with high temperature water (175-350°C, 10-90min) to obtain nitrogen and phosphorous nutrients as a water soluble fraction (WS). Yields of nitrogen and phosphorous recovered in WS varied from 38 to 100% and from 57 to 99%, respectively. Maximum yields of nitrogen containing compounds in WS were proteins (43%), amino acids (12%) and ammonia (60%) at treatment temperatures of 175, 250 and 350°C, respectively. Maximum yield of phosphorous in WS was 99% at a treatment temperature of 250°C. Cultivation experiments of microalgae (A. limacinum SR21) using WS obtained at 200 and 250°C showed positive growth. Water soluble fractions from hydrothermal treatment of defatted microalgae are effective nitrogen and phosphorous nutrient sources for microalgae cultivation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Corn nitrogen fertilization rate tools compared over eight midwest states

USDA-ARS?s Scientific Manuscript database

Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail both when N is over-applied and result in excess N being lost to the environment, or when N is under-applied and the result in decreased yield and economic returns...

Interactive effects of pH, EC and nitrogen on yields and nutrient absorption of rice (Oryza sativa L.)

USDA-ARS?s Scientific Manuscript database

Soil salinity and sodicity can not only directly restrain crop growth by osmotic and specific ion stresses, it also may reduce grain yield indirectly by impacting plant absorption of essential nutrients. Ensuring adequate nitrogen is an important management aspect of rice production in saline-sodic ...

Enhanced efficiency fertilizer’s effect on cotton yield and greenhouse gas emissions

USDA-ARS?s Scientific Manuscript database

Interest in the use of enhanced-efficiency nitrogen fertilizer (EENFs) sources has increased in recent years due to the potential of these new EENF sources to increase crop yield, while at the same time decreasing N loss from agricultural fields. Nitrogen is the most essential nutrient needed to op...

Linking watershed nitrogen sources with nitrogen dynamics in rivers of western Oregon, USA

EPA Science Inventory

We found a wide range of riverine N yields from the study basins, ranging from one to 70 kg N/ha/yr. Across the study basins, N export was more strongly correlated to fertilizer application rates than percent of agricultural area in the watershed. Low watershed N yields reflect...

Maize (Zea mays L.) yield response to nitrogen as influenced by spatio-temporal variations of soil-water-topography dynamics

USDA-ARS?s Scientific Manuscript database

Reducing nitrogen (N) loss from agricultural lands and applying N fertilizer at rates that satisfy both economic and environmental objectives is critical for sustainable agricultural management. This study investigated spatial variability in maize yield response to N and its controlling factors alon...

Tightly-coupled plant-soil nitrogen cycling: Implications for multiple ecosystem services on organic farms across an intensively managed agricultural landscape

USDA-ARS?s Scientific Manuscript database

Variability among farms across an agricultural landscape may reveal diverse biophysical contexts and experiences that show innovations and insights to improve nitrogen (N) cycling and yields, and thus the potential for multiple ecosystem services. In order to assess potential tradeoffs between yield...

Nitrogen source and rate effects on furrow irrigated corn yields and NUE

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) rate studies were conducted under furrow irrigated corn (Zea mays L.) production on a silty clay soil to compare polymer-coated urea (PCU) and stabilized urea (SU; contains urease and nitrification inhibitors) effects on corn yields, plant N uptake and N use efficiency (NUE) to granular...

REGIONAL ANALYSIS OF INORGANIC NITROGEN YIELD AND RETENTION IN HIGH-ELEVATION ECOSYSTEMS OF THE SIERRA NEVADA AND ROCKY MOUNTAINS

EPA Science Inventory

Yields and retention of inorganic nitrogen (DIN) and nitrate concentrations in surface runoff are summarized for 28 high elevation watersheds in the Sierra Nevada, California and Rocky Mountains of Wyoming and Colorado. Catchments ranged in elevation from 2475 to 3603 m and from...

Nitrogen conversion under rapid pyrolysis of two types of aquatic biomass and corresponding blends with coal.

PubMed

Yuan, Shuai; Chen, Xue-li; Li, Wei-feng; Liu, Hai-feng; Wang, Fu-chen

2011-11-01

Rapid pyrolysis of two types of aquatic biomass (blue-green algae and water hyacinth), and their blends with two coals (bituminous and anthracite) was carried out in a high-frequency furnace. Nitrogen conversions during rapid pyrolysis of the two biomass and the interactions between the biomass and coals on nitrogen conversions were investigated. Results show that little nitrogen retained in char after the biomass pyrolysis, and NH(3) yields were higher than HCN. During co-pyrolysis of biomass and coal, interactions between biomass and coal decreased char-N yields and increased volatile-N yields, but the total yields of NH(3)+HCN in volatile-N were decreased in which HCN formations were decreased consistently, while NH(3) formations were only decreased in the high-temperature range but promoted in the low-temperature range. Interactions between blue-green algae and coals are stronger than those between water hyacinth and coal, and interactions between biomass and bituminous are stronger than those between biomass and anthracite. Copyright © 2011 Elsevier Ltd. All rights reserved.

Winter wheat response to irrigation, nitrogen fertilization, and cold hazards in the Community Land Model 5

NASA Astrophysics Data System (ADS)

Lu, Y.

2017-12-01

Winter wheat is a staple crop for global food security, and is the dominant vegetation cover for a significant fraction of earth's croplands. As such, it plays an important role in soil carbon balance, and land-atmosphere interactions in these key regions. Accurate simulation of winter wheat growth is not only crucial for future yield prediction under changing climate, but also for understanding the energy and water cycles for winter wheat dominated regions. A winter wheat growth model has been developed in the Community Land Model 4.5 (CLM4.5), but its responses to irrigation and nitrogen fertilization have not been validated. In this study, I will validate winter wheat growth response to irrigation and nitrogen fertilization at five winter wheat field sites (TXLU, KSMA, NESA, NDMA, and ABLE) in North America, which were originally designed to understand winter wheat response to nitrogen fertilization and water treatments (4 nitrogen levels and 3 irrigation regimes). I also plan to further update the linkages between winter wheat yield and cold hazards. The previous cold damage function only indirectly affects yield through reduction on leaf area index (LAI) and hence photosynthesis, such approach could sometimes produce an unwanted higher yield when the reduced LAI saved more nutrient in the grain fill stage.

Relationship of nitrogen use efficiency with the activities of enzymes involved in nitrogen uptake and assimilation of finger millet genotypes grown under different nitrogen inputs.

PubMed

Gupta, Nidhi; Gupta, Atul K; Gaur, Vikram S; Kumar, Anil

2012-01-01

Nitrogen responsiveness of three-finger millet genotypes (differing in their seed coat colour) PRM-1 (brown), PRM-701 (golden), and PRM-801 (white) grown under different nitrogen doses was determined by analyzing the growth, yield parameters and activities of nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase; GOGAT, and glutamate dehydrogenase (GDH) at different developmental stages. High nitrogen use efficiency and nitrogen utilization efficiency were observed in PRM-1 genotype, whereas high nitrogen uptake efficiency was observed in PRM-801 genotype. At grain filling nitrogen uptake efficiency in PRM-1 negatively correlated with NR, GS, GOGAT activities whereas it was positively correlated in PRM-701 and PRM-801, however, GDH showed a negative correlation. Growth and yield parameters indicated that PRM-1 responds well at high nitrogen conditions while PRM-701 and PRM-801 respond well at normal and low nitrogen conditions respectively. The study indicates that PRM-1 is high nitrogen responsive and has high nitrogen use efficiency, whereas golden PRM-701 and white PRM-801 are low nitrogen responsive genotypes and have low nitrogen use efficiency. However, the crude grain protein content was higher in PRM-801 genotype followed by PRM-701 and PRM-1, indicating negative correlation of nitrogen use efficiency with source to sink relationship in terms of seed protein content.

Manipulating vineyard nitrogen on a saline site: 1. Effect of nitrogen on growth, grape yield and nutrients of Vitis vinifera L. cv Shiraz.

PubMed

Bell, Sally-Jean; Francis, I Leigh

2013-08-15

With increased prevalence of saline irrigation water applied to vines worldwide, the issue of appropriate nitrogen management is of concern. Different rates of nitrogen per vine as urea were applied to Shiraz vines on own roots over four seasons in a low-rainfall, saline growing environment. Application of nitrogen in the vineyard early in the season not only altered the vine nitrogen status but also increased some other elements in the petioles, notably chloride and sodium but also manganese and magnesium. In contrast, nitrogen application decreased petiole phosphorus. In comparison with the majority of nitrogen studies on non-saline sites, nitrogen-induced growth responses were restricted under the saline conditions in this study. While some changes in canopy density in response to nitrogen were observed, this did not affect light interception in the fruit zone. Yield responses were varied and could be related to the nutritional conditions under which bud development and flowering took place. This study demonstrated that current best practice guidelines, in terms of rate of nitrogen applied, for correcting a nitrogen deficiency on a non-saline site may not be appropriate for saline sites and that application of nitrogen can increase the potential for salt toxicity in vines. © 2013 Society of Chemical Industry.

Coupling loss characteristics of runoff-sediment-adsorbed and dissolved nitrogen and phosphorus on bare loess slope.

PubMed

Wu, Lei; Qiao, Shanshan; Peng, Mengling; Ma, Xiaoyi

2018-05-01

Soil and nutrient loss is a common natural phenomenon but it exhibits unclear understanding especially on bare loess soil with variable rainfall intensity and slope gradient, which makes it difficult to design control measures for agricultural diffuse pollution. We employ 30 artificial simulated rainfalls (six rainfall intensities and five slope gradients) to quantify the coupling loss correlation of runoff-sediment-adsorbed and dissolved nitrogen and phosphorus on bare loess slope. Here, we show that effects of rainfall intensity on runoff yield was stronger than slope gradient with prolongation of rainfall duration, and the effect of slope gradient on runoff yield reduced gradually with increased rainfall intensity. But the magnitude of initial sediment yield increased significantly from an average value of 6.98 g at 5° to 36.08 g at 25° with increased slope gradient. The main factor of sediment yield would be changed alternately with the dual increase of slope gradient and rainfall intensity. Dissolved total nitrogen (TN) and dissolved total phosphorus (TP) concentrations both showed significant fluctuations with rainfall intensity and slope gradient, and dissolved TP concentration was far less than dissolved TN. Under the double influences of rainfall intensity and slope gradient, adsorbed TN concentration accounted for 7-82% of TN loss concentration with an average of 58.6% which was the main loss form of soil nitrogen, adsorbed TP concentration accounted for 91.8-98.7% of TP loss concentration with an average of 96.6% which was also the predominant loss pathway of soil phosphorus. Nitrate nitrogen (NO 3 - -N) accounted for 14.59-73.92% of dissolved TN loss, and ammonia nitrogen (NH 4 + -N) accounted for 1.48-18.03%. NO 3 - -N was the main loss pattern of TN in runoff. Correlation between dissolved TN, runoff yield, and rainfall intensity was obvious, and a significant correlation was also found between adsorbed TP, sediment yield, and slope gradient. Our results provide the underlying insights needed to guide the control of nitrogen and phosphorus loss on loess hills.

Water productivity, yield, and berry composition in sustained versus regulated deficit irrigation of Merlot grapevines

USDA-ARS?s Scientific Manuscript database

The wine grape cultivar Merlot (Vitis vinifera L.) was irrigated at incremental fractions of estimated crop evapotranspiration or a regulated deficit (RDI) regime to identify which practice best optimized water productivity and berry composition without compromising yield. Three severities of susta...

Growth and yield of Giant Sequoia

Treesearch

David J. Dulitz

1986-01-01

Very little information exists concerning growth and yield of giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz). For old-growth trees, diameter growth is the single factor adding increment since maximum height has been obtained. Diameter growth averages 0.04 inches per year in normal old-growth trees but will fluctuate with changes in the...

Effects of biochar addition to soil on nitrogen fluxes in a winter wheat lysimeter experiment

NASA Astrophysics Data System (ADS)

Hüppi, Roman; Leifeld, Jens; Neftel, Albrecht; Conen, Franz; Six, Johan

2014-05-01

Biochar is a carbon-rich, porous residue from pyrolysis of biomass that potentially increases crop yields by reducing losses of nitrogen from soils and/or enhancing the uptake of applied fertiliser by the crops. Previous research is scarce about biochar's ability to increase wheat yields in temperate soils or how it changes nitrogen dynamics in the field. In a lysimeter system with two different soils (sandy/silt loam) nitrogen fluxes were traced by isotopic 15N enriched fertiliser to identify changes in nitrous oxide emissions, leaching and plant uptake after biochar addition. 20t/ha woodchip-waste biochar (pH=13) was applied to these soils in four lysimeters per soil type; the same number of lysimeters served as a control. The soils were cropped with winter wheat during the season 2012/2013. 170 kg-N/ha ammonium nitrate fertiliser with 10% 15N was applied in 3 events during the growing season and 15N concentrations where measured at different points in time in plant, soil, leachate and emitted nitrous oxide. After one year the lysimeter system showed no difference between biochar and control treatment in grain- and straw yield or nitrogen uptake. However biochar did reduce nitrous oxide emissions in the silt loam and losses of nitrate leaching in sandy loam. This study indicates potential reduction of nitrogen loss from cropland soil by biochar application but could not confirm increased yields in an intensive wheat production system.

Climate variability and nitrogen rate interactions affecting corn nitrogen use efficiency in Alabama

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) fertilization is an important practice to increase yield; however, plant–soil interactions to in-season changes in climatic conditions result on site-specific responses of corn to nitrogen rates. The objective of this study was to evaluate the effect of different climatic conditions and...

Biofiltration of air polluted with methane at concentration levels similar to swine slurry emissions: influence of ammonium concentration.

PubMed

Veillette, Marc; Avalos Ramirez, Antonio; Heitz, Michèle

2012-01-01

An evaluation of the effect of ammonium on the performance of two up-flow inorganic packed bed biofilters treating methane was conducted. The air flow rate was set to 3.0 L min(-1) for an empty bed residence time of 6.0 min. The biofilter was fed with a methane concentration of 0.30% (v/v). The ammonium concentration in the nutrient solution was increased by small increments (from 0.01 to 0.025 gN-NH(4) (+) L(-1)) for one biofilter and by large increments of 0.05 gN-NH(4) (+) L(-1) in the other biofilter. The total concentration of nitrogen was kept constant at 0.5 gN-NH(4) (+) L(-1) throughout the experiment by balancing ammonium with nitrate. For both biofilters, the methane elimination capacity, carbon dioxide production, nitrogen bed retention and biomass content decreased with the ammonium concentration in the nutrient solution. The biofilter with smaller ammonium increments featured a higher elimination capacity and carbon dioxide production rate, which varied from 4.9 to 14.3 g m(-3) h(-1) and from 11.5 to 30 g m(-3) h(-1), respectively. Denitrification was observed as some values of the nitrate production rate were negative for ammonium concentrations below 0.2 gN-NH(4) (+) L(-1). A Michalelis-Menten-type model fitted the ammonium elimination rate and the nitrate production rate.

Environmental influences on tree and stand increment, proceedings of the mensuration, growth and yield instruments and methods in forest mensuration workshop

Treesearch

Dale S. Solomon; Thomas B. Brann

1986-01-01

An international conference on Environmental Influences on Tree and Stand Increment was held at the University of New Hampshire, Durham, New Hampshire, USA between September 23 and 27, 1985. The meeting included recommendations from a previous I.U.F.R.O. meeting in Vienna, Austria. Demands for forest resources are increasing but the forest land base is constantly...

The best and worst of corn nitrogen rate recommendation tools used in the Midwest

USDA-ARS?s Scientific Manuscript database

Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail when N is over-applied and results in excess N being lost to the environment, or when N is under-applied and results in decreased yield and economic returns. The p...

Water and temperature stresses impact canola (Brassica napus L.) fatty acid, protein and yield over nitrogen and sulfur

USDA-ARS?s Scientific Manuscript database

Interactive effects of weather and soil nutrient status often control crop productivity. An experiment was conducted to determine effects of N and S fertilizer rate, soil water, and atmospheric temperature on canola fatty acid (FA), total oil, protein and grain yield. Nitrogen and S were assessed in...

A wheat CCAAT box-binding transcription factor increases the grain yield of wheat with less fertilizer input.

PubMed

Qu, Baoyuan; He, Xue; Wang, Jing; Zhao, Yanyan; Teng, Wan; Shao, An; Zhao, Xueqiang; Ma, Wenying; Wang, Junyi; Li, Bin; Li, Zhensheng; Tong, Yiping

2015-02-01

Increasing fertilizer consumption has led to low fertilizer use efficiency and environmental problems. Identifying nutrient-efficient genes will facilitate the breeding of crops with improved fertilizer use efficiency. This research performed a genome-wide sequence analysis of the A (NFYA), B (NFYB), and C (NFYC) subunits of Nuclear Factor Y (NF-Y) in wheat (Triticum aestivum) and further investigated their responses to nitrogen and phosphorus availability in wheat seedlings. Sequence mining together with gene cloning identified 18 NFYAs, 34 NFYBs, and 28 NFYCs. The expression of most NFYAs positively responded to low nitrogen and phosphorus availability. In contrast, microRNA169 negatively responded to low nitrogen and phosphorus availability and degraded NFYAs. Overexpressing TaNFYA-B1, a low-nitrogen- and low-phosphorus-inducible NFYA transcript factor on chromosome 6B, significantly increased both nitrogen and phosphorus uptake and grain yield under differing nitrogen and phosphorus supply levels in a field experiment. The increased nitrogen and phosphorus uptake may have resulted from the fact that that overexpressing TaNFYA-B1 stimulated root development and up-regulated the expression of both nitrate and phosphate transporters in roots. Our results suggest that TaNFYA-B1 plays essential roles in root development and in nitrogen and phosphorus usage in wheat. Furthermore, our results provide new knowledge and valuable gene resources that should be useful in efforts to breed crops targeting high yield with less fertilizer input. © 2015 American Society of Plant Biologists. All Rights Reserved.

A Wheat CCAAT Box-Binding Transcription Factor Increases the Grain Yield of Wheat with Less Fertilizer Input1

PubMed Central

Qu, Baoyuan; He, Xue; Wang, Jing; Zhao, Yanyan; Teng, Wan; Shao, An; Zhao, Xueqiang; Ma, Wenying; Wang, Junyi; Li, Bin; Li, Zhensheng; Tong, Yiping

2015-01-01

Increasing fertilizer consumption has led to low fertilizer use efficiency and environmental problems. Identifying nutrient-efficient genes will facilitate the breeding of crops with improved fertilizer use efficiency. This research performed a genome-wide sequence analysis of the A (NFYA), B (NFYB), and C (NFYC) subunits of Nuclear Factor Y (NF-Y) in wheat (Triticum aestivum) and further investigated their responses to nitrogen and phosphorus availability in wheat seedlings. Sequence mining together with gene cloning identified 18 NFYAs, 34 NFYBs, and 28 NFYCs. The expression of most NFYAs positively responded to low nitrogen and phosphorus availability. In contrast, microRNA169 negatively responded to low nitrogen and phosphorus availability and degraded NFYAs. Overexpressing TaNFYA-B1, a low-nitrogen- and low-phosphorus-inducible NFYA transcript factor on chromosome 6B, significantly increased both nitrogen and phosphorus uptake and grain yield under differing nitrogen and phosphorus supply levels in a field experiment. The increased nitrogen and phosphorus uptake may have resulted from the fact that that overexpressing TaNFYA-B1 stimulated root development and up-regulated the expression of both nitrate and phosphate transporters in roots. Our results suggest that TaNFYA-B1 plays essential roles in root development and in nitrogen and phosphorus usage in wheat. Furthermore, our results provide new knowledge and valuable gene resources that should be useful in efforts to breed crops targeting high yield with less fertilizer input. PMID:25489021

Assessment of total nitrogen in the upper Connecticut River basin in New Hampshire, Vermont, and Massachusetts, December 2002-September 2005

USGS Publications Warehouse

Deacon, Jeffrey R.; Smith, Thor E.; Johnston, Craig M.; Moore, Richard B.; Blake, Laura J.; Weidman, Rebecca M.

2006-01-01

A study of total nitrogen concentrations and loads was conducted from December 2002 to September 2005 at 13 river sites in the upper Connecticut River Basin. Ten sites were selected to represent contributions of nitrogen from forested, agricultural, and urban land. Three sites were distributed spatially on the main stem of the Connecticut River to assess the cumulative total nitrogen loads. To further improve the understanding of the sources and concentrations and loads of total nitrogen in the upper Connecticut River Basin, ambient surface water-quality sampling was supplemented with sampling of effluent from 19 municipal and paper mill wastewater-treatment facilities. Mean concentrations of total nitrogen ranged from 0.19 to 2.8 milligrams per liter (mg/L) at river sampling sites. Instantaneous mean loads of total nitrogen ranged from 162 to 58,300 pounds per day (lb/d). Estimated mean annual loads of total nitrogen ranged from 49,100 to 21.6 million pounds per year (lb/yr) with about 30 to 55 percent of the loads being transported during the spring. The estimated mean annual yields of total nitrogen ranged from 1,190 to 7,300 pounds per square mile per year (lb/mi2)/yr. Mean concentrations of total nitrogen ranged from 4.4 to 30 mg/L at wastewater-treatment sampling sites. Instantaneous mean loads of total nitrogen from municipal wastewater-treatment facilities ranged from 36 to 1,780 lb/d. Instantaneous mean loads of total nitrogen from paper mill wastewater-treatment facilities ranged from 96 to 160 lb/d. The median concentration of total nitrogen was 0.24 mg/L at forested sites, 0.48 mg/L at agricultural sites, 0.54 mg/L at urban sites, 0.48 mg/L at main-stem sites, and 14 mg/L at wastewater-treatment sites. Concentrations of total nitrogen at forested sites were significantly less than at all other site types (p0.05) but were significantly greater (p<0.05) than at forested sites and significantly less than concentrations at wastewater-treatment sites (p<0.05). Total nitrogen concentrations at wastewater-treatment sites were significantly different from all other site types (p<0.05). Annual yields of total nitrogen ranged from 732 to 1,920 (lb/mi2)/yr at forested sites; 1,550 to 2,980 (lb/mi2)/yr at agricultural sites; 1,280 to 1,860 (lb/mi2)/yr at urban sites that were not directly affected by wastewater effluent; 7,090 to 7,770 (lb/mi2)/yr at an urban site directly affected by wastewater effluent; and 1,300 to 2,390 (lb/mi2)/yr at main-stem sites. In this study, the mean annual load and yield of total nitrogen at the Connecticut River at Wells River, VT, was estimated at 4.47 million lb/yr and 1,690 (lb/mi2)/yr, respectively. The mean annual load and yield of total nitrogen at the Connecticut River at North Walpole, NH, was estimated at 9.60 million lb/yr and 1,750 (lb/mi2)/yr, respectively. The mean annual load and yield of total nitrogen leaving the upper Connecticut River Basin, as estimated at the Connecticut River at Thompsonville, CT, was 21.6 million lb/yr and 2,230 (lb/mi2)/yr, respectively.

Spatial and Temporal Variations of Crop Fertilization and Soil Fertility in the Loess Plateau in China from the 1970s to the 2000s

PubMed Central

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

Water resources of Monroe County, New York, water years 2003-08: Streamflow, constituent loads, and trends in water quality

USGS Publications Warehouse

Hayhurst, Brett A.; Coon, William F.; Eckhardt, David A.V.

2010-01-01

This report, the sixth in a series published since 1994, presents analyses of hydrologic data in Monroe County for the period October 2002 through September 2008. Streamflows and water quality were monitored at nine sites by the Monroe County Department of Health and the U.S. Geological Survey. Streamflow yields (flow per unit area) were highest in Northrup Creek, which had sustained flows from year-round inflow from the village of Spencerport wastewater-treatment plant and seasonal releases from the New York State Erie (Barge) Canal. Genesee River streamflow yields also were high, at least in part, as a result of higher rainfall and lower evapotranspiration rates in the upper part of the Genesee River Basin than in the other study basins. The lowest streamflow yields were measured in Honeoye Creek, which reflected a decrease in flows due to the withdrawals from Hemlock and Canadice Lakes for the city of Rochester water supply. Water samples collected at nine monitoring sites were analyzed for nutrients, chloride, sulfate, and total suspended solids. The loads of constituents, which were computed from the concentration data and the daily flows recorded at each of the monitoring sites, are estimates of the mass of the constituents that was transported in the streamflow. Annual yields (loads per unit area) also were computed to assess differences in constituent transport among the study basins. All urban sites - Allen Creek and the two downstream sites on Irondequoit Creek - had seasonally high concentrations and annual yields of chloride. Chloride loads are attributed to the application of road-deicing salts to the county's roadways and are related to population and road densities. The less-urbanized sites in the study - Genesee River, Honeoye Creek, and Oatka Creek - had relatively low concentrations and yields of chloride. The highest concentrations and yields of sulfate were measured in Black Creek, Oatka Creek, and Irondequoit Creek at Railroad Mills and are attributable to dissolution of sulfate from gypsum (calcium sulfate) deposits in Silurian shale bedrock that crops out upstream from these monitoring sites. Northrup Creek had the highest concentrations of phosphorus, orthophosphate, and nitrogen, and high yields of nitrate plus nitrite nitrogen and ammonia plus organic nitrogen. These results are attributed to discharges from the Spencerport wastewater-treatment plant (which ceased operation in June 2008), diversions from the New York State Erie (Barge) Canal, and manure and fertilizers applied to agricultural fields. Concentrations and yields of nitrate plus nitrite nitrogen also were high in Oatka Creek and Black Creek; basins with substantial agricultural land uses. Allen Creek had the second highest yield of ammonia plus organic nitrogen. Honeoye Creek, which drains a relatively undeveloped basin, had the lowest yields of nitrogen constituents. The second highest median concentrations and highest sample concentrations of phosphorus and orthophosphate, as well as the highest phosphorus yields, were measured in the Genesee River. A comparison of the yields computed for the two downstream sites on Irondequoit Creek - above Blossom Road and at Empire Boulevard - permitted an assessment of the mitigative effects of the Ellison Park wetland on constituent loads, which would otherwise be transported to Irondequoit Bay. These effects also include those provided by a flow-control structure (installed mid-way through the wetland during February 1997), which was designed to increase the dispersal and short-term detention of stormflows in the wetland. The wetland decreased yields of particulate constituents - phosphorus and ammonia plus organic nitrogen - but had little effect on the yields of dissolved constituents - chloride, sulfate, and nitrate plus nitrite nitrogen. Trends in flow-adjusted concentrations were identified at all sites for most of the nutrient constituents that were evaluated. All of the linear time tren

[Effects of N application on wheat powdery mildew occurrence, nitrogen accumulation and allocation in intercropping system].

PubMed

Zhu, Jin Hui; Dong, Yan; Xiao, Jing Xiu; Zheng, Yi; Tang, Li

2017-12-01

The main objective of this field experiment was to study the effects of wheat and faba bean intercropping on occurrence of wheat powdery mildew, nitrogen content, accumulation and allocation of wheat plant at 4 nitrogen levels of N 0 (0 kg·hm -2 ), N 1 (112.5 kg·hm -2 ), N 2 (225 kg·hm -2 ), N 3 (337.5 kg·hm -2 ), and to explore the relationship between N content, accumulation, allocation and the occurrence of wheat powdery mildew. The results showed that both monocropped and intercropped wheat yields increased with nitrogen application, with the highest yields of monocropped and intercropped wheat being 4146 kg·hm -2 and 4679 kg·hm -2 at N 2 le-vel, respectively. The occurrence and development of wheat powdery mildew become more severe with the increase of N application and area under disease progression curve (AUDPC) were averagely increased by 39.6%-55.6%(calculated with disease incidence, DI) and 92.5%-217.0% (calculated with disease severity index, DSI) with N 1 , N 2 and N 3 treatments. The disease severity index was more affected by nitrogen regulation than by disease incidence. The nitrogen content and accumulation of wheat plant were significantly increased by 8.4%-51.6% and 19.7%-133.7% with nitrogen application, but there was no significant effect on N allocation ratio. Compared with monocropped wheat, yield of intercropped wheat was averagely increased by 12%, whereas, the AUDPC(DI) and AUDPC(DSI) of intercropped wheat were averagely decreased by 11.5% and 30.7%, respectively. The control effect of the disease severity index by intercropping was better than disease incidence. The nitrogen content, accumulation and nitrogen allocation ratio in intercropped wheat leaves were significantly decreased by 6.6%-12.5%, 1.4%-6.9% and 9.0%-15.5% respectively at the peak infection stage of powdery mildew. Overall findings showed that the maximum rate of nitrogen application for wheat should not exceed 225 kg·hm -2 when taking into account both disease control and yield effect.

Nitrogen removal in maturation waste stabilisation ponds via biological uptake and sedimentation of dead biomass.

PubMed

Camargo Valero, M A; Mara, D D; Newton, R J

2010-01-01

In this work a set of experiments was undertaken in a pilot-scale WSP system to determine the importance of organic nitrogen sedimentation on ammonium and total nitrogen removals in maturation ponds and its seasonal variation under British weather conditions, from September 2004 to May 2007. The nitrogen content in collected sediment samples varied from 4.17% to 6.78% (dry weight) and calculated nitrogen sedimentation rates ranged from 273 to 2868 g N/ha d. High ammonium removals were observed together with high concentrations of chlorophyll-a in the pond effluent. Moreover, chlorophyll-a had a very good correlation with the corresponding increment of VSS (algal biomass) and suspended organic nitrogen (biological nitrogen uptake) in the maturation pond effluents. Therefore, when ammonium removal reached its maximum, total nitrogen removal was very poor as most of the ammonia taken up by algae was washed out in the pond effluent in the form of suspended solids. After sedimentation of the dead algal biomass, it was clear that algal-cell nitrogen was recycled from the sludge layer into the pond water column. Recycled nitrogen can either be taken up by algae or washed out in the pond effluent. Biological (mainly algal) uptake of inorganic nitrogen species and further sedimentation of dead biomass (together with its subsequent mineralization) is one of the major mechanisms controlling in-pond nitrogen recycling in maturation WSP, particularly when environmental and operational conditions are favourable for algal growth.

Diagnostic yield and optimal duration of continuous-loop event monitoring for the diagnosis of palpitations. A cost-effectiveness analysis

NASA Technical Reports Server (NTRS)

Zimetbaum, P. J.; Kim, K. Y.; Josephson, M. E.; Goldberger, A. L.; Cohen, D. J.

1998-01-01

BACKGROUND: Continuous-loop event recorders are widely used for the evaluation of palpitations, but the optimal duration of monitoring is unknown. OBJECTIVE: To determine the yield, timing, and incremental cost-effectiveness of each week of event monitoring for palpitations. DESIGN: Prospective cohort study. PATIENTS: 105 consecutive outpatients referred for the placement of a continuous-loop event recorder for the evaluation of palpitations. MEASUREMENTS: Diagnostic yield, incremental cost, and cost-effectiveness for each week of monitoring. RESULTS: The diagnostic yield of continuous-loop event recorders was 1.04 diagnoses per patient in week 1, 0.15 diagnoses per patient in week 2, and 0.01 diagnoses per patient in week 3 and beyond. Over time, the cost-effectiveness ratio increased from $98 per new diagnosis in week 1 to $576 per new diagnosis in week 2 and $5832 per new diagnosis in week 3. CONCLUSIONS: In patients referred for evaluation of palpitations, the diagnostic yield of continuous-loop event recording decreases rapidly after 2 weeks of monitoring. A 2-week monitoring period is reasonably cost-effective for most patients and should be the standard period for continuous-loop event recording for the evaluation of palpitations.

Formation of nitrogen-containing compounds during microwave pyrolysis of microalgae: Product distribution and reaction pathways.

PubMed

Huang, Feng; Tahmasebi, Arash; Maliutina, Kristina; Yu, Jianglong

2017-12-01

The formation of nitrogen-containing compounds in bio-oil during microwave pyrolysis of Chlorella and Spirulina microalgae has been investigated in this study. Activated carbon (AC) and magnetite (Fe 3 O 4 ) were used as microwave receptors during microwave pyrolysis experiments. It has been found that the use of Fe 3 O 4 increased the total yield of bio-oil. The use of different microwave receptors did not seem to have affected the total yield of nitrogen-containing compounds in the bio-oil. However, Fe 3 O 4 promoted the formation of nitrogen-containing aliphatics, thereby reducing the formation of nitrogen-containing aromatics. The use of AC promoted the dehydration reactions during amino acid decomposition, thereby enhancing the formation of nitrogen-containing aromatics during pyrolysis. From the gas chromatography-mass spectrometry (GC-MS) analysis results, the major high-value nitrogen-containing compounds in the pyrolysis bio-oil of Chlorella and Spirulina were identified as indole and dodecamide. The formation mechanisms of nitrogen-containing compounds were proposed and discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of Nitrogen Rate and Planting Density for Improving Yield, Nitrogen Use Efficiency, and Lodging Resistance in Oilseed Rape

PubMed Central

Khan, Shahbaz; Anwar, Sumera; Kuai, Jie; Ullah, Sana; Fahad, Shah; Zhou, Guangsheng

2017-01-01

Yield and lodging related traits are essential for improving rapeseed production. The objective of the present study was to investigate the influence of plant density (D) and nitrogen (N) rates on morphological and physiological traits related to yield and lodging in rapeseed. We evaluated Huayouza 9 for two consecutive growing seasons (2014–2016) under three plant densities (LD, 10 plants m−2; MD, 30 plants m−2; HD, 60 plants m−2) and four N rates (0, 60, 120, and 180 kg ha−1). Experiment was laid out in split plot design using density as a main factor and N as sub-plot factor with three replications each. Seed yield was increased by increasing density and N rate, reaching a peak at HD with 180 kg N ha−1. The effect of N rate was consistently positive in increasing the plant height, pod area index, 1,000 seed weight, shoot and root dry weights, and root neck diameter, reaching a peak at 180 kg N ha−1. Plant height was decreased by increasing D, whereas the maximum radiation interception (~80%) and net photosynthetic rate were recorded at MD at highest N. Lodging resistance and nitrogen use efficiency significantly increased with increasing D from 10 to 30 plants m−2, and N rate up to 120 kg ha−1, further increase of D and N decreased lodging resistance and NUE. Hence, our study implies that planting density 30 plants m−2 can improve yield, nitrogen use efficiency, and enhance lodging resistance by improving crop canopy. PMID:28536581

Maximum soil organic carbon storage in Midwest U.S. cropping systems when crops are optimally nitrogen-fertilized

USDA-ARS?s Scientific Manuscript database

Nitrogen fertilizer is critical to optimize short-term crop yield, but its long-term effect on soil organic C (SOC) is actively debated. Using 60 site-years of maize (Zea mays L.) yield response to a wide range of N fertilizer rates in continuous maize and annually rotated maize-soybean [Glycine max...

Effects of land-applied ammonia scrubber solutions on yield, nitrogen uptake, soil test phosphorus and phosphorus runoff

USDA-ARS?s Scientific Manuscript database

Ammonia (NH3) scrubbers reduce amounts of NH3 and dust released from animal rearing facilities, while generating nitrogen (N) rich solutions, which may be used as fertilizer. The objective of this study was to determine the effects of various NH3 scrubber solutions on yields, N uptake by forage, so...

Water-quality characteristics in runoff for three discovery farms in North Dakota, 2008-12

USGS Publications Warehouse

Nustad, Rochelle A.; Rowland, Kathleen M.; Wiederholt, Ronald

2015-01-01

Consistent patterns in water quality emerged at each individual farm, but similarities among farms also were observed. Suspended sediment, total phosphorus, and ammonia concentrations generally decreased downstream from feeding areas, and were primarily affected by surface runoff processes such as dilution, settling out of sediment, or vegetative uptake. Because surface runoff affects these constituents, increased annual surface runoff volume tended to result in increased loads and yields. No significant change in nitrate plus nitrite concentration were observed downstream from feeding areas because additional processes such as high solubility, nitrification, denitrification, and surface-groundwater interaction affect nitrate plus nitrite. For nitrate plus nitrite, increases in annual runoff volume did not consistently relate to increases in annual loads and yields. It seems that temporal distribution of precipitation and surface-groundwater interaction affected nitrate plus nitrite loads and yields. For surface drainage sites, the primary form of nitrogen was organic nitrogen whereas for subsurface drainage sites, the primary form of nitrogen was nitrate plus nitrite nitrogen.

Farmland-atmosphere feedbacks amplify decreases in diffuse nitrogen pollution in a freeze-thaw agricultural area under climate warming conditions.

PubMed

Gao, Xiang; Ouyang, Wei; Hao, Zengchao; Shi, Yandan; Wei, Peng; Hao, Fanghua

2017-02-01

Although climate warming and agricultural land use changes are two of the primary instigators of increased diffuse pollution, they are usually considered separately or additively. This likely lead to poor decisions regarding climate adaptation. Climate warming and farmland responses have synergistic consequences for diffuse nitrogen pollution, which are hypothesized to present different spatio-temporal patterns. In this study, we propose a modeling framework to simulate the synergistic impacts of climate warming and warming-induced farmland shifts on diffuse pollution. Active accumulated temperature response for latitudinal and altitudinal directions was predicted based on a simple agro-climate model under different temperature increments (△T 0 is from 0.8°C to 1.4°C at an interval of 0.2°C). Spatial distributions of dryland shift to paddy land were determined by considering accumulated temperature. Different temperature increments and crop distributions were inserted into Soil and Water Assessment Tool model, which quantified the spatio-temporal changes of nitrogen. Warming led to a decrease of the annual total nitrogen loading (2.6%-14.2%) in the low latitudes compared with baseline, which was larger than the decrease (0.8%-6.2%) in the high latitudes. The synergistic impacts amplified the decrease of the loading in the low and high latitudes at the sub-basin scale. Warming led to a decrease of the loading at a rate of 0.35kg/ha/°C, which was lower than the synergistic impacts (3.67kg/ha/°C) at the watershed level. However, warming led to the slight increase of the annual averaged NO3 (LAT) (0.16kg/ha/°C), which was amplified by the synergistic impacts (0.22kg/ha/°C). Expansion of paddy fields led to a decrease in the monthly total nitrogen loading throughout the year, but amplified an increase in the loading in August and September. The decreased response in spatio-temporal nitrogen patterns is substantially amplified by farmland-atmosphere feedbacks associated with farmland shifts in response to warming. Copyright © 2016 Elsevier B.V. All rights reserved.

Occurrence, distribution, and transport of nutrients in Eastern Iowa Rivers

USGS Publications Warehouse

Becher, Kent D.

2001-01-01

Total nitrogen loads contributed to the Mississippi River from the Eastern Iowa Basins during 1996, 1997, and 1998 were 97,000, 120,000, and 230,000 metric tons respectively. Total phosphorus loads contributed to the Mississippi River from the Eastern Iowa Basins during 1996, 1997, and 1998 were 6,900, 4,600, and 8,800 metric tons, respectively. The highest nitrogen and phosphorus yields typically occurred in streams draining small watersheds that were dominated by a single land use and geology. Sampling sites located in drainage basins with higher row-crop percentage typically had higher nitrogen and phosphorus yields. Sites that were located in the Des Moines Lobe and the Southern Iowa Drift Plain typically had higher phosphorus yields probably due to more erodible soils and steeper slopes.

The incremental impact of cardiac MRI on clinical decision-making.

PubMed

Rajwani, Adil; Stewart, Michael J; Richardson, James D; Child, Nicholas M; Maredia, Neil

2016-01-01

Despite a significant expansion in the use of cardiac MRI (CMR), there is inadequate evaluation of its incremental impact on clinical decision-making over and above other well-established modalities. We sought to determine the incremental utility of CMR in routine practice. 629 consecutive CMR studies referred by 44 clinicians from 9 institutions were evaluated. Pre-defined algorithms were used to determine the incremental influence on diagnostic thinking, influence on clinical management and thus the overall clinical utility. Studies were also subdivided and evaluated according to the indication for CMR. CMR provided incremental information to the clinician in 85% of cases, with incremental influence on diagnostic thinking in 85% of cases and incremental impact on management in 42% of cases. The overall incremental utility of CMR exceeded 90% in 7 out of the 13 indications, whereas in settings such as the evaluation of unexplained ventricular arrhythmia or mild left ventricular systolic dysfunction, this was <50%. CMR was frequently able to inform and influence decision-making in routine clinical practice, even with analyses that accepted only incremental clinical information and excluded a redundant duplication of imaging. Significant variations in yield were noted according to the indication for CMR. These data support a wider integration of CMR services into cardiac imaging departments. These data are the first to objectively evaluate the incremental value of a UK CMR service in clinical decision-making. Such data are essential when seeking justification for a CMR service.

Water and Temperature Stresses Impact Canola (Brassica napus L.) Fatty Acid, Protein, and Yield over Nitrogen and Sulfur.

PubMed

Hammac, W Ashley; Maaz, Tai M; Koenig, Richard T; Burke, Ian C; Pan, William L

2017-12-06

Interactive effects of weather and soil nutrient status often control crop productivity. An experiment was conducted to determine effects of nitrogen (N) and sulfur (S) fertilizer rate, soil water, and atmospheric temperature on canola (Brassica napus L.) fatty acid (FA), total oil, protein, and grain yield. Nitrogen and sulfur were assessed in a 4-yr study with two locations, five N rates (0, 45, 90, 135, and 180 kg ha -1 ), and two S rates (0 and 17 kg ha -1 ). Water and temperature were assessed using variability across 12 site-years of dryland canola production. Effects of N and S were inconsistent. Unsaturated FA, oleic acid, grain oil, protein, and theoretical maximum grain yield were highly related to water and temperature variability across the site-years. A nonlinear model identified water and temperature conditions that enabled production of maximum unsaturated FA content, oleic acid content, total oil, protein, and theoretical maximum grain yield. Water and temperature variability played a larger role than soil nutrient status on canola grain constituents and yield.

Genomic regions associated with the nitrogen limitation response revealed in a global wheat core collection.

PubMed

Bordes, Jacques; Ravel, C; Jaubertie, J P; Duperrier, B; Gardet, O; Heumez, E; Pissavy, A L; Charmet, G; Le Gouis, J; Balfourier, F

2013-03-01

Modern wheat (Triticum aestivum L.) varieties in Western Europe have mainly been bred, and selected in conditions where high levels of nitrogen-rich fertilizer are applied. However, high input crop management has greatly increased the risk of nitrates leaching into groundwater with negative impacts on the environment. To investigate wheat nitrogen tolerance characteristics that could be adapted to low input crop management, we supplied 196 accessions of a wheat core collection of old and modern cultivars with high or moderate amounts of nitrogen fertilizer in an experimental network consisting of three sites and 2 years. The main breeding traits were assessed including grain yield and grain protein content. The response to nitrogen level was estimated for grain yield and grain number per m(2) using both the difference and the ratio between performance at the two input levels and the slope of joint regression. A large variability was observed for all the traits studied and the response to nitrogen level. Whole genome association mapping was carried out using 899 molecular markers taking into account the five ancestral group structure of the collection. We identified 54 main regions involving almost all chromosomes that influence yield and its components, plant height, heading date and grain protein concentration. Twenty-three regions, including several genes, spread over 16 chromosomes were involved in the response to nitrogen level. These chromosomal regions may be good candidates to be used in breeding programs to improve the performance of wheat varieties at moderate nitrogen input levels.

Genetic and agronomic assessment of cob traits in corn under low and normal nitrogen management conditions.

PubMed

Jansen, Constantin; Zhang, Yongzhong; Liu, Hongjun; Gonzalez-Portilla, Pedro J; Lauter, Nick; Kumar, Bharath; Trucillo-Silva, Ignacio; Martin, Juan Pablo San; Lee, Michael; Simcox, Kevin; Schussler, Jeff; Dhugga, Kanwarpal; Lübberstedt, Thomas

2015-07-01

Exploring and understanding the genetic basis of cob biomass in relation to grain yield under varying nitrogen management regimes will help breeders to develop dual-purpose maize. With rising energy demands and costs for fossil fuels, alternative energy from renewable sources such as maize cobs will become competitive. Maize cobs have beneficial characteristics for utilization as feedstock including compact tissue, high cellulose content, and low ash and nitrogen content. Nitrogen is quantitatively the most important nutrient for plant growth. However, the influence of nitrogen fertilization on maize cob production is unclear. In this study, quantitative trait loci (QTL) have been analyzed for cob morphological traits such as cob weight, volume, length, diameter and cob tissue density, and grain yield under normal and low nitrogen regimes. 213 doubled-haploid lines of the intermated B73 × Mo17 (IBM) Syn10 population have been resequenced for 8575 bins, based on SNP markers. A total of 138 QTL were found for six traits across six trials using composite interval mapping with ten cofactors and empirical comparison-wise thresholds (P = 0.001). Despite moderate to high repeatabilities across trials, few QTL were consistent across trials and overall levels of explained phenotypic variance were lower than expected some of the cob trait × trial combinations (R (2) = 7.3-43.1 %). Variation for cob traits was less affected by nitrogen conditions than by grain yield. Thus, the economics of cob usage under low nitrogen regimes is promising.

Effects of nitrogen fertilizer application on greenhouse gas emissions and economics of corn production.

PubMed

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.

Study on the effect of magnetic field treatment of newly isolated Paenibacillus sp.

PubMed

Li, Jie; Yi, Yanli; Cheng, Xilei; Zhang, Dageng; Irfan, Muhammad

2015-12-01

Symbiotic nitrogen fixation in plants occurs in roots with the help of some bacteria which help in soil nitrogen fertility management. Isolation of significant environment friendly bacteria for nitrogen fixation is very important to enhance yield in plants. In this study effect of different magnetic field intensity and treatment time was studied on the morphology, physiology and nitrogen fixing capacity of newly isolated Paenibaccilus sp. from brown soil. The bacterium was identified by 16S rDNA sequence having highest similarity (99%) with Paenibacillus sp as revealed by BLAST. Different magnetic intensities such as 100mT, 300mT and 500mT were applied with processing time of 0, 5, 10, 20 and 30 minutes. Of all these treatment 300mT with processing time of 10 minutes was found to be most suitable treatment. Results revealed that magnetic treatment improve the growth rate with shorter generation time leading to increased enzyme activities (catalase, peroxidase and superoxide dismutase) and nitrogen fixing efficiencies. High magnetic field intensity (500mT) caused ruptured cell morphology and decreased enzyme activities which lead to less nitrogen fixation. It is concluded that appropriate magnetic field intensity and treatment time play a vital role in the growth of soil bacteria which increases the nitrogen fixing ability which affects the yield of plant. These results were very helpful in future breading programs to enhance the yield of soybean.

Tracing the evolutionary path to nitrogen-fixing crops.

PubMed

Delaux, Pierre-Marc; Radhakrishnan, Guru; Oldroyd, Giles

2015-08-01

Nitrogen-fixing symbioses between plants and bacteria are restricted to a few plant lineages. The plant partner benefits from these associations by gaining access to the pool of atmospheric nitrogen. By contrast, other plant species, including all cereals, rely only on the scarce nitrogen present in the soil and what they can glean from associative bacteria. Global cereal yields from conventional agriculture are dependent on the application of massive levels of chemical fertilisers. Engineering nitrogen-fixing symbioses into cereal crops could in part mitigate the economic and ecological impacts caused by the overuse of fertilisers and provide better global parity in crop yields. Comparative phylogenetics and phylogenomics are powerful tools to identify genetic and genomic innovations behind key plant traits. In this review we highlight recent discoveries made using such approaches and we discuss how these approaches could be used to help direct the engineering of nitrogen-fixing symbioses into cereals. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Use of collagen hydrolysate as a complex nitrogen source for the synthesis of penicillin by Penicillium chrysogenum.

PubMed

Leonhartsberger, S; Lafferty, R M; Korneti, L

1993-09-01

Optimal conditions for both biomass formation and penicillin synthesis by a strain of Penicillium chrysogenum were determined when using a collagen-derived nitrogen source. Preliminary investigations were carried out in shaken flask cultures employing a planned experimental program termed the Graeco-Latin square technique (Auden et al., 1967). It was initially determined that up to 30% of a conventional complex nitrogen source such as cottonseed meal could be replaced by the collagen-derived nitrogen source without decreasing the productivity with respect to the penicillin yield. In the pilot scale experiments using a 30 l stirred tank type of bioreactor, higher penicillin yields were obtained when 70% of the conventional complex nitrogen source in the form of cottonseed meal was replaced by the collagen hydrolysate. Furthermore, the maximum rate of penicillin synthesis continued for over a longer period when using collagen hydrolysate as a complex nitrogen source. Penicillin synthesis rates were determined using a linear regression.

Active sensing: An innovative tool for evaluating grain yield and nitrogen use efficiency of multiple wheat genotypes

NASA Astrophysics Data System (ADS)

Naser, Mohammed Abdulridha

Precision agricultural practices have significantly contributed to the improvement of crop productivity and profitability. Remote sensing based indices, such as Normalized Difference Vegetative Index (NDVI) have been used to obtain crop information. It is used to monitor crop development and to provide rapid and nondestructive estimates of plant biomass, nitrogen (N) content and grain yield. Remote sensing tools are helping improve nitrogen use efficiency (NUE) through nitrogen management and could also be useful for high NUE genotype selection. The objectives of this study were: (i) to determine if active sensor based NDVI readings can differentiate wheat genotypes, (ii) to determine if NDVI readings can be used to classify wheat genotypes into grain yield productivity classes, (iii) to identify and quantify the main sources of variation in NUE across wheat genotypes, and (iv) to determine if normalized difference vegetation index (NDVI) could characterize variability in NUE across wheat genotypes. This study was conducted in north eastern Colorado for two years, 2010 and 2011. The NDVI readings were taken weekly during the winter wheat growing season from March to late June, in 2010 and 2011 and NUE were calculated as partial factor productivity and as partial nitrogen balance at the end of the season. For objectives i and ii, the correlation between NDVI and grain yield was determined using Pearson's product-moment correlation coefficient (r) and linear regression analysis was used to explain the relationship between NDVI and grain yield. The K-means clustering algorithm was used to classify mean NDVI and mean grain yield into three classes. For objectives iii and iv, the parameters related to NUE were also calculated to measure their relative importance in genotypic variation of NUE and power regression analysis between NDVI and NUE was used to characterize the relationship between NDVI and NUE. The results indicate more consistent association between grain yield and NDVI and between NDVI and NUE later in the season, after anthesis and during mid-grain filling stage under dryland and a poor association in wheat grown in irrigated conditions. The results suggest that below saturation of NDVI values (about 0.9), (i.e. prior to full canopy closure and after the beginning of senescence or most of the season under dryland conditions) NDVI could assess grain yield and NUE. The results also indicate that nitrogen uptake efficiency was the main source of variation of NUE among genotypes grown in site-years with lower yield. Overall, results from this study demonstrate that NDVI readings successfully classified wheat genotypes into grain yield classes across dryland and irrigated conditions and characterized variability in NUE across wheat genotypes.

Retardation effect of nitrogen compounds and condensed aromatics on shale oil catalytic cracking processing and their characterization.

PubMed

Li, Nan; Chen, Chen; Wang, Bin; Li, Shaojie; Yang, Chaohe; Chen, Xiaobo

Untreated shale oil, shale oil treated with HCl aqueous solution and shale oil treated with HCl and furfural were used to do comparative experiments in fixed bed reactors. Nitrogen compounds and condensed aromatics extracted by HCl and furfural were characterized by electrospray ionization Fourier transform cyclotron resonance mass spectrometry and gas chromatography and mass spectrometry, respectively. Compared with untreated shale oil, the conversion and yield of liquid products increased considerably after removing basic nitrogen compounds by HCl extraction. Furthermore, after removing nitrogen compounds and condensed aromatics by both HCl and furfural, the conversion and yield of liquid products further increased. In addition, N 1 class species are predominant in both basic and non-basic nitrogen compounds, and they are probably indole, carbazole, cycloalkyl-carbazole, pyridine and cycloalkyl-pyridine. As for the condensed aromatics, most of them possess aromatic rings with two to three rings and zero to four carbon atom.

Coordinated response of photosynthesis, carbon assimilation, and triacylglycerol accumulation to nitrogen starvation in the marine microalgae Isochrysis zhangjiangensis (Haptophyta).

PubMed

Wang, Hai-Tao; Meng, Ying-Ying; Cao, Xu-Peng; Ai, Jiang-Ning; Zhou, Jian-Nan; Xue, Song; Wang, Wei-liang

2015-02-01

The photosynthetic performance, carbon assimilation, and triacylglycerol accumulation of Isochrysis zhangjiangensis under nitrogen-deplete conditions were studied to understand the intrinsic correlations between them. The nitrogen-deplete period was divided into two stages based on the photosynthetic parameters. During the first stage, carbon assimilation was not reduced compared with that under favorable conditions. The marked increase in triacylglycerols and the variation in the fatty acid profile suggested that triacylglycerols were mainly derived from de novo synthesized acyl groups. In the second stage, the triacylglycerol content continued increasing while the carbohydrate content decreased from 44.0% to 26.3%. These results indicated that the intracellular conversion of carbohydrates to triacylglycerols occurred. Thus, we propose that sustainable carbon assimilation and incremental triacylglycerol production can be achieved by supplying appropriate amounts of nitrogen in medium to protect the photosynthetic process from severe damage using the photosynthetic parameters as indicators. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stable isotope time series and dentin increments elucidate Pleistocene proboscidean paleobiology

NASA Astrophysics Data System (ADS)

Fisher, Daniel; Rountrey, Adam; Smith, Kathlyn; Fox, David

2010-05-01

Investigations of stable isotope composition of mineralized tissues have added greatly to our knowledge of past climates and dietary behaviors of organisms, even when they are implemented through 'bulk sampling', in which a single assay yields a single, time-averaged value. Likewise, the practice of 'sclerochronology', which documents periodic structural increments comprising a growth record for accretionary tissues, offers insights into rates of growth and age data at a scale of temporal resolution permitted by the nature of structural increments. We combine both of these approaches to analyze dental tissues of late Pleistocene proboscideans. Tusk dentin typically preserves a record of accretionary growth consisting of histologically distinct increments on daily, approximately weekly, and yearly time scales. Working on polished transverse or longitudinal sections, we mill out a succession of temporally controlled dentin samples bounded by clear structural increments with a known position in the sequence of tusk growth. We further subject each sample (or an aliquot thereof) to multiple compositional analyses - most frequently to assess δ18O and δ13C of hydroxyapatite carbonate, and δ13C and δ15N of collagen. This yields, for each animal and each series of years investigated, a set of parallel compositional time series with a temporal resolution of 1-2 months (or finer if we need additional precision). Patterns in variation of thickness of periodic sub-annual increments yield insight into intra-annual and inter-annual variation of tusk growth rate. This is informative even by itself, but it is still more valuable when coupled with compositional time series. Further, the controls on different stable isotope systems are sufficiently different that the data ensemble yields 'much more than the sum of its parts.' By assessing how compositions and growth rates covary, we monitor with greater confidence changes in local climate, diet, behavior, and health status. We illustrate the potential of this approach with case studies that reveal: season of birth and age of weaning in juvenile mammoths; age of maturation in male mastodons; season of musth in mammoths and mastodons; and season of death and tests of simultaneity of death in mammoths and mastodons. The data provided by histological and stable isotope analyses rarely reveal cause of death directly, but they can, in concert with other observations, affect perceptions of the likelihood of competing interpretations of cause of death. Most important, paleobiological inferences based on these studies can be integrated over broad geographic and temporal scales to show how specific paleobiological traits changed through time, prior to extinction. These studies have great power for investigating causes of extinction because contrasting patterns of change are expected under different hypothesized drivers of extinction.

Leaf nitrogen remobilisation for plant development and grain filling.

PubMed

Masclaux-Daubresse, C; Reisdorf-Cren, M; Orsel, M

2008-09-01

A major challenge of modern agriculture is to reduce the excessive input of fertilisers and, at the same time, to improve grain quality without affecting yield. One way to achieve this goal is to improve plant nitrogen economy through manipulating nitrogen recycling, and especially nitrogen remobilisation, from senescing plant organs. In this review, the contribution of nitrogen remobilisation efficiency (NRE) to global nitrogen use efficiency (NUE), and tools dedicated to the determination of NRE are described. An overall examination of the physiological, metabolic and genetic aspects of nitrogen remobilisation is presented.

Ionic composition and nitrate in drainage water from fields fertilized with different nitrogen sources, middle swamp watershed, North Carolina, August 2000-August 2001

USGS Publications Warehouse

Harden, Stephen L.; Spruill, Timothy B.

2004-01-01

A study was conducted from August 2000 to August 2001 to characterize the influence of fertilizer use from different nitrogen sources on the quality of drainage water from 11 subsurface tile drains and 7 surface field ditches in a North Carolina Coastal Plain watershed. Agricultural fields receiving commercial fertilizer (conventional sites), swine lagoon effluent (spray sites), and wastewater-treatment plant sludge (sludge site) in the Middle Swamp watershed were investigated. The ionic composition of drainage water in tile drains and ditches varied depending on fertilizer source type. The dominant ions identified in water samples from tile drains and ditches include calcium, magnesium, sodium, chloride, nitrate, and sulfate, with tile drains generally having lower pH, low or no bicarbonates, and higher nitrate and chloride concentrations. Based on fertilizer source type, median nitrate-nitrogen concentrations were significantly higher at spray sites (32.0 milligrams per liter for tiles and 8.2 milligrams per liter for ditches) relative to conventional sites (6.8 milligrams per liter for tiles and 2.7 milligrams per liter for ditches). The median instantaneous nitrate-nitrogen yields also were significantly higher at spray sites (420 grams of nitrogen per hectare per day for tile drains and 15.6 grams of nitrogen per hectare per day for ditches) relative to conventional sites (25 grams of nitrogen per hectare per day for tile drains and 8.1 grams of nitrogen per hectare per day for ditches). The tile drain site where sludge is applied had a median nitrate-nitrogen concentration of 10.5 milligrams per liter and a median instantaneous nitrate-nitrogen yield of 93 grams of nitrogen per hectare per day, which were intermediate to those of the conventional and spray tile drain sites. Results from this study indicate that nitrogen loadings and subsequent edge-of-field nitrate-nitrogen yields through tile drains and ditches were significantly higher at sites receiving applications of swine lagoon effluent compared to sites receiving commercial fertilizer.

Foliar nitrogen content and tree growth after prescribed fire in ponderosa pine.

Treesearch

J.D. Landsberg; P.H. Cochran; M.M. Finck; R.E. Martin

1984-01-01

This initial study of prescribed burning in ponderosa pine (Pinus ponderosa Doug. ex Laws.) stands in central Oregon showed that all periodic annual growth increments were reduced for trees alive four growing seasons later. Height growth was reduced 8 percent in areas burned by fires with moderate fuel consumption and 18 percent in areas with high...

Biomass and Nutrient Accumulation in a Cottonwood Plantation - The First Four Years

Treesearch

John K. Francis; James B. Baker

1981-01-01

For the first 4 years, height increment of an eastern cottonwood plantation on a clayey soil was greatest in the first growing season; diameter growth was greatest in the second growing season; and annual production of biomass was greatest in the third year. Nitrogen, phosphorus, and possibly magnesium are translocated from leaves into bark and other tissue before leaf...

Bounding salt marsh nitrogen fluxes: development of an ecohydrological salt marsh model

EPA Science Inventory

A mass-balance approach to characterize nitrogen flux in a 2-hectare, meso-haline saltmarsh yielded extensive flow and water chemistry data. However, a significant, unevenly distributed population of the nitrogen fixer Alnus rubra (red alder) in the 20-hectare upland catchment l...

Why the different responses between single and split nitrogen applications?

USDA-ARS?s Scientific Manuscript database

Split- opposed to single-nitrogen applications may improve corn (Zea mays L.) production, N use efficiency, and lessen environmental impacts due to fertilization. However, there has been an inconsistent response of yield, plant nitrogen (N) uptake, and residual soil nitrates (RSN) when comparing sin...

Basal area growth, carbon isotope discrimination, and intrinsic ...

EPA Pesticide Factsheets

Many hectares of intensively managed Douglas-fir (Pseudotsuga menziesii Mirb. Franco) stands in western North America are fertilized with nitrogen to increase growth rates. Understanding the mechanisms of response facilitates prioritization of stands for treatment. The objective of this study was to test the hypothesis that the short-term basal area growth response to a single application of 224 kg N ha-1 as urea was associated with reduced stable carbon isotope discrimination (∆13C) and increased intrinsic water use efficiency (iWUE) in a 20-yr-old plantation of Douglas-fir in the Oregon Coast Range, USA. Increment cores were measured to estimate earlywood, latewood, and total basal area increment over a time series from 1997 to 2015. Stable carbon isotope discrimination and iWUE were estimated using earlywood and latewood stable carbon isotope concentrations in tree-ring holocellulose starting seven years before fertilization in early 2009 and ending seven years after treatment. A highly significant interaction effect between fertilization treatment and year was found for total basal area growth and earlywood basal area increment. Fertilized trees showed significant total basal area growth and earlywood basal area increment in the first (2009) and second (2010) growing seasons after fertilization in 2009. A marginally significant fertilization effect was found for latewood basal area increment only in the first growing season after treatment. A significant i

A multi-environmental study of recent breeding progress on nitrogen use efficiency in wheat (Triticum aestivum L.).

PubMed

Cormier, Fabien; Faure, Sébastien; Dubreuil, Pierre; Heumez, Emmanuel; Beauchêne, Katia; Lafarge, Stéphane; Praud, Sébastien; Le Gouis, Jacques

2013-12-01

By comparing 195 varieties in eight trials, this study assesses nitrogen use efficiency improvement in high and low nitrogen conditions in European winter wheat over the last 25 years. In a context where European agriculture practices have to deal with environmental concerns and nitrogen (N) fertiliser cost, nitrogen use efficiency (NUE) has to be improved. This study assessed genetic progress in winter wheat (Triticum aestivum L.) NUE. Two hundred and twenty-five European elite varieties were tested in four environments under two levels of N. Global genetic progress was assessed on additive genetic values and on genotype × N interaction, covering 25 years of European breeding. To avoid sampling bias, quality, precocity and plant height were added as covariates in the analyses when needed. Genotype × environment interactions were highly significant for all the traits studied to such an extent that no additive genetic effect was detected on N uptake. Genotype × N interactions were significant for yield, grain protein content (GPC), N concentration in straw, N utilisation, and NUE. Grain yield improvement (+0.45 % year(-1)) was independent of the N treatment. GPC was stable, thus grain nitrogen yield was improved (+0.39 % year(-1)). Genetic progress on N harvest index (+0.12 % year(-1)) and on N concentration in straw (-0.52 % year(-1)) possibly revealed improvement in N remobilisation. There has been an improvement of NUE additive genetic value (+0.33 % year(-1)) linked to better N utilisation (+0.20 % year(-1)). Improved yield stability was detected as a significant improvement of NUE in low compared to high N conditions. The application of these results to breeding programs is discussed.

Heterologous Expression of ATG8c from Soybean Confers Tolerance to Nitrogen Deficiency and Increases Yield in Arabidopsis

PubMed Central

Liu, Dong; Chai, Wenting; Gong, Qingqiu; Wang, Ning Ning

2012-01-01

Nitrogen is an essential element for plant growth and yield. Improving Nitrogen Use Efficiency (NUE) of crops could potentially reduce the application of chemical fertilizer and alleviate environmental damage. To identify new NUE genes is therefore an important task in molecular breeding. Macroautophagy (autophagy) is an intracellular process in which damaged or obsolete cytoplasmic components are encapsulated in double membraned vesicles termed autophagosomes, then delivered to the vacuole for degradation and nutrient recycling. One of the core components of autophagosome formation, ATG8, has been shown to directly mediate autophagosome expansion, and the transcript of which is highly inducible upon starvation. Therefore, we postulated that certain homologs of Saccharomyces cerevisiae ATG8 (ScATG8) from crop species could have potential for NUE crop breeding. A soybean (Glycine max, cv. Zhonghuang-13) ATG8, GmATG8c, was selected from the 11 family members based on transcript analysis upon nitrogen deprivation. GmATG8c could partially complement the yeast atg8 mutant. Constitutive expression of GmATG8c in soybean callus cells not only enhanced nitrogen starvation tolerance of the cells but accelerated the growth of the calli. Transgenic Arabidopsis over-expressing GmATG8c performed better under extended nitrogen and carbon starvation conditions. Meanwhile, under optimum growth conditions, the transgenic plants grew faster, bolted earlier, produced larger primary and axillary inflorescences, eventually produced more seeds than the wild-type. In average, the yield was improved by 12.9%. We conclude that GmATG8c may serve as an excellent candidate for breeding crops with enhanced NUE and better yield. PMID:22629371

Grey water footprint reduction in irrigated crop production: effect of nitrogen application rate, nitrogen form, tillage practice and irrigation strategy

NASA Astrophysics Data System (ADS)

Chukalla, Abebe D.; Krol, Maarten S.; Hoekstra, Arjen Y.

2018-06-01

Grey water footprint (WF) reduction is essential given the increasing water pollution associated with food production and the limited assimilation capacity of fresh water. Fertilizer application can contribute significantly to the grey WF as a result of nutrient leaching to groundwater and runoff to streams. The objective of this study is to explore the effect of the nitrogen application rate (from 25 to 300 kg N ha-1), nitrogen form (inorganic N or manure N), tillage practice (conventional or no-tillage) and irrigation strategy (full or deficit irrigation) on the nitrogen load to groundwater and surface water, crop yield and the N-related grey water footprint of crop production by a systematic model-based assessment. As a case study, we consider irrigated maize grown in Spain on loam soil in a semi-arid environment, whereby we simulate the 20-year period 1993-2012. The water and nitrogen balances of the soil and plant growth at the field scale were simulated with the Agricultural Policy Environmental eXtender (APEX) model. As a reference management package, we assume the use of inorganic N (nitrate), conventional tillage and full irrigation. For this reference, the grey WF at a usual N application rate of 300 kg N ha-1 (with crop yield of 11.1 t ha-1) is 1100 m3 t-1, which can be reduced by 91 % towards 95 m3 t-1 when the N application rate is reduced to 50 kg N ha-1 (with a yield of 3.7 t ha-1). The grey WF can be further reduced to 75 m3 t-1 by shifting the management package to manure N and deficit irrigation (with crop yield of 3.5 t ha-1). Although water pollution can thus be reduced dramatically, this comes together with a great yield reduction, and a much lower water productivity (larger green plus blue WF) as well. The overall (green, blue and grey) WF per tonne is found to be minimal at an N application rate of 150 kg N ha-1, with manure, no-tillage and deficit irrigation (with crop yield of 9.3 t ha-1). The paper shows that there is a trade-off between grey WF and crop yield, as well as a trade-off between reducing water pollution (grey WF) and water consumption (green and blue WF). Applying manure instead of inorganic N and deficit instead of full irrigation are measures that reduce both water pollution and water consumption with a 16 % loss in yield.

Influence of hydration and annealing on structure, PSL yield and spatial resolution of pressed powder imaging plates of the X-ray storage phosphor CsBr:Eu2+

NASA Astrophysics Data System (ADS)

Kersting, E.; von Seggern, H.

2017-08-01

A new production route for europium doped cesium bromide (CsBr:Eu2+) imaging plates has been developed, synthesizing CsBr:Eu2+ powder from a precipitation reaction of aqueous CsBr solution with ethanol. This new route allows the control of features like homogeneous grain size and grain shape of the obtained powder. After drying and subsequent compacting the powder, disk-like samples were fabricated, and their resulting photostimulated luminescence (PSL) properties like yield and spatial resolution were determined. It will be shown that hydration of such disks causes the CsBr:Eu2+ powder to recrystallize starting from the humidity exposed surfaces to the sample interior up to a completely polycrystalline sample resulting in a decreasing PSL yield and an increasing resolution. Subsequent annealing leads to grain refinement combined with a large PSL yield increment and a minor effect on the spatial resolution. By first annealing the "as made" disk, one observes a strong increment of the PSL yield and almost no effect on the spatial resolution. During subsequent hydration, the recrystallization is hindered by minor structural changes of the grains. The related PSL yield drops slightly with increasing hydration time, and the spatial resolution drops considerably. The obtained PSL properties with respect to structure will be discussed with a simple model.

Nitrogen Sources Screening for Ethanol Production Using Carob Industrial Wastes.

PubMed

Raposo, S; Constantino, A; Rodrigues, F; Rodrigues, B; Lima-Costa, M E

2017-02-01

Nowadays, bioethanol production is one of the most important technologies by the necessity to identify alternative energy resources, principally when based on inexpensive renewable resources. However, the costs of 2nd-generation bioethanol production using current biotechnologies are still high compared to fossil fuels. The feasibility of bioethanol production, by obtaining high yields and concentrations of ethanol, using low-cost medium, is the primary goal, leading the research done today. Batch Saccharomyces cerevisiae fermentation of high-density sugar from carob residues with different organic (yeast extract, peptone, urea) and inorganic nitrogen sources (ammonium sulfate, ammonium nitrate) was performed for evaluating a cost-effective ethanol production, with high ethanol yield and productivity. In STR batch fermentation, urea has proved to be a very promising nitrogen source in large-scale production of bioethanol, reaching an ethanol yield of 44 % (w/w), close to theoretical maximum yield value and an ethanol production of 115 g/l. Urea at 3 g/l as nitrogen source could be an economical alternative with a great advantage in the sustainability of ethanol production from carbohydrates extracted from carob. Simulation studies, with experimental data using SuperPro Design software, have shown that the bioethanol production biorefinery from carob wastes could be a very promising way to the valorization of an endogenous resource, with a competitive cost.

Enhancement of docosahexaenoic acid (DHA) production from Schizochytrium sp. S31 using different growth medium conditions.

PubMed

Sahin, Deniz; Tas, Ezgi; Altindag, Ulkü Hüma

2018-01-24

Schizochytrium species is one of the most studied microalgae for production of docosahexaenoic acid (DHA) which is an omega-3 fatty acid with positive effects for human health. However, high cost and low yield in production phase makes optimization of cultivation process inevitable. We focus on the optimization of DHA production using Schizochytrium sp. using different media supplements; glucose, fructose and glycerol as carbon variants, proteose peptone and tryptone as nitrogen variants. The highest biomass (5.61 g/L) and total fatty acid yield (1.74 g/L) were obtained in proteose peptone medium which was used as the alternative nitrogen source instead of yeast extract. The highest DHA yield (0.40 g/L) was achieved with glycerol as the carbon source although it had the second lowest biomass production after ethanol containing medium. Ethanol, as an alternative carbon source and a precursor for acetyl-CoA, increased DHA percentage in total lipid content from 29.94 to 40.04% but decreasing the biomass drastically. Considering different carbon and nitrogen sources during cultivation of Schizochytrium sp. will improve DHA production. Combination of proteose peptone and glycerol as nitrogen and carbon sources, respectively, and addition of ethanol with a proper timing will be useful to have higher DHA yield.

Mixed plantations of Eucalyptus and leguminous trees enhance biomass production

Treesearch

Dean S. DeBell; Craig D. Whitesell; Thomas H. Schubert

1985-01-01

Two Eucalyptus species-E. saligna Sm. and E. grandis Hill-are especially favored in Hawaii forwood, fiber, and fuel production because of their quick growth and high yields. Their growth is limited, however, on many sites by low levels of available nitrogen. Supplemental nitrogen can be provided by nitrogen-...

Effects of biochar amendment and fertilizer sources on serrano chili pepper yield, uptake, and nitrogen fate

USDA-ARS?s Scientific Manuscript database

Efficient nitrogen (N) management strategies are a key approach in addressing the increase of food demand and environmental protection. Failing to achieve adequate nitrogen use efficiency (NUE) in agricultural systems can cause damaging outcomes including degradative water quality, increase in green...

Cover crop, N-rate impacts on corn yield and soil N

USDA-ARS?s Scientific Manuscript database

Nitrogen fertilizer is a significant input expense for producers, as conversion of stable nitrogen into plant available reactive forms such as NH4 or NO3 is energy intensive and costly. These reactive forms of nitrogen (Nr), critical for crop production, can escape from agricultural systems into sur...

A facile approach towards increasing the nitrogen-content in nitrogen-doped carbon nanotubes via halogenated catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ombaka, L.M.; Ndungu, P.G.; Department of Applied Chemistry, Doornfontein Campus, University of Johannesburg, P.O. Box 17011, Johannesburg 2028

Nitrogen-doped carbon nanotubes (N-CNTs) have been synthesized at 850 °C via a CVD deposition technique by use of three ferrocenyl derivative catalysts, i.e. para-CN, -CF{sub 3} and -Cl substituted-phenyl rings. The synthesized catalysts have been characterized by NMR, IR, HR-MS and XRD. The XRD analysis of the para-CF{sub 3} catalyst indicates that steric factors influence the X-ray structure of 1,1′-ferrocenylphenyldiacrylonitriles. Acetonitrile or pyridine was used as carbon and nitrogen sources to yield mixtures of N-CNTs and carbon spheres (CS). The N-CNTs obtained from the para-CF{sub 3} catalysts, in pyridine, have the highest nitrogen-doping level, show a helical morphology and aremore » less thermally stable compared with those synthesized by use of the para-CN and -Cl as catalyst. This suggests that fluorine heteroatoms enhance nitrogen-doping in N-CNTs and formation of helical-N-CNTs (H-N-CNTs). The para-CF{sub 3} and para-Cl catalysts in acetonitrile yielded iron-filled N-CNTs, indicating that halogens promote encapsulation of iron into the cavity of N-CNT. The use of acetonitrile, as carbon and nitrogen source, with the para-CN and -Cl as catalysts also yielded a mixture of N-CNTs and carbon nanofibres (CNFs), with less abundance of CNFs in the products obtained using para-Cl catalysts. However, para-CF{sub 3} catalyst in acetonitrile gave N-CNTs as the only shaped carbon nanomaterials. - Graphical abstract: Graphical abstract showing the synthesis of N-CNTs using halogenated-ferrocenyl derivatives as catalyst with pyridine or acetonitrile as nitrogen and carbon sources via the chemical vapour deposition technique. - Highlights: • N-CNTs were synthesized from halogenated ferrocenyl catalysts. • Halogenated catalysts promote nitrogen-doping and pyridinic nitrogen in N-CNTs. • Halogenated catalysts facilitate iron filling of N-CNTs.« less

[Effects of supplemental irrigation by monitoring soil moisture on the'water-nitrogen utilization of wheat and soil NO3(-)-N leaching].

PubMed

Shi, Yu; Yu, Zhen-wen; He, Jian-ning; Zhang, Yong-li

2016-02-01

Field experiments were conducted during 2012-2014 wheat growing seasons. With no irrigation in the whole stage (WO) treatment as control, three supplemental irrigation treatments were designed based on average relative soil moisture contents at 0-140-cm layer, at jointing and anthesis stages (65% for treatment W1 ; 70% for treatment W2; 75% for treatment W3; respectively), to examine effects of supplemental irrigation on nitrogen accumulation and translocation, grain yield, water use efficiency, and soil nitrate nitrogen leaching in wheat field., Soil water consumption amount, the percentage of soil water consumption and water irrigation to total water consumption in W2 were higher, and soil water consumption of W2 in 100-140 cm soil layer was also higher. The nitrogen accumulation before anthesis and after anthesis were presented as W2, W3>W1>W0, the nitrogen accumulation in vegetative organs at maturity as W3>W2>Wl>W0, and the nitrogen translocation from vegetative organs to grain and the nitrogen accumulation in grain at maturity as W2> W3>W1>W0. At maturity, soil NO3(-)-N content in 0-60 cm soil layer was presented. as W0>W1>W2>W3, that in 80-140 cm soil layer was significantly higher in W3 than in the other treatments, and no significant difference was found in 140-200 cm soil layer among all treatments. W treatment obtained the highest grain yield, water use efficiency, nitrogen uptake efficiency and partial productivity of applied nitrogen. As far as grain yield, water use efficiency, nitrogen uptake efficiency and soil NO3(1)-N leaching were concerned, the W2 regime was the optimal irrigation treatment in this experiment.

Characteristic of riverine dissolved inorganic nitrogen export in subtropic high-standing island, Taiwan

NASA Astrophysics Data System (ADS)

Lee, Li-Chin; Huang, -Chuan, Jr.; Lee, Tsung-Yu; Shih, Yu-Ting

2015-04-01

Extreme increase of anthropogenic nitrogen (e.g. fertilizer and excretion) has altered the nitrogen cycling and terrestrial ecosystems. Taiwan located between eastern Asia and Oceania is the hotspot of global riverine DIN (dissolved inorganic nitrogen, including NH4, NO3, and NO2) export, but rarely documented comprehensively. Totally 50 catchments, covering 2/3 of this island, with different anthropogenic activities are involved in this study. The monthly sampling for NH4 and seasonal sampling for NO3 and NO2 supplemented with daily discharge are used to estimate the riverine DIN export. Meanwhile, the landscape characteristics, land-use, and population density are also used to discriminate the characteristics of riverine DIN export. Results showed that the observed riverine DIN concentration and yield vary from 17.7-603.5 μM and 575.0-15588.9 kg-N km-2 yr-1 corresponding to the increase of anthropogenic activities. The arithmetic mean of DIN concentration and yield are 126.7μM and 3594.7 kg-N km-2 yr-1, respectively. The unexpected high yields can attribute to abundant precipitation, heavy fertilizer application, and high population. For concentration variation, no significant variation can be found in the pristine and agriculture-dominated catchments, whereas the strong dilution effect in the wet season is characterized in the intensively-disturbed catchments. Although there are some seasonal variations in concentration, the yields in wet season are almost doubled than that in dry season indicating the strong control of streamflow. For speciation, NH4 is the dominant species in intensively-disturbed catchment, but NO3 dominates the DIN composition for the pristine and agriculture-dominated catchments. Our result can provide a strong basis for supplementary estimation for regional to global study and DIN export control which is the aim of the Kampala Declaration on global nitrogen management. Keywords: dissolved inorganic nitrogen, anthropogenic nitrogen, Taiwan.

[Effect of NH4(+) -N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism and main chemical composition of Pinellia ternata].

PubMed

Hu, Long-Jiao; Wang, Kang-Cai; Li, Can-Wen

2013-07-01

To study the effect of nitrogen forms on nitrogen metabolism and main chemical composition of Pinellia ternate. Through the soilless cultivation experiment and based at the same nitrogen level and different NH4(+) -N/NO3(-) -N ratios, nitrate reductase (NR) activity, glutamine synthetase (GS) activity, the content of nitrate nitrogen and ammonium nitrogen in different parts of P. ternate were determined. The contents of total alkaloid, free total organic acids and guanosine in the tuber were determined. The yield of bulbil and tuber was calculated. The test results showed that, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of nitrate reductase decreased, the content of nitrate nitrogen in the leaves, petioles and tuber increasing initially, then decreased, and the content of nitrate nitrogen in the root decreased. Meanwhile, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of glutamine synthetase in the leaves, petioles and root increased, the activity of glutamine synthetase in the tuber increasing initially, then decreased. The contents of ammonium nitrogen in the leaves, tuber and root increased initially, then decreased, and the contents of ammonium nitrogen in the petioles increased with the NH4(+)(-N/NO3(-)-N ratio increasing. The yield of bulbil and tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 75: 25. The content of total alkaloid and guanosine in the tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 0: 100, and the contents were 0.245% and 0.0197% respectively. With the NH4(+)-N/NO3(-) -N ratio of 50: 50, the content of free total organic acids was the highest, it reached 0.7%, however, the content of free total organic acids was the lowest at the NH4(+) -N/NO3(-) -N ratio of 0: 100. Nitrogen fertilization significant influences the nitrogen metabolism, the yield and main chemical composition of P. ternate.

Pyrolysis of cassava rhizome in a counter-rotating twin screw reactor unit.

PubMed

Sirijanusorn, Somsak; Sriprateep, Keartisak; Pattiya, Adisak

2013-07-01

A counter-rotating twin screw reactor unit was investigated for its behaviour in the pyrolysis of cassava rhizome biomass. Several parameters such as pyrolysis temperature in the range of 500-700°C, biomass particle size of <0.6mm, the use of sand as heat transfer medium, nitrogen flow rate of 4-10 L/min and nitrogen pressure of 1-3 bar were thoroughly examined. It was found that the pyrolysis temperature of 550°C could maximise the bio-oil yield (50 wt.%). The other optimum parameters for maximising the bio-oil yield were the biomass particle size of 0.250-0.425 mm, the nitrogen flow rate of 4 L/min and the nitrogen pressure of 2 bar. The use of the heat transfer medium could increase the bio-oil yield to a certain extent. Moreover, the water content of bio-oil produced with the counter-rotating twin screw reactor was relatively low, whereas the solids content was relatively high, compared to some other reactor configurations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fertilizer nitrogen, soil chemical properties, and their determinacy on rice yield: Evidence from 92 paddy fields of a large-scale farm in the Kanto Region of Japan

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.

Optimum dry-cooling sub-systems for a solar air conditioner

NASA Technical Reports Server (NTRS)

Chen, J. L. S.; Namkoong, D.

1978-01-01

Dry-cooling sub-systems for residential solar powered Rankine compression air conditioners were economically optimized and compared with the cost of a wet cooling tower. Results in terms of yearly incremental busbar cost due to the use of dry-cooling were presented for Philadelphia and Miami. With input data corresponding to local weather, energy rate and capital costs, condenser surface designs and performance, the computerized optimization program yields design specifications of the sub-system which has the lowest annual incremental cost.

Finite Element Analysis of a Dynamically Loaded Flat Laminated Plate

DTIC Science & Technology

1980-07-01

and the elements are stacked in the thickness direction to represent various material layers. This analysis allows for orthotropic, elastic- plastic or...INCREMENTS 27 V. PLASTICITY 34 Orthotropic Elastic- Plastic Yielding 34 Orthotropic Elastic-Viscoplastic Yielding 37 VI. ELEMENT EQUILIBRIUM...with time, consequently the materials are assumed to be represented by elastic- plastic and elastic-viscoplastic models. The finite element model

Nutrient additions in pristine Patagonian Sphagnum bog vegetation: can phosphorus addition alleviate (the effects of) increased nitrogen loads.

PubMed

Fritz, C; van Dijk, G; Smolders, A J P; Pancotto, V A; Elzenga, T J T M; Roelofs, J G M; Grootjans, A P

2012-05-01

Sphagnum-bog ecosystems have a limited capability to retain carbon and nutrients when subjected to increased nitrogen (N) deposition. Although it has been proposed that phosphorus (P) can dilute negative effects of nitrogen by increasing biomass production of Sphagnum mosses, it is still unclear whether P-addition can alleviate physiological N-stress in Sphagnum plants. A 3-year fertilisation experiment was conducted in lawns of a pristine Sphagnum magellanicum bog in Patagonia, where competing vascular plants were practically absent. Background wet deposition of nitrogen was low (≈ 0.1-0.2 g · N · m(-2) · year(-1)). Nitrogen (4 g · N · m(-2) · year(-1)) and phosphorus (1 g · P · m(-2) · year(-1)) were applied, separately and in combination, six times during the growing season. P-addition substantially increased biomass production of Sphagnum. Nitrogen and phosphorus changed the morphology of Sphagnum mosses by enhancing height increment, but lowering moss stem density. In contrast to expectations, phosphorus failed to alleviate physiological stress imposed by excess nitrogen (e.g. amino acid accumulation, N-saturation and decline in photosynthetic rates). We conclude that despite improving growth conditions by P-addition, Sphagnum-bog ecosystems remain highly susceptible to nitrogen additions. Increased susceptibility to desiccation by nutrients may even worsen the negative effects of excess nitrogen especially in windy climates like in Patagonia. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Dissolved Solids in Streams of the Conterminous United States

NASA Astrophysics Data System (ADS)

Anning, D. W.; Flynn, M.

2014-12-01

Studies have shown that excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, municipal, and industrial water users. Such effects motivated the U.S. Geological Survey's National Water-Quality Assessment Program to develop a SPAtially-Referenced Regression on Watershed Attributes (SPARROW) model to improve the understanding of dissolved solids in streams of the United States. Using the SPARROW model, annual dissolved-solids loads from 2,560 water-quality monitoring stations were statistically related to several spatial datasets serving as surrogates for dissolved-solids sources and transport processes. Sources investigated in the model included geologic materials, road de-icers, urban lands, cultivated lands, and pasture lands. Factors affecting transport from these sources to streams in the model included climate, soil, vegetation, terrain, population, irrigation, and artificial-drainage characteristics. The SPARROW model was used to predict long-term mean annual conditions for dissolved-solids sources, loads, yields, and concentrations in about 66,000 stream reaches and corresponding incremental catchments nationwide. The estimated total amount of dissolved solids delivered to the Nation's streams is 272 million metric tons (Mt) annually, of which 194 million Mt (71%) are from geologic sources, 38 million Mt (14%) are from road de-icers, 18 million Mt (7%) are from pasture lands, 14 million Mt (5 %) are from urban lands, and 8 million Mt (3%) are from cultivated lands. The median incremental-catchment yield delivered to local streams is 26 metric tons per year per square kilometer [(Mt/yr)/km2]. Ten percent of the incremental catchments yield less than 4 (Mt/yr)/km2, and 10 percent yield more than 90 (Mt/yr)/km2. In 13% of the reaches, predicted flow-weighted concentrations exceed 500 mg/L—the U.S. Environmental Protection Agency secondary non-enforceable drinking-water standard.

Physiological Mechanisms Underlying the High-Grain Yield and High-Nitrogen Use Efficiency of Elite Rice Varieties under a Low Rate of Nitrogen Application in China.

PubMed

Wu, Lilian; Yuan, Shen; Huang, Liying; Sun, Fan; Zhu, Guanglong; Li, Guohui; Fahad, Shah; Peng, Shaobing; Wang, Fei

2016-01-01

Selecting rice varieties with a high nitrogen (N) use efficiency (NUE) is the best approach to reduce N fertilizer application in rice production and is one of the objectives of the Green Super Rice (GSR) Project in China. However, the performance of elite candidate GSR varieties under low N supply remains unclear. In the present study, differences in the grain yield and NUE of 13 and 14 candidate varieties with two controls were determined at a N rate of 100 kg ha(-1) in field experiments in 2014 and 2015, respectively. The grain yield for all of the rice varieties ranged from 8.67 to 11.09 t ha(-1), except for a japonica rice variety YG29, which had a grain yield of 6.42 t ha(-1). HY549 and YY4949 produced the highest grain yield, reflecting a higher biomass production and harvest index in 2014 and 2015, respectively. Total N uptake at maturity (TNPM) ranged from 144 to 210 kg ha(-1), while the nitrogen use efficiency for grain production (NUEg) ranged from 35.2 to 62.0 kg kg(-1). Both TNPM and NUEg showed a significant quadratic correlation with grain yield, indicating that it is possible to obtain high grain yield and NUEg with the reduction of TNPM. The correlation between N-related parameters and yield-related traits suggests that promoting pre-heading growth could increase TNPM, while high biomass accumulation during the grain filling period and large panicles are important for a higher NUEg. In addition, there were significant and negative correlations between the NUEg and N concentrations in leaf, stem, and grain tissues at maturity. Further improvements in NUEg require a reduction in the stem N concentration but not the leaf N concentration. The daily grain yield was the only parameter that significantly and positively correlated with both TNPMand NUEg. This study determined variations in the grain yield and NUE of elite candidate GSR rice varieties and provided plant traits that could be used as selection criteria in breeding N-efficient rice varieties.

Boron/Carbon/Silicon/Nitrogen Ceramics And Precursors

NASA Technical Reports Server (NTRS)

Riccitiello, Salvatore; Hsu, Ming TA; Chen, Timothy S.

1996-01-01

Ceramics containing various amounts of boron, carbon, silicon, and nitrogen made from variety of polymeric precursors. Synthesized in high yield from readily available and relatively inexpensive starting materials. Stable at room temperature; when polymerized, converted to ceramics in high yield. Ceramics resist oxidation and other forms of degradation at high temperatures; used in bulk to form objects or to infiltrate other ceramics to obtain composites having greater resistance to oxidation and high temperatures.

The first nitrogen index app for mobile devices: using portable technology for smart agricultural management

USDA-ARS?s Scientific Manuscript database

Nitrogen fertilizer from organic and inorganic sources is used across the world’s agroecosystems. It contributes to higher yields and higher economic returns to farmers, and is essential for food security. However, when more is applied than necessary, significant amounts of nitrogen can exit the sy...

GLOBAL TRANSCRIPTION PROFILING REVEALS DIFFERENTIAL RESPONSES TO CHRONIC NITROGEN STRESS AND PUTATIVE NITROGEN REGULATORY COMPONENTS IN ARABIDOPSIS

EPA Science Inventory

Background: A large quantity of nitrogen (N) fertilizer is used for crop production to achieve high yields at a significant economic and environmental cost. Efforts have been directed to understanding the molecular basis of plant responses to N and to identifying N-responsive gen...

Nitrogen requirements at bulb initiation for production of intermediate-day onions

USDA-ARS?s Scientific Manuscript database

The effect of nitrogen application on growth, nitrogen (N) uptake, yield, and quality of intermediate-day onion (Allium cepa L. ‘Guimar’) was evaluated in the field in southern Portugal. Plants were fertilized with 30 kg/ha N at transplanting, 10 kg/ha N at 29 days after transplanting (DAT) during ...

The nitrogen efficiency of MSW composts as measured by triticale uptake in a 3-year field experiment

NASA Astrophysics Data System (ADS)

Weber, Jerzy; Licznar, Michal; Bekier, Jakub; Drozd, Jerzy; Jamroz, Elzbieta; Kocowicz, Andrzej; Parylak, Danuta; Kordas, Leszek; Licznar, Stanislawa

2010-05-01

This paper presents results of three year field experiment, where two different composts produced from municipal solid wastes were applied to sandy soil. The experiment was established on soil developed from loam sand, according to U.S.D.A. textural classes (81% of sand, 12% of silt, and 7% of clay), of a slightly acidic reaction (pH KCl 6.05 - 6.44). The plough layer (0 - 25 cm) contained about 5.0 g/kg of organic carbon. Both composts were alkaline in reaction and contained high amounts of plant available forms of phosphorus, potassium and magnesium. Composts were used non-recurrently in rates of 18, 36, and 72 t/ha, calculated on dry matter basis. Control objects (0 and NPK) were plots without fertilization, as well as plots fertilized each year with mineral forms of NPK. Field experiment was conducted in 15 m2 plots, using five replications in a randomized block design. Spring triticale (x Triticosecale Wittm.) cultivated in a 3-year monoculture was used as the experiment plant. Soil samples were collected each year after harvesting. Changes in triticale yield were considered in relation to soil properties and nitrogen content in triticale straw and grain. Application of composts caused beneficial changes in soil fertility, connected mainly with an increase of soil organic matter and content of available forms of P, K, and Mg. These effects were observed throughout three years of the experiment. However, significantly higher values of organic carbon - as compared to control (0 and NPK) - were observed only in plots with medium and highest compost doses. This effect was very clear in the first year, while significant differences in soil carbon content were still observed in next two years. The yield of triticale straw and grain depended significantly on fertilization with composts, but beneficial effect of compost was observed only in the first year. Yield similar to NPK control was found only on plots where the highest dose of compost was applied. Next two years, all compost amended plots indicated distinctly lower yield than that on NPK control. Decrease of yield was accompanied by decreased level of nitrogen in triticale straw and grain, although soil of compost amended and NPK fertilized plots indicated the same level of total nitrogen. In the third year dramatic decrease of soil total nitrogen was observed in (0) control, as result of exhausting available nitrogen, while soil amended with composts still contained nitrogen present in non-mineralized organic matter. The yield of triticale grown on soil amended with compost produced from municipal solid wastes was limited by not sufficient amount of plant available nitrogen. Nitrogen efficiency measured as amount of N taken up by triticale grain and straw - after depriving N uptake by triticale grown on control (0) - was very low, around 3 % in the first year and around 1% in the third year. Application of MSW composts is a good alternative for mineral fertilization, however supplementary fertilization with mineral nitrogen is necessary, depending on compost dose and quality.

[Effects of postponing nitrogen application on photosynthetic characteristics and grain yield of winter wheat subjected to water stress after heading stage].

PubMed

Yang, Ming-da; Ma, Shou-chen; Yang, Shen-jiao; Zhang, Su-yu; Guan, Xiao-kang; Li, Xue-mei; Wang, Tong-chao; Li, Chun-xi

2015-11-01

A pot culture experiment was conducted to study the effects of postponing nitrogen (N) application on photosynthetic characteristics and grain yield of winter wheat subjected to water stress after heading stage. Equal in the total N rate in winter wheat growth season, N application was split before sowing, and/or at jointing and /or at anthesis at the ratio of 10:0:0 (N1), 6:4:0 (N2) and 4:3:3 (N3), combined with unfavorable water condition (either waterlogged or drought) with the sufficient water condition as control. The results showed that, under each of the water condition, both N2 and N3 treatments significantly improved the leaf photosynthetic rate and the SPAD value of flag leaf compared with N1 treatment during grain filling stage, and also the crop ear number, grain number per spike and above-ground biomass were increased. Although postponing nitrogen application increased water consumption, both grain yield and water use efficiency were increased. Compared with sufficient water supply, drought stress and waterlogging stress significantly reduced the photosynthetic rate of flag leaves at anthesis and grain filling stages, ear number, 1000-grain mass and yield under all of the N application patterns. The decline of photosynthetic rate under either drought stress or waterlogging stress was much less in N2 and N3 than in N1 treatments, just the same as the grain yield. The results indicated that postponing nitrogen application could regulate winter wheat yield as well as its components to alleviate the damages, caused by unfavorable water stress by increasing flag leaf SPAD and maintaining flag leaf photosynthetic rate after anthesis, and promoting above-ground dry matter accumulation.

The effect of nitrogen rate on vine kill, tuber skinning injury, tuber yield and size distribution, and tuber nutrients and phytonutrients in two potato cultivars grown for early potato production

USDA-ARS?s Scientific Manuscript database

Early potatoes are typically produced using less nitrogen than a full season potato crop as high rates of nitrogen may delay tuber set and lead to excessive vine growth that is difficult to terminate prior to harvest. Bintje and Ciklamen potato cultivars were grown with preplant soil nitrogen levels...

Fixation of nitrogen in the presence of water vapor

DOEpatents

Harteck, Paul

1984-01-01

A process for the fixation of nitrogen is disclosed which comprises combining a mixture of nitrogen, oxygen, metal oxide and water vapor, initially heating the combination to initiate a reaction which forms nitrate, but at a temperature and pressure range below the dissociation pressure of the nitrate. With or without the water component, the yield of fixed nitrogen is increased by the use of a Linde Molecular Sieve Catalyst.

Roadside increments in PM10, NOx and NO2 concentrations observed over 2 months at a major highway in New Zealand.

PubMed

Longley, Ian; Somervell, Elizabeth; Gray, Sally

Continuous and simultaneous observational particulate matter (measured as PM 10 ), nitrogen dioxide (NO 2 ) and oxides of nitrogen (NO x ) data were captured at a kerbside site alongside a major highway in Auckland, New Zealand, and at a pair of setback sites within 250 m of the highway, day and night over 8 weeks. The three measurement sites were intended to allow emissions from the highway to be largely isolated from other sources. By filtering the data and subtracting upwind concentrations, the average roadside increment was calculated to be 1.8, 7.2 and 101.4 μg m -3 for PM 10 , NO 2 and NO x , respectively, relative to a predominantly upwind setback site, and -0.1, 9.4 and 98.5 μg m -3 for PM 10 , NO 2 and NO x , respectively, relative to a downwind setback site. The negative value for PM 10 was attributed to local evening heating sources impacting the setback site. On days when peak 24 h PM 10 concentrations were observed, the absolute kerbside increment was 2.1 μg m -3 . The absolute roadside 24 h average PM 10 increment varied diurnally, peaking (on average) at 2.4 μg m -3 during peak traffic hours. The largest observed 24-h average PM 10 roadside increment was 6.9 μg m -3 and exceeded 5 μg m -3 on nine occasions. On each of these occasions, the daily mean wind speed was less than 2 m s -1 . The diurnally averaged difference in NO x concentrations between the kerbside site and the setback sites clearly resembled the diurnal cycle in traffic volume, and peaked during the morning traffic peak at around 180 μg m -3 . Background NO x concentrations were slightly higher in our study compared to a similar study in Las Vegas but absolute roadside concentrations were higher. This may be consistent with higher NO x emission factors in Auckland, but differences in the precise distance of the monitor from the road lanes and differences in meteorology need to be considered.

Can rising CO2 concentrations in the atmosphere mitigate the impact of drought years on tree growth?

NASA Astrophysics Data System (ADS)

Achim, Alexis; Plumpton, Heather; Auty, David; Ogee, Jerome; MacCarthy, Heather; Bert, Didier; Domec, Jean-Christophe; Oren, Ram; Wingate, Lisa

2015-04-01

Atmospheric CO2 concentrations and nitrogen deposition rates have increased substantially over the last century and are expected to continue unabated. As a result, terrestrial ecosystems will experience warmer temperatures and some may even experience droughts of a more intense and frequent nature that could lead to widespread forest mortality. Thus there is mounting pressure to understand and predict how forest growth will be affected by such environmental interactions in the future. In this study we used annual tree growth data from the Duke Free Air CO2 Enrichment (FACE) experiment to determine the effects of elevated atmospheric CO2 concentration (+200 ppm) and Nitrogen fertilisation (11.2 g of N m-2 yr-1) on the stem biomass increments of mature loblolly pine (Pinus taeda L.) trees from 1996 to 2010. A non-linear mixed-effects model was developed to provide estimates of annual ring specific gravity in all trees using cambial age and annual ring width as explanatory variables. Elevated CO2 did not have a significant effect on annual ring specific gravity, but N fertilisation caused a slight decrease of approximately 2% compared to the non-fertilised in both the ambient and CO2-elevated plots. When basal area increments were multiplied by wood specific gravity predictions to provide estimates of stem biomass, there was a 40% increase in the CO2-elevated plots compared to those in ambient conditions. This difference remained relatively stable until the application of the fertilisation treatment, which caused a further increase in biomass increments that peaked after three years. Unexpectedly the magnitude of this second response was similar in the CO2-elevated and ambient plots (about 25% in each after 3 years), suggesting that there was no interaction between the concentration of CO2 and the availability of soil N on biomass increments. Importantly, during drier years when annual precipitation was less than 1000 mm we observed a significant decrease in annual increments across all treatments. However, the relative difference in growth between CO2-elevated and ambient plots was greater during drought years, providing evidence that tree growth in the future might become less sensitive to water shortages under elevated CO2 conditions.

Understanding nitrate uptake, signaling and remobilisation for improving plant nitrogen use efficiency.

PubMed

Kant, Surya

2018-02-01

The majority of terrestrial plants use nitrate as their main source of nitrogen. Nitrate also acts as an important signalling molecule in vital physiological processes required for optimum plant growth and development. Improving nitrate uptake and transport, through activation by nitrate sensing, signalling and regulatory processes, would enhance plant growth, resulting in improved crop yields. The increased remobilisation of nitrate, and assimilated nitrogenous compounds, from source to sink tissues further ensures higher yields and quality. An updated knowledge of various transporters, genes, activators, and microRNAs, involved in nitrate uptake, transport, remobilisation, and nitrate-mediated root growth, is presented. An enhanced understanding of these components will allow for their orchestrated fine tuning in efforts to improving nitrogen use efficiency in plants. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Alterations in leaf nitrogen metabolism indicated the structural changes of subtropical forest by canopy addition of nitrogen.

PubMed

Liu, Nan; Wang, Jiaxin; Guo, Qinfeng; Wu, Shuhua; Rao, Xingquan; Cai, Xi'an; Lin, Zhifang

2018-09-30

Globally, nitrogen deposition increment has caused forest structural changes due to imbalanced plant nitrogen metabolism and subsequent carbon assimilation. Here, a 2 consecutive-year experiment was conducted to reveal the effects of canopy addition of nitrogen (CAN) on nitrogen absorption, assimilation, and allocation in leaves of three subtropical forest woody species (Castanea henryi, Ardisia quinquegona, and Blastus cochinchinensis). We hypothesized that CAN altered leaf nitrogen absorption, assimilation and partitioning of different plants in different ways in subtropical forest. It shows that CAN increased maximum photosynthetic rate (A max ), photosynthetic nitrogen use efficiency (PNUE), and metabolic protein content of the two understory species A. quinquegona and B. cochinchinensis. By contrary, for the overstory species, C. henryi, A max , PNUE, and metabolic protein content were significantly reduced in response to CAN. We found that changes in leaf nitrogen metabolism were mainly due to the differences in enzyme (e.g. Ribulose-1,5-bisphosphate carboxylase, nitrate reductase, nitrite reductase and glutamine synthetase) activities under CAN treatment. Our results indicated that C. henryi may be more susceptible to CAN treatment, and both A. quinquegona and B. cochinchinensis could better adapt to CAN treatment but in different ways. Our findings may partially explain the ongoing degradation of subtropical forest into a community dominated by small trees and shrubs in recent decades. It is possible that persistent high levels of atmospheric nitrogen deposition will lead to the steady replacement of dominant woody species in this subtropical forest. Copyright © 2018 Elsevier Inc. All rights reserved.

Growing Chlorella sp. on meat processing wastewater for nutrient removal and biomass production.

PubMed

Lu, Qian; Zhou, Wenguang; Min, Min; Ma, Xiaochen; Chandra, Ceria; Doan, Yen T T; Ma, Yiwei; Zheng, Hongli; Cheng, Sibo; Griffith, Richard; Chen, Paul; Chen, Chi; Urriola, Pedro E; Shurson, Gerald C; Gislerød, Hans R; Ruan, Roger

2015-12-01

In this work, Chlorella sp. (UM6151) was selected to treat meat processing wastewater for nutrient removal and biomass production. To balance the nutrient profile and improve biomass yield at low cost, an innovative algae cultivation model based on wastewater mixing was developed. The result showed that biomass yield (0.675-1.538 g/L) of algae grown on mixed wastewater was much higher than that on individual wastewater and artificial medium. Wastewater mixing eased the bottleneck for algae growth and contributed to the improved biomass yield. Furthermore, in mixed wastewater with sufficient nitrogen, ammonia nitrogen removal efficiencies (68.75-90.38%) and total nitrogen removal efficiencies (30.06-50.94%) were improved. Wastewater mixing also promoted the synthesis of protein in algal cells. Protein content of algae growing on mixed wastewater reached 60.87-68.65%, which is much higher than that of traditional protein source. Algae cultivation model based on wastewater mixing is an efficient and economical way to improve biomass yield. Copyright © 2015 Elsevier Ltd. All rights reserved.

Production of oxalic acid from sugar beet molasses by formed nitrogen oxides.

PubMed

Gürü, M; Bilgesü, A Y; Pamuk, V

2001-03-01

Production of oxalic acid from sugar beet molasses was developed in a series of three reactors. Nitrogen oxides formed were used to manufacture oxalic acid in the second and third reactor. Parameters affecting the reaction were determined to be, air flow rate, temperature, the amount of V2O5 catalyst and the concentrations of molasses and H2SO4. The maximum yields in the second and third reactors were 78.9% and 74.6% of theoretical yield, respectively. Also, kinetic experiments were performed and the first-order rate constants were determined for the glucose consumption rate. Nitrogen oxides in off-gases from the final reactor were absorbed in water and concentrated sulphuric acid and reused in the following reactors giving slightly lower yields under similar conditions. In this novel way, it was possible to recover NO(x) and to prevent air pollution. Meanwhile, it was possible to reduce the unit cost of reactant for oxalic acid production. A maximum 77.5% and 74.1% of theoretical yield was obtained by using the absorption solutions with NO(x).

Production of raw cassava starch-degrading enzyme by Penicillium and its use in conversion of raw cassava flour to ethanol.

PubMed

Lin, Hai-Juan; Xian, Liang; Zhang, Qiu-Jiang; Luo, Xue-Mei; Xu, Qiang-Sheng; Yang, Qi; Duan, Cheng-Jie; Liu, Jun-Liang; Tang, Ji-Liang; Feng, Jia-Xun

2011-06-01

A newly isolated strain Penicillium sp. GXU20 produced a raw starch-degrading enzyme which showed optimum activity towards raw cassava starch at pH 4.5 and 50 °C. Maximum raw cassava starch-degrading enzyme (RCSDE) activity of 20 U/ml was achieved when GXU20 was cultivated under optimized conditions using wheat bran (3.0% w/v) and soybean meal (2.5% w/v) as carbon and nitrogen sources at pH 5.0 and 28 °C. This represented about a sixfold increment as compared with the activity obtained under basal conditions. Starch hydrolysis degree of 95% of raw cassava flour (150 g/l) was achieved after 72 h of digestion by crude RCSDE (30 U/g flour). Ethanol yield reached 53.3 g/l with fermentation efficiency of 92% after 48 h of simultaneous saccharification and fermentation of raw cassava flour at 150 g/l using the RCSDE (30 U/g flour), carried out at pH 4.0 and 40 °C. This strain and its RCSDE have potential applications in processing of raw cassava starch to ethanol.

Optimizing irrigation and nitrogen for wheat through empirical modeling under semi-arid environment.

PubMed

Saeed, Umer; Wajid, Syed Aftab; Khaliq, Tasneem; Zahir, Zahir Ahmad

2017-04-01

Nitrogen fertilizer availability to plants is strongly linked with water availability. Excessive or insufficient use of nitrogen can cause reduction in grain yield of wheat and environmental issues. The per capita per annum water availability in Pakistan has reduced to less than 1000 m 3 and is expected to reach 800 m 3 during 2025. Irrigating crops with 3 or more than 3 in. of depth without measuring volume of water is not a feasible option anymore. Water productivity and economic return of grain yield can be improved by efficient management of water and nitrogen fertilizer. A study was conducted at post-graduate agricultural research station, University of Agriculture Faisalabad, during 2012-2013 and 2013-2014 to optimize volume of water per irrigation and nitrogen application. Split plot design with three replications was used to conduct experiment; four irrigation levels (I 300  = 300 mm, I 240  = 240 mm, I 180  = 180 mm, I 120  = 120 mm for whole growing season at critical growth stages) and four nitrogen levels (N 60  = 60 kg ha -1 , N 120  = 120 kg ha -1 , N 180  = 180 kg ha -1 , and N 240  = 240 kg ha -1 ) were randomized as main and sub-plot factors, respectively. The recorded data on grain yield was used to develop empirical regression models. The results based on quadratic equations and economic analysis showed 164, 162, 158, and 107 kg ha -1 nitrogen as economic optimum with I 300 , I 240 , I 180 , and I 120 mm water, respectively, during 2012-2013. During 2013-2014, quadratic equations and economic analysis showed 165, 162, 161, and 117 kg ha -1 nitrogen as economic optimum with I 300 , I 240 , I 180 , and I 120 mm water, respectively. The optimum irrigation level was obtained by fitting economic optimum nitrogen as function of total water. Equations predicted 253 mm as optimum irrigation water for whole growing season during 2012-2013 and 256 mm water as optimum for 2013-2014. The results also revealed that reducing irrigation from I 300 to I 240 mm during 2012-2013 and 2013-2014 did not reduce crop yield significantly (P < 0.01). The excessive nitrogen application ranged from 31.2 to 55.4% at N 180 and N 240 kg ha -1 for different levels of irrigation. It is concluded from study that irrigation and nitrogen relationship can be used for efficient management of irrigation and nitrogen and to reduce nitrogen losses. The empirical equations developed in this study can help farmers of semi-arid environment to calculate optimum level of irrigation and nitrogen for maximum economic return from wheat.

Growth, yield, and disease resistance of 7- to 12-year-old poplar clones in the north central United States.

Treesearch

D.A. Netzer; D.N. Tolsted; M. E. Ostry; J. G. Isebrands; D.E. Riemenschneider; K.T. Ward

2002-01-01

Summarizes growth, yield, and disease resistance of 95 poplar clones at or near rotation age (culmination of mean annual increment). Plantations were established from 1986 to 1992 in Wisconsin, Minnesota, North and South Dakota. Clones DN164, DN177, DN154, NM2, NE264, DN170, and DN21 are recommended for further testing.

Container longleaf pine seedling morphology in response to varying rates of nitrogen fertilization in the nursery and subsequent growth after outplanting

Treesearch

D. Paul Jackson; R. Kasten Dumroese; James P. Barnett; William B. Patterson

2007-01-01

A fertilization rate of 2 or 3 mg nitrogen (N) per week for 20 weeks yielded longleaf pine (Pinus palustris) seedlings grown inside a greenhouse that survived well and produced good root collar diameter (RCD) growth the first year after outplanting. Of a range of fertilization rates (0.5 to 4 mg N/week), the 2 mg rate yielded seedlings that did not...

Effect of nitrogen and fish manure fertilization on growth and chemical composition of lettuce

NASA Astrophysics Data System (ADS)

Yildirim, Ertan; Kul, Raziye; Turan, Metin; Ekinci, Melek; Alak, Gonca; Atamanalp, Muhammet

2016-04-01

Present experiment was designed to determine the response of various dozes of fish manure (FM) and commercial fertilizers on plant growth, yield and nutrient content of lettuce. The treatments consisted of fish manure, commercial fertilizer and the combination of fish manure and commercial fertilizer with four dozes of nitrogen (0 kg/ha, 100 kg/ha, 150 kg/ha and 200 kg/ha). The results of the study showed that treatments significantly affected the growth and chemical characteristics of lettuce. The best results in regard to plant growth and yield were obtained from 100 and 150 kg kg/ha nitrogen dozes of the combination of fish manure and commercial fertilizer.

Overexpressing of OsAMT1-3, a High Affinity Ammonium Transporter Gene, Modifies Rice Growth and Carbon-Nitrogen Metabolic Status

PubMed Central

Bao, Aili; Liang, Zhijun; Zhao, Zhuqing; Cai, Hongmei

2015-01-01

AMT1-3 encodes the high affinity NH4+ transporter in rice roots and is predominantly expressed under nitrogen starvation. In order to evaluate the effect of AMT1-3 gene on rice growth, nitrogen absorption and metabolism, we generated AMT1-3-overexpressing plants and analyzed the growth phenotype, yield, carbon and nitrogen metabolic status, and gene expression profiles. Although AMT1-3 mRNA accumulated in transgenic plants, these plants displayed significant decreases in growth when compared to the wild-type plants. The nitrogen uptake assay using a 15N tracer revealed poor nitrogen uptake ability in AMT1-3-overexpressing plants. We found significant decreases in AMT1-3-overexpressing plant leaf carbon and nitrogen content accompanied with a higher leaf C/N ratio. Significant changes in soluble proteins and carbohydrates were also observed in AMT1-3-overexpressing plants. In addition, metabolite profile analysis demonstrated significant changes in individual sugars, organic acids and free amino acids. Gene expression analysis revealed distinct expression patterns of genes that participate in carbon and nitrogen metabolism. Additionally, the correlation between the metabolites and gene expression patterns was consistent in AMT1-3-overexpressing plants under both low and high nitrogen growth conditions. Therefore, we hypothesized that the carbon and nitrogen metabolic imbalance caused by AMT1-3 overexpressing attributed to the poor growth and yield of transgenic plants. PMID:25915023

Microplume model of spatial-yield spectra. [applying to electron gas degradation in molecular nitrogen gas

NASA Technical Reports Server (NTRS)

Green, A. E. S.; Singhal, R. P.

1979-01-01

An analytic representation for the spatial (radial and longitudinal) yield spectra is developed in terms of a model containing three simple 'microplumes'. The model is applied to electron energy degradation in molecular nitrogen gas for 0.1 to 5 keV incident electrons. From the nature of the cross section input to this model it is expected that the scaled spatial yield spectra for other gases will be quite similar. The model indicates that each excitation, ionization, etc. plume should have its individual spatial and energy dependence. Extensions and aeronomical and radiological applications of the model are discussed.

Initial evaluation of rectal bleeding in young persons: a cost-effectiveness analysis.

PubMed

Lewis, James D; Brown, Alphonso; Localio, A Russell; Schwartz, J Sanford

2002-01-15

Evaluation of rectal bleeding in young patients is a frequent diagnostic challenge. To determine the relative cost-effectiveness of alternative diagnostic strategies for young patients with rectal bleeding. Cost-effectiveness analysis using a Markov model. Probability estimates were based on published medical literature. Cost estimates were based on Medicare reimbursement rates and published medical literature. Persons 25 to 45 years of age with otherwise asymptomatic rectal bleeding. The patient's lifetime. Modified societal perspective. Diagnostic strategies included no evaluation, colonoscopy, flexible sigmoidoscopy, barium enema, anoscopy, or any feasible combination of these procedures. Life expectancy and costs. For 35-year-old patients, the no-evaluation strategy yielded the least life expectancy. The incremental cost-effectiveness of flexible sigmoidoscopy compared with no evaluation or with any strategy incorporating anoscopy (followed by further evaluation if no anal disease was found on anoscopy) was less than $5300 per year of life gained. A strategy of flexible sigmoidoscopy plus barium enema yielded the greatest life expectancy, with an incremental cost of $23 918 per additional life-year gained compared with flexible sigmoidoscopy alone. As patient age at presentation of rectal bleeding increased, evaluation of the entire colon became more cost-effective. The incremental cost-effectiveness of flexible sigmoidoscopy plus barium enema compared with colonoscopy was sensitive to estimates of the sensitivity of the tests. In a probabilistic sensitivity analysis comparing flexible sigmoidoscopy with anoscopy followed by flexible sigmoidoscopy if needed, the middle 95th percentile of the distribution of the incremental cost-effectiveness ratios ranged from flexible sigmoidoscopy yielding an increased life expectancy at reduced cost to $52 158 per year of life gained (mean, $11 461 per year of life saved). Evaluation of the colon of persons 25 to 45 years of age with otherwise asymptomatic rectal bleeding increases the life expectancy at a cost comparable to that of colon cancer screening.

Effects of nitrogen rate and application method on early production and fruit quality in highbush blueberry

USDA-ARS?s Scientific Manuscript database

A field study was conducted to examine the effects of nitrogen (N) rate and method of N fertilizer application on growth, yield, and fruit quality in highbush blueberry (Vaccinium corymbosum L.) during the first 4 years after planting in south-coastal BC. Nitrogen was applied at 0-150% of current pr...

AMT1;1 transgenic rice plants with enhanced NH4(+) permeability show superior growth and higher yield under optimal and suboptimal NH4(+) conditions.

PubMed

Ranathunge, Kosala; El-Kereamy, Ashraf; Gidda, Satinder; Bi, Yong-Mei; Rothstein, Steven J

2014-03-01

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4(+)). The NH4(+) uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4(+) transport in rice plants. However, little is known about its involvement in NH4(+) uptake in rice roots and subsequent effects on NH4(+) assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4(+) permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4(+) content in the shoots and roots than the WT. Direct NH4(+) fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4(+) contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4(+) levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions.

Case study of developing an integrated water and nitrogen scheme for agricultural systems on the North China Plain

NASA Astrophysics Data System (ADS)

Liu, Y.; Tao, F.; Luo, Y.; Ma, J.

2013-12-01

Appropriate irrigation and nitrogen fertilization, along with suitable crop management strategies, are essential prerequisites for optimum yields in agricultural systems. This research attempts to provide a scientific basis for sustainable agricultural production management for the North China Plain and other semi-arid regions. Based on a series of 72 treatments over 2003-2008, an optimized water and nitrogen scheme for winter wheat/summer maize cropping system was developed. Integrated systems incorporating 120 mm of water with 80 kg N ha-1 N fertilizer were used to simulate winter wheat yields in Hebei and 120 mm of water with 120 kg N ha-1 were used to simulate winter wheat yields in Shandong and Henan provinces in 2000-2007. Similarly, integrated treatments of 40 kg N ha-1 N fertilizer were used to simulate summer maize yields in Hebei, and 80 kg N ha-1 was used to simulate summer maize yields in Shandong and Henan provinces in 2000-2007. Under the optimized scheme, 341.74 107 mm ha-1 of water and 575.79 104 Mg of urea fertilizer could be saved per year under the wheat/maize rotation system. Despite slight drops in the yields of wheat and maize in some areas, water and fertilizer saving has tremendous long-term eco-environmental benefits.

High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI)

NASA Astrophysics Data System (ADS)

Lawrence, J. P.; Anand, J. S.; Vande Hey, J. D.; Leigh, R. R.; Monks, P. S.; Leigh, R. J.

2015-06-01

Nitrogen Dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI) remote sensing system. The ANDI system includes an imaging (UV)-vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2) concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK. Retrieved NO2 columns at a surface resolution of 80 m x 20 m revealed hot spots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands) and a power station (Ratcliffe-on-Soar). In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hot spots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

[Effects of controlled release nitrogen fertilizer application on dry matter accumulation and nitrogen balance of summer maize].

PubMed

Si, Dong-Xia; Cui, Zhen-Ling; Chen, Xin-Ping; Lü, Fu-Tang

2014-06-01

Effects of four controlled release nitrogen (N) fertilizers, including two kinds of polyester coated urea (Ncau, CRU) and phosphate (NhnP) and humic acid (NhnF) coated urea on assimilates accumulation and nitrogen balance of summer maize were investigated in a mode of one-time fertilization at the regional N recommended rate. The results showed that the N release curves of the two controlled release fertilizers CRU and Ncau matched well with the summer maize N uptake. Compared with the regional N recommendation rate, CRU could increase maize yield by 4.2% and Ncau could maintain the same yield level. CRU significantly increased the dry matter accumulation rate after anthesis of summer maize, but Ncau markedly increased the dry matter accumulated ratio before anthesis. Meanwhile, CRU could reduce the apparent N losses by 19 kg N x hm(-2) in the case of large precipitation. However, NhnF and NhnP caused the yield losses by 0.1%-8.9%, and enhanced the apparent N losses. Therefore, both CRU and Ncau with one-time fertilization could be a simplified alternative to the "total control, staging regulation" fertilization technique at the regional N recommended rate for summer maize production.

Variable-rate nitrogen application algorithm based on canopy reflected spectrum and its influence on wheat

NASA Astrophysics Data System (ADS)

Liang, Hongxia; Zhao, Chunjiang; Huang, Wenjiang; Liu, Liangyun; Wang, Jihua; Ma, Youhua

2005-01-01

This study was to develop the time-specific and time-critical method to overcome the limitations of traditional field sampling methods for variable rate fertilization. Farmers, agricultural managers and grain processing enterprises are interested in measuring and assessing soil and crop status in order to apply adequate fertilizer quantities to crop growth. This paper focused on studying the relationship between vegetation index (OSAVI) and nitrogen content to determine the amount of nitrogen fertilizer recommended for variable rate management in precision agriculture. The traditional even rate fertilizer management was chosen as the CK. The grain yield, ear numbers, 1000-grain weight and grain protein content were measured among the CK, uniform treatments and variable rate fertilizer treatments. It indicated that variable rate fertilization reduced the variability of wheat yield, ear numbers and dry biomass, but it didn't increased crop yield and grain protein content significantly and did not decrease the variety of 1000-grain weight, compared to traditional rate application. The nitrogen fertilizer use efficiency was improved, for this purpose, the variable rate technology based on vegetation index could be used to prevent under ground water pollution and environmental deterioration.

[Effects of plastic film mulching and nitrogen application rate on net global warming potential in semiarid rain-fed maize cropland].

PubMed

Liu, Jian Can; Wang, Ze Lin; Yue, Shan Chao; Li, Shi Qing

2018-04-01

A one-year field experiment was conducted to evaluate the effects of plastic film mulching (FM) and nitrogen application rates applied to rain-fed maize fields on net global warming potential (Net GWP) and greenhouse gas intensity (GHGI) at the Changwu Agricultural and Ecological Experimental Station. Both GWP and GHGI were affected by the plastic film mulching and nitrogen application rate. Under the FM treatment, maize yield ranged from 1643 to 16699 kg·hm -2 , the net GWP (CO 2 -eq) ranged from 595 to 4376 kg·hm -2 ·a -1 , and the GHGI (CO 2 -eq) ranged from 213 to 358 kg·t -1 . The grain yield of maize, net GWP and GHGI for the UM (no mulching) treatment were 956 to 8821 kg·hm -2 , 342 to 4004 kg·hm -2 ·a -1 and 204 to 520 kg·t -1 , respectively. The results suggested that plastic film mulching could simultaneously improve grain yield and decrease GHGI in rain-fed cropland along with nitrogen fertilizer of 250 kg·hm -2 .

Cumulative release characteristics of controlled-release nitrogen and potassium fertilizers and their effects on soil fertility, and cotton growth

PubMed Central

Yang, Xiuyi; Geng, Jibiao; Li, Chengliang; Zhang, Min; Tian, Xiaofei

2016-01-01

To investigate the interacting effects of polymer coated urea (PCU) and polymer coated potassium chloride (PCPC) on cotton growth, an experiment was conducted with containerized plants in 2014 and 2015. There were two kinds of nitrogen fertilizer, PCU and urea, which were combined with PCPC at three application rates (40, 80 and 120 kg ha−1). The kinds of nitrogen fertilizer formed the main plot, while individual rates of PCPC were the subplots. The results suggested N and K release patterns for PCU and PCPC in the soil were closely matched to the N and K requirements by cotton. Soil inorganic nitrogen contents significantly increased by using PCU instead of urea, and the same trend was observed with soil available potassium contents, which also had increased rates. Meanwhile, the number of bolls and lint yields of cotton in the PCU treatments were 4.9–35.3% and 2.9–40.7% higher than from urea treatments. Lint yields also increased by 9.1–12.7% with PCPC80 and PCPC120 treatments compared with PCPC40 treatment at the same nitrogen type. Hence, application of PCU combined with 80 kg ha−1 of PCPC fertilizer on cotton increased the yields and fertilizer use efficiencies in addition to improving fiber quality and delaying leaf senescence. PMID:27966638

Final Environmental Impact Statement Evolved Expendable Launch Vehicle Program

DTIC Science & Technology

1998-04-01

source, permit application compliance, permit issuance, renewal and revision, and permit review by the U.S. EPA and any affected states. Because...Quality Standards NH3 = ammonia NOx = nitrogen oxides OSHA = Occupational Safety and Health Administration PEL = Permissible Exposure Level ppm = parts...NO or NO2 incremental concentrations during an abort were predicted by REEDM for only the DIV-S vehicle configuration. Ammonia was predicted by REEDM

Impact of genetic risk information and type of disease on perceived risk, anticipated affect, and expected consequences of genetic tests.

PubMed

Cameron, Linda D; Sherman, Kerry A; Marteau, Theresa M; Brown, Paul M

2009-05-01

Genetic tests vary in their prediction of disease occurrence, with some mutations conferring relatively low risk and others indicating near certainty. The authors assessed how increments in absolute risk of disease influence risk perceptions, interest, and expected consequences of genetic tests for diseases of varying severity. Adults (N = 752), recruited from New Zealand, Australia, and the United Kingdom for an online analogue study, were randomly assigned to receive information about a test of genetic risk for diabetes, heart disease, colon cancer, or lung cancer. The lifetime risk varied across conditions by 10% increments, from 20% to 100%. Participants completed measures of perceived likelihood of disease for individuals with mutations, risk-related affect, interest, and testing consequences. Analyses revealed two increment clusters yielding differences in likelihood perceptions: A "moderate-risk" cluster (20%-70%), and a "high-risk" cluster (80%-100%). Risk increment influenced anticipated worry, feelings of risk, testing-induced distress, and family obligations, with nonlinear patterns including disproportionately high responses for the 50% increment. Risk increment did not alter testing interest or perceived benefits. These patterns of effects held across the four diseases. Magnitude of risk from genetic testing has a nonlinear influence on risk-related appraisals and affect but is unrelated to test interest.

Interactions of Nitrogen Source and Rate and Weed Removal Timing Relative to Nitrogen Content in Corn and Weeds and Corn Grain Yield.

PubMed

Knight, Alexandra M; Everman, Wesley J; Jordan, David L; Heiniger, Ronnie W; Smyth, T Jot

2017-01-01

Adequate fertility combined with effective weed management is important in maximizing corn ( Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth ( Amaranthus palmeri S. Wats.) and large crabgrass ( Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield.

Maize Yield Response to Water Supply and Fertilizer Input in a Semi-Arid Environment of Northeast China

PubMed Central

Yin, Guanghua; Gu, Jian; Zhang, Fasheng; Hao, Liang; Cong, Peifei; Liu, Zuoxin

2014-01-01

Maize grain yield varies highly with water availability as well as with fertilization and relevant agricultural management practices. With a 311-A optimized saturation design, field experiments were conducted between 2006 and 2009 to examine the yield response of spring maize (Zhengdan 958, Zea mays L) to irrigation (I), nitrogen fertilization (total nitrogen, urea-46% nitrogen,) and phosphorus fertilization (P2O5, calcium superphosphate-13% P2O5) in a semi-arid area environment of Northeast China. According to our estimated yield function, the results showed that N is the dominant factor in determining maize grain yield followed by I, while P plays a relatively minor role. The strength of interaction effects among I, N and P on maize grain yield follows the sequence N+I >P+I>N+P. Individually, the interaction effects of N+I and N+P on maize grain yield are positive, whereas that of P+I is negative. To achieve maximum grain yield (10506.0 kg·ha−1) for spring maize in the study area, the optimum application rates of I, N and P are 930.4 m3·ha−1, 304.9 kg·ha−1 and 133.2 kg·ha−1 respectively that leads to a possible economic profit (EP) of 10548.4 CNY·ha−1 (CNY, Chinese Yuan). Alternately, to obtain the best EP (10827.3 CNY·ha−1), the optimum application rates of I, N and P are 682.4 m3·ha−1, 241.0 kg·ha−1 and 111.7 kg·ha−1 respectively that produces a potential grain yield of 10289.5 kg·ha−1. PMID:24465896

Relation of water quality to land use in the drainage basins of four tributaries to the Toms River, New Jersey, 1994-95

USGS Publications Warehouse

Hunchak-Kariouk, Kathryn

1999-01-01

The influence of land use on the water quality of four tributaries to the Toms River, which drains nearly one-half of the Barnegat Bay wateshed, was studied during the initial phase of a multiyear investigation. Water samples were collected from and streamflows were measured in Long Swamp Creek, Wrangel Brook, Davenport Branch, and Jakes Creek during periods of base flow and stormflow in the growing and nongrowing seasons during May 1994 to October 1995. The drainage areas upstream from the seven measurement sites were characterized as highly developed, moderately developed, slightly developed, or undeveloped. Concentrations were determined and area-normalized instantaneous loads (yields) were estimated for total nitrogen, ammonia, nitrate, organic nitrogen, hydrolyzable phosphorus plus orthosphosphorus, orthophosphorus, total suspended solids, and fecal-coliform bacteria in the water samples. Specific conductance, pH, temperature, and dissolved oxygen were measured. Yields of total nitrogen, nitrate, and organic nitrogen at sites on Wrangel Brook, which drains moderately developed areas, were either larger than or similar to yields at the site on Long Swamp Creek, which drains a highly developed area. The magnitude of these yields probably was not related directly to the intensity of land development, but more likely was influenced by the type of development, the amount of base flow, and historical land use in the basin. The large concentrations of total nitrogen and nitrate in base flow in Wrangel Brook could have resulted from fertilizers that were applied to high-maintenance lawns and from agricultural runoff that has remained in the ground water since the 1950's and eventually was discharged to streams. Yields of ammonia appear to be partly related to the intensity of land development and storm runoff. Yields of ammonia at the site on Long Swamp Creek (a highly developed area) were either larger than or similar to yields at sites on Wrangel Brook (moderately developed areas). Yields were smallest at the site on Davenport Branch, which drains a slightly developed area. Yields of hydrolyzable phosphorus plus orthophosphorus and yields of orthophosphorus appear to be related to the intensity of development. Concentrations of hydrolyzable phosphorus plus orthophosphorus were greater in Long Swamp Creek (highly developed areas) than in Wrangel Brook (moderately developed areas). Concentrations of orthophosphorus were largest in Wrangel Brook (moderately developed) and Long Swamp Creek (highly developed). Total suspended solids and bacteria were somewhat related to intensity of development. Yields of total suspended solids were greater at sites downstream from highly and moderately developed areas than from slightly developed areas. Yields of bacteria were strongly related to streamflow and season. Specific conductance appears to be related to streamflow. pH probably was related to intensity of land development; pH was greater (more basic) in streams draining highly developed areas than in those draining other areas. Concentrations of dissolved oxygen were affected more by water temperature than by intensity of development or streamflow.

Influence of low versus moderate glycemic index of diet on substrate oxidation and energy expenditure during incremental exercise in endurance athletes: a randomized counterbalanced cross-over trial.

PubMed

Durkalec-Michalski, Krzysztof; Zawieja, Emilia Ewa; Zawieja, Bogna Ewa; Podgórski, Tomasz; Jurkowska, Dominika; Jeszka, Jan

2017-12-18

The study was aimed at assessing the influence of 3-week low glycemic index (LGI) versus moderate glycemic index (MGI) diet on substrate oxidation during incremental exercise. 17 runners completed two 3-week trials of either LGI or MGI diet in a randomised counterbalanced manner. Before and after each trial the incremental cycling test was performed. Metabolic alternations were observed only within tested diets and no significant differences in fat and carbohydrate (CHO) oxidation were found between MGI and LGI diets. Following MGI diet CHO oxidation rate increased. The AUC of fat oxidation decreased after both diets. Percent contribution of fat to energy yield declined, whereas contribution of CHO was augmented following MGI diet. This study indicates that the 3-week MGI diet increased the rate of carbohydrate oxidation during incremental cycling test and improved performance in acute intense exercise test, while both high-carbohydrate diets downregulated fat oxidation rate.

Reducing nitrogen losses through ammonia volatilization and surface runoff to improve apparent nitrogen recovery of double cropping of late rice using controlled release urea.

PubMed

Li, Pengfei; Lu, Jianwei; Hou, Wenfeng; Pan, Yonghui; Wang, Yang; Khan, Muhammad Rizwan; Ren, Tao; Cong, Rihuan; Li, Xiaokun

2017-04-01

Controlled release fertilizer can reduce nitrogen losses to the environment while increasing grain yield and improving apparent nitrogen recovery (ANR) of rice. However, few studies have evaluated the comparative efficacy of different polymer-coated urea products on nitrogen (N) losses, ANR, and N uptake of rice. A 2-year field experiment was conducted to compare the effects of three different types of polymer-coated urea fertilizer on nitrogen losses through NH 3 volatilization and surface runoff to the environment, ANR, grain yield, and N uptake as compared to conventional urea of rice. Six treatments including (1) control with 0 kg N ha -1 (CK), (2) basal application of urea (U b ), (3) split application (U s ) of urea (50% at transplanting, 25% at tillering, and 25% at panicle stages), (4) CRU-1 (polyurethane-coated urea), (5) CRU-2 (degradable polymer-coated urea), and (6) CRU-3 (water-based polymer-coated urea) all applied at 165 kg N ha -1 . It was found that CRU-2 resulted in the highest grain yield and panicle numbers among the N fertilization treatments in 2013 and 2014. Applying CRU could help increase N uptake in rice, reduce N losses through NH 3 volatilization and surface runoff, and hence improve ANR. Its single dose can meet the nutrient demand of the rice plant. Controlled release urea could be adopted as an effective mitigation alternative to retard N losses through NH 3 volatilization and surface runoff while improving ANR of double cropping of late rice.

Agricultural land use and water quality in the upper St. Joseph River basin, Michigan

USGS Publications Warehouse

Cummings, T. Ray

1978-01-01

Land use in the upper St. Joseph River basin of south-central Michigan is primarily agricultural. In the 144-square-mile area, the chemical and physical characteristics of water are determined by the climate and soils, as well as by land conservation practices. Municipal waste discharges affect water quality at some locations, as do the larger lakes and ponds. Data indicate that mean discharge from the basin is 135 cubic feet per second. About half this flow is contributed to the St. Joseph River by three major tributaries: Beebe Creek (36 cubic feet per second); Sand Creek (24 cubic feet per second); and Soap Creek (13 cubic feet per second). Runoff from 21 drainage areas delineated for the investigation ranged from 0.22 to 4.07 cubic feet per second per square mile; both the higher and lower values are largely the result of naturally occurring inter- and intrabasin transfers of water.Suspended-sediment concentrations are low throughout the basin, rarely exceeding 100 milligrams per liter. Mean concentrations at four daily sampling stations on the major tributaries and on the St. Joseph River ranged from 9.7 milligrams per liter to 38 milligrams per liter. The maximum sediment yield was 182 pounds per acre per year. Deposition of sediment in five of the 21 areas resulted in a net loss of sediment transported, and thus “negative” yields.Nitrogen and phosphorus concentrations do not vary greatly from site to site. Mean concentrations of total nitrogen at downstream sites on Beebe, Sand, and Soap Creeks, and on the St. Joseph River ranged from 1.5 to 1.8 milligrams per liter. About 90 percent of all nitrogen, and 66 percent of all phosphorus, is transported in solution. Land used principally for agriculture has a mean total nitrogen yield of 4.9 pounds per acre per year and a mean total phosphorus yield of 0.13 pounds per year. A comparison of total nitrogen and total phosphorus yields with type of agricultural use showed few relationships; nitrogen yield, however, seems to decrease as the percentage of land in row crop and small grain increases. A relation between amount of fertilizer applied to land and the amount in streams could not be demonstrated.Only about 6 percent of the total nitrogen and about 1 percent of the total phosphorus added to the land in animal wastes, in precipitation, and applied as fertilizer, is transported from the basin by the St. Joseph River at Clarendon. Estimates also suggest that almost three times as much nitrogen, and twice as much phosphorus, fall in precipitation on the basin as is transported from the basin by runoff. In general, land conservation practices of the past seem to have been effective in minimizing erosion and leaching of soils in the basin.

Hardwood Regrowth and Yields on Bottomland Clay Soil Following Clearcutting

Treesearch

Roger M. Krinard; Robert L. Johnson

1986-01-01

Five years of regrowth of a clearcut hardwood stand on the Delta Experimental Forest in Mississippi were evaluated to determine growth and development and biomass yields. Dry weight mean annual increments for years 1 through 5 following harvesting of an 1 l-year-old hardwood stand on Sharkey clay soil were 0.6, 1.9, 2.4, 3.5, and 3.2 tons per acre per year,...

Biomass and nitrogen-use efficiency of grain sorghum (Sorghum bicolor L.) with nitrogen and supplemental irrigation in Coastal Plain Region, USA

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...

Effects of land use on water quality and transport of selected constituents in streams in Mecklenburg County, North Carolina, 1994–98

USGS Publications Warehouse

Ferrell, Gloria M.

2001-01-01

Transport rates for total solids, total nitrogen, total phosphorus, biochemical oxygen demand, chromium, copper, lead, nickel, and zinc during 1994–98 were computed for six stormwater-monitoring sites in Mecklenburg County, North Carolina. These six stormwater-monitoring sites were operated by the Mecklenburg County Department of Environmental Protection, in cooperation with the City of Charlotte, and are located near the mouths of major streams. Constituent transport at the six study sites generally was dominated by nonpoint sources, except for nitrogen and phosphorus at two sites located downstream from the outfalls of major municipal wastewater-treatment plants.To relate land use to constituent transport, regression equations to predict constituent yield were developed by using water-quality data from a previous study of nine stormwater-monitoring sites on small streams in Mecklenburg County. The drainage basins of these nine stormwater sites have relatively homogeneous land-use characteristics compared to the six study sites. Mean annual construction activity, based on building permit files, was estimated for all stormwater-monitoring sites and included as an explanatory variable in the regression equations. These regression equations were used to predict constituent yield for the six study sites. Predicted yields generally were in agreement with computed yields. In addition, yields were predicted by using regression equations derived from a national urban water-quality database. Yields predicted from the regional regression equations generally were about an order of magnitude lower than computed yields.Regression analysis indicated that construction activity was a major contributor to transport of the constituents evaluated in this study except for total nitrogen and biochemical oxygen demand. Transport of total nitrogen and biochemical oxygen demand was dominated by point-source contributions. The two study basins that had the largest amounts of construction activity also had the highest total solids yields (1,300 and 1,500 tons per square mile per year). The highest total phosphorus yields (3.2 and 1.7 tons per square mile per year) attributable to nonpoint sources also occurred in these basins. Concentrations of chromium, copper, lead, nickel, and zinc were positively correlated with total solids concentrations at most of the study sites (Pearson product-moment correlation >0.50). The site having the highest median concentrations of chromium, copper, and nickel also was the site having the highest computed yield for total solids.

Silicon Nanoparticles with Surface Nitrogen: 90% Quantum Yield with Narrow Luminescence Bandwidth and the Ligand Structure Based Energy Law.

PubMed

Li, Qi; Luo, Tian-Yi; Zhou, Meng; Abroshan, Hadi; Huang, Jingchun; Kim, Hyung J; Rosi, Nathaniel L; Shao, Zhengzhong; Jin, Rongchao

2016-09-27

Silicon nanoparticles (NPs) have been widely accepted as an alternative material for typical quantum dots and commercial organic dyes in light-emitting and bioimaging applications owing to silicon's intrinsic merits of least toxicity, low cost, and high abundance. However, to date, how to improve Si nanoparticle photoluminescence (PL) performance (such as ultrahigh quantum yield, sharp emission peak, high stability) is still a major issue. Herein, we report surface nitrogen-capped Si NPs with PL quantum yield up to 90% and narrow PL bandwidth (full width at half-maximum (fwhm) ≈ 40 nm), which can compete with commercial dyes and typical quantum dots. Comprehensive studies have been conducted to unveil the influence of particle size, structure, and amount of surface ligand on the PL of Si NPs. Especially, a general ligand-structure-based PL energy law for surface nitrogen-capped Si NPs is identified in both experimental and theoretical analyses, and the underlying PL mechanisms are further discussed.

Effect of liquid nitrogen pre-treatment on various types of wool waste fibres for biogas production.

PubMed

Kuzmanova, Elena; Zhelev, Nikolai; Akunna, Joseph C

2018-05-01

This study investigated the role of liquid nitrogen (LN 2 ) in increasing microbial accessibility of wool proteins for biogas production. It involves a mechanical size reduction of four different types of raw wool fibres, namely, Blackface, Bluefaced Leicester, Texel and Scotch Mule, in presence of liquid nitrogen, followed by the determination of the methane production potential of the pre-treated wool fibres. The highest methane yield, 157.3 cm 3 g -1 VS, was obtained from pre-treated Scotch mule wool fibre culture, and represented more than 80% increase when compared to the yield obtained from its raw equivalent culture. The increase in biogas yield was attributed to the effectiveness of LN 2 in enhancing particle size reduction and the consequent increase in wool solubility and bioavailability. Results also showed that LN 2 pre-treatment can enhance size reduction but has limited effect on the molecular structure. The study also showed that the biogas potential of waste wool fibres varies with the type and source of wool.

Local formation of nitrogen-vacancy centers in diamond by swift heavy ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwartz, J.; Aloni, S.; Ogletree, D. F.

2014-12-03

In this paper, we exposed nitrogen-implanted diamonds to beams of swift heavy ions (~1 GeV, ~4 MeV/u) and find that these irradiations lead directly to the formation of nitrogen vacancy (NV) centers, without thermal annealing. We compare the photoluminescence intensities of swift heavy ion activated NV - centers to those formed by irradiation with low-energy electrons and by thermal annealing. NV - yields from irradiations with swift heavy ions are 0.1 of yields from low energy electrons and 0.02 of yields from thermal annealing. We discuss possible mechanisms of NV center formation by swift heavy ions such as electronic excitationsmore » and thermal spikes. While forming NV centers with low efficiency, swift heavy ions could enable the formation of three dimensional NV - assemblies over relatively large distances of tens of micrometers. Finally and further, our results show that NV center formation is a local probe of (partial) lattice damage relaxation induced by electronic excitations from swift heavy ions in diamond.« less

Total nutrient and sediment loads, trends, yields, and nontidal water-quality indicators for selected nontidal stations, Chesapeake Bay Watershed, 1985–2011

USGS Publications Warehouse

Langland, Michael J.; Blomquist, Joel D.; Moyer, Douglas; Hyer, Kenneth; Chanat, Jeffrey G.

2013-01-01

The U.S. Geological Survey, in cooperation with Chesapeake Bay Program (CBP) partners, routinely reports long-term concentration trends and monthly and annual constituent loads for stream water-quality monitoring stations across the Chesapeake Bay watershed. This report documents flow-adjusted trends in sediment and total nitrogen and phosphorus concentrations for 31 stations in the years 1985–2011 and for 32 stations in the years 2002–2011. Sediment and total nitrogen and phosphorus yields for 65 stations are presented for the years 2006–2011. A combined nontidal water-quality indicator (based on both trends and yields) indicates there are more stations classified as “improving water-quality trend and a low yield” than “degrading water-quality trend and a high yield” for total nitrogen. The same type of 2-way classification for total phosphorus and sediment results in equal numbers of stations in each indicator class.

Scattering of hydrogen, nitrogen and water ions from micro pore optic plates for application in spaceborne plasma instrumentation

NASA Astrophysics Data System (ADS)

Stude, Joan; Wieser, Martin; Barabash, Stas

2016-10-01

Time-of-flight mass spectrometers for upcoming space missions into enhanced radiation environments need to be small, light weight and energy efficient. Time-of-flight systems using surface interactions as start-event generation can be smaller than foil-type instruments. Start surfaces for such applications need to provide narrow angular scattering, high ionization yields and high secondary electron emissions to be effective. We measured the angular scattering, energy distribution and positive ionization yield of micro pore optics for incident hydrogen, nitrogen and water ions at 2 keV. Positive ionization yields of 2% for H+ , 0.5% for N+ and 0.2% for H2O+ were detected.

Nitrogen Source and Rate Management Improve Maize Productivity of Smallholders under Semiarid Climates.

PubMed

Amanullah; Iqbal, Asif; Ali, Ashraf; Fahad, Shah; Parmar, Brajendra

2016-01-01

Nitrogen is one of the most important factor affecting maize ( Zea mays L.) yield and income of smallholders under semiarid climates. Field experiments were conducted to investigate the impact of different N-fertilizer sources [urea, calcium ammonium nitrate (CAN), and ammonium sulfate (AS)] and rates (50, 100, 150, and 200 kg ha -1 ) on umber of rows ear -1 (NOR ear -1 ), number of seeds row -1 (NOS row -1 ), number of seeds ear -1 (NOS ear -1 ), number of ears per 100 plants (NOEP 100 plants -1 ), grain yield plant -1 , stover yield (kg ha -1 ), and shelling percentage (%) of maize genotypes "Local cultivars (Azam and Jalal) vs. hybrid (Pioneer-3025)." The experiment was conducted at the Agronomy Research Farm of the University of Agriculture Peshawar during summers of 2008 (year one) and 2010 (year two). The results revealed that the N treated (rest) plots (the average of all the experimental plots treated with N) had produced higher yield and yield components, and shelling percentage over N-control plots (plots where N was not applied). Application of nitrogen at the higher rate increased yield and yield components in maize (200 > 150 > 100 > 50 kg N ha -1 ). Application of AS and CAN had more beneficial impact on yield and yield components of maize as compared to urea (AS > CAN > urea). Hybrid maize (P-3025) produced significantly higher yield and yield components as well as higher shelling percentage than the two local cultivars (P-3025 > Jalal = Azam). Application of ammonium sulfate at the rate of 200 kg N ha -1 to hybrid maize was found most beneficial in terms of higher productivity and grower's income in the study area. For the two local cultivars, application of 150 kg N ha -1 was found more beneficial over 120 kg N ha -1 (recommended N rate) in terms of greater productivity and growers income.

Nitrogen Source and Rate Management Improve Maize Productivity of Smallholders under Semiarid Climates

PubMed Central

Amanullah; Iqbal, Asif; Ali, Ashraf; Fahad, Shah; Parmar, Brajendra

2016-01-01

Nitrogen is one of the most important factor affecting maize (Zea mays L.) yield and income of smallholders under semiarid climates. Field experiments were conducted to investigate the impact of different N-fertilizer sources [urea, calcium ammonium nitrate (CAN), and ammonium sulfate (AS)] and rates (50, 100, 150, and 200 kg ha−1) on umber of rows ear−1 (NOR ear−1), number of seeds row−1 (NOS row−1), number of seeds ear−1 (NOS ear−1), number of ears per 100 plants (NOEP 100 plants−1), grain yield plant−1, stover yield (kg ha−1), and shelling percentage (%) of maize genotypes “Local cultivars (Azam and Jalal) vs. hybrid (Pioneer-3025).” The experiment was conducted at the Agronomy Research Farm of the University of Agriculture Peshawar during summers of 2008 (year one) and 2010 (year two). The results revealed that the N treated (rest) plots (the average of all the experimental plots treated with N) had produced higher yield and yield components, and shelling percentage over N-control plots (plots where N was not applied). Application of nitrogen at the higher rate increased yield and yield components in maize (200 > 150 > 100 > 50 kg N ha−1). Application of AS and CAN had more beneficial impact on yield and yield components of maize as compared to urea (AS > CAN > urea). Hybrid maize (P-3025) produced significantly higher yield and yield components as well as higher shelling percentage than the two local cultivars (P-3025 > Jalal = Azam). Application of ammonium sulfate at the rate of 200 kg N ha−1 to hybrid maize was found most beneficial in terms of higher productivity and grower's income in the study area. For the two local cultivars, application of 150 kg N ha−1 was found more beneficial over 120 kg N ha−1 (recommended N rate) in terms of greater productivity and growers income. PMID:27965685

[Effects of applying controlled-release fertilizer blended with conventional nitrogen fertilizer on Chinese cabbage yield and quality as well as nitrogen losses].

PubMed

Yang, Jun-gang; Xu, Kai; Tong, Er-jian; Cao, Bing; Ni, Xiao-hui; Xu, Jun-xiang

2010-12-01

An open field experiment was conducted to study the effects of applying controlled-release fertilizer blended with rapidly available chemical N fertilizer on Chinese cabbage yield and quality as well as nitrogen losses, including ammonia volatilization and NO3- -N accumulation and leaching in Beijing suburb. The results showed that a combined application of 2:1 controlled-release fertilizer and urea fertilizer (total N rate 150 kg x hm(-2)) did not induce the reduction of Chinese cabbage yield, and decreased the leaf nitrate and organic acid contents significantly, compared with conventional urea N application (300 kg x hm(-2)), and had no significant difference in the cabbage yield and leaf nitrate content, compared with applying 150 kg x hm(-2) of urea N. The combined application of 2:1 controlled-release fertilizer and urea fertilizer improved the N use efficiency of Chinese cabbage, and reduced the ammonia volatilization and NO3- -N leaching. At harvest, the NO3- -N concentrations in 20-40, 60-80 and 80-100 cm soil layers were significantly lower in the combined application treatment than in urea N treatment.

Low-temperature hydrothermal pretreatment followed by dry anaerobic digestion: A sustainable strategy for manure waste management regarding energy recovery and nutrients availability.

PubMed

Huang, Weiwei; Zhao, Ziwen; Yuan, Tian; Huang, Wenli; Lei, Zhongfang; Zhang, Zhenya

2017-12-01

This study evaluated the feasibility of low-temperature hydrothermal (HT) pretreatment for improving dry anaerobic digestion (AD) of swine manure (SM) and nutrient elements reclamation, with specific goals to minimize the drawbacks of conventional HT process including high energy consumption, inhibitory compounds formation and unfavorable pH/alkalinity decrease. Pretreatment at 110-130°C for holding 30min increased the soluble organic carbon (SOC) concentration in SM by 13-26%. After being mixed with inocula, the pretreated SM was applied for dry AD tests successfully without initial pH adjustment, achieving a CH 4 yield of 280.18-328.93ml/g-VS fed (14-34% increase compared to that from raw SM). Energy assessment indicated a positive net gain of 0.95kJ/g-VS by adopting HT pretreatment at 130°C. Except for increment in CH 4 yield, low-temperature HT pretreatment also promoted organic-N mineralization, increasing N fractions in the digestate available for plants. After 70days' dry AD, a high ammonia-N to total nitrogen (TN) ratio of 71% was obtained for the SM sample pretreated at 130°C, in sharp contrast to that of 38% in raw SM. P bioavailability in the final digestate was not greatly affected by the HT pretreatment since the labile organics were mostly degraded after AD, in which P existing forms were influenced by the multivalent metals content in SM. Overall, 23-27% of the total P was potentially bioavailable in all digestates. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparative study of nitrogen conversion during pyrolysis of coconut fiber, its corresponding biochar and their blends with lignite.

PubMed

Liu, Zhengang; Balasubramanian, Rajasekhar

2014-01-01

In the present study, the conversion of fuel-N to HCN and NH3 was investigated during rapid pyrolysis of raw biomass (coconut fiber), its corresponding biochar and their blends with lignite within a temperature range of 600-900°C. The results showed that the raw biomass and the biochar showed totally different nitrogen partitioning between NH3 and HCN. HCN was the dominant nitrogen pollutant from pyrolysis of raw biomass, while for the biochar pyrolysis the yield of NH3 was slightly higher than that of HCN. Synergistic interactions occurred within both raw biomass/lignite and biochar/lignite blends, especially for the biochar/lignite blend, and resulted in reduced yields of HCN and NH3, decreased the total nitrogen percentage retained in the char and promoted harmless N2 formation. These findings suggest that biochar/lignite co-firing for energy production may have the enhanced benefit of reduced emissions of nitrogen pollutants than raw biomass/lignite. Copyright © 2013 Elsevier Ltd. All rights reserved.

Changes in the yield of chlorophyll a from dissolved available inorganic nitrogen after an enrichment event—applications for predicting eutrophication in coastal waters

NASA Astrophysics Data System (ADS)

Edwards, V. R.; Tett, P.; Jones, K. J.

2003-11-01

An understanding of the dynamic relationship between nitrogen supply and the formation of phytoplankton biomass is important in predicting and avoiding marine eutrophication. This relationship can be expressed as the short-term yield q of chlorophyll from dissolved available inorganic nitrogen (DAIN), the sum of nitrate, nitrite and ammonium. This paper communicates the results of a continuous culture nitrate enrichment experiment undertaken to investigate the cumulative yield of chlorophyll from DAIN ( q). The purposes of the study were: to acquire a better understanding of the relationship between chlorophyll formation and DAIN; to obtain values that could be used in models for predicting eutrophication. The results of a time series experiment carried out using microplankton (all organisms <200 μm in size) indicate that the parameter q does not have a single value but is affected by the ecophysiological response of phytoplankton to changing nutrient status after an enrichment event. It is also dependent on changes in the allocation of nitrogen between autotrophs and heterotrophs. The value of yield obtained at the height of the bloom can be represented by q (max) (2.35 μg chl (μmol N) -1). The post-bloom, steady state value of q can be represented by qeq (0.95 μg chl (μmol N) -1). The microcosm steady state yield was not significantly different from the median value obtained from synoptic studies of Scottish west coast waters. It is proposed that qeq is the most appropriate value for assessing the general potential for eutrophication resulting from continuous nutrient enrichment into coastal waters. It is further proposed that q (max) be used for cases of sporadic enrichment and where a short burst of unrestricted growth may be detrimental.

Preparation of high nitrogen compound and materials therefrom

DOEpatents

Huynh, My Hang V [Los Alamos, NM; Hiskey, Michael A [Los Alamos, NM

2006-10-10

The high-nitrogen compound of the formula ##STR00001## was prepared. Pyrolysis of the compound yields carbon nitrides C.sub.2N.sub.3 and C.sub.3N.sub.5. The carbon nitrides vary in their density, texture, and morphology.

Predicting success of methotrexate treatment by pretreatment HCG level and 24-hour HCG increment.

PubMed

Levin, Gabriel; Saleh, Narjes A; Haj-Yahya, Rani; Matan, Liat S; Avi, Benshushan

2018-04-01

To evaluate β-human chorionic gonadotropin (β-HCG) level and its 24-hour increment as predictors of successful methotrexate treatment for ectopic pregnancy. Data were retrospectively reviewed from women with ectopic pregnancy who were treated by single-dose methotrexate (50 mg/m 2 ) at a university hospital in Jerusalem, Israel, between January 1, 2000, and June 30, 2015. Serum β-HCG before treatment and its percentage increment in the 24 hours before treatment were compared between treatment success and failure groups. Sixty-nine women were included in the study. Single-dose methotrexate treatment was successful for 44 (63.8%) women. Both mean β-HCG level and its 24-hour increment were lower for women with successful treatment than for those with failed treatment (respectively, 1224 IU\\L vs 2362 IU\\L, P=0.018; and 13.5% vs 29.6%, P=0.009). Receiver operator characteristic curve analysis yielded cutoff values of 1600 IU\\L and 14% increment with a positive predictive value of 75% and 82%, respectively, for treatment success. β-HCG level and its 24-hour increment were independent predictors of treatment outcome by logistic regression (both P<0.01). A β-HCG increment of less than 14% in the 24 hours before single-dose methotrexate and serum β-HCG of less than 1600 IU\\L were found to be good predictors of treatment success. © 2017 International Federation of Gynecology and Obstetrics.

Root Ideotype Influences Nitrogen Transport and Assimilation in Maize

PubMed Central

Dechorgnat, Julie; Francis, Karen L.; Dhugga, Kanwarpal S.; Rafalski, J. A.; Tyerman, Stephen D.; Kaiser, Brent N.

2018-01-01

Maize (Zea mays, L.) yield is strongly influenced by external nitrogen inputs and their availability in the soil solution. Overuse of nitrogen-fertilizers can have detrimental ecological consequences through increased nitrogen pollution of water and the release of the potent greenhouse gas, nitrous oxide. To improve yield and overall nitrogen use efficiency (NUE), a deeper understanding of nitrogen uptake and utilization is required. This study examines the performance of two contrasting maize inbred lines, B73 and F44. F44 was selected in Florida on predominantly sandy acidic soils subject to nitrate leaching while B73 was selected in Iowa on rich mollisol soils. Transcriptional, enzymatic and nitrogen transport analytical tools were used to identify differences in their N absorption and utilization capabilities. Our results show that B73 and F44 differ significantly in their genetic, enzymatic, and biochemical root nitrogen transport and assimilatory pathways. The phenotypes show a strong genetic relationship linked to nitrogen form, where B73 showed a greater capacity for ammonium transport and assimilation whereas F44 preferred nitrate. The contrasting phenotypes are typified by differences in root system architecture (RSA) developed in the presence of both nitrate and ammonium. F44 crown roots were longer, had a higher surface area and volume with a greater lateral root number and density than B73. In contrast, B73 roots (primary, seminal, and crown) were more abundant but lacked the defining features of the F44 crown roots. An F1 hybrid between B73 and F44 mirrored the B73 nitrogen specificity and root architecture phenotypes, indicating complete dominance of the B73 inbred. This study highlights the important link between RSA and nitrogen management and why both variables need to be tested together when defining NUE improvements in any selection program. PMID:29740466

Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system.

PubMed

Guo, Ruiying; Li, Xiaolin; Christie, Peter; Chen, Qing; Zhang, Fusuo

2008-02-01

Two-year greenhouse cucumber experiments were conducted to investigate seasonal effects on fruit yield, dry matter allocation, and N uptake in a double-cropping system with different fertilizer management. Seasonal effects were much greater than fertilizer effects, and winter-spring (WS) cucumber attained higher fruit yields and N uptake than autumn-winter (AW) cucumber due to lower cumulative air temperatures during fruit maturation in the AW season. Fertilizer N application and apparent N loss under recommended N management (Nmr) decreased by 40-78% and 33-48% without yield loss compared to conventional N management (Nmt) over four growing seasons. However, there were no seasonal differences in N recommendations, taking into consideration seasonal differences in crop N demand, critical nutrient supply in the root zone and N mineralization rate.

Effects of Long-Term Nitrogen Management on Nitrogen Budgets of Irrigated No-till Corn

USDA-ARS?s Scientific Manuscript database

Effects of nitrogen management on irrigated no-till (NT) corn (Zea Mays L) yields were studied from the 1999 to 2015 growing seasons in a Fort Collins clay loam soil at the CSU ARDEC near Fort Collins, CO. The NT N fertilizer rates averaged 0, 34, 67, 134, 202 and 246 kg N ha-1. Fifteen corn plants...

Nitrogen and tillage management affect corn cellulosic yield, composition, and ethanol potential

USDA-ARS?s Scientific Manuscript database

Corn (Zea mays L.) stover and cobs remaining after grain harvest can serve as a feedstock for cellulosic ethanol production. Field trials were conducted at two locations in Minnesota over three years to determine how corn cellulosic yield composition and ethanol yield are influenced by tillage syste...

N fertilization for improved forage yields has little impact on nutritive value

USDA-ARS?s Scientific Manuscript database

Applications of soil amendments or fertilizers containing nitrogen are a routine part of most grass forage management strategies, with the primary goal of improving forage yields. But an increase in yield is usually accompanied by a decrease in nutritive value. In order to better evaluate this trade...

Yield potential and nitrogen requirements of Miscanthus × giganteus on eroded soil

USDA-ARS?s Scientific Manuscript database

Miscanthus × giganteus yield and fertilizer N requirements have been well studied in Europe and parts of the United States, but few reports have investigated its production on eroded claypan soils economically marginal for grain crops. This study was conducted to evaluate yield potential and fertili...

Demand impact and policy implications from taxing nitrogen fertilizer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foltz, J.C.

1992-12-01

Recent concern has focused on nitrogen fertilizer as a potential contaminant of groundwater. A demand function for fertilizer was developed using the quantity of fertilizer purchased, corn yield, real price of nitrogen fertilizer, lagged fertilizer purchases, a land value variable and the real price of corn as explanatory variables. Short and long-run price elasticities of demand were estimated to be inelastic. Support was found for the hypothesis that demand for nitrogen fertilizer has become more price inelastic over time. From a policy standpoint, a tax on nitrogen fertilizer may not be the most effective method to reduce consumption.

Water-quality characteristics, trends, and nutrient and sediment loads of streams in the Treyburn development area, North Carolina, 1988–2009

USGS Publications Warehouse

Fine, Jason M.; Harned, Douglas A.; Oblinger, Carolyn J.

2013-01-01

Streamflow and water-quality data, including concentrations of nutrients, metals, and pesticides, were collected from October 1988 through September 2009 at six sites in the Treyburn development study area. A review of water-quality data for streams in and near a 5,400-acre planned, mixed-use development in the Falls Lake watershed in the upper Neuse River Basin of North Carolina indicated only small-scale changes in water quality since the previous assessment of data collected from 1988 to 1998. Loads and yields were estimated for sediment and nutrients, and temporal trends were assessed for specific conductance, pH, and concentrations of dissolved oxygen, suspended sediment, and nutrients. Water-quality conditions for the Little River tributary and Mountain Creek may reflect development within these basins. The nitrogen and phosphorus concentrations at the Treyburn sites are low compared to sites nationally. The herbicides atrazine, metolachlor, prometon, and simazine were detected frequently at Mountain Creek and Little River tributary but concentrations are low compared to sites nationally. Little River tributary had the lowest median suspended-sediment yield over the 1988–2009 study period, whereas Flat River tributary had the largest median yield. The yields estimated for suspended sediment and nutrients were low compared to yields estimated for other basins in the Southeastern United States. Recent increasing trends were detected in total nitrogen concentration and suspended-sediment concentrations for Mountain Creek, and an increasing trend was detected in specific conductance for Little River tributary. Decreasing trends were detected in dissolved nitrite plus nitrate nitrogen, total ammonia plus organic nitrogen, sediment, and specific conductance for Flat River tributary. Water chemical concentrations, loads, yields, and trends for the Treyburn study sites reflect some effects of upstream development. These measures of water quality are generally low, however, compared to regional and national averages.

Effect of optimal daily fertigation on migration of water and salt in soil, root growth and fruit yield of cucumber (Cucumis sativus L.) in solar-greenhouse.

PubMed

Liang, Xinshu; Gao, Yinan; Zhang, Xiaoying; Tian, Yongqiang; Zhang, Zhenxian; Gao, Lihong

2014-01-01

Inappropriate and excessive irrigation and fertilization have led to the predominant decline of crop yields, and water and fertilizer use efficiency in intensive vegetable production systems in China. For many vegetables, fertigation can be applied daily according to the actual water and nutrient requirement of crops. A greenhouse study was therefore conducted to investigate the effect of daily fertigation on migration of water and salt in soil, and root growth and fruit yield of cucumber. The treatments included conventional interval fertigation, optimal interval fertigation and optimal daily fertigation. Generally, although soil under the treatment optimal interval fertigation received much lower fertilizers than soil under conventional interval fertigation, the treatment optimal interval fertigation did not statistically decrease the economic yield and fruit nutrition quality of cucumber when compare to conventional interval fertigation. In addition, the treatment optimal interval fertigation effectively avoided inorganic nitrogen accumulation in soil and significantly (P<0.05) increased the partial factor productivity of applied nitrogen by 88% and 209% in the early-spring and autumn-winter seasons, respectively, when compared to conventional interval fertigation. Although soils under the treatments optimal interval fertigation and optimal daily fertigation received the same amount of fertilizers, the treatment optimal daily fertigation maintained the relatively stable water, electrical conductivity and mineral nitrogen levels in surface soils, promoted fine root (<1.5 mm diameter) growth of cucumber, and eventually increased cucumber economic yield by 6.2% and 8.3% and partial factor productivity of applied nitrogen by 55% and 75% in the early-spring and autumn-winter seasons, respectively, when compared to the treatment optimal interval fertigation. These results suggested that optimal daily fertigation is a beneficial practice for improving crop yield and the water and fertilizers use efficiency in solar greenhouse.

Effect of Optimal Daily Fertigation on Migration of Water and Salt in Soil, Root Growth and Fruit Yield of Cucumber (Cucumis sativus L.) in Solar-Greenhouse

PubMed Central

Liang, Xinshu; Gao, Yinan; Zhang, Xiaoying; Tian, Yongqiang; Zhang, Zhenxian; Gao, Lihong

2014-01-01

Inappropriate and excessive irrigation and fertilization have led to the predominant decline of crop yields, and water and fertilizer use efficiency in intensive vegetable production systems in China. For many vegetables, fertigation can be applied daily according to the actual water and nutrient requirement of crops. A greenhouse study was therefore conducted to investigate the effect of daily fertigation on migration of water and salt in soil, and root growth and fruit yield of cucumber. The treatments included conventional interval fertigation, optimal interval fertigation and optimal daily fertigation. Generally, although soil under the treatment optimal interval fertigation received much lower fertilizers than soil under conventional interval fertigation, the treatment optimal interval fertigation did not statistically decrease the economic yield and fruit nutrition quality of cucumber when compare to conventional interval fertigation. In addition, the treatment optimal interval fertigation effectively avoided inorganic nitrogen accumulation in soil and significantly (P<0.05) increased the partial factor productivity of applied nitrogen by 88% and 209% in the early-spring and autumn-winter seasons, respectively, when compared to conventional interval fertigation. Although soils under the treatments optimal interval fertigation and optimal daily fertigation received the same amount of fertilizers, the treatment optimal daily fertigation maintained the relatively stable water, electrical conductivity and mineral nitrogen levels in surface soils, promoted fine root (<1.5 mm diameter) growth of cucumber, and eventually increased cucumber economic yield by 6.2% and 8.3% and partial factor productivity of applied nitrogen by 55% and 75% in the early-spring and autumn-winter seasons, respectively, when compared to the treatment optimal interval fertigation. These results suggested that optimal daily fertigation is a beneficial practice for improving crop yield and the water and fertilizers use efficiency in solar greenhouse. PMID:24475204

Nitrogen management for first-year corn after alfalfa

USDA-ARS?s Scientific Manuscript database

Rotating alfalfa with corn can increase corn yield potential due to improved soil physical properties that enhance water infiltration and root extension, altered soil microbial communities, and reduced pest pressure. In addition, fertilizer nitrogen (N) requirements are commonly reduced by about 100...

Microstructural Analysis of TiAl x N y O z Coatings Fabricated by DC Reactive Sputtering

NASA Astrophysics Data System (ADS)

García-González, L.; Hernández-Torres, J.; Flores-Ramírez, N.; Martínez-Castillo, J.; García-Ramírez, P. J.; Muñoz-Saldaña, J.; Espinoza-Beltrán, F. J.

2009-02-01

TiAl x N y O z coatings were prepared by DC reactive sputtering on AISI D2 tool steel substrates, using a target of Ti-Al-O fabricated from a mixture of powders of Ti (22.60 wt.%), Al (24.77 wt.%), and O (52.63 wt.%). The coatings were deposited on substrates at room temperature in a reactive atmosphere of nitrogen and argon under a pressure of 8.5 × 10-3 mbar. X-ray diffraction, electron dispersive spectroscopy, Raman scattering, and nanoindentation techniques were employed to investigate the coatings. The results show that the increment in the nitrogen flow affects the structure and the mechanical properties of the coatings. The sample with the lowest nitrogen flow presented the highest hardness (10.5 GPa) and the Young’s modulus (179.5 GPa). The hardness of the coatings TiAl x N y O z as a function of crystalline grain size shows a behavior consistent with the Hall-Petch relation.

Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

PubMed Central

Qin, Wei; Hu, Chunsheng; Oenema, Oene

2015-01-01

Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge. PMID:26586114

Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis.

PubMed

Qin, Wei; Hu, Chunsheng; Oenema, Oene

2015-11-20

Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

NASA Astrophysics Data System (ADS)

Qin, Wei; Hu, Chunsheng; Oenema, Oene

2015-11-01

Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

Observations of Uranus' satellites: Bibliography and literature search

NASA Technical Reports Server (NTRS)

Jacobson, R. A.

1985-01-01

A literature search has yielded more than 10,000 observations of the satellites of Uranus made from 1787 to 1985. The type (photographic, micrometer) and the number of observations are tabulated in 5 year increments and a complete bibliography is provided.

Visible sub-band gap photoelectron emission from nitrogen doped and undoped polycrystalline diamond films

NASA Astrophysics Data System (ADS)

Elfimchev, S.; Chandran, M.; Akhvlediani, R.; Hoffman, A.

2017-07-01

In this study the origin of visible sub-band gap photoelectron emission (PEE) from polycrystalline diamond films is investigated. The PEE yields as a function of temperature were studied in the wavelengths range of 360-520 nm. Based on the comparison of electron emission yields from diamond films deposited on silicon and molybdenum substrates, with different thicknesses and nitrogen doping levels, we suggested that photoelectrons are generated from nitrogen related centers in diamond. Our results show that diamond film thickness and substrate material have no significant influence on the PEE yield. We found that nanocrystalline diamond films have low electron emission yields, compared to microcrystalline diamond, due to the presence of high amount of defects in the former, which trap excited electrons before escaping into the vacuum. However, the low PEE yield of nanocrystalline diamond films was found to increase with temperature. The phenomenon was explained by the trap assisted photon enhanced thermionic emission (ta-PETE) model. According to the ta-PETE model, photoelectrons are trapped by shallow traps, followed by thermal excitation at elevated temperatures and escape into the vacuum. Activation energies of trap levels were estimated for undoped nanocrystalline, undoped microcrystalline and N-doped diamond films using the Richardson-Dushman equation, which gives 0.13, 0.39 and 0.04 eV, respectively. Such low activation energy of trap levels makes the ta-PETE process very effective at elevated temperatures.

Interactions of Nitrogen Source and Rate and Weed Removal Timing Relative to Nitrogen Content in Corn and Weeds and Corn Grain Yield

PubMed Central

Knight, Alexandra M.; Heiniger, Ronnie W.; Smyth, T. Jot

2017-01-01

Adequate fertility combined with effective weed management is important in maximizing corn (Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth (Amaranthus palmeri S. Wats.) and large crabgrass (Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield. PMID:28487878

Tropical legume crop rotation and nitrogen fertilizer effects on agronomic and nitrogen efficiency of rice.

PubMed

Rahman, Motior M; Islam, Aminul M; Azirun, Sofian M; Boyce, Amru N

2014-01-01

Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m(-2) preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m(-2). No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m(-2) achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13-23% higher grain yield than rice after fallow rotation with 8 g N m(-2). The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m(-2) can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m(-2). The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.

Surface-water characteristics and quality on the Osage Reservation, Osage County, Oklahoma, 1999

USGS Publications Warehouse

Abbott, Marvin M.; Tortorelli, Robert L.

2002-01-01

Concern about the effects of early oil-industry practices of surface disposal of produced-brine water prompted an investigation of the surface-water quality on the Osage Reservation. About 38,600 oil wells have been drilled on the Osage Reservation since drilling began in 1896. The Osage Reservation comprises three major drainage basins. The Caney River Basin is in the northeast, the Bird Creek Basin is in the southeast, and the Salt Creek Basin in the west. Variations in streamflow on the Osage Reservation during a year primarily result from variations in the quantity and frequency of rainfall, evapotranspiration, and reservoir operations. Most streams do not flow during low rainfall periods in late summer, early fall, and in winter. Percent of mean annual discharge is largest during March through June, averaging 54 to 62 percent and smallest during December, January, July, and August, averaging only 14 to 21 percent. The basin areas of Caney River in the reservation (251 square miles), Salt Creek (273 square miles), and Sand Creek (227 square miles) are about the same and the basin areas of the Bird Creek Basin (418 square miles) and Homily Creek Basin (383 square miles) are similar in area. One hundred forty surface-water sites were sampled once during either February, March or August 1999. The surface-drainage areas, incremental basins, between sample sites along a stream, range in size from 0.26 to 123 square miles with a median of 8.6 square miles. Total number of oil wells upgradient of the samples sites is 31,432 or 80 percent of the total in the reservation. The total number of oil wells in the Caney River Basin in the reservation (2,975 wells), Salt Creek Basin (4,619 wells), and Sand Creek Basin (3,858 wells) are about the same and the total number of oil wells in the Bird Creek Basin (8,858 wells) and Hominy Creek Basin (7,842 wells) are similar. The number of oil wells per square mile in the incremental basins ranges for 0.86 to 154. Surface-water quality monitoring had been conducted previously at two sites included in this study. Dissolved chloride concentrations for the two samples collected during 1999 were equaled or exceeded at both sites by the historical data. There is no statistically significant difference between the distribution of the dissolved chloride concentrations from the surface water and nearby ground-water samples. The surface-water quality samples had significantly lesser concentrations of dissolved solids, sulfate, and nitrite plus nitrate as nitrogen than the ground-water samples. Chloride yield, reported in tons per day per square mile, is the chloride load divided by the basin area upstream of the sample site. The mean of the chloride yields for all the samples was 0.07 ton per day per square mile. Many sample locations where yields were greater than 0.07 ton per day per square mile were areas where dissolved chloride concentrations from surface-water samples were greater than 250 milligrams per liter in an earlier water-quality investigation. An investigation of possible relations between the surface-water quality data and the oil-well construction data for the incremental basins and for 1-mile radial distance upstream in the incremental basins was conducted. The oil-well data also were grouped by the time periods of activity into pre-1930, 1930 to 1970, and post-1970. These groups attempt to account for differences in industry drilling and producing practices associated with various periods. No statistically significant correlations were found between the surface-water quality data and the oil-well construction data.

Biomass Content Governs Fermentation Rate in Nitrogen-Deficient Wine Musts

PubMed Central

Varela, Cristian; Pizarro, Francisco; Agosin, Eduardo

2004-01-01

Problematic fermentations are common in the wine industry. Assimilable nitrogen deficiency is the most prevalent cause of sluggish fermentations and can reduce fermentation rates significantly. A lack of nitrogen diminishes a yeast's metabolic activity, as well as the biomass yield, although it has not been clear which of these two interdependent factors is more significant in sluggish fermentations. Under winemaking conditions with different initial nitrogen concentrations, metabolic flux analysis was used to isolate the effects. We quantified yeast physiology and identified key metabolic fluxes. We also performed cell concentration experiments to establish how biomass yield affects the fermentation rate. Intracellular analysis showed that trehalose accumulation, which is highly correlated with ethanol production, could be responsible for sustaining cell viability in nitrogen-poor musts independent of the initial assimilable nitrogen content. Other than the higher initial maintenance costs in sluggish fermentations, the main difference between normal and sluggish fermentations was that the metabolic flux distributions in nitrogen-deficient cultures revealed that the specific sugar uptake rate was substantially lower. The results of cell concentration experiments, however, showed that in spite of lower sugar uptake, adding biomass from sluggish cultures not only reduced the time to finish a problematic fermentation but also was less likely to affect the quality of the resulting wine as it did not alter the chemistry of the must. PMID:15184136

Nitrogen Recycling and Flowering Time in Perennial Bioenergy Crops

PubMed Central

Schwartz, Christopher; Amasino, Richard

2013-01-01

Perennials have a number of traits important for profitability and sustainability of a biofuel crop. Perennialism is generally defined as the ability to grow and reproduce in multiple years. In temperate climates, many perennial plants enter dormancy during winter and recycle nutrients, such as nitrogen, to below ground structures for the next growing season. Nitrogen is expensive to produce and application of nitrogen increases the potent greenhouse gas NOx. Perennial bioenergy crops have been evaluated for biomass yields with nitrogen fertilization, location, year, and genotype as variables. Flowering time and dormancy are closely related to the N recycling program. Substantial variation for flowering time and dormancy has been identified in the switchgrass (Panicum virgatum L.) species, which provides a source to identify the genetic components of N recycling, and for use in breeding programs. Some studies have addressed recycling specifically, but flowering time and developmental differences were largely ignored, complicating interpretation of the results. Future studies on recycling need to appreciate plant developmental stage to allow comparison between experiments. A perennial/annual model(s) and more environmentally controlled experiments would be useful to determine the genetic components of nitrogen recycling. Increasing biomass yield per unit of nitrogen by maximizing recycling might mean the difference for profitability of a biofuel crop and has the added benefit of minimizing negative environmental effects from agriculture. PMID:23626592

The effect of functional forms of nitrogen on fuel-NOx emissions.

PubMed

Zhang, Linghui; Su, Dagen; Zhong, Mingfeng

2015-01-01

This work explores the effects of different nitrogen functional forms on fuel-NOx emissions at 900 °C. The majority of tests are performed with an excess air coefficient of 1.4. Fuel-NOx is detected by measuring N-(1-naphthyl) ethylenediamine dihydrochloride (C₁₂H₁₆Cl₂N₂) via spectrophotometry. The different functional forms of nitrogen in the raw materials are identified by using X-ray photoelectron spectroscopy (XPS). A reliable density functional theory (DFT) method at the B3LYP/6-311++G** level is employed to investigate the reaction pathways of all functional forms of nitrogen during combustion. The results indicate that the functional forms of nitrogen influence the formation of nitrogen oxides. While under the same experimental conditions, fuel-NOx emissions increase by using less activation energy and nitrogen-containing groups with poor thermal stability. It is determined that fuel-NOx emissions vary in the following order: glycine > pyrrole > pyridine > methylenedi-p-phenylene diisocyanate (MDI). Glycine is the chain structure of amino acids in waste-leather and has low activation energy and poor thermal stability. With these properties, it is noted that glycine produces the most fuel-NOx in all of the raw materials studied. More pyrrole than pyridine in coal lead to high yields of fuel-NOx. The lowest yields of fuel-NO x are obtained using polyurethanes in waste-PU.

Model Identification and FE Simulations: Effect of Different Yield Loci and Hardening Laws in Sheet Forming

NASA Astrophysics Data System (ADS)

Flores, P.; Duchêne, L.; Lelotte, T.; Bouffioux, C.; El Houdaigui, F.; Van Bael, A.; He, S.; Duflou, J.; Habraken, A. M.

2005-08-01

The bi-axial experimental equipment developed by Flores enables to perform Baushinger shear tests and successive or simultaneous simple shear tests and plane-strain tests. Such experiments and classical tensile tests investigate the material behavior in order to identify the yield locus and the hardening models. With tests performed on two steel grades, the methods applied to identify classical yield surfaces such as Hill or Hosford ones as well as isotropic Swift type hardening or kinematic Armstrong-Frederick hardening models are explained. Comparison with the Taylor-Bishop-Hill yield locus is also provided. The effect of both yield locus and hardening model choice will be presented for two applications: Single Point Incremental Forming (SPIF) and a cup deep drawing.

Designing a new cropping system for high productivity and sustainable water usage under climate change

NASA Astrophysics Data System (ADS)

Meng, Qingfeng; Wang, Hongfei; Yan, Peng; Pan, Junxiao; Lu, Dianjun; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

2017-02-01

The food supply is being increasingly challenged by climate change and water scarcity. However, incremental changes in traditional cropping systems have achieved only limited success in meeting these multiple challenges. In this study, we applied a systematic approach, using model simulation and data from two groups of field studies conducted in the North China Plain, to develop a new cropping system that improves yield and uses water in a sustainable manner. Due to significant warming, we identified a double-maize (M-M; Zea mays L.) cropping system that replaced the traditional winter wheat (Triticum aestivum L.) -summer maize system. The M-M system improved yield by 14-31% compared with the conventionally managed wheat-maize system, and achieved similar yield compared with the incrementally adapted wheat-maize system with the optimized cultivars, planting dates, planting density and water management. More importantly, water usage was lower in the M-M system than in the wheat-maize system, and the rate of water usage was sustainable (net groundwater usage was ≤150 mm yr-1). Our study indicated that systematic assessment of adaptation and cropping system scale have great potential to address the multiple food supply challenges under changing climatic conditions.

Vibration Penalty Estimates for Indoor Annoyance Caused by Sonic Boom

NASA Technical Reports Server (NTRS)

Rathsam, Jonathan; Klos, Jacob

2016-01-01

Commercial supersonic flight is currently forbidden over land because sonic booms have historically caused unacceptable annoyance levels in overflown communities. NASA is providing data and expertise to noise regulators as they consider relaxing the ban for future quiet supersonic aircraft. One key objective is a predictive model for indoor annoyance based on factors such as noise and indoor vibration levels. The current study quantified the increment in indoor sonic boom annoyance when sonic booms can be felt directly through structural vibrations in addition to being heard. A shaker mounted below each chair in the sonic boom simulator emulated vibrations transmitting through the structure to that chair. The vibration amplitudes were determined from numeric models of a large range of residential structures excited by the same sonic boom waveforms used in the experiment. The analysis yielded vibration penalties, which are the increments in sound level needed to increase annoyance as much as the vibration does. For sonic booms at acoustic levels from 75 to 84 dB Perceived Level, vibration signals with lower amplitudes (+1 sigma) yielded penalties from 0 to 5 dB, and vibration signals with higher amplitudes (+3 sigma) yielded penalties from 6 to 10 dB.

Nitrogen in Chinese coals

USGS Publications Warehouse

Wu, D.; Lei, J.; Zheng, B.; Tang, X.; Wang, M.; Hu, Jiawen; Li, S.; Wang, B.; Finkelman, R.B.

2011-01-01

Three hundred and six coal samples were taken from main coal mines of twenty-six provinces, autonomous regions, and municipalities in China, according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields. Nitrogen was determined by using the Kjeldahl method at U. S. Geological Survey (USGS), which exhibit a normal frequency distribution. The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%. Nitrogen in coal exists primarily in organic form. There is a slight positive relationship between nitrogen content and coal ranking. ?? 2011 Science Press, Institute of Geochemistry, CAS and Springer Berlin Heidelberg.

Evaluation of natural materials as exogenous carbon sources for biological treatment of low carbon-to-nitrogen wastewater.

PubMed

Ramírez-Godínez, Juan; Beltrán-Hernández, Icela; Álvarez-Hernández, Alejandro; Coronel-Olivares, Claudia; Contreras-López, Elizabeth; Quezada-Cruz, Maribel; Vázquez-Rodríguez, Gabriela

2015-01-01

In the bacterial processes involved in the mitigation of nitrogen pollution, an adequately high carbon-to-nitrogen (C : N) ratio is key to sustain denitrification. We evaluated three natural materials (woodchips, barley grains, and peanut shells) as carbon sources for low C : N wastewater. The amount of organic matter released from these materials to aqueous media was evaluated, as well as their pollution swapping potential by measuring the release of total Kjeldahl nitrogen, N-NH4 (+), NO2 (-), and NO3 (-), and total phosphorous. Barley grains yielded the highest amount of organic matter, which also showed to be the most easily biodegradable. Woodchips and peanut shells released carbon rather steadily and so they would not require frequent replenishment from biological reactors. These materials produced eluates with lower concentrations of nutrients than the leachates from barley grains. However, as woodchips yielded lower amounts of suspended solids, they constitute an adequate exogenous source for the biological treatment of carbon-deficient effluents.

Evaluation of Natural Materials as Exogenous Carbon Sources for Biological Treatment of Low Carbon-to-Nitrogen Wastewater

PubMed Central

Ramírez-Godínez, Juan; Beltrán-Hernández, Icela; Álvarez-Hernández, Alejandro; Coronel-Olivares, Claudia; Contreras-López, Elizabeth; Quezada-Cruz, Maribel

2015-01-01

In the bacterial processes involved in the mitigation of nitrogen pollution, an adequately high carbon-to-nitrogen (C : N) ratio is key to sustain denitrification. We evaluated three natural materials (woodchips, barley grains, and peanut shells) as carbon sources for low C : N wastewater. The amount of organic matter released from these materials to aqueous media was evaluated, as well as their pollution swapping potential by measuring the release of total Kjeldahl nitrogen, N-NH4 +, NO2 −, and NO3 −, and total phosphorous. Barley grains yielded the highest amount of organic matter, which also showed to be the most easily biodegradable. Woodchips and peanut shells released carbon rather steadily and so they would not require frequent replenishment from biological reactors. These materials produced eluates with lower concentrations of nutrients than the leachates from barley grains. However, as woodchips yielded lower amounts of suspended solids, they constitute an adequate exogenous source for the biological treatment of carbon-deficient effluents. PMID:26495313

Bio-energy Alliance High-Tonnage Bio-energy Crop Production and Conversion into Conventional Fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capareda, Sergio; El-Halwagi, Mahmoud; Hall, Kenneth R.

2012-11-30

Maintaining a predictable and sustainable supply of feedstock for bioenergy conversion is a major goal to facilitate the efficient transition to cellulosic biofuels. Our work provides insight into the complex interactions among agronomic, edaphic, and climatic factors that affect the sustainability of bioenergy crop yields. Our results provide science-based agronomic response measures that document how to better manage bioenergy sorghum production from planting to harvest. We show that harvest aids provide no significant benefit as a means to decrease harvest moisture or improve bioenergy yields. Our efforts to identify optimal seeding rates under varied edaphic and climatological conditions reinforce previousmore » findings that sorghum is a resilient plant that can efficiently adapt to changing population pressures by decreasing or increasing the numbers of additional shoots or tillers – where optimal seeding rates for high biomass photoperiod sensitive sorghum is 60,000 to 70,000 seeds per acre and 100,000 to 120,000 seeds per acre for sweet varieties. Our varietal adaptability trials revealed that high biomass photoperiod sensitive energy sorghum consistently outperforms conventional photoperiod insensitive sweet sorghum and high biomass forage sorghum as the preferred bioenergy sorghum type, with combined theoretical yields of both cellulosic and fermentable water-soluble sugars producing an average yield of 1,035 gallons of EtOH per acre. Our nitrogen trials reveal that sweet sorghums produce ample amounts of water-soluble sugars with minimal increases in nitrogen inputs, and that excess nitrogen can affect minor increases in biomass yields and cellulosic sugars but decrease bioenergy quality by decreasing water-soluble sugar concentrations and increasing ash content, specifically when plant tissue nitrogen concentrations exceed 0.6 %, dry weight basis. Finally, through our growth and re-growth trials, we show that single-cut high biomass sorghum bioenergy yields significantly exceed those of multiple-cut high biomass sorghum systems. Our agronomic yield and quality data will be uploaded to the Bioenergy KDF Website before the end of February 2013, with a date for public access to be determined pending peer-reviewed publication of our findings.« less

Irrigation and Nitrogen Regimes Promote the Use of Soil Water and Nitrate Nitrogen from Deep Soil Layers by Regulating Root Growth in Wheat.

PubMed

Liu, Weixing; Ma, Geng; Wang, Chenyang; Wang, Jiarui; Lu, Hongfang; Li, Shasha; Feng, Wei; Xie, Yingxin; Ma, Dongyun; Kang, Guozhang

2018-01-01

Unreasonably high irrigation levels and excessive nitrogen (N) supplementation are common occurrences in the North China Plain that affect winter wheat production. Therefore, a 6-yr-long stationary field experiment was conducted to investigate the effects of irrigation and N regimes on root development and their relationship with soil water and N use in different soil layers. Compared to the non-irrigated treatment (W0), a single irrigation at jointing (W1) significantly increased yield by 3.6-45.6%. With increases in water (W2, a second irrigation at flowering), grain yield was significantly improved by 14.1-45.3% compared to the W1 treatments during the drier growing seasons (2010-2011, 2012-2013, and 2015-2016). However, under sufficient pre-sowing soil moisture conditions, grain yield was not increased, and water use efficiency (WUE) decreased significantly in the W2 treatments during normal precipitation seasons (2011-2012, 2013-2014, and 2014-2015). Irrigating the soil twice inhibited root growth into the deeper soil depth profiles and thus weakened the utilization of soil water and NO 3 -N from the deep soil layers. N applications increased yield by 19.1-64.5%, with a corresponding increase in WUE of 66.9-83.9% compared to the no-N treatment (N0). However, there was no further increase in grain yield and the WUE response when N rates exceeded 240 and 180 kg N ha -1 , respectively. A N application rate of 240 kg ha -1 facilitated root growth in the deep soil layers, which was conducive to utilization of soil water and NO 3 -N and also in reducing the residual NO 3 -N. Correlation analysis indicated that the grain yield was significantly positively correlated with soil water storage (SWS) and nitrate nitrogen accumulation (SNA) prior to sowing. Therefore, N rates of 180-240 kg ha -1 with two irrigations can reduce the risk of yield loss that occurs due to reduced precipitation during the wheat growing seasons, while under better soil moisture conditions, a single irrigation at jointing was effective and more economical.

Microbial denitrogenation of fossil fuels.

PubMed

Benedik, M J; Gibbs, P R; Riddle, R R; Willson, R C

1998-09-01

The microbial degradation of nitrogen compounds from fossil fuels is important because of the contribution these contaminants make to the formation of nitrogen oxides (NOx) and hence to air pollution and acid rain. They also contribute to catalyst poisoning during the refining of crude oil, thus reducing process yields. We review the current status of microbial degradation of aromatic nitrogen compounds and discuss the potential of microbial processes to alleviate these problems.

Rice production with minimal irrigation and no nitrogen fertilizer by intensive use of treated municipal wastewater.

PubMed

Muramatsu, Ayumi; Watanabe, Toru; Sasaki, Atsushi; Ito, Hiroaki; Kajihara, Akihiko

2014-01-01

We designed a new cultivation system of rice with circulated irrigation to remove nitrogen from treated municipal wastewater effectively and assessed the possibility of nitrogen removal in the new system without any adverse effects on rice production through bench-scale experiments through two seasons. Overgrowth of the rice plant, which can lead to lodging and tasteless rice, was found in the first season probably because nitrogen supply based on standard practice in normal paddy fields was too much in the closed irrigation system. In the second season, therefore, the amount of treated wastewater initially applied to the system was reduced but this resulted in a considerably decreased yield. On the other hand, the taste of the rice was significantly improved. The two-season experiments revealed that the new system enabled rice production with minimal irrigation (approximately 50% on the yield base compared to normal paddy fields) and no nitrogen fertilizer. The system also achieved >95% removal of nitrogen from the treated wastewater used for circulated irrigation. The accumulation of harmful metals in the rice was not observed after one season of cultivation in the new system. The accumulation after cultivation using the same soil repeatedly for a longer time should be examined by further studies.

AMT1;1 transgenic rice plants with enhanced NH4 + permeability show superior growth and higher yield under optimal and suboptimal NH4 + conditions

PubMed Central

Rothstein, Steven J.

2014-01-01

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4 +). The NH4 + uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4 + transport in rice plants. However, little is known about its involvement in NH4 + uptake in rice roots and subsequent effects on NH4 + assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4 + permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4 + content in the shoots and roots than the WT. Direct NH4 + fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4 + contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4 + levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions. PMID:24420570

Non-equilbrium dynamics of ecosystem processes in a changing world

NASA Astrophysics Data System (ADS)

Reid, Joseph Pignatello

The relatively mild and stable climate of the last 10,000 years betrays a history of environmental variability and rapid changes. Humans have recently accelerated global environmental change, ushering in the Anthropocene. Meeting accelerating demands for food, energy, and goods and services has accelerated species extinctions, shows of reactive nitrogen and phosphorus, and warming of the atmosphere. I address the over- arching question of how ecosystems will respond to changing and variable environments through several focused studies. Each study examines an ecosystem response to ex- pected environmental changes in the future. To address how the changing environment affects the sizes and turnover rates of slowly and quickly cycling soil carbon pools, I analyzed the responses of grassland soils to simulated species diversity loss, increased deposition of nitrogen and increased atmospheric CO2. I used a soil respiration experiment to fit models of soil carbon pool turnover to respired carbon dioxide. Species diversity, nitrogen deposition and atmospheric CO2 had no effect on the total soil carbon after 8 years of treatments. Although total soil carbon did not change, the rates of cycling in the fast and slow pools changed in response to elevated CO2 and diversity loss treatments. Nitrogen treatments increased the size of the slowly cycling carbon pool. Precipitation variability has increased around most of the world since the industrial revolution. I used plant mesocosms in a greenhouse experiment to manipulate rainfall variability and mycorrhizal associations. I hypothesized that 1) rewetting events re- sult in higher nitrogen uxes from dry soils than moist soils, 2) a repeated pattern of events caused by low-frequency simulated rainfall results in higher nitrogen uxes and 3) the better ability of ectomycorrhizal fungi relative to arbuscular mycorrhizal fungi to decompose and assimilate organic nitrogen reduces leaching losses of nitrogen caused by both rewetting events and patterns of repeated events. In response to individual rewetting events, drier soils released more nitrate and total nitrogen than wetter soils. Ectomycorrhizal treatments slightly reduced the effect of antecedent soil moisture on total nitrogen and nitrate losses from rewetting events. This supports my hypotheses iii that drier soils release more nitrogen after rainfall events and that ectomycorrhizal asso- ciations can reduce nitrogen losses associated with soil rewetting events. However, only ammonium increased in proportion to the variance in rainfall quantity and mycorrhizal treatments had no effect, largely refuting my hypothesis that soils would release more nitrogen when exposed to higher variability patterns of rainfall. The current pressures that humans place on the environment are only expected to increase as populations and incomes continue to climb. The more than 9 billion peo- ple expected on the planet by 2050 require food, energy, shelter and other goods and services. Historically, producing those benefits has resulted in environmental damage, especially nitrogen pollution through agricultural fertilizers, atmospheric nitrogen de- position and human waste. I developed a model to test the effectiveness of various technologies and strategies to reduce the environmental harms associated with meeting the needs of human well-being. I tested the effects of increased crop yields through genetic gains, increased nutrient efficiency in agricultural systems, reduced meat con- sumption, reduced food waste and improved wastewater treatment on nitrogen yield. The tested levers were mildly effective at reducing nitrogen yield from the baseline busi- ness as usual (BAU) scenario, but still resulted in at least 15% greater nitrogen yield than the present. Applied in combination, in the 'Super Ag' scenario, the levers out performed the sum of their contributions when applied singly. Some levers were more effective in some places than others. Taken together, these results suggest that there is no one solution, and that solutions will be most effective when developed for local conditions and applied in combination.

Long-term Tillage and Cropping Sequence Effect on Dryland Crop Yields and Carbon and Nitrogen Cycling

USDA-ARS?s Scientific Manuscript database

Improved management practices are needed to increase dryland crop yields and soil organic matter compared with conventional farming practices in the northern Great Plains. We evaluated the 21-yr effect of tillage and cropping sequence on dryland grain and biomass (stems + leaves) yields and N uptake...

Isotopic disproportionation during hydrogen isotopic analysis of nitrogen-bearing organic compounds

USGS Publications Warehouse

Nair, Sreejesh; Geilmann, Heike; Coplen, Tyler B.; Qi, Haiping; Gehre, Matthias; Schimmelmann, Arndt; Brand, Willi A.

2015-01-01

Rationale High-precision hydrogen isotope ratio analysis of nitrogen-bearing organic materials using high-temperature conversion (HTC) techniques has proven troublesome in the past. Formation of reaction products other than molecular hydrogen (H2) has been suspected as a possible cause of incomplete H2 yield and hydrogen isotopic fractionation. Methods The classical HTC reactor setup and a modified version including elemental chromium, both operated at temperatures in excess of 1400 °C, have been compared using a selection of nitrogen-bearing organic compounds, including caffeine. A focus of the experiments was to avoid or suppress hydrogen cyanide (HCN) formation and to reach quantitative H2 yields. The technique also was optimized to provide acceptable sample throughput. Results The classical HTC reaction of a number of selected compounds exhibited H2 yields from 60 to 90 %. Yields close to 100 % were measured for the experiments with the chromium-enhanced reactor. The δ2H values also were substantially different between the two types of experiments. For the majority of the compounds studied, a highly significant relationship was observed between the amount of missing H2and the number of nitrogen atoms in the molecules, suggesting the pyrolytic formation of HCN as a byproduct. A similar linear relationship was found between the amount of missing H2 and the observed hydrogen isotopic result, reflecting isotopic fractionation. Conclusions The classical HTC technique to produce H2 from organic materials using high temperatures in the presence of glassy carbon is not suitable for nitrogen-bearing compounds. Adding chromium to the reaction zone improves the yield to 100 % in most cases. The initial formation of HCN is accompanied by a strong hydrogen isotope effect, with the observed hydrogen isotope results on H2 being substantially shifted to more negative δ2H values. The reaction can be understood as an initial disproportionation leading to H2 and HCN with the HCN-hydrogen systematically enriched in 2H by more than 50 ‰. In the reaction of HCN with chromium, H2 and chromium-containing solid residues are formed quantitatively.

31 CFR 356.20 - How does the Treasury determine auction awards?

Code of Federal Regulations, 2010 CFR

2010-07-01

... and bond issues. We set the interest rate at a 1/8 of one percent increment. If a Treasury inflation-protected securities auction results in a negative or zero yield, the interest rate will be set at zero, and...

High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI)

NASA Astrophysics Data System (ADS)

Lawrence, J. P.; Anand, J. S.; Vande Hey, J. D.; White, J.; Leigh, R. R.; Monks, P. S.; Leigh, R. J.

2015-11-01

Nitrogen dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI) remote sensing system. The ANDI system includes an imaging UV/Vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2) concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK on a cloud-free winter day in February 2013. Retrieved NO2 columns gridded to a surface resolution of 80 m × 20 m revealed hotspots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands) and a power station (Ratcliffe-on-Soar). In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hotspots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

Geochemistry and characteristics of nitrogen transport at a confined animal feeding operation in a coastal plain agricultural watershed, and implications for nutrient loading in the Neuse River basin, North Carolina, 1999-2002

USGS Publications Warehouse

Spruill, T.B.; Tesoriero, A.J.; Mew, H.E.; Farrell, K.M.; Harden, S.L.; Colosimo, A.B.; Kraemer, S.R.

2005-01-01

Chemical, geologic, hydrologic, and age-dating information collected between 1999 and 2002 were used to examine the transport of contaminants, primarily nitrogen, in ground water and the pathways to surface water in a coastal plain setting in North Carolina. Data were collected from more than 35 wells and 4 surface-water sampling sites located in a 0.59 square-mile basin to examine detailed hydrogeology and geochemical processes affecting nutrient fate and transport. Two additional surface-water sampling sites were located downstream from the primary study site to evaluate basin-scale effects. Chemical and flow data also were collected at an additional 10 sites in the Coastal Plain portion of the Neuse River basin located between Kinston and New Bern, North Carolina, to evaluate loads transported in the Neuse River and primary tributary basins. At the Lizzie Research Station study site in North Carolina, horizontal flow is induced by the presence of a confining unit at shallow depth. Age-dating, chemical, and piezometric data indicate that horizontal flow from the surficial aquifer is the dominant source of ground water to streamflow. Nitrogen applied on cultivated fields at the Lizzie Research Station is substantially reduced as it moves from recharge to discharge areas. Denitrification in deeper parts of the aquifer and in riparian zones is indicated by a characterization of redox conditions in the aquifer and by the presence of excess nitrogen gas. Direct ground-water discharge of nitrate to surface water during base-flow conditions is unlikely to be significant because of strongly reducing conditions that occur in the riparian zones of these streams. Nitrate loads from a drainage tile at the study site may account for much of the nitrate load in the receiving stream, indicating that a major source of nutrients from ground water to this stream is artificial drainage. During base-flow conditions when the streams are not flowing, it is hypothesized that the mineralization of organic matter on the streambed is the source of nitrate and(or) ammonium in the stream. Base flow is a small contributor to nitrogen loads, because both flows and inorganic nitrogen concentrations are low during summer months. Effects of a confined hog operation on ground-water quality also were evaluated. The use of sprayed swine wastes to fertilize crops at the Lizzie Research Station study site since 1995 resulted in increased concentrations of nitrate and other chemical constituents in ground water beneath spray fields when compared to ground water beneath fields treated with commercial fertilizer. The nitrate concentration in ground water from the spray field well increased by a factor of 3.5 after 4 years of spray applications. Nitrate concentrations ranged from 10 to 35 milligrams per liter, and one concentration as high as 56 milligrams per liter was observed in water from this well in spring 2002. This finding is in agreement with findings of other studies conducted in the Coastal Plain of North Carolina that nitrate concentrations were significantly higher in ground water from cultivated fields sprayed with swine wastes than from fields treated with commercial fertilizer. Loads and yields of nitrogen and phosphorus in 14 streams in the Neuse River basin were evaluated for calendar years 2000 and 2001. Data indicate that anthropogenic effects on nitrogen yields were greatest in the first-order stream studied (yields were greater than 2 tons per square mile [ton/mi2] and 1 ton/mi2 or less in second- and higher-order streams) in the Little Contentnea Creek subbasin. Nitrogen yields in streams in the Contentnea Creek subbasin ranged from 0.59 to 2 ton/mi2 with typical yields of approximately 1 ton/mi2. Contentnea Creek near Evansdale had the highest yield (2 ton/mi2), indicating that a major source of nitrogen is upstream from this station. Nitrogen yields were lower at Contentnea Creek at Hookerton in 2000 and 2001 compared to previous yi

Insights into nitrogen allocation and recycling from nitrogen elemental analysis and 15N isotope labelling in 14 genotypes of willow.

PubMed

Brereton, Nicholas J B; Pitre, Frederic E; Shield, Ian; Hanley, Steven J; Ray, Michael J; Murphy, Richard J; Karp, Angela

2014-11-01

Minimizing nitrogen (N) fertilization inputs during cultivation is essential for sustainable production of bioenergy and biofuels. The biomass crop willow (Salix spp.) is considered to have low N fertilizer requirements due to efficient recycling of nutrients during the perennial cycle. To investigate how successfully different willow genotypes assimilate and allocate N during growth, and remobilize and consequently recycle N before the onset of winter dormancy, N allocation and N remobilization (to and between different organs) were examined in 14 genotypes of a genetic family using elemental analysis and (15)N as a label. Cuttings were established in pots in April and sampled in June, August and at onset of senescence in October. Biomass yield of the trees correlated well with yields recorded in the field. Genotype-specific variation was observed for all traits measured and general trends spanning these sampling points were identified when trees were grouped by biomass yield. Nitrogen reserves in the cutting fuelled the entirety of the canopy establishment, yet earlier cessation of this dependency was linked to higher biomass yields. The stem was found to be the major N reserve by autumn, which constitutes a major source of N loss at harvest, typically every 2-3 years. These data contribute to understanding N remobilization in short rotation coppice willow and to the identification of traits that could potentially be selected for in breeding programmes to further improve the sustainability of biomass production. © The Author 2013. Published by Oxford University Press.

Normalized Difference Vegetation Index as a Tool for Wheat Yield Estimation: A Case Study from Faisalabad, Pakistan

PubMed Central

Sultana, Syeda Refat; Ali, Amjed; Ahmad, Ashfaq; Mubeen, Muhammad; Zia-Ul-Haq, M.; Ahmad, Shakeel; Ercisli, Sezai; Jaafar, Hawa Z. E.

2014-01-01

For estimation of grain yield in wheat, Normalized Difference Vegetation Index (NDVI) is considered as a potential screening tool. Field experiments were conducted to scrutinize the response of NDVI to yield behavior of different wheat cultivars and nitrogen fertilization at agronomic research area, University of Agriculture Faisalabad (UAF) during the two years 2008-09 and 2009-10. For recording the value of NDVI, Green seeker (Handheld-505) was used. Split plot design was used as experimental model in, keeping four nitrogen rates (N1 = 0 kg ha−1, N2 = 55 kg ha−1, N3 = 110 kg ha−1, and N4 = 220 kg ha−1) in main plots and ten wheat cultivars (Bakkhar-2001, Chakwal-50, Chakwal-97, Faisalabad-2008, GA-2002, Inqlab-91, Lasani-2008, Miraj-2008, Sahar-2006, and Shafaq-2006) in subplots with four replications. Impact of nitrogen and difference between cultivars were forecasted through NDVI. The results suggested that nitrogen treatment N4 (220 kg ha−1) and cultivar Faisalabad-2008 gave maximum NDVI value (0.85) at grain filling stage among all treatments. The correlation among NDVI at booting, grain filling, and maturity stages with grain yield was positive (R 2 = 0.90; R 2 = 0.90; R 2 = 0.95), respectively. So, booting, grain filling, and maturity can be good depictive stages during mid and later growth stages of wheat crop under agroclimatic conditions of Faisalabad and under similar other wheat growing environments in the country. PMID:25045744

Estimation of total nitrogen and total phosphorus in streams of the Middle Columbia River Basin (Oregon, Washington, and Idaho) using SPARROW models, with emphasis on the Yakima River Basin, Washington

USGS Publications Warehouse

Johnson, Henry M.; Black, Robert W.; Wise, Daniel R.

2013-01-01

The watershed model SPARROW (Spatially Related Regressions on Watershed attributes) was used to predict total nitrogen (TN) and total phosphorus (TP) loads and yields for the Middle Columbia River Basin in Idaho, Oregon, and Washington. The new models build on recently published models for the entire Pacific Northwest, and provide revised load predictions for the arid interior of the region by restricting the modeling domain and recalibrating the models. Results from the new TN and TP models are provided for the entire region, and discussed with special emphasis on the Yakima River Basin, Washington. In most catchments of the Yakima River Basin, the TN and TP in streams is from natural sources, specifically nitrogen fixation in forests (TN) and weathering and erosion of geologic materials (TP). The natural nutrient sources are overshadowed by anthropogenic sources of TN and TP in highly agricultural and urbanized catchments; downstream of the city of Yakima, most of the load in the Yakima River is derived from anthropogenic sources. Yields of TN and TP from catchments with nearly uniform land use were compared with other yield values and export coefficients published in the scientific literature, and generally were in agreement. The median yield of TN was greatest in catchments dominated by agricultural land and smallest in catchments dominated by grass and scrub land. The median yield of TP was greatest in catchments dominated by forest land, but the largest yields (90th percentile) of TP were from agricultural catchments. As with TN, the smallest TP yields were from catchments dominated by grass and scrub land.

Vertical variation of a black soil's properties in response to freeze-thaw cycles and its links to shift of microbial community structure.

PubMed

Han, Ziming; Deng, Mingwen; Yuan, Anqi; Wang, Jiahui; Li, Hao; Ma, Jincai

2018-06-01

Soil freeze-thaw cycles (FTCs) change soil physical, chemical, and biological properties, however information regarding their vertical variations in response to FTCs is limited. In this work, black soil (silty loam) packed soil columns were exposed to 8 FTCs, and soil properties were determined for each of vertical layer of soil columns. The results revealed that after FTCs treatment, moisture and electrical conductivity (EC) salinity tended to increase in upper soil layers. Increments of ammonium nitrogen (NH 4 + -N) and nitrate nitrogen (NO 3 - -N) in top layers (0-10cm) were greater than those in other layers, and increments of water soluble organic carbon (WSOC) and decrease of microbial biomass carbon (MBC) in middle layers (10-20cm) were greater than those in both ends. Overall, microbial community structure was mainly influenced by soil physical properties (moisture and EC) and chemical properties (pH and WSOC). For bacterial (archaeal) and fungal communities, soil physical properties, chemical properties and their interaction explained 79.73% and 82.66% of total variation, respectively. Our results provided insights into the vertical variation of soil properties caused by FTCs, and such variation had a major impact on the change of structure and composition of soil bacterial and fungal communities. Copyright © 2017 Elsevier B.V. All rights reserved.

Topsoil depth effects on corn yield and nitrogen uptake efficiency

USDA-ARS?s Scientific Manuscript database

Decades of erosion on claypan soil fields under row crop production has led to varying topsoil thickness across fields of the Midwest, resulting in variable crop fertilizer requirements across landscapes. Determining how these crop needs, specifically nitrogen, vary across fields is crucial for gett...

Multiple nitrogen components in lunar soil sample 12023

NASA Technical Reports Server (NTRS)

Brilliant, D. R.; Franchi, I. A.; Pillinger, C. T.

1993-01-01

Nitrogen is one of the enigmatic elements in lunar soils and breccias. The large range in (delta)N-15 values found within lunar soils was initially attributed to a secular increase in the N-15/N-14 ratio of 50 percent within the solar corona, and hence in the implanted nitrogen within the lunar regolith. However, more recent explanations have proposed a two (or many) component mixing model of solar wind nitrogen with some hypothetical non-solar components. Such components could include indigenous lunar nitrogen, nitrogen contained in interstellar grains in primitive meteorites, and magnetospheric nitrogen from the terrestrial atmosphere. To understand the makeup of multi-component mixtures it is advantageous to have carbon and noble gas data measured simultaneously, particularly in the case of lunar soils, where the solar wind is a likely fundamental contributor of nitrogen. To this end, a new nitrogen instrument was adapted to give some of the desired data in parallel. Conjoint measurements of N abundance and (delta)N-15 together with N/Ar-36 and Ar-36/Ar-38 ratios obtained during a stepped combustion of lunar soil 12023. The results are preliminary to a much more comprehensive investigation of well characterized fractions of the sample which we still have available from a previous study. Stepped combustion of a sample of 12023,7 yielded 94 ppm nitrogen with a (delta)N-15 = +22.2 percent, as well as the characteristic heavy-light-heavy pattern observed for lunar samples. The low temperature maximum was +75.1 percent at 550 C, the minimum at 800 C with (delta)N-15 = -16.7 percent and the high temperature (delta)N-15 peak is +90.6 percent at 1250 C. The major releases of nitrogen occurred between 650 C - 800 C in the form of a double peak; a third, substantial release occurred at 1150 C yielding 14.2 ppm of nitrogen coinciding with a small but recognizable drop in (delta)N-15 against a regularly increasing trend.

Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields.

PubMed

Arai-Sanoh, Yumiko; Takai, Toshiyuki; Yoshinaga, Satoshi; Nakano, Hiroshi; Kojima, Mikiko; Sakakibara, Hitoshi; Kondo, Motohiko; Uga, Yusaku

2014-07-03

To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study.

Declining spatial efficiency of global cropland nitrogen allocation

NASA Astrophysics Data System (ADS)

Mueller, Nathaniel D.; Lassaletta, Luis; Runck, Bryan C.; Billen, Gilles; Garnier, Josette; Gerber, James S.

2017-02-01

Efficiently allocating nitrogen (N) across space maximizes crop productivity for a given amount of N input and reduces N losses to the environment. Here we quantify changes in the global spatial efficiency of cropland N use by calculating historical trade-off frontiers relating N inputs to possible N yield assuming efficient allocation. Time series cropland N budgets from 1961 to 2009 characterize the evolution of N input-yield response functions across 12 regions and are the basis for constructing trade-off frontiers. Improvements in agronomic technology have substantially increased cropping system yield potentials and expanded N-driven crop production possibilities. However, we find that these gains are compromised by the declining spatial efficiency of N use across regions. Since the start of the Green Revolution, N inputs and yields have moved farther from the optimal frontier over time; in recent years (1994-2009), global N surplus has grown to a value that is 69% greater than what is possible with efficient N allocation between regions. To reflect regional pollution and agricultural development goals, we construct scenarios that restrict reallocation, finding that these changes only slightly decrease potential gains in nitrogen use efficiency. Our results are inherently conservative due to the regional unit of analysis, meaning a larger potential exists than is quantified here for cross-scale policies to promote spatially efficient N use.

EnviroAtlas - Cultivated biological nitrogen fixation in agricultural lands by 12-digit HUC in the Conterminous United States, 2006

EPA Pesticide Factsheets

This EnviroAtlas dataset contains data on the mean cultivated biological nitrogen fixation (C-BNF) in cultivated crop and hay/pasture lands per 12-digit Hydrologic Unit (HUC) in 2006. Nitrogen (N) inputs from the cultivation of legumes, which possess a symbiotic relationship with N-fixing bacteria, were calculated with a recently developed model relating county-level yields of various leguminous crops with BNF rates. We accessed county-level data on annual crop yields for soybeans (Glycine max L.), alfalfa (Medicago sativa L.), peanuts (Arachis hypogaea L.), various dry beans (Phaseolus, Cicer, and Lens spp.), and dry peas (Pisum spp.) for 2006 from the USDA Census of Agriculture (http://www.agcensus.usda.gov/index.php). We estimated the yield of the non-alfalfa leguminous component of hay as 32% of the yield of total non-alfalfa hay (http://www.agcensus.usda.gov/index.php). Annual rates of C-BNF by crop type were calculated using a model that relates yield to C-BNF. We assume yield data reflect differences in soil properties, water availability, temperature, and other local and regional factors that can influence root nodulation and rate of N fixation. We distributed county-specific, C-BNF rates to cultivated crop and hay/pasture lands delineated in the 2006 National Land Cover Database (30 x 30 m pixels) within the corresponding county. C-BNF data described here represent an average input to a typical agricultural land type within a county, i.e., they are not

Seeing the trees for the forest: Nitrogen deposition alters tree growth and survival across the northeastern U.S., responses vary by species.

NASA Astrophysics Data System (ADS)

Thomas, R. Q.; Canham, C. D.; Weathers, K. C.; Goodale, C. L.

2008-12-01

Assessments of regional forest carbon (C) balance have long speculated a role for atmospheric nitrogen (N) deposition. To date, however, evidence for an N effect has been restricted to plot-level fertilization and 15N experiments, biogeochemical modeling studies, and recent and controversial correlations between nitrogen deposition and C balance across 20 intensive C monitoring sites. These studies have yielded widely varying conclusions on the magnitude and even the direction of response (positive or negative effects on C storage). We assessed the effects of N deposition on forest growth and survival using forest inventory data from > 160,000 trees, spanning a 19-state region of the northeastern United States, and estimates of total (wet and plot-specific dry) inorganic N inputs (N deposition to the plots ranged from 3.2 to 11 kg N ha-1 y-1). The growth rates of 14 of the region's 24 most common tree species responded to N deposition. Nine species showed a monotonic increase in aboveground growth rates across the range of N deposition and some of these species experienced a doubling of growth rates. Four species showed humped-shaped responses. A single species, Pinus resinosa (red pine), showed a monotonic decline in growth across the range of deposition. Species responsiveness to N deposition increased with mean growth rate of the species. In the analysis of survival, 13 of the 24 species responded to N: eight species showed a monotonic decrease, 3 showed a monotonic increase and 1 showed a humped-shape response in survival. The stand-level analysis showed a distinctly humped-shaped relationship between N deposition and aboveground C increment, peaking at 6 kg N ha-1 yr-1, which can likely be explained by the distribution of species and their individual growth and mortality responses. Overall, our data suggest that moderate levels of N deposition have enhanced aboveground C accumulation in temperate forests of the northeastern U.S., but the shape and trajectory of the response is species-specific.

Differential recovery of water quality parameters eight years after severe wildfire and salvage logging in Alberta's southern Rocky Mountains

NASA Astrophysics Data System (ADS)

Silins, U.; Bladon, K. D.; Stone, M.; Emelko, M. B.; Collins, A.; Boon, S.; Williams, C.; Wagner, M. J.; Martens, A. M.; Anderson, A.

2012-12-01

Broad regions of western North America rely on water supplies that originate from forested regions of the Rocky Mountain cordillera where landuse pressures, and stresses including changing natural disturbance regimes associated with shifting climates has been impacting critical source water supplies from this region. Increases in magnitude and severity of wildfires along with impacts on downstream water supplies has been observed along the length of the North American Rocky Mountain chain, however, the longevity of these impacts (including impacts to important water quality parameters) remain highly uncertain because processes regulating recovery from such disturbances can span a range of timescales from a few years to decades depending on both the hydro-climatic regime, and which water quality parameters are important. Studies document such long-term changes are few. The Southern Rockies Watershed Project (SRWP) was established to document the magnitude and recovery from the severe 2003 Lost Creek wildfire in the Crowsnest Pass region of southwest Alberta, Canada. Hydrology, water quality (physical & chemical) have been studies in 9 instrumented catchments (4-14 km2) encompassing burned, burned and salvage logged, prescribed burned, and unburned (reference) conditions since late winter 2004. While most important water quality parameters were strongly elevated in burned and burned-salvage logged catchments after the fire, strongly differential rates of recovery were observed for contaminant concentration, export, and yield across a range of water quality parameters (2004-2011). For example, while various nitrogen (N) species (total nitrogen, dissolved nitrogen, NO3-, NH4+) showed 2-7 fold increases in concentration the first 1-2 years after the wildfire, N recovered back to baseline concentrations 4-5 years after the wildfire. In contrast, eight full years after the wildfire (2011), no recovery of sediment or phosphorus (P) production (soluble reactive, total dissolved, particulate, and total P) has been evident. Incremental impacts of management intervention by salvage logging over wildfire alone were observed for most water quality parameters. Sedimentary geology, glacial history of this region, along with predominance of fine fluvial sediments are likely implicated in both the strong sediment-P coupling and longevity of wildfire impacts observed in this region.

Local formation of nitrogen-vacancy centers in diamond by swift heavy ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwartz, J.; Ilmenau University of Technology, Department of Microelectronics and Nanoelectric Systems, 98684 Ilmenau; Aloni, S.

2014-12-07

We exposed nitrogen-implanted diamonds to beams of swift heavy ions (∼1 GeV, ∼4 MeV/u) and find that these irradiations lead directly to the formation of nitrogen vacancy (NV) centers, without thermal annealing. We compare the photoluminescence intensities of swift heavy ion activated NV{sup −} centers to those formed by irradiation with low-energy electrons and by thermal annealing. NV{sup −} yields from irradiations with swift heavy ions are 0.1 of yields from low energy electrons and 0.02 of yields from thermal annealing. We discuss possible mechanisms of NV center formation by swift heavy ions such as electronic excitations and thermal spikes. While formingmore » NV centers with low efficiency, swift heavy ions could enable the formation of three dimensional NV{sup −} assemblies over relatively large distances of tens of micrometers. Further, our results show that NV center formation is a local probe of (partial) lattice damage relaxation induced by electronic excitations from swift heavy ions in diamond.« less

Microstructures and impact toughness behavior of Al 5083 alloy processed by cryorolling and afterwards annealing

NASA Astrophysics Data System (ADS)

Singh, Dharmendra; Rao, P. Nageswara; Jayaganthan, R.

2013-08-01

The influence of rolling at liquid nitrogen temperature and annealing on the microstructure and mechanical properties of Al 5083 alloy was studied in this paper. Cryorolled samples of Al 5083 show significant improvements in strength and hardness. The ultimate tensile strength increases up to 340 MPa and 390 MPa for the 30% and 50% cryorolled samples, respectively. The cryorolled samples, with 30% and 50% reduction, were subjected to Charpy impact testing at various temperatures from -190°C to 100°C. It is observed that increasing the percentage of reduction of samples during cryorolling has significant effect on decreasing impact toughness at all temperatures by increasing yield strength and decreasing ductility. Annealing of samples after cryorolling shows remarkable increment in impact toughness through recovery and recrystallization. The average grain size of the 50% cryorolled sample (14 μm) after annealing at 350°C for 1 h is found to be finer than that of the 30% cryorolled sample (25 μm). The scanning electron microscopy (SEM) analysis of fractured surfaces shows a large-size dimpled morphology, resembling the ductile fracture mechanism in the starting material and fibrous structure with very fine dimples in cryorolled samples corresponding to the brittle fracture mechanism.

Health and Economic Implications of National Treatment Coverage for Cardiovascular Disease in India: Cost-Effectiveness Analysis.

PubMed

Basu, Sanjay; Bendavid, Eran; Sood, Neeraj

2015-11-01

Whether to cover cardiovascular disease costs is an increasingly pressing question for low- and middle-income countries. We sought to identify the impact of expanding national insurance to cover primary prevention, secondary prevention, and tertiary treatment for cardiovascular disease in India. We incorporated data from coverage experiments into a validated microsimulation model of myocardial infarction and stroke in India to evaluate the cost-effectiveness of alternate coverage strategies. Coverage of primary prevention alone saved 3.6 million disability-adjusted life-years (DALY) per annum at an incremental cost-effectiveness ratio of $469 per DALY averted when compared with the status quo of no coverage. Coverage of primary and secondary preventions was dominated by a strategy of covering primary prevention and tertiary treatment, which prevented 6.6 million DALYs at an incremental cost-effectiveness ratio of $2241 per DALY averted, when compared with that of primary prevention alone. The combination of all 3 categories yielded the greatest impact at an incremental cost per DALY averted of $5588 when compared with coverage of primary prevention plus tertiary treatment. When compared with the status quo of no coverage, coverage of all 3 categories of prevention/treatment yielded an incremental cost-effectiveness ratio of $1331 per DALY averted. In sensitivity analyses, coverage of primary preventive treatments remained cost-effective even if adherence and access to therapy were low, but tertiary coverage would require avoiding unnecessary procedures to remain cost-effective. Coverage of all 3 major types of cardiovascular treatment would be expected to have high impact and reasonable cost-effectiveness in India across a broad spectrum of access and adherence levels. © 2015 American Heart Association, Inc.

Oil and eicosapentaenoic acid production by the diatom Phaeodactylum tricornutum cultivated outdoors in Green Wall Panel (GWP®) reactors.

PubMed

Rodolfi, Liliana; Biondi, Natascia; Guccione, Alessia; Bassi, Niccolò; D'Ottavio, Massimo; Arganaraz, Gimena; Tredici, Mario R

2017-10-01

Phaeodactylum tricornutum is a widely studied diatom and has been proposed as a source of oil and polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA). Recent studies indicate that lipid accumulation occurs under nutritional stress. Aim of this research was to determine how changes in nitrogen availability affect productivity, oil yield, and fatty acid (FA) composition of P. tricornutum UTEX 640. After preliminary laboratory trials, outdoor experiments were carried out in 40-L GWP® reactors under different nitrogen regimes in batch. Nitrogen replete cultures achieved the highest productivity of biomass (about 18 g m -2  d -1 ) and EPA (about 0.35 g m -2  d -1 ), whereas nitrogen-starved cultures achieved the highest FA productivity (about 2.6 g m -2  d -1 ). The annual potential yield of P. tricornutum grown outdoors in GWP® reactors is 730 kg of EPA per hectare under nutrient-replete conditions and 5,800 kg of FA per hectare under nitrogen starvation. Biotechnol. Bioeng. 2017;114: 2204-2210. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

The Nitrate-Inducible NAC Transcription Factor TaNAC2-5A Controls Nitrate Response and Increases Wheat Yield1[OPEN

PubMed Central

He, Xue; Qu, Baoyuan; Li, Wenjing; Zhao, Xueqiang; Teng, Wan; Ma, Wenying; Ren, Yongzhe; Li, Bin; Li, Zhensheng; Tong, Yiping

2015-01-01

Nitrate is a major nitrogen resource for cereal crops; thus, understanding nitrate signaling in cereal crops is valuable for engineering crops with improved nitrogen use efficiency. Although several regulators have been identified in nitrate sensing and signaling in Arabidopsis (Arabidopsis thaliana), the equivalent information in cereals is missing. Here, we isolated a nitrate-inducible and cereal-specific NAM, ATAF, and CUC (NAC) transcription factor, TaNAC2-5A, from wheat (Triticum aestivum). A chromatin immunoprecipitation assay showed that TaNAC2-5A could directly bind to the promoter regions of the genes encoding nitrate transporter and glutamine synthetase. Overexpression of TaNAC2-5A in wheat enhanced root growth and nitrate influx rate and, hence, increased the root’s ability to acquire nitrogen. Furthermore, we found that TaNAC2-5A-overexpressing transgenic wheat lines had higher grain yield and higher nitrogen accumulation in aerial parts and allocated more nitrogen in grains in a field experiment. These results suggest that TaNAC2-5A is involved in nitrate signaling and show that it is an exciting gene resource for breeding crops with more efficient use of fertilizer. PMID:26371233

Influence of land use and open-water wetlands on water quality in the Lake Wallenpaupack basin, northeastern Pennsylvania

USGS Publications Warehouse

Sams, James I.; Day, Rick L.; Stiteler, John M.

1999-01-01

The recreational value of Lake Wallenpaupack, along with its proximity to the New York and New Jersey metropolitan areas, has resulted in residential development in parts of the watershed. Some of these developments encroach on existing ponds, lakes, and wetlands and result in the conversion of forest land to residential areas. Sediment and nutrients in runoff from these residential areas, and inputs from agricultural areas, sewage treatment plants, and atmospheric deposition, have had a significant effect on water quality in Lake Wallenpaupack.Water-quality data collected in the Lake Wallenpaupack watershed from 1991 through 1994 indicate the influence of land use on water resources. Water samples collected from a forested undeveloped basin contained lower concentrations of suspended sediment, nitrogen, and total phosphorus than samples collected from the basins of Ariel Creek and Purdy Creek that drain areas having mixed land use with residential developments. Sediment yields were three to four times higher in the developed basins of Purdy and Ariel Creeks compared to the forested undeveloped basin. Annual yields for total nitrogen for Ariel Creek and Purdy Creek were between three to five times greater than yields from the forested basin. For the 1993 water year, the annual yield for dissolved nitrate plus nitrite (as nitrogen) from Ariel Creek Basin was 1,410 pounds per square mile, or about 60 times greater than the 24 pounds per square mile from the undeveloped basin. The total-phosphorus yield from the Ariel Creek Basin was 216 pounds per square mile for the 1994 water year. This was about three times greater than the 74 pounds per square mile from the forested basin. The total-phosphorus yield for the Purdy Creek Basin was 188 pounds per square mile for the 1994 water year, or 2.5 times greater than the yield from the undeveloped forested basin. Only slight differences were observed in dissolved orthophosphate phosphorus loadings between the basins. All three basins displayed seasonal differences in water quality. Most of the annual yield occurred during early spring as a result of snowmelt runoff.Data collected from the Stevens Creek sites showed that an open-water wetland was very effective in removing sediment and total phosphorus but was not as effective in removing dissolved orthophosphate phosphorus and nitrogen. The wetland removed more than 96 percent of the sediment.

Analytic description of the frictionally engaged in-plane bending process incremental swivel bending (ISB)

NASA Astrophysics Data System (ADS)

Frohn, Peter; Engel, Bernd; Groth, Sebastian

2018-05-01

Kinematic forming processes shape geometries by the process parameters to achieve a more universal process utilizations regarding geometric configurations. The kinematic forming process Incremental Swivel Bending (ISB) bends sheet metal strips or profiles in plane. The sequence for bending an arc increment is composed of the steps clamping, bending, force release and feed. The bending moment is frictionally engaged by two clamping units in a laterally adjustable bending pivot. A minimum clamping force hindering the material from slipping through the clamping units is a crucial criterion to achieve a well-defined incremental arc. Therefore, an analytic description of a singular bent increment is developed in this paper. The bending moment is calculated by the uniaxial stress distribution over the profiles' width depending on the bending pivot's position. By a Coulomb' based friction model, necessary clamping force is described in dependence of friction, offset, dimensions of the clamping tools and strip thickness as well as material parameters. Boundaries for the uniaxial stress calculation are given in dependence of friction, tools' dimensions and strip thickness. The results indicate that changing the bending pivot to an eccentric position significantly affects the process' bending moment and, hence, clamping force, which is given in dependence of yield stress and hardening exponent. FE simulations validate the model with satisfactory accordance.

Quantifying yield gaps in wheat production in Russia

NASA Astrophysics Data System (ADS)

Schierhorn, Florian; Faramarzi, Monireh; Prishchepov, Alexander V.; Koch, Friedrich J.; Müller, Daniel

2014-08-01

Crop yields must increase substantially to meet the increasing demands for agricultural products. Crop yield increases are particularly important for Russia because low crop yields prevail across Russia’s widespread and fertile land resources. However, reliable data are lacking regarding the spatial distribution of potential yields in Russia, which can be used to determine yield gaps. We used a crop growth model to determine the yield potentials and yield gaps of winter and spring wheat at the provincial level across European Russia. We modeled the annual yield potentials from 1995 to 2006 with optimal nitrogen supplies for both rainfed and irrigated conditions. Overall, the results suggest yield gaps of 1.51-2.10 t ha-1, or 44-52% of the yield potential under rainfed conditions. Under irrigated conditions, yield gaps of 3.14-3.30 t ha-1, or 62-63% of the yield potential, were observed. However, recurring droughts cause large fluctuations in yield potentials under rainfed conditions, even when the nitrogen supply is optimal, particularly in the highly fertile black soil areas of southern European Russia. The highest yield gaps (up to 4 t ha-1) under irrigated conditions were detected in the steppe areas in southeastern European Russia along the border of Kazakhstan. Improving the nutrient and water supply and using crop breeds that are adapted to the frequent drought conditions are important for reducing yield gaps in European Russia. Our regional assessment helps inform policy and agricultural investors and prioritize research that aims to increase crop production in this important region for global agricultural markets.

Metabolic flux analysis of Cyanothece sp. ATCC 51142 under mixotrophic conditions.

PubMed

Alagesan, Swathi; Gaudana, Sandeep B; Sinha, Avinash; Wangikar, Pramod P

2013-11-01

Cyanobacteria are a group of photosynthetic prokaryotes capable of utilizing solar energy to fix atmospheric carbon dioxide to biomass. Despite several "proof of principle" studies, low product yield is an impediment in commercialization of cyanobacteria-derived biofuels. Estimation of intracellular reaction rates by (13)C metabolic flux analysis ((13)C-MFA) would be a step toward enhancing biofuel yield via metabolic engineering. We report (13)C-MFA for Cyanothece sp. ATCC 51142, a unicellular nitrogen-fixing cyanobacterium, known for enhanced hydrogen yield under mixotrophic conditions. Rates of reactions in the central carbon metabolism under nitrogen-fixing and -non-fixing conditions were estimated by monitoring the competitive incorporation of (12)C and (13)C from unlabeled CO2 and uniformly labeled glycerol, respectively, into terminal metabolites such as amino acids. The observed labeling patterns suggest mixotrophic growth under both the conditions, with a larger fraction of unlabeled carbon in nitrate-sufficient cultures asserting a greater contribution of carbon fixation by photosynthesis and an anaplerotic pathway. Indeed, flux analysis complements the higher growth observed under nitrate-sufficient conditions. On the other hand, the flux through the oxidative pentose phosphate pathway and tricarboxylic acid cycle was greater in nitrate-deficient conditions, possibly to supply the precursors and reducing equivalents needed for nitrogen fixation. In addition, an enhanced flux through fructose-6-phosphate phosphoketolase possibly suggests the organism's preferred mode under nitrogen-fixing conditions. The (13)C-MFA results complement the reported predictions by flux balance analysis and provide quantitative insight into the organism's distinct metabolic features under nitrogen-fixing and -non-fixing conditions.

Concentrations, loads, and yields of select constituents from major tributaries of the Mississippi and Missouri Rivers in Iowa, water years 2004-2008

USGS Publications Warehouse

Garrett, Jessica D.

2012-01-01

Excess nutrients, suspended-sediment loads, and the presence of pesticides in Iowa rivers can have deleterious effects on water quality in State streams, downstream major rivers, and the Gulf of Mexico. Fertilizer and pesticides are used to support crop growth on Iowa's highly productive agricultural landscape and for household and commercial lawns and gardens. Water quality was characterized near the mouths of 10 major Iowa tributaries to the Mississippi and Missouri Rivers from March 2004 through September 2008. Stream loads were calculated for select ions, nutrients, and sediment using approximately monthly samples, and samples from storm and snowmelt events. Water-quality samples collected using standard streamflow-integrated protocols were analyzed for major ions, nutrients, carbon, pesticides, and suspended sediment. Statistical data summaries of sample data used parametric and nonparametric techniques to address potential bias related to censored data and multiple levels of censoring of data below analytical detection limits. Constituent stream loads were computed using standard pre-defined models in S-LOADEST that include streamflow and time terms plus additional terms for streamflow variability and streamflow anomalies. Streamflow variability terms describe the difference in streamflow from recent average conditions, whereas streamflow anomaly terms account for deviations from average conditions from long- to short-term sequentially. Streamflow variability or anomaly terms were included in 44 of 80 site/constituent individual models, demonstrating the usefulness of these terms in increasing accuracy of the load estimates. Constituent concentrations in Iowa streams exhibit streamflow, seasonal, and spatial patterns related to the landform and climate gradients across the studied basins. The streamflow-concentration relation indicated dilution for ions such as chloride and sulfate. Other constituent concentrations, such as dissolved organic carbon and suspended sediment, increased with streamflow. Nitrogen concentrations (total nitrogen and nitrate plus nitrite) increased with low and moderate streamflows, but decreased with high streamflows. Seasonal patterns observed in constituent concentrations were affected by streamflow, algae blooms, and pesticide application. The various landform regions produced different water-quality responses across the study basins; for example, total phosphorus, suspended sediment, and turbidity were greatest from the steep, loess-dominated southwestern Iowa basins. Nutrient concentrations, though not regulated for drinking water at the study sites, were high compared to drinking-water limits and criteria for protection of aquatic life proposed for other Midwestern states (Iowa criteria for aquatic life have not been proposed). Nitrate plus nitrite concentrations exceeded the drinking-water limit [10 milligrams per liter (mg/L)] in 11 percent of all samples at the 10 sites, and exceeded Minnesota's proposed aquatic life criteria (4.9 mg/L) in 68 percent of samples. The Wisconsin standard for total phosphorus (0.1 mg/L) was exceeded in 92 percent of samples. Ammonia standards, current during sample collection and at publication of this report, for protection of aquatic life were met for all samples, but draft criteria proposed in 2009 to protect more sensitive species like mussels, were exceeded at three sites. Loads and yields also differed among sites and years. The Big Sioux, Little Sioux, and Des Moines Rivers produced the greatest sulfate yields. Mississippi River tributaries had greater chloride yields than Missouri River tributaries. The Big Sioux River also had the lowest silica yields and total nitrogen and nitrate yields, whereas nitrogen yields were greater in the northeastern rivers. The Boyer and Nishnabotna River total phosphorus yields were the greatest in the study. The Boyer River orthophosphate yields were greatest except in 2008, when the Maquoketa River produced the greatest yield. Rivers in southwestern Iowa's Western Loess Hills and Steeply Rolling Loess Prairie ecoregions had the greatest suspended-sediment yields, whereas the smallest yields were in the Big Sioux and Wapsipinicon Rivers. In the 10 Iowa rivers studied, combined annual total nitrogen stream transport ranged from 3.68 to 9.95 tons per square mile per year, and total phosphorus transport ranged from 0.138 to 0.570 tons per square mile per year. Six-month loads relative to fertilizer use ranged from 8 to 56 percent for nitrogen, and 1.0 to 11.1 percent for phosphorus. The smallest loads relative to fertilizer use for both nitrogen and phosphorus occurred in July-December of dry years, and the largest nitrogen and phosphorus loads relative to use were in wet years from January-June.

[Influence of different levels of irrigation and nitrogen application on the root growth and yield of spring wheat under permanent raised bed.

PubMed

Chen, Juan; Ma, Zhong Ming; Lyu, Xiao Dong; Liu, Ting Ting

2016-05-01

To establish an optimum combination of water and nitrogen for spring under permanent raised bed (PRB) tillage, a field investigation was carried out to assess effects of irrigation and N application on root growth, yield, irrigation water productivity and N efficiency. The experiment followed a completely randomized split-plot design, taking furrow irrigation 1200 m 3 ·hm -2 (W 1 ), 2400 m 3 ·hm -2 (W 2 ), 3600 m 3 ·hm -2 (W 3 ) as main plot treatments, and N rates (0, 90, 180, 270 kg·hm -2 ) the sub-plot treatments. Our results showed that the root mass density (RWD) was significantly affected by irrigation and N application, the RWD of spring wheat reached a maximum at the filling stage, followed by a slow decline until maturity, while the effect of N on RWD depended on soil water conditions. The application of N 2 produced the maximum RWD under W 2 irrigation, the application of N 1 produced the maximum RWD under W 1 irrigation, and the application of N 3 produced the maximum RWD under W 3 irrigation. The order of irrigation regime effect on RWD of spring wheat was W 2 >W 3 >W 1 . The order of irrigation regime and N rate effect on RWD of spring wheat was irrigation>N>irrigation and N interaction. W 2 N 2 treatment produced the highest RWD value. The root-to-shoot ratio (R/S) descended with the rising of irrigation water and nitrogen amount, and the combined treatment (W 1 N 0 ) produced the maximum R/S. The root system was mainly distributed in the 0-40 cm soil layer, in which the RWD accounted for 85% of the total RWD in 0-80 cm soil depth. There was a significantly positive relationship between RWD in the 0-40 cm and the yield of spring wheat, RWD in the 40-60 cm had higher linear dependence on the yield of spring wheat. W 2 increased the proportion of RWD in the deep soil layer (40-60 cm). The irrigation and N rate had a significant impact on biomass and grain yield of spring wheat, the biomass increased as the N rate and water amount increased, W 2 N 2 treatment produced the highest grain yield, irrigation water productivity descended with increasing the irrigation amount, and the nitrogen agronomic efficiency descended with increasing N rate. It was concluded that the irrigation level W 2 (2400 m 3 ·hm -2 ) and nitrogen level N 2 (180 kg·hm -2 ) could be recommended as the best combination of water and N, which promoted the root growth, improved grain yield, water and nitrogen use efficiencies of spring wheat production under PRB tillage in the experimental area.

Thermal elastoplastic structural analysis of non-metallic thermal protection systems

NASA Technical Reports Server (NTRS)

Chung, T. J.; Yagawa, G.

1972-01-01

An incremental theory and numerical procedure to analyze a three-dimensional thermoelastoplastic structure subjected to high temperature, surface heat flux, and volume heat supply as well as mechanical loadings are presented. Heat conduction equations and equilibrium equations are derived by assuming a specific form of incremental free energy, entropy, stresses and heat flux together with the first and second laws of thermodynamics, von Mises yield criteria and Prandtl-Reuss flow rule. The finite element discretization using the linear isotropic three-dimensional element for the space domain and a difference operator corresponding to a linear variation of temperature within a small time increment for the time domain lead to systematic solutions of temperature distribution and displacement and stress fields. Various boundary conditions such as insulated surfaces and convection through uninsulated surface can be easily treated. To demonstrate effectiveness of the present formulation a number of example problems are presented.

Nitrogen and harvest impact on biomass yield of established switchgrass (Panicum virgatum L.)

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) has been identified as the model herbaceous biomass energy crop by the United States Department of Energy as it is capable of being a viable bioenergy feedstock while providing multiple environmental benefits when grown on marginal soil landscapes. Nitrogen (N) fert...

Fusing corn nitrogen recommendation tools for an improved canopy reflectance sensor performance

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) rate recommendation tools are utilized to help producers maximize corn grain yield production. Many of these tools provide recommendations at field scales but often fail when corn N requirements are variable across the field. Canopy reflectance sensors are capable of capturing within-fi...

Potato stolon and tuber growth influenced by nitrogen form

USDA-ARS?s Scientific Manuscript database

Potato tuber initiation and its growth are key processes determining tuber yield, which are closely related to stolon growth, and are influenced by many factors including N nutrition. We investigated the influences of different forms of nitrogen (N) on stolon and tuber growth in sand culture with a ...

HYDROGIOLOGIC FRAMEWORK, GROUND-WATER GEOCHEMISTRY, AND ASSESSMENT OF NITROGEN YIELD FROM BASE FLOW IN TWO AGRICULTURAL WATERSHEDS, KENT COUNTY, MARYLAND

EPA Science Inventory

Hydrostratigraphic and geochemical data collected in two adjacent watersheds on the Delmarva Peninsula, in Kent County, Maryland, indicate that shallow subsurface stratigraphy is an important factor that affects the concentrations of nitrogen in ground water discharging as stream...

Root yield and quality of sugarbeet hybrids with pollinators selected for sodium, potassium, or amino-nitrogen concentration

USDA-ARS?s Scientific Manuscript database

Sodium, potassium, and amino-nitrogen, collectively referred to as impurities, are natural constituents of sugarbeet that impede sucrose extraction during factory operations. Lines selected specifically for low or high concentration of a single impurity component were crossed as pollinators with a ...

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...

Nitrogen source and application method impact on corn yield and nutrient uptake

USDA-ARS?s Scientific Manuscript database

Farmers are looking for better management practices to enhance production and reduce negative environmental impact from nitrogen (N) fertilizer application since N is one of the most important and costly nutrient inputs for crop production. In this field experiment pre-plant swine effluent applicati...

Nitrogen competition between corn and weeds in soils under organic and conventional management

USDA-ARS?s Scientific Manuscript database

Cropping systems research has shown that organic systems can have comparable yields to conventional systems at higher weed biomass levels. Higher weed tolerance in organic systems could be due to differences in labile soil organic matter and nitrogen (N) mineralization potential. The objective of ou...

Assessing Nitrogen Status of Dryland Wheat Using the Canopy Chlorophyll Content Index

USDA-ARS?s Scientific Manuscript database

Ground-based, active light sensing relies upon the Normalized Difference Vegetation Index (NDVI) for assessing crop nitrogen (N) response and applying N fertilizer. However, NDVI may not work well in semiarid environments where biomass and yields depend upon plant water. This study evaluated the C...

Watermelon juice: A promising feedstock supplement, diluent, and nitrogen supplement for ethanol biofuel production

USDA-ARS?s Scientific Manuscript database

Processing of watermelons to produce the neutraceuticals lycopene and citrulline yields a waste stream of watermelon juice at the rate of over 500 L/Mt of watermelons. Since watermelon juice contains 7-10% readily fermentable sugars, its potential as feedstock, diluent, and nitrogen supplement was ...

Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rydzak, Thomas; Garcia, David; Stevenson, David M.

Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. And while recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in C. thermocellum. Deletion of glnA reduced levels of secretedmore » valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine and α-ketoglutarate levels indicative of nitrogen-rich conditions. Here, we propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine/α-ketoglutarate levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.« less

Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum.

PubMed

Rydzak, Thomas; Garcia, David; Stevenson, David M; Sladek, Margaret; Klingeman, Dawn M; Holwerda, Evert K; Amador-Noguez, Daniel; Brown, Steven D; Guss, Adam M

2017-05-01

Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2 ), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum. Copyright © 2017. Published by Elsevier Inc.

Understanding nutrients in the Chesapeake Bay watershed and implications for management and restoration: the Eastern Shore

USGS Publications Warehouse

Ator, Scott W.; Denver, Judith M.

2015-03-12

The Eastern Shore includes only a small part of the Chesapeake Bay watershed, but contributes disproportionately large loads of the excess nitrogen and phosphorus that have contributed to ecological and economic degradation of the bay in recent decades. Chesapeake Bay is the largest estuary in the United States and a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades by excessive nitrogen and phosphorus in the water column, however, which cause harmful algal blooms and decreased water clarity, submerged aquatic vegetation, and dissolved oxygen. The disproportionately large nitrogen and phosphorus yields from the Eastern Shore to Chesapeake Bay are attributable to human land-use practices as well as natural hydrogeologic and soil conditions. Applications of nitrogen and phosphorus compounds to the Eastern Shore from human activities are intensive. More than 90 percent of nitrogen and phosphorus reaching the land in the Eastern Shore is applied as part of inorganic fertilizers or manure, or (for nitrogen) fixed directly from the atmosphere in cropland. Also, hydrogeologic and soil conditions promote the movement of these compounds from application areas on the landscape to groundwater and (or) surface waters, and the proximity of much of the Eastern Shore to tidal waters limits opportunities for natural removal of these compounds in the landscape. The Eastern Shore only includes 7 percent of the Chesapeake Bay watershed, but receives nearly twice as much nitrogen and phosphorus applications (per area) as the remainder of the watershed and yields greater nitrogen and phosphorus, on average, to the bay. Nitrogen and phosphorus commonly occur in streams at concentrations that may adversely affect aquatic ecosystems and have increased in recent decades.

Investigation of the nonlinear seismic behavior of knee braced frames using the incremental dynamic analysis method

NASA Astrophysics Data System (ADS)

Sheidaii, Mohammad Reza; TahamouliRoudsari, Mehrzad; Gordini, Mehrdad

2016-06-01

In knee braced frames, the braces are attached to the knee element rather than the intersection of beams and columns. This bracing system is widely used and preferred over the other commonly used systems for reasons such as having lateral stiffness while having adequate ductility, damage concentration on the second degree convenience of repairing and replacing of these elements after Earthquake. The lateral stiffness of this system is supplied by the bracing member and the ductility of the frame attached to the knee length is supplied through the bending or shear yield of the knee member. In this paper, the nonlinear seismic behavior of knee braced frame systems has been investigated using incremental dynamic analysis (IDA) and the effects of the number of stories in a building, length and the moment of inertia of the knee member on the seismic behavior, elastic stiffness, ductility and the probability of failure of these systems has been determined. In the incremental dynamic analysis, after plotting the IDA diagrams of the accelerograms, the collapse diagrams in the limit states are determined. These diagrams yield that for a constant knee length with reduced moment of inertia, the probability of collapse in limit states heightens and also for a constant knee moment of inertia with increasing length, the probability of collapse in limit states increases.

24-Epibrassinolide ameliorates salt stress effects in the symbiosis Medicago truncatula-Sinorhizobium meliloti and regulates the nodulation in cross-talk with polyamines.

PubMed

López-Gómez, Miguel; Hidalgo-Castellanos, Javier; Lluch, Carmen; Herrera-Cervera, José A

2016-11-01

Brassinosteroids (BRs) are steroid plant hormones that have been shown to be involved in the response to salt stress in cross-talk with other plant growth regulators such as polyamines (PAs). In addition, BRs are involved in the regulation of the nodulation in the rhizobium-legume symbiosis through the alteration of the PAs content in leaves. In this work, we have studied the effect of exogenous 24-epibrassinolide (EBL) in the response to salinity of nitrogen fixation in the symbiosis Medicago truncatula-Sinorhizobium meliloti. Foliar spraying of EBL restored the growth of plants subjected to salt stress and provoked an increment of the nitrogenase activity. In general, PAs levels in leaves and nodules decreased by the salt and EBL treatments, however, the co-treatment with NaCl and EBL augmented the foliar spermine (Spm) concentration. This increment of the Spm levels was followed by a reduction of the membrane oxidative damage and a diminution of the proline accumulation. The effect of BRs on the symbiotic interaction was evaluated by the addition of 0.01, 0.1 and 0.5 μM EBL to the growing solution, which provoked a reduction of the nodule number and an increment of the PAs levels in shoot. In conclusion, foliar treatment with EBL had a protective effect against salt stress in the M. truncatula-S. meliloti symbiosis mediated by an increment of the Spm levels. Treatment of roots with EBL incremented PAs levels in shoot and reduced the nodule number which suggests a cross-talk between PAs and BRs in the nodule suppression and the protection against salt stress. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Value of Diffusion-Weighted Magnetic Resonance Imaging for Prediction and Early Assessment of Response to Neoadjuvant Radiochemotherapy in Rectal Cancer: Preliminary Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambrecht, Maarten, E-mail: maarten.lambrecht@uzleuven.be; Vandecaveye, Vincent; De Keyzer, Frederik

2012-02-01

Purpose: To evaluate diffusion-weighted magnetic resonance imaging (DWI) for response prediction before and response assessment during and early after preoperative radiochemotherapy (RCT) for locally advanced rectal cancer (LARC). Methods and Materials: Twenty patients receiving RCT for LARC underwent MRI including DWI before RCT, after 10-15 fractions and 1 to 2 weeks before surgery. Tumor volume and apparent diffusion coefficient (ADC; b-values: 0-1000 s/mm{sup 2}) were determined at all time points. Pretreatment tumor ADC and volume, tumor ADC change ( Increment ADC), and volume change ( Increment V) between pretreatment and follow-up examinations were compared with histopathologic findings after total mesorectalmore » excision (pathologic complete response [pCR] vs. no pCR, ypT0-2 vs. ypT3-4, T-downstaging or not). The discriminatory capability of pretreatment tumor ADC and volume, Increment ADC, and Increment V for the detection of pCR was compared with receiver operating characteristics analysis. Results: Pretreatment ADC was significantly lower in patients with pCR compared with patients without (in mm{sup 2}/s: 0.94 {+-} 0.12 Multiplication-Sign 10{sup -3} vs. 1.19 {+-} 0.22 Multiplication-Sign 10{sup -3}, p = 0.003), yielding a sensitivity of 100% and specificity of 86% for detection of pCR. The volume reduction during and after RCT was significantly higher in patients with pCR compared with patients without (in %: {Delta}V{sub during}: -62 {+-} 16 vs. -33 {+-} 16, respectively, p = 0.015; and {Delta}V{sub post}: -86 {+-} 12 vs. -60 {+-} 21, p = 0.012), yielding a sensitivity of 83% and specificity of 71% for the {Delta}V{sub during} and, respectively, 83% and 86% for the {Delta}V{sub post}. The Increment ADC during ({Delta}ADC{sub during}) and after RCT ({Delta}ADC{sub post}) showed a significantly higher value in patients with pCR compared with patients without (in %: {Delta}ADC{sub during}: 72 {+-} 14 vs. 16 {+-} 12, p = 0.0006; and {Delta}ADC{sub post}: 88 {+-} 35 vs. 26 {+-} 19, p = 0.0011), yielding a sensitivity and specificity of 100% for the {Delta}ADC{sub during} and, respectively, 100% and 93% for the {Delta}ADC{sub post}. Conclusions: These initial findings indicate that DWI, using pretreatment ADC, {Delta}ADC{sub during}, and {Delta}ADC{sub post} may be useful for prediction and early assessment of pathologic response to preoperative RCT of LARC, with higher accuracy than volumetric measurements.« less

Genetic Improvements in Rice Yield and Concomitant Increases in Radiation- and Nitrogen-Use Efficiency in Middle Reaches of Yangtze River

PubMed Central

Zhu, Guanglong; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao; Wang, Fei

2016-01-01

The yield potential of rice (Oryza sativa L.) has experienced two significant growth periods that coincide with the introduction of semi-dwarfism and the utilization of heterosis. In present study, we determined the annual increase in the grain yield of rice varieties grown from 1936 to 2005 in Middle Reaches of Yangtze River and examined the contributions of RUE (radiation-use efficiency, the conversion efficiency of pre-anthesis intercepted global radiation to biomass) and NUE (nitrogen-use efficiency, the ratio of grain yield to aboveground N accumulation) to these improvements. An examination of the 70-year period showed that the annual gains of 61.9 and 75.3 kg ha−1 in 2013 and 2014, respectively, corresponded to an annual increase of 1.18 and 1.16% in grain yields, respectively. The improvements in grain yield resulted from increases in the harvest index and biomass, and the sink size (spikelets per panicle) was significantly enlarged because of breeding for larger panicles. Improvements were observed in RUE and NUE through advancements in breeding. Moreover, both RUE and NUE were significantly correlated with the grain yield. Thus, our study suggests that genetic improvements in rice grain yield are associated with increased RUE and NUE. PMID:26876641

Controlling composition and color characteristics of Monascus pigments by pH and nitrogen sources in submerged fermentation.

PubMed

Shi, Kan; Song, Da; Chen, Gong; Pistolozzi, Marco; Wu, Zhenqiang; Quan, Lei

2015-08-01

Submerged fermentations of Monascus anka were performed with different nitrogen sources at different pH in 3 L bioreactors. The results revealed that the Monascus pigments dominated by different color components (yellow pigments, orange pigments or red pigments) could be selectively produced through pH control and nitrogen source selection. A large amount of intracellular pigments dominated by orange pigments and a small amount of water-soluble extracellular yellow pigments were produced at low pH (pH 2.5 and 4.0), independently of the nitrogen source employed. At higher pH (pH 6.5), the role of the nitrogen source became more significant. In particular, when ammonium sulfate was used as nitrogen source, the intracellular pigments were dominated by red pigments with a small amount of yellow pigments. Conversely, when peptone was used, intracellular pigments were dominated by yellow pigments with a few red pigments derivatives. Neither the presence of peptone nor ammonium sulfate promoted the production of intracellular orange pigments while extracellular pigments with an orangish red color were observed in both cases, with a higher yield when peptone was used. Two-stage pH control fermentation was then performed to improve desirable pigments yield and further investigate the effect of pH and nitrogen sources on pigments composition. These results provide a useful strategy to produce Monascus pigments with different composition and different color characteristics. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Effect of increasing dietary metabolizable protein on nitrogen efficiency in Holstein dairy cows

PubMed Central

Imran, Muhammad; Pasha, Talat Naseer; Shahid, Muhammad Qamer; Babar, Imran; Naveed ul Haque, Muhammad

2017-01-01

Objective The objective of the study was to determine the effects of increasing levels of metabolizable protein (MP) on lactation performance and nitrogen (N) efficiencies in lactating dairy cows. Methods Nine multiparous cows in mid lactation [113±25 days in milk] received three treatments in a 3×3 Latin square design with a period length of 21 days. The treatments were three diets, designed to provide similar energy and increasing supply of MP (g/d) (2,371 [low], 2,561 [medium], and 2,711 [high] with corresponding crude protein levels [%]) 15.2, 18.4, and 20.9, respectively. Results Increasing MP supplies did not modify dry matter intake, however, it increased milk protein, fat, and lactose yield linearly. Similarly, fat corrected milk increased linearly (9.3%) due to an increase in both milk yield (5.2%) and milk fat content (7.8%). No effects were observed on milk protein and lactose contents across the treatments. Milk nitrogen efficiency (MNE) decreased from 0.26 to 0.20; whereas, the metabolic efficiency of MP decreased from 0.70 to 0.60 in low to high MP supplies, respectively. The concentration of blood urea nitrogen (BUN) increased linearly in response to increasing MP supplies. Conclusion Increasing MP supplies resulted in increased milk protein yield; however, a higher BUN and low MNE indicated an efficient utilization of dietary protein at low MP supplies. PMID:28002937

Tropical Legume Crop Rotation and Nitrogen Fertilizer Effects on Agronomic and Nitrogen Efficiency of Rice

PubMed Central

Rahman, Motior M.; Islam, Aminul M.; Azirun, Sofian M.; Boyce, Amru N.

2014-01-01

Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m−2 preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m−2. No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m−2 achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13–23% higher grain yield than rice after fallow rotation with 8 g N m−2. The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m−2 can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m−2. The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility. PMID:24971378

Intermittent illumination increases biophotolytic hydrogen yield by Anabaena cylindrica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeffries, T.W.; Leach, K.L.

Intermittent illumination increased H/sub 2/ and C/sub 2/H/sub 4/ yields per unit of light from growing cells and from nitrogen-starved cells by 1.7- and 1.35-fold, respectively, as compared with continuous illumination.

Combining Accuracy and Efficiency: An Incremental Focal-Point Method Based on Pair Natural Orbitals.

PubMed

Fiedler, Benjamin; Schmitz, Gunnar; Hättig, Christof; Friedrich, Joachim

2017-12-12

In this work, we present a new pair natural orbitals (PNO)-based incremental scheme to calculate CCSD(T) and CCSD(T0) reaction, interaction, and binding energies. We perform an extensive analysis, which shows small incremental errors similar to previous non-PNO calculations. Furthermore, slight PNO errors are obtained by using T PNO = T TNO with appropriate values of 10 -7 to 10 -8 for reactions and 10 -8 for interaction or binding energies. The combination with the efficient MP2 focal-point approach yields chemical accuracy relative to the complete basis-set (CBS) limit. In this method, small basis sets (cc-pVDZ, def2-TZVP) for the CCSD(T) part are sufficient in case of reactions or interactions, while some larger ones (e.g., (aug)-cc-pVTZ) are necessary for molecular clusters. For these larger basis sets, we show the very high efficiency of our scheme. We obtain not only tremendous decreases of the wall times (i.e., factors >10 2 ) due to the parallelization of the increment calculations as well as of the total times due to the application of PNOs (i.e., compared to the normal incremental scheme) but also smaller total times with respect to the standard PNO method. That way, our new method features a perfect applicability by combining an excellent accuracy with a very high efficiency as well as the accessibility to larger systems due to the separation of the full computation into several small increments.

Path-integral method for the source apportionment of photochemical pollutants

NASA Astrophysics Data System (ADS)

Dunker, A. M.

2015-06-01

A new, path-integral method is presented for apportioning the concentrations of pollutants predicted by a photochemical model to emissions from different sources. A novel feature of the method is that it can apportion the difference in a species concentration between two simulations. For example, the anthropogenic ozone increment, which is the difference between a simulation with all emissions present and another simulation with only the background (e.g., biogenic) emissions included, can be allocated to the anthropogenic emission sources. The method is based on an existing, exact mathematical equation. This equation is applied to relate the concentration difference between simulations to line or path integrals of first-order sensitivity coefficients. The sensitivities describe the effects of changing the emissions and are accurately calculated by the decoupled direct method. The path represents a continuous variation of emissions between the two simulations, and each path can be viewed as a separate emission-control strategy. The method does not require auxiliary assumptions, e.g., whether ozone formation is limited by the availability of volatile organic compounds (VOCs) or nitrogen oxides (NOx), and can be used for all the species predicted by the model. A simplified configuration of the Comprehensive Air Quality Model with Extensions (CAMx) is used to evaluate the accuracy of different numerical integration procedures and the dependence of the source contributions on the path. A Gauss-Legendre formula using three or four points along the path gives good accuracy for apportioning the anthropogenic increments of ozone, nitrogen dioxide, formaldehyde, and nitric acid. Source contributions to these increments were obtained for paths representing proportional control of all anthropogenic emissions together, control of NOx emissions before VOC emissions, and control of VOC emissions before NOx emissions. There are similarities in the source contributions from the three paths but also differences due to the different chemical regimes resulting from the emission-control strategies.

Path-integral method for the source apportionment of photochemical pollutants

NASA Astrophysics Data System (ADS)

Dunker, A. M.

2014-12-01

A new, path-integral method is presented for apportioning the concentrations of pollutants predicted by a photochemical model to emissions from different sources. A novel feature of the method is that it can apportion the difference in a species concentration between two simulations. For example, the anthropogenic ozone increment, which is the difference between a simulation with all emissions present and another simulation with only the background (e.g., biogenic) emissions included, can be allocated to the anthropogenic emission sources. The method is based on an existing, exact mathematical equation. This equation is applied to relate the concentration difference between simulations to line or path integrals of first-order sensitivity coefficients. The sensitivities describe the effects of changing the emissions and are accurately calculated by the decoupled direct method. The path represents a continuous variation of emissions between the two simulations, and each path can be viewed as a separate emission-control strategy. The method does not require auxiliary assumptions, e.g., whether ozone formation is limited by the availability of volatile organic compounds (VOC's) or nitrogen oxides (NOx), and can be used for all the species predicted by the model. A simplified configuration of the Comprehensive Air Quality Model with Extensions is used to evaluate the accuracy of different numerical integration procedures and the dependence of the source contributions on the path. A Gauss-Legendre formula using 3 or 4 points along the path gives good accuracy for apportioning the anthropogenic increments of ozone, nitrogen dioxide, formaldehyde, and nitric acid. Source contributions to these increments were obtained for paths representing proportional control of all anthropogenic emissions together, control of NOx emissions before VOC emissions, and control of VOC emissions before NOx emissions. There are similarities in the source contributions from the three paths but also differences due to the different chemical regimes resulting from the emission-control strategies.

Electron correlation at the MgF2(110) surface: a comparison of incremental and local correlation methods.

PubMed

Hammerschmidt, Lukas; Maschio, Lorenzo; Müller, Carsten; Paulus, Beate

2015-01-13

We have applied the Method of Increments and the periodic Local-MP2 approach to the study of the (110) surface of magnesium fluoride, a system of significant interest in heterogeneous catalysis. After careful assessment of the approximations inherent in both methods, the two schemes, though conceptually different, are shown to yield nearly identical results. This remains true even when analyzed in fine detail through partition of the individual contribution to the total energy. This kind of partitioning also provides thorough insight into the electron correlation effects underlying the surface formation process, which are discussed in detail.

Electrochemical wastewater treatment: influence of the type of carbon and of nitrogen on the organic load removal.

PubMed

Fernandes, Annabel; Coelho, João; Ciríaco, Lurdes; Pacheco, Maria José; Lopes, Ana

2016-12-01

Boron-doped diamond (BDD) and Ti/Pt/PbO 2 anodes were utilized to perform the electrodegradation of synthetic samples containing humic acid in the presence of different organic and inorganic carbon-containing and nitrogen-containing compounds. The influence of the chloride ion in the degradation process of the different synthetic samples was also assessed. The results showed that the anodic oxidation process can efficiently degrade recalcitrant compounds such as humic acid. The presence of carbonate in solution enhances the nitrogen removal, whereas it hinders the oxidation of the organic compounds. When organic nitrogen is present, it is converted to NH 4 + , which in turn is oxidized to nitrate and to volatile nitrogen compounds. Hydroxyl radicals are more prone to oxidize the organic nitrogen than the ammonium nitrogen. The presence of chloride enhances the organic matter and nitrogen removal rates, BDD being the anode material that yields the highest removals.

Solubility of Nitrogen in Superaustenitic Stainless Steels During Air Induction Melting

NASA Astrophysics Data System (ADS)

Chandrasekar, A.; Anburaj, J.; Narayanan, R.; Balusamy, V.; Mohamed Nazirudeen, S. S.

2013-04-01

The amount of nitrogen contained in super austenitic stainless steels (SASS) influences their properties significantly. The effect of maximum amount of nitrogen in the highly alloyed Cr and Ni SASS containing further additions of Mo and Mn is studied. The calculated nitrogen contents of the experimental alloys are compared with the actual nitrogen contents obtained in the alloys produced using induction melting furnace. The actual nitrogen content of the alloys is always lower than the calculated value, and this discrepancy is due to the presence of positive interaction parameters of Ni, Cu, and Si in the alloy. However, the yield of nitrogen in the liquid SASS is improved significantly with additions of Mn and Mo contents. The construction of multicomponent phase diagrams for SASS is demonstrated using Thermo-Calc software. SASS containing more nitrogen exhibited a very high strength without loss of toughness.

Guidance on Implementing the Nitrogen Dioxide (NO2) PSD Increments

EPA Pesticide Factsheets

This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Use of nitrogen-fixing bacteria as biofertiliser for non-legumes: prospects and challenges.

PubMed

Bhattacharjee, Rumpa Biswas; Singh, Aqbal; Mukhopadhyay, S N

2008-08-01

The potential of nitrogen-fixing (NF) bacteria to form a symbiotic relationship with leguminous plants and fix atmospheric nitrogen has been exploited in the field to meet the nitrogen requirement of the latter. This phenomenon provides an alternative to the use of the nitrogenous fertiliser whose excessive and imbalanced use over the decades has contributed to green house emission (N2O) and underground water leaching. Recently, it was observed that non-leguminous plants like rice, sugarcane, wheat and maize form an extended niche for various species of NF bacteria. These bacteria thrive within the plant, successfully colonizing roots, stems and leaves. During the association, the invading bacteria benefit the acquired host with a marked increase in plant growth, vigor and yield. With increasing population, the demand of non-leguminous plant products is growing. In this regard, the richness of NF flora within non-leguminous plants and extent of their interaction with the host definitely shows a ray of hope in developing an ecofriendly alternative to the nitrogenous fertilisers. In this review, we have discussed the association of NF bacteria with various non-leguminous plants emphasizing on their potential to promote host plant growth and yield. In addition, plant growth-promoting traits observed in these NF bacteria and their mode of interaction with the host plant have been described briefly.

Effect of salinity stress on phenotypic plasticity, yield stability, and signature of stable isotopes of carbon and nitrogen in safflower.

PubMed

Hussain, Muhammad Iftikhar; Al-Dakheel, Abdullah J

2018-06-05

Salinity is one of the major factors contributing in land degradation, disturbance of soil biology, a structure that leads to unproductive land with low crop yield potential especially in arid and semiarid regions of the world. Appropriate crops with sufficient stress tolerance capacity and non-conventional water resources should have to be managed in a sustainable way to bring these marginal lands under cultivation for future food security. The goal of the present study was to evaluate salinity tolerant potential (0, 7, and 14 dS m -1 ) of six safflower genotypes that can be adapted to the hyper arid climate of UAE and its marginal soil. Several agro-morphological and physiological traits such as plant dry biomass (PDM), number of branches (BN), number of capitula (CN), seed yield (SY), stable isotope composition of nitrogen (δ 15 N) and carbon (δ 13 C), intercellular CO 2 concentration from inside to ambient air (Ci/Ca), intrinsic water use efficiency (iWUE), carbon (C%) and nitrogen (N %), and harvest index (HI) were evaluated as indicative of the functional performance of safflower genotypes under salt stress. Results indicated that salinity significantly affected the seed yield at all levels and varied significantly among genotypes. The BN, PDM, CN, and δ 13 C attributes showed clear differentiation between tolerant and susceptible genotypes. The δ 13 C results indicate that the tolerant genotypes suffer less from stress, may be due to better rooting. Tolerant genotypes showed lower iWUE values but possess higher yield. Safflower genotypes (PI248836 and PI167390) proved to be salt tolerant, stable, and higher seed and biomass yielder. There was no G × E interaction but the genotypes that produce higher yield under control were still best even under salt stress conditions. Although salinity reduced crop yield, some tolerant genotypes demonstrate adaptation and good yield potential under saline marginal environment.

Effect of subsoiling in fallow period on soil water storage and grain protein accumulation of dryland wheat and its regulatory effect by nitrogen application.

PubMed

Sun, Min; Gao, ZhiQiang; Zhao, WeiFeng; Deng, LianFeng; Deng, Yan; Zhao, HongMei; Ren, AiXia; Li, Gang; Yang, ZhenPing

2013-01-01

To provide a new way to increase water storage and retention of dryland wheat, a field study was conducted at Wenxi experimental site of Shanxi Agricultural University. The effect of subsoiling in fallow period on soil water storage, accumulation of proline, and formation of grain protein after anthesis were determined. Our results showed that subsoiling in fallow period could increase water storage in the 0-300 cm soil at pre-sowing stage and at anthesis stage with low or medium N application, especially for the 60-160 cm soil. However, the proline content, glutamine synthetase (GS) activity, glutamate dehydrogenase (GDH) activity in flag leaves and grains were all decreased by subsoiling in fallow period. In addition, the content of albumin, gliadin, and total protein in grains were also decreased while globulin content, Glu/Gli, protein yield, and glutelin content were increased. With N application increasing, water storage of soil layers from 20 to 200 cm was decreased at anthesis stage. High N application resulted in the increment of proline content and GS activity in grains. Besides, correlation analysis showed that soil storage in 40-160 cm soil was negatively correlated with proline content in grains; proline content in grains was positively correlated with GS and GDH activity in flag leaves. Contents of albumin, globulin and total protein in grains were positively correlated with proline content in grains and GDH activity in flag leaves. In conclusion, subsoiling in fallow period, together with N application at 150 kg·hm(-2), was beneficial to increase the protein yield and Glu/Gli in grains which improve the quality of wheat.

Effect of Subsoiling in Fallow Period on Soil Water Storage and Grain Protein Accumulation of Dryland Wheat and Its Regulatory Effect by Nitrogen Application

PubMed Central

Sun, Min; Gao, ZhiQiang; Zhao, WeiFeng; Deng, LianFeng; Deng, Yan; Zhao, HongMei; Ren, AiXia; Li, Gang; Yang, ZhenPing

2013-01-01

To provide a new way to increase water storage and retention of dryland wheat, a field study was conducted at Wenxi experimental site of Shanxi Agricultural University. The effect of subsoiling in fallow period on soil water storage, accumulation of proline, and formation of grain protein after anthesis were determined. Our results showed that subsoiling in fallow period could increase water storage in the 0–300 cm soil at pre-sowing stage and at anthesis stage with low or medium N application, especially for the 60–160 cm soil. However, the proline content, glutamine synthetase (GS) activity, glutamate dehydrogenase (GDH) activity in flag leaves and grains were all decreased by subsoiling in fallow period. In addition, the content of albumin, gliadin, and total protein in grains were also decreased while globulin content, Glu/Gli, protein yield, and glutelin content were increased. With N application increasing, water storage of soil layers from 20 to 200 cm was decreased at anthesis stage. High N application resulted in the increment of proline content and GS activity in grains. Besides, correlation analysis showed that soil storage in 40–160 cm soil was negatively correlated with proline content in grains; proline content in grains was positively correlated with GS and GDH activity in flag leaves. Contents of albumin, globulin and total protein in grains were positively correlated with proline content in grains and GDH activity in flag leaves. In conclusion, subsoiling in fallow period, together with N application at 150 kg·hm−2, was beneficial to increase the protein yield and Glu/Gli in grains which improve the quality of wheat. PMID:24098371

Transgenic plants that exhibit enhanced nitrogen assimilation

DOEpatents

Coruzzi, Gloria M.; Brears, Timothy

2005-03-08

The present invention relates to a method for producing plants with improved agronomic and nutritional traits. Such traits include enhanced nitrogen assimilatory and utilization capacities, faster and more vigorous growth, greater vegetative and reproductive yields, and enriched or altered nitrogen content in vegetative and reproductive parts. More particularly, the invention relates to the engineering of plants modified to have altered expression of key enzymes in the nitrogen assimilation and utilization pathways. In one embodiment of the present invention, the desired altered expression is accomplished by engineering the plant for ectopic overexpression of one of more the native or modified nitrogen assimilatory enzymes. The invention also has a number of other embodiments, all of which are disclosed herein.

Transgenic plants that exhibit enhanced nitrogen assimilation

DOEpatents

Coruzzi, Gloria M.; Brears, Timothy

1999-01-01

The present invention relates to a method for producing plants with improved agronomic and nutritional traits. Such traits include enhanced nitrogen assimilatory and utilization capacities, faster and more vigorous growth, greater vegetative and reproductive yields, and enriched or altered nitrogen content in vegetative and reproductive parts. More particularly, the invention relates to the engineering of plants modified to have altered expression of key enzymes in the nitrogen assimilation and utilization pathways. In one embodiment of the present invention, the desired altered expression is accomplished by engineering the plant for ectopic overexpression of one of more the native or modified nitrogen assimilatory enzymes. The invention also has a number of other embodiments, all of which are disclosed herein.

Transgenic plants that exhibit enhanced nitrogen assimilation

DOEpatents

Coruzzi, Gloria M.; Brears, Timothy

2000-01-01

The present invention relates to a method for producing plants with improved agronomic and nutritional traits. Such traits include enhanced nitrogen assimilatory and utilization capacities, faster and more vigorous growth, greater vegetative and reproductive yields, and enriched or altered nitrogen content in vegetative and reproductive parts. More particularly, the invention relates to the engineering of plants modified to have altered expression of key enzymes in the nitrogen assimilation and utilization pathways. In one embodiment of the present invention, the desired altered expression is accomplished by engineering the plant for ectopic overexpression of one of more the native or modified nitrogen assimilatory enzymes. The invention also has a number of other embodiments, all of which are disclosed herein.

[Effects of reduced N application rate on yield and nutrient uptake and utilization in maize-soybean relay strip intercropping system].

PubMed

Yong, Tai-Wen; Liu, Xiao-Ming; Wen-Yu, Liu; Su, Ben-Ying; Song, Chun; Yang, Feng; Wang, Xiao-Chun; Yang, Wen-Yu

2014-02-01

A field experiment with three N application rates (0, 180, 240 N kg x hm(-2), representing zero, reduced and conventional N application, respectively) and three planting patterns (maize monoculture, soybean monoculture and maize-soybean relay strip intercropping) was conducted to reveal the effects of cropping patterns and N application rates on yield, nutrient uptake and nitrogen use efficiency of maize and soybean. The results showed that the grain yield, N, P and K uptake and harvest index of the intercropped maize reduced slightly compared with the monoculture maize, however these indices of the intercropped soybean increased significantly compared with the monoculture. With the increase in nitrogen fertilizer application, the excellence of relay strip intercropping was weakened in the maize-soybean intercropping system. The grain yield, economic coefficient, N, P and K uptake, harvest index, N agronomy efficiency and N uptake efficiency of maize and soybean increased significantly at the reduced nitrogen rate (180 N kg x hm(-2)), but the rate of soil N contribution declined, compared with the conventional rate of N application by local farmers (240 N kg x hm(-2)). In the reduced nitrogen rate treatment, total soil N and P contents of the maize strip reduced, whereas the total soil N, P and K contents of soybean strip and the total K content of maize strip increased compared with the zero N application treatment. With the reduced N application, the annual total grain yield, N, P and K uptake of above-ground biomass in the maize-soybean relay strip intercropping system were higher than in the monoculture, and the land equivalent ratio (LER) was 2.28. N uptake efficiency of maize in the relay strip intercropping system was 20.2% higher than in the maize monoculture, and the index of soybean was 30.5% lower than in the monoculture. The rate of soil N contribution in the relay strip intercropping system was 20.0% and 8.8% lower than in the maize and soybean monoculture, respectively. The reduced N application in the maize-soybean relay strip intercropping system was helpful to promote annual grain yield and improve N utilization efficiency.

Nitrogen and phosphorus fluxes from watersheds of the northeast U.S. from 1930 to 2000: Role of anthropogenic nutrient inputs, infrastructure, and runoff

NASA Astrophysics Data System (ADS)

Hale, Rebecca L.; Grimm, Nancy B.; Vörösmarty, Charles J.; Fekete, Balazs

2015-03-01

An ongoing challenge for society is to harness the benefits of nutrients, nitrogen (N) and phosphorus (P), while minimizing their negative effects on ecosystems. While there is a good understanding of the mechanisms of nutrient delivery at small scales, it is unknown how nutrient transport and processing scale up to larger watersheds and whole regions over long time periods. We used a model that incorporates nutrient inputs to watersheds, hydrology, and infrastructure (sewers, wastewater treatment plants, and reservoirs) to reconstruct historic nutrient yields for the northeastern U.S. from 1930 to 2002. Over the study period, yields of nutrients increased significantly from some watersheds and decreased in others. As a result, at the regional scale, the total yield of N and P from the region did not change significantly. Temporal variation in regional N and P yields was correlated with runoff coefficient, but not with nutrient inputs. Spatial patterns of N and P yields were best predicted by nutrient inputs, but the correlation between inputs and yields across watersheds decreased over the study period. The effect of infrastructure on yields was minimal relative to the importance of soils and rivers. However, infrastructure appeared to alter the relationships between inputs and yields. The role of infrastructure changed over time and was important in creating spatial and temporal heterogeneity in nutrient input-yield relationships.

Global sensitivity and uncertainty analysis of the nitrate leaching and crop yield simulation under different water and nitrogen management practices

USDA-ARS?s Scientific Manuscript database

Agricultural system models have become important tools in studying water and nitrogen (N) dynamics, as well as crop growth, under different management practices. Complexity in input parameters often leads to significant uncertainty when simulating dynamic processes such as nitrate leaching or crop y...

Impacts of enhanced-efficiency nitrogen fertilizers on greenhouse gas emissions in a coastal plain soil under cotton

USDA-ARS?s Scientific Manuscript database

Enhanced-efficiency nitrogen fertilizers (EENFs) have the potential to increase crop yield while also decreasing N loss from agricultural fields. However, effects of EENFs on emissions of greenhouse gases (GHGs) need to be studied at a variety of locations and cropping systems. The effects of these ...

Glutamine synthetase in durum wheat: Genotypic variation and relationship with grain protein content

USDA-ARS?s Scientific Manuscript database

Nitrogen Use Efficiency (NUE), one of the most valuable indicators for nitrogen use in crops, both in terms of yield and final grain protein content (GPC), is a very complex trait. The identification of wheat varieties with high NUE, as well as the characterization of central enzymes involved in th...

Microarray and growth analyses identify differences and similarities of early corn response to weeds, shade, and nitrogen stress

USDA-ARS?s Scientific Manuscript database

Weed interference with crop growth is often attributed to water, nutrient, or light competition; however, specific physiological responses to these stresses are not well described. This study’s objective was to compare growth, yield, and gene expression responses of corn to nitrogen (N), low light (...

From the lab bench: Mixtures of grasses and legumes for extending the grazing season

USDA-ARS?s Scientific Manuscript database

A column was written to discuss how clovers and warm-season legumes, such as alfalfa and birdsfoot trefoil, in mixture with grasses can enhance the overall nutritive value of the overall forage, increase dry matter yield, and contribute nitrogen to the soil via the nitrogen fixing Rhizobia bacteria ...

Dealing with drought: Securing nitrogen with cover crops

USDA-ARS?s Scientific Manuscript database

This year the drought in the Midwest has significantly reduced the growth and yield of all crops. When the growth of the cash crop has been reduced by drought or any other cause it is important to remember that more nitrogent than normal will remain in the soil after harvest. This nitrogen will be v...

Flush of CO2 as a short-term biological indicator of soil nitrogen mineralization in the Southeast

USDA-ARS?s Scientific Manuscript database

Determining the appropriate nitrogen (N) rate is critical to farm economics and environmental protection. In North Carolina, N fertilizer recommendations are not modified by residual inorganic N or biologically active N, but only by realistic yield expectation set for each soil type by crop. However...

Genome-wide association analysis of diverse soybean genotypes reveals novel markers for nitrogen traits

USDA-ARS?s Scientific Manuscript database

Nitrogen is a primary plant nutrient that plays a major role in achieving maximum economic yield. Insufficient availability most often limits soybean crop growth. Symbiotic N2 fixation in soybean is highly sensitive to limited water availability, and breeding for reduced N2 fixation sensitivity to ...

Tomato response to legume cover crop and nitrogen: differing enhancement patterns of fruit yield, photosynthesis and gene expression

USDA-ARS?s Scientific Manuscript database

Tomatoes responded to soil and residue from a hairy vetch cover crop differently on many levels than tomato response to inorganic nitrogen. Tomato fruit production, plant biomass parameters, and photosynthesis were higher in plants grown in vetch than bare soil. Tomato growth and photosynthesis metr...

N 2 gas is an effective fertilizer for bioethanol production by Zymomonas mobilis

DOE PAGES

Kremer, Timothy A.; LaSarre, Breah; Posto, Amanda L.; ...

2015-02-02

A nascent cellulosic ethanol industry is struggling to become cost-competitive against corn ethanol and gasoline. Millions of dollars are spent on nitrogen supplements to make up for the low nitrogen content of the cellulosic feedstock. In this paper, we show for the first time to our knowledge that the ethanol-producing bacterium, Zymomonas mobilis, can use N 2 gas in lieu of traditional nitrogen supplements. Despite being an electron-intensive process, N 2 fixation by Z. mobilis did not divert electrons away from ethanol production, as the ethanol yield was greater than 97% of the theoretical maximum. In a defined medium, Z.more » mobilis produced ethanol 50% faster per cell and generated half the unwanted biomass when supplied N 2 instead of ammonium. In a cellulosic feedstock-derived medium, Z. mobilis achieved a similar cell density and a slightly higher ethanol yield when supplied N 2 instead of the industrial nitrogen supplement, corn steep liquor. Finally, we estimate that N 2-utilizing Z. mobilis could save a cellulosic ethanol production facility more than $1 million/y.« less

N2 gas is an effective fertilizer for bioethanol production by Zymomonas mobilis

PubMed Central

Kremer, Timothy A.; LaSarre, Breah; Posto, Amanda L.; McKinlay, James B.

2015-01-01

A nascent cellulosic ethanol industry is struggling to become cost-competitive against corn ethanol and gasoline. Millions of dollars are spent on nitrogen supplements to make up for the low nitrogen content of the cellulosic feedstock. Here we show for the first time to our knowledge that the ethanol-producing bacterium, Zymomonas mobilis, can use N2 gas in lieu of traditional nitrogen supplements. Despite being an electron-intensive process, N2 fixation by Z. mobilis did not divert electrons away from ethanol production, as the ethanol yield was greater than 97% of the theoretical maximum. In a defined medium, Z. mobilis produced ethanol 50% faster per cell and generated half the unwanted biomass when supplied N2 instead of ammonium. In a cellulosic feedstock-derived medium, Z. mobilis achieved a similar cell density and a slightly higher ethanol yield when supplied N2 instead of the industrial nitrogen supplement, corn steep liquor. We estimate that N2-utilizing Z. mobilis could save a cellulosic ethanol production facility more than $1 million/y. PMID:25646422

Supercritical water oxidation of quinazoline: Reaction kinetics and modeling.

PubMed

Gong, Yanmeng; Guo, Yang; Wang, Shuzhong; Song, Wenhan; Xu, Donghai

2017-03-01

This paper presents a first quantitative kinetic model for supercritical water oxidation (SCWO) of quinazoline that describes the formation and interconversion of intermediates and final products at 673-873 K. The set of 11 reaction pathways for phenol, pyrimidine, naphthalene, NH 3 , etc, involved in the simplified reaction network proved sufficient for fitting the experimental results satisfactorily. We validated the model prediction ability on CO 2 yields at initial quinazoline loading not used in the parameter estimation. Reaction rate analysis and sensitivity analysis indicate that nearly all reactions reach their thermodynamic equilibrium within 300 s. The pyrimidine yielding from quinazoline is the dominant ring-opening pathway and provides a significant contribution to CO 2 formation. Low sensitivity of NH 3 decomposition rate to concentration confirms its refractory nature in SCWO. Nitrogen content in liquid products decreases whereas that in gaseous phase increases as reaction time prolonged. The nitrogen predicted by the model in gaseous phase combined with the experimental nitrogen in liquid products gives an accurate nitrogen balance of conversion process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Co-production of bio-ethanol, xylonic acid and slow-release nitrogen fertilizer from low-cost straw pulping solid residue.

PubMed

Huang, Chen; Ragauskas, Arthur J; Wu, Xinxing; Huang, Yang; Zhou, Xuelian; He, Juan; Huang, Caoxing; Lai, Chenhuan; Li, Xin; Yong, Qiang

2018-02-01

A novel bio-refinery sequence yielding varieties of co-products was developed using straw pulping solid residue. This process utilizes neutral sulfite pretreatment which under optimal conditions (160 °C and 3% (w/v) sulfite charge) provides 64.3% delignification while retaining 90% of cellulose and 67.3% of xylan. The pretreated solids exhibited excellent enzymatic digestibility, with saccharification yields of 86.9% and 81.1% for cellulose and xylan, respectively. After pretreatment, the process of semi-simultaneous saccharification and fermentation (S-SSF) and bio-catalysis was investigated. The results revealed that decreased ethanol yields were achieved when solid loading increased from 5% to 30%. An acceptable ethanol yield of 76.8% was obtained at 20% solid loading. After fermentation, bio-catalysis of xylose remaining in fermentation broth resulted in near 100% xylonic acid (XA) yield at varied solid loadings. To complete the co-product portfolio, oxidation ammoniation of the dissolved lignin successfully transformed it into biodegradable slow-release nitrogen fertilizer with excellent agricultural properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water quality in the St Croix National Scenic Riverway, Wisconsin

USGS Publications Warehouse

Graczyk, D.J.

1986-01-01

Yields for suspended sediment, total phosphorus, total nitrogen, and dissolved solids at the study stations were consistently lower than at other stations in the State. Suspendedsediment yields ranged from 1.9 to 13.3 tons per square mile. The average suspended-sediment yield for Wisconsin is 80 tons per square mile. Total phosphorous and the other constituents exhibited the same trend.

Responses of Nitrogen Utilization and Apparent Nitrogen Loss to Different Control Measures in the Wheat and Maize Rotation System

PubMed Central

Peng, Zhengping; Liu, Yanan; Li, Yingchun; Abawi, Yahya; Wang, Yanqun; Men, Mingxin; An-Vo, Duc-Anh

2017-01-01

Nitrogen (N) is an essential macronutrient for plant growth and excessive application rates can decrease crop yield and increase N loss into the environment. Field experiments were carried out to understand the effects of N fertilizers on N utilization, crop yield and net income in wheat and maize rotation system of the North China Plain (NCP). Compared to farmers’ N rate (FN), the yield of wheat and maize in reduction N rate by 21–24% based on FN (RN) was improved by 451 kg ha-1, N uptakes improved by 17 kg ha-1 and net income increased by 1671 CNY ha-1, while apparent N loss was reduced by 156 kg ha-1. The controlled-release fertilizer with a 20% reduction of RN (CRF80%), a 20% reduction of RN together with dicyandiamide (RN80%+DCD) and a 20% reduction of RN added with nano-carbon (RN80%+NC) all resulted in an improvement in crop yield and decreased the apparent N losses compared to RN. Contrasted with RN80%+NC, the total crop yield in RN80%+DCD improved by 1185 kg ha-1, N uptake enhanced by 9 kg ha-1 and net income increased by 3929 CNY ha-1, while apparent N loss was similar. Therefore, a 37–39% overall decrease in N rate compared to farmers plus the nitrification inhibitor, DCD, was effective N control measure that increased crop yields, enhanced N efficiencies, and improved economic benefits, while mitigating apparent N loss. There is considerable scope for improved N use effieincy in the intensive wheat -maize rotation of the NCP. PMID:28228772

Effect of comprehensive cardiac telerehabilitation on one-year cardiovascular rehospitalization rate, medical costs and quality of life: A cost-effectiveness analysis.

PubMed

Frederix, Ines; Hansen, Dominique; Coninx, Karin; Vandervoort, Pieter; Vandijck, Dominique; Hens, Niel; Van Craenenbroeck, Emeline; Van Driessche, Niels; Dendale, Paul

2016-05-01

Notwithstanding the cardiovascular disease epidemic, current budgetary constraints do not allow for budget expansion of conventional cardiac rehabilitation programmes. Consequently, there is an increasing need for cost-effectiveness studies of alternative strategies such as telerehabilitation. The present study evaluated the cost-effectiveness of a comprehensive cardiac telerehabilitation programme. This multi-centre randomized controlled trial comprised 140 cardiac rehabilitation patients, randomized (1:1) to a 24-week telerehabilitation programme in addition to conventional cardiac rehabilitation (intervention group) or to conventional cardiac rehabilitation alone (control group). The incremental cost-effectiveness ratio was calculated based on intervention and health care costs (incremental cost), and the differential incremental quality adjusted life years (QALYs) gained. The total average cost per patient was significantly lower in the intervention group (€2156 ± €126) than in the control group (€2720 ± €276) (p = 0.01) with an overall incremental cost of €-564.40. Dividing this incremental cost by the baseline adjusted differential incremental QALYs (0.026 QALYs) yielded an incremental cost-effectiveness ratio of €-21,707/QALY. The number of days lost due to cardiovascular rehospitalizations in the intervention group (0.33 ± 0.15) was significantly lower than in the control group (0.79 ± 0.20) (p = 0.037). This paper shows the addition of cardiac telerehabilitation to conventional centre-based cardiac rehabilitation to be more effective and efficient than centre-based cardiac rehabilitation alone. These results are useful for policy makers charged with deciding how limited health care resources should best be allocated in the era of exploding need. © The European Society of Cardiology 2015.

Designing a new cropping system for high productivity and sustainable water usage under climate change

PubMed Central

Meng, Qingfeng; Wang, Hongfei; Yan, Peng; Pan, Junxiao; Lu, Dianjun; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

2017-01-01

The food supply is being increasingly challenged by climate change and water scarcity. However, incremental changes in traditional cropping systems have achieved only limited success in meeting these multiple challenges. In this study, we applied a systematic approach, using model simulation and data from two groups of field studies conducted in the North China Plain, to develop a new cropping system that improves yield and uses water in a sustainable manner. Due to significant warming, we identified a double-maize (M-M; Zea mays L.) cropping system that replaced the traditional winter wheat (Triticum aestivum L.) –summer maize system. The M-M system improved yield by 14–31% compared with the conventionally managed wheat-maize system, and achieved similar yield compared with the incrementally adapted wheat-maize system with the optimized cultivars, planting dates, planting density and water management. More importantly, water usage was lower in the M-M system than in the wheat-maize system, and the rate of water usage was sustainable (net groundwater usage was ≤150 mm yr−1). Our study indicated that systematic assessment of adaptation and cropping system scale have great potential to address the multiple food supply challenges under changing climatic conditions. PMID:28155860

Influence of Pre- and Postharvest Summer Pruning on the Growth, Yield, Fruit Quality, and Carbohydrate Content of Early Season Peach Cultivars

PubMed Central

Ikinci, Ali

2014-01-01

Winter and summer pruning are widely applied processes in all fruit trees, including in peach orchard management. This study was conducted to determine the effects of summer prunings (SP), as compared to winter pruning (WP), on shoot length, shoot diameter, trunk cross sectional area (TCSA) increment, fruit yield, fruit quality, and carbohydrate content of two early ripening peach cultivars (“Early Red” and “Maycrest”) of six years of age, grown in semiarid climate conditions, in 2008 to 2010. The trees were grafted on GF 677 rootstocks, trained with a central leader system, and spaced 5 × 5 m apart. The SP carried out after harvesting in July and August decreased the shoot length significantly; however, it increased its diameter. Compared to 2009, this effect was more marked in year 2010. In general, control and winter pruned trees of both cultivars had the highest TCSA increment and yield efficiency. The SP increased the average fruit weight and soluble solids contents (SSC) more than both control and WP. The titratable acidity showed no consistent response to pruning time. The carbohydrate accumulation in shoot was higher in WP and in control than in SP trees. SP significantly affected carbohydrate accumulation; postharvest pruning showed higher carbohydrate content than preharvest pruning. PMID:24737954

Nitrogen loads from selected rivers in the Long Island Sound Basin, 2005–13, Connecticut and Massachusetts

USGS Publications Warehouse

Mullaney, John R.

2016-03-29

Total nitrogen loads at 14 water-quality monitoring stations were calculated by using discrete measurements of total nitrogen and continuous streamflow data for the period 2005–13 (water years 2006–13). Total nitrogen loads were calculated by using the LOADEST computer program.Overall, for water years 2006–13, streamflow in Connecticut was generally above normal. Total nitrogen yields ranged from 1,160 to 23,330 pounds per square mile per year. Total nitrogen loads from the French River at North Grosvenordale and the Still River at Brookfield Center, Connecticut, declined noticeably during the study period. An analysis of the bias in estimated loads indicated unbiased results at all but one station, indicating generally good fit for the LOADEST models.

Genetic Basis for Variation in Wheat Grain Yield in Response to Varying Nitrogen Application.

PubMed

Mahjourimajd, Saba; Taylor, Julian; Sznajder, Beata; Timmins, Andy; Shahinnia, Fahimeh; Rengel, Zed; Khabaz-Saberi, Hossein; Kuchel, Haydn; Okamoto, Mamoru; Langridge, Peter

2016-01-01

Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. Nitrogen fertilisers represent a significant production cost, in both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass production after establishment and showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation in NUE has been shown previously. Here we describe the genetic characterisation of NUE and identify genetic loci underlying N response under different N fertiliser regimes in a bread wheat population of doubled-haploid lines derived from a cross between two Australian genotypes (RAC875 × Kukri) bred for a similar production environment. NUE field trials were carried out at four sites in South Australia and two in Western Australia across three seasons. There was genotype-by-environment-by-treatment interaction across the sites and also good transgressive segregation for yield under different N supply in the population. We detected some significant Quantitative Trait Loci (QTL) associated with NUE and N response at different rates of N application across the sites and years. It was also possible to identify lines showing positive N response based on the rankings of their Best Linear Unbiased Predictions (BLUPs) within a trial. Dissecting the complexity of the N effect on yield through QTL analysis is a key step towards elucidating the molecular and physiological basis of NUE in wheat.

Irrigation and Nitrogen Regimes Promote the Use of Soil Water and Nitrate Nitrogen from Deep Soil Layers by Regulating Root Growth in Wheat

PubMed Central

Liu, Weixing; Ma, Geng; Wang, Chenyang; Wang, Jiarui; Lu, Hongfang; Li, Shasha; Feng, Wei; Xie, Yingxin; Ma, Dongyun; Kang, Guozhang

2018-01-01

Unreasonably high irrigation levels and excessive nitrogen (N) supplementation are common occurrences in the North China Plain that affect winter wheat production. Therefore, a 6-yr-long stationary field experiment was conducted to investigate the effects of irrigation and N regimes on root development and their relationship with soil water and N use in different soil layers. Compared to the non-irrigated treatment (W0), a single irrigation at jointing (W1) significantly increased yield by 3.6–45.6%. With increases in water (W2, a second irrigation at flowering), grain yield was significantly improved by 14.1–45.3% compared to the W1 treatments during the drier growing seasons (2010–2011, 2012–2013, and 2015–2016). However, under sufficient pre-sowing soil moisture conditions, grain yield was not increased, and water use efficiency (WUE) decreased significantly in the W2 treatments during normal precipitation seasons (2011–2012, 2013–2014, and 2014–2015). Irrigating the soil twice inhibited root growth into the deeper soil depth profiles and thus weakened the utilization of soil water and NO3-N from the deep soil layers. N applications increased yield by 19.1–64.5%, with a corresponding increase in WUE of 66.9–83.9% compared to the no-N treatment (N0). However, there was no further increase in grain yield and the WUE response when N rates exceeded 240 and 180 kg N ha−1, respectively. A N application rate of 240 kg ha−1 facilitated root growth in the deep soil layers, which was conducive to utilization of soil water and NO3-N and also in reducing the residual NO3-N. Correlation analysis indicated that the grain yield was significantly positively correlated with soil water storage (SWS) and nitrate nitrogen accumulation (SNA) prior to sowing. Therefore, N rates of 180–240 kg ha−1 with two irrigations can reduce the risk of yield loss that occurs due to reduced precipitation during the wheat growing seasons, while under better soil moisture conditions, a single irrigation at jointing was effective and more economical. PMID:29449850

Effect of systemic herbicides on N2-fixing and phosphate solubilizing microorganisms in relation to availability of nitrogen and phosphorus in paddy soils of West Bengal.

PubMed

Das, Amal Chandra; Debnath, Anjan

2006-11-01

A field experiment has been conducted with four systemic herbicides viz., butachlor [N-(butoxymethyl)-2-chloro-2',6'-diethyl-acetanilide], fluchloralin [N-(2-chloroethyl)-(2,6-dinitro-N-propyl-4-trifluoromethyl) aniline], oxadiazon [5-terbutyl-3-(2,4-dichloro-5-isopro poxyphenyl)-1,3,4-oxadiazol-2-one] and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenyl)-4-(trifluoromethyl) benzene] at their recommended field rates (2.0, 1.5, 0.4 and 0.12kga.i.ha(-1), respectively) to investigate their effects on growth and activities of aerobic non-symbiotic N(2)-fixing bacteria and phosphate solubilizing microorganisms in relation to availability of nitrogen and phosphorus in the rhizosphere soils as well as yield of the rice crop (Oryza sativa L cv. IR-36). Application of herbicides, in general, highly stimulated the population and activities of the target microorganisms, which resulted in a greater amount of atmospheric nitrogen fixation and phosphate solubilization in the rhizosphere soils of the test crop. The greater microbial activities subsequently augmented the mineralization and availability of nitrogen and phosphorus in the soil solution, which in turn increased the yield of the crop. Among the herbicides, oxyfluorfen was most stimulative followed by fluchloralin and oxadiazon in augmenting the microbial activities in soil. Butachlor also accentuated the mineralization and availability of nitrogen due to higher incitement of non-symbiotic N(2)-fixing bacteria in paddy soil. The grain and straw yields of the crop were also significantly increased due to the application of oxyfluorfen (20.2% and 21%) followed by fluchloralin (13.1% and 15.4%) and butachlor (9.1% and 10.2%), respectively.

Effects of improving nitrogen management on nitrogen utilization, nitrogen balance, and reactive nitrogen losses in a Mollisol with maize monoculture in Northeast China.

PubMed

Yan, Li; Zhang, Zhi-Dan; Zhang, Jin-Jing; Gao, Qiang; Feng, Guo-Zhong; Abelrahman, A M; Chen, Yuan

2016-03-01

Traditional fertilization led to higher apparent N surplus, and optimized fertilization can reduce residual nitrogen in soils with keeping high yield. But in continuous spring maize cropping zone in Mollisol in Northeast China, the effect of the optimized N management on N balance and comprehensive environment was not clear. The primary objective of this study was to compare the differences of two fertilizations (traditional farmer N management (FNM) with single basal fertilizer and improvement N management (INM) by soil testing with top-dressing) in gain yield, N uptake and N efficiency, soil N balance, reactive N losses, and environment assessment. The results showed that INM treatment has no remarkable effect on grain yield and N uptake; N partial factor productivity (PFPN) of INM treatment was 19.8 % significantly higher than the FNM treatment. Nmin in soils of INM treatment reached to 111.0 kg ha(-1), which was 27.1 % lower than the FNM treatment after 6 years of continuous maize cropping; the apparent N Losses (ANL) and apparent N surplus (ANS) of INM were only half of FNM by soil N balance analysis. In reactive N losses, comparing with FNM treatment, INM treatment reduced NH3 volatilization, N2O emission, N leaching, and N runoff by 17.8, 35.6, 45, and 38.3 %, respectively, during planting period, and in integrated environment assessment by life cycle assessment (LCA) method, producing 1 t maize grain, energy depletion, acidification, eutrophication, and climate change impacts of INM treatment decreased 26.19, 30.16, 32.61, and 22.75 %, respectively. Therefore, INM treatment is a better N management strategy in comprehensive analysis.

Chicken feather hydrolysate as an inexpensive complex nitrogen source for PHA production by Cupriavidus necator on waste frying oils.

PubMed

Benesova, P; Kucera, D; Marova, I; Obruca, S

2017-08-01

The chicken feather hydrolysate (FH) has been tested as a potential complex nitrogen source for the production of polyhydroxyalkanoates by Cupriavidus necator H16 when waste frying oil was used as a carbon source. The addition of FH into the mineral salt media with decreased inorganic nitrogen source concentration improved the yields of biomass and polyhydrohyalkanoates. The highest yields were achieved when 10 vol.% of FH prepared by microwave-assisted alkaline hydrolysis of 60 g l -1 feather was added. In this case, the poly(3-hydroxybutyrate) (PHB) yields were improved by more than about 50% as compared with control cultivation. A positive impact of FH was also observed for accumulation of copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) when sodium propionate was used as a precursor. The copolymer has superior processing and mechanical properties in comparison with PHB homopolymer. The application of FH eliminated the inhibitory effect of propionate and resulted in altered content of 3-hydroxyvalerate (3HV) in copolymer. Therefore, the hydrolysed feather can serve as an excellent complex source of nitrogen for the polyhydroxyalkanoates (PHA) production. Moreover, by the combination of two inexpensive types of waste, such as waste frying oil and feather hydrolysate, it is possible to produce PHA with substantially improved efficiency and sustainability. Millions of tons of feathers, important waste product of poultry-processing industry, are disposed off annually without any further benefits. Thus, there is an inevitable need for new technologies that enable ecologically and economically sensible processing of this waste. Herein, we report that alkali-hydrolysed feathers can be used as a complex nitrogen source considerably improving polyhydroxyalkanoates production on waste frying oil employing Cupriavidus necator. © 2017 The Society for Applied Microbiology.

Nitrogen modulation of legume root architecture signaling pathways involves phytohormones and small regulatory molecules.

PubMed

Mohd-Radzman, Nadiatul A; Djordjevic, Michael A; Imin, Nijat

2013-10-01

Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

Effect of inorganic nitrogenous fertilizer on productivity of recently reclaimed saline sodic soils with and without biofertilizer.

PubMed

Mehdi, S M; Sarfraz, M; Shabbir, G; Abbas, G

2007-07-15

Saline sodic soils after reclamation become infertile due to leaching of most of the nutrients along with salts from the rooting medium. Microbes can play a vital role in the productivity improvement of such soils. In this study a saline sodic field having EC, 6.5 dS m(-1), pH, 9.1 and gypsum requirement (GR) 3.5 tons acre(-1) was reclaimed by applying gypsum at the rate of 100% GR. Rice and wheat crops were transplanted/sown for three consecutive years. Inorganic nitrogenous fertilizer was used with and without biofertilizers i.e., Biopower (Azospirillum) for rice and diazotroph inoculums for wheat. Nitrogen was applied at the rate of 0, 75% of recommended dose (RD), RD, 125% of RD and 150% of RD. Recommended dose of P without K was applied to all the plots. Biopower significantly improved Paddy and straw yield of rice over inorganic nitrogenous fertilizer. In case of wheat diazotroph inoculum improved grain and straw yield significantly over inorganic nitrogenous fertilizer. Among N fertilizer rates, RD + 25% additional N fertilizer was found to be the best dose for rice and wheat production in recently reclaimed soils. Nitrogen concentration and its uptake by paddy, grain and straw were also increased by biopower and diazotroph inoculum over inorganic nitrogenous fertilizer. Among N fertilizer rates, RD + 25% additional N fertilizer was found to be the best dose for nitrogen concentration and its uptake by paddy, grain and straw. Total soil N, available P and extractable K were increased while salinity/sodicity parameters were decreased with the passage of time. The productivity of the soil was improved more by biofertilizers over inorganic N fertilizers.

Estimated loads and yields of suspended soils and water-quality constituents in Kentucky streams

USGS Publications Warehouse

Crain, Angela S.

2001-01-01

Loads and yields of suspended solids, nutrients, major ions, trace elements, organic carbon, fecal coliform, dissolved oxygen, and alkalinity were estimated for 22 streams in 11 major river basins in Kentucky. Mean daily discharge was estimated at ungaged stations or stations with incomplete discharge records using drainage-area ratio, regression analysis, or a combination of the two techniques. Streamflow was partitioned into total and base flow and used to estimate loads and yields for suspended solids and water-quality constituents by use of the ESTIMATOR and FLUX computer programs. The relative magnitude of constituent transport to streams from groundand surface-water sources was determined for the 22 stations. Nutrient and suspended solids yields for drainage basins with relatively homogenous land use were used to estimate the total-flow and base-flow yields of nutrient and suspended solids for forested, agricultural, and urban land. Yields of nutrients?nitrite plus nitrate, ammonia plus organic nitrogen, and total phosphorus?in forested drainage basins were generally less than 1 ton per square mile per year ((ton/mi2)/yr) and were generally less than 2 (ton/mi2)/yr in agricultural drainage basins. The smallest total-flow yields for nitrogen (nitrite plus nitrate) was estimated at Levisa Fork at Paintsville in which 95 percent of the land is forested. This site also had one of the smallest total-flow yields for ammonia plus organic nitrogen. In general, nutrient yields from forested lands were lower than those from urban and agricultural land. Some of the largest estimated total-flow yields of nutrients among agricultural basins were for streams in the Licking River Basin, the North Fork Licking River near Milford, and the South Fork Licking River at Cynthiana. Agricultural land constitutes greater than 75 percent of the drainage area in these two basins. Possible sources of nutrients discharging into the Licking River are farm and residential fertilizers. Estimated base-flow yields of suspended solids and nutrients at several basins in the larger Green River and Lower Cumberland River Basins were about half of their estimated total-flow yields. The karst terrain in these basins makes the ground water highly susceptible to contamination, especially if a confining unit is thin or absent.

Decreasing Nitrogen Fertilizer Input Had Little Effect on Microbial Communities in Three Types of Soils

PubMed Central

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

Variable diffusion in stock market fluctuations

NASA Astrophysics Data System (ADS)

Hua, Jia-Chen; Chen, Lijian; Falcon, Liberty; McCauley, Joseph L.; Gunaratne, Gemunu H.

2015-02-01

We analyze intraday fluctuations in several stock indices to investigate the underlying stochastic processes using techniques appropriate for processes with nonstationary increments. The five most actively traded stocks each contains two time intervals during the day where the variance of increments can be fit by power law scaling in time. The fluctuations in return within these intervals follow asymptotic bi-exponential distributions. The autocorrelation function for increments vanishes rapidly, but decays slowly for absolute and squared increments. Based on these results, we propose an intraday stochastic model with linear variable diffusion coefficient as a lowest order approximation to the real dynamics of financial markets, and to test the effects of time averaging techniques typically used for financial time series analysis. We find that our model replicates major stylized facts associated with empirical financial time series. We also find that ensemble averaging techniques can be used to identify the underlying dynamics correctly, whereas time averages fail in this task. Our work indicates that ensemble average approaches will yield new insight into the study of financial markets' dynamics. Our proposed model also provides new insight into the modeling of financial markets dynamics in microscopic time scales.

Nutrient concentrations and loads and Escherichia coli densities in tributaries of the Niantic River estuary, southeastern Connecticut, 2005 and 2008–2011

USGS Publications Warehouse

Mullaney, John R.

2013-01-01

Nutrient concentrations and loads and Escherichia coli (E. coli) densities were studied in 2005 and from 2008 through 2011 in water-quality samples from tributaries of the Niantic River Estuary in southeastern Connecticut. Data from a water-quality survey of the base flow of subbasins in the watershed in June 2005 were used to determine the range of total nitrogen concentrations (0.09 to 2.4 milligrams per liter), instantaneous loads (less than 1 to 62 pounds per day) and the yields of total nitrogen ranging from 0.02 to 11.2 pounds per square mile per day (less than 1 to 7.2 kilograms per hectare per year) from basin segments. Nitrogen yields were positively correlated with the amount of developed land in each subbasin. Stable isotope measurements of nitrate (δ15N) and oxygen (δ18O) ranged from 3.9 to 9.4 per mil and 0.7 to 4.1 per mil, respectively, indicating that likely sources of nitrate in base flow are soil nitrate and ammonium fertilizers, sewage or animal waste, or a mixture of these sources. Continuous streamflow and monthly water-quality sampling, with additional storm event sampling, were conducted at the three major tributaries (Latimer Brook, Oil Mill Brook, and Stony Brook) of the Niantic River from October 2008 through September 2011. Samples were analyzed for nitrogen and phosphorus constituents and E. coli densities. Total freshwater discharge from these tributaries, which is reduced by upstream withdrawals, ranged from 25.9 to 37.8 million gallons per day. Total nitrogen and phosphorus concentrations generally were low, with the mean values below the U.S. Environmental Protection Agency recommended nutrient concentration values of 0.71 milligram per liter and 0.031 milligram per liter, respectively. Total nitrogen was predominantly in the form of total ammonia plus organic nitrogen at the Oil Mill Brook and Stony Brook sites and in the form of nitrate at Latimer Brook. Annual total nitrogen loads that flowed into the Niantic River estuary from the three major tributaries, calculated with the Load Estimator computer program, ranged from 41,400 to 60,700 pounds, with about 52 to 59 percent of the load as total ammonia plus organic nitrogen. Total phosphorus loads ranged from 1,770 to 3,540 pounds per year. Yields of total nitrogen were highest from Latimer Brook, with the range from the three tributaries between 1,100 and 2,720 pounds per square mile per year. Total phosphorus yields ranged from 52 to 185 pounds per square mile per year. The geometric means of E. coli densities in samples from the three Niantic River tributaries were less than the State of Connecticut water-quality standard of 126 colony-forming units per 100 milliliters; however, individual samples from all three tributaries had densities as high as 2,400 to 2,900 colony-forming units per 100 milliliters. High densities of E. coli were more likely to be present in samples collected during wet weather events.

Enhanced Lipid and Biodiesel Production from Glucose-Fed Activated Sludge: Kinetics an Microbial Community Analysis

EPA Science Inventory

An innovative approach to increase biofuel feedstock lipid yields from municipal sewage sludge via manipulation of carbon:nitrogen (C:N) ratio and glucose loading in activated sludge bioreactors was investigated. Sludge lipid and fatty acid methyl ester (biodiesel) yields (% cel...

Nitrogen management of switchgrass and miscanthus on marginal soils

USDA-ARS?s Scientific Manuscript database

Miscanthus × giganteus and switchgrass yield and fertilizer N requirements have been well studied in Europe and parts of the United States, but few reports have investigated their production on eroded claypan soils economically marginal for grain crops. This study was conducted to evaluate yield pot...

Self-absorption Effects on Alpha-Induced Atmospheric Nitrogen Fluorescence Yield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bachelor, Paula P.; Jordan, David V.; Harper, Warren W.

2009-12-01

Nitrogen fluorescence induced by alpha, beta and gamma radiation can be used to detect the presence of radioactive contamination in the environment. Successful measurement of fluorescence yield involves a number of factors, including: known fluorescence signal rate during the measurement; the effective alpha spectrum of the radioactive sources used in the measurement; optical attenuation length of the fluorescence signal in air during the measurement; the absolute throughput of the instrumentation; calibration of the instrumentation; and radiation transport modeling of the "effective" array exposure rate given the spectrum of the alpha particles. Field testing of optical instrumentation was conducted to measuremore » the nitrogen fluorescence yield from the alpha radiation generated from americium-241 (241Am) decay. The 241Am test sources were prepared by direct evaporation of ~1 mCi in nitric acid solution, and some solids were visible on the surface of the sources. A laboratory study was conducted with lower activities of 241Am to determine whether the presence of solids on the surface of the sources prepared both by direct evaporation and by electrodeposition onto stainless steel disks produced sufficient self-absorption to cause a decrease in expected fluorescence. Alpha spectroscopy was used to determine the apparent activity of the sources versus the known activity deposited on the surface. Results from the self-absorption laboratory studies were used to correct the activity values in the model and calculate the nitrogen fluorescence generated by the 241Am during the field experiments.« less

Mineralizable soil nitrogen as an index of nitrogen availability to forest trees

Treesearch

Robert F. Powers

1980-01-01

Soil N mineralized during 14-day anaerobic incubation at 30°C is evaluated as an index of forest soil fertility and site productivity. Mineralizable soil N determined under standard conditions correlates significantly with N mineralized anaerobically for 6 months in the field, with site index and yield potential of Pinus ponderosa L....

The leaking soil nitrogen cycle and rising atmospheric N2O: Is there anything we can do to cap the well?

USDA-ARS?s Scientific Manuscript database

Nutrient management refers to the addition and management of synthetic or organic fertilizers to soils primarily for purposes of increasing the supply of nutrients and efficiency of crop nutrient uptake in order to improve yields while minimizing environmental impact. Nitrogen (N) is generally the m...

Changes in soil surface chemistry after fifty years of tillage and nitrogen fertilization

USDA-ARS?s Scientific Manuscript database

Knowledge gained on the long-term effects of crop management practices on soil fertility is critical in developing nutrient management strategies to optimize crop yields. This study examined the long-term effects of nitrogen (N) fertilizer application (N rates of 0, 22, 45 and 67 kg N ha-1) and till...

Genome-wide association study of carbon and nitrogen metabolism in the maize nested association mapping population

USDA-ARS?s Scientific Manuscript database

Carbon (C) and nitrogen (N) metabolism are critical to plant growth and development and at the basis of yield and adaptation. We have applied high throughput metabolite analyses to over 12,000 diverse field grown samples from the maize nested association mapping population. This allowed us to identi...

Ecosystem services altered by human changes in the nitrogen cycle: a new perspective for US decision making Ecology Letters

EPA Science Inventory

The human alteration of the nitrogen (N) cycle has yielded many benefits, but also has altered ecosystems and degraded air and water quality in many areas. Here we explore the science available to connect the effects of increasing N on ecosystem structure and function to ecosyst...

Limited seed and seed yield response of calendula to applied nitrogen does not justify risk of environmental damage from high urea application rates

USDA-ARS?s Scientific Manuscript database

Calendula (Calendula officinalis L.) is a source of industrial oil, which can serve as a domestic substitute for petroleum or imported specialty crop oils. Traditionally, calendula has been grown for medicinal or ornamental properties. However, little is known about nitrogen (N) requirement of growi...

Trends In Nutrient and Sediment Concentrations and Loads In Major River Basins of the South-Central United States, 1993-2004

USGS Publications Warehouse

Rebich, Richard A.; Demcheck, Dennis K.

2008-01-01

Nutrient and sediment data collected at 115 sites by Federal and State agencies from 1993 to 2004 were analyzed by the U.S. Geological Survey to determine trends in concentrations and loads for selected rivers and streams that drain into the northwestern Gulf of Mexico from the south-central United States, specifically from the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf Basins. Trends observed in the study area were compared to determine potential regional patterns and to determine cause-effect relations with trends in hydrologic and human-induced factors such as nutrient sources, streamflow, and implementation of best management practices. Secondary objectives included calculation of loads and yields for the study period as a basis for comparing the delivery of nutrients and sediment to the northwestern Gulf of Mexico from the various rivers within the study area. In addition, loads were assessed at seven selected sites for the period 1980-2004 to give hydrologic perspective to trends in loads observed during 1993-2004. Most study sites (about 64 percent) either had no trends or decreasing trends in streamflow during the study period. The regional pattern of decreasing trends in streamflow during the study period appeared to correspond to moist conditions at the beginning of the study period and the influence of three drought periods during the study period, of which the most extreme was in 2000. Trend tests were completed for ammonia at 49 sites, for nitrite plus nitrate at 69 sites, and for total nitrogen at 41 sites. For all nitrogen constituents analyzed, no trends were observed at half or more of the sites. No regional trend patterns could be confirmed because there was poor spatial representation of the trend sites. Decreasing trends in flow-adjusted concentrations of ammonia were observed at 25 sites. No increasing trends in concentrations of ammonia were noted at any sites. Flow-adjusted concentrations of nitrite plus nitrate decreased at 7 sites and increased at14 sites. Flow-adjusted concentrations of total nitrogen decreased at 2 sites and increased at 12 sites. Improvements to municipal wastewater treatment facilities contributed to the decline of ammonia concentrations at selected sites. Notable increasing trends in nitrite plus nitrate and total nitrogen at selected study sites were attributed to both point and nonpointsources. Trend patterns in total nitrogen generally followed trend patterns in nitrite plus nitrate, which was understandable given that nitrite plus nitrate loads generally were 70-90 percent of the total nitrogen loads at most sites. Population data were used as a surrogate to understand the relation between changes in point sources and nutrient trends because data from wastewater treatment plants were inconsistent for this study area. Although population increased throughout the study area during the study period, there was no observed relation between increasing trends in nitrogen in study area streams and increasing trends in population. With respect to other nitrogen sources, statistical results did suggest that increasing trends in nitrogen could be related to increasing trends in nitrogen from either commercial fertilizer use and/or land application of manure. Loads of ammonia, nitrite plus nitrate, and total nitrogen decreased during the study period, but some trends in nitrogen loads were part of long-term decreases since 1980. For example, ammonia loads were shown to decrease at nearly all sites over the past decade, but at selected sites, these decreasing trends were part of much longer trends since 1980. The Mississippi and Atchafalaya Rivers contributed the highest nitrogen loads to the northwestern Gulf of Mexico as expected; however, nitrogen yields from smaller rivers had similar or higher yields than yields from the Mississippi River. Trend tests were completed for orthophosphorus at 34 sites and for total phosphorus at 52 sites. No trends were observed in abo

Constituent concentrations, loads, and yields to Beaver Lake, Arkansas, water years 1999-2008

USGS Publications Warehouse

Bolyard, Susan E.; De Lanois, Jeanne L.; Green, W. Reed

2010-01-01

Beaver Lake is a large, deep-storage reservoir used as a drinking-water supply and considered a primary watershed of concern in the State of Arkansas. As such, information is needed to assess water quality, especially nutrient enrichment, nutrient-algal relations, turbidity, and sediment issues within the reservoir system. Water-quality samples were collected at three main inflows to Beaver Lake: the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. Water-quality samples collected over the period represented different flow conditions (from low to high). Constituent concentrations, flow-weighted concentrations, loads, and yields from White River, Richland Creek, and War Eagle Creek to Beaver Lake for water years 1999-2008 were documented for this report. Constituents include total ammonia plus organic nitrogen, dissolved nitrite plus nitrate nitrogen, dissolved orthophosphorus (soluble reactive phosphorus), total phosphorus, total nitrogen, dissolved organic carbon, total organic carbon, and suspended sediment. Linear regression models developed by computer program S-LOADEST were used to estimate loads for each constituent for the 10-year period at each station. Constituent yields and flow-weighted concentrations for each of the three stations were calculated for the study. Constituent concentrations and loads and yields varied with time and varied among the three tributaries contributing to Beaver Lake. These differences can result from differences in precipitation, land use, contributions of nutrients from point sources, and variations in basin size. Load and yield estimates varied yearly during the study period, water years 1999-2008, with the least nutrient and sediment load and yields generally occurring in water year 2006, and the greatest occurring in water year 2008, during a year with record amounts of precipitation. Flow-weighted concentrations of most constituents were greatest at War Eagle Creek near Hindsville than White River near Fayetteville and Richland Creek at Goshen. Loads and yields of most constituents were greater at the War Eagle Creek and White River stations than at the Richland Creek Station.

Response of rice cultivars to rates of nitrogen and potassium application in field and pot conditions.

PubMed

Bahmaniar, M A; Ranjbar, G A

2007-05-01

Nitrogen and potassium are the yield-limiting nutrients in rice production regions of Iran. Use of N and K efficient cultivars is an important complementary strategy in improving rice yield, increasing the quality properties of rice grains and reducing cost of production. In order to consider the effects of different amounts of N and K application on rice (Oryza sativa L.) yield and yield components in pot and field conditions these experiments were undertaken in 2004 at Sari Agricultural Station, Iran. Four levels of N (0, 50, 100 and 150 Kg N ha(-1) in field and 0, 0.6, 1.2 and 1.8 g N pot(-1) in pot) corresponding with four levels of K (0, 75, 150 and 225 kg K2O ha(-1) in field and 0, 0.5, 1 and 1.5 g K2O pot(-1) in pot) were applied in a split-factorial plot design with three replications in both pot and field experiments, variously. Grain yield, number of grain per panicle, number of tiller, plant height, length of flag leaf, total and shoot dry matter, 1000 grain weight and harvest index have been increased by N application in field conditions. However, in pot conditions grain yield, number of grain per panicle, number of tiller, plant height, width of flag leaf, total and shoot dry matter, leaf nitrogen contents and harvest index have significantly been increased (p < or = 0.05). Potassium application in field conditions has significantly affected on all characteristics but 1000 grain weight and leaf N and K contents. Simultaneous application of N and K have increasingly affected on grain yield, plant height, shoot dry matter and harvest index in field conditions and on plant height, length of flag leaf and shoot dry matter in pot conditions (p < or = 0.05).

Hydrologic conditions and quality of rainfall and storm runoff for two agricultural areas of the Oso Creek Watershed, Nueces County, Texas, 2005-07

USGS Publications Warehouse

Ockerman, Darwin J.

2008-01-01

The U.S. Geological Survey, in cooperation with the Texas State Soil and Water Conservation Board, Coastal Bend Bays and Estuaries Program, and Texas AgriLife Research and Extension Center at Corpus Christi, studied hydrologic conditions and quality of rainfall and storm runoff of two (primarily) agricultural areas (subwatersheds) of the Oso Creek watershed in Nueces County, Texas. One area, the upper West Oso Creek subwatershed, is 5,145 acres. The other area, a subwatershed drained by an unnamed Oso Creek tributary (hereinafter, Oso Creek tributary), is 5,287 acres. Rainfall and runoff (streamflow) were continuously monitored at the outlets of the two subwatersheds during October 2005-September 2007. Fourteen rainfall samples were collected and analyzed for nutrients and major inorganic ions. Nineteen composite runoff samples (10 West Oso Creek, nine Oso Creek tributary) were collected and analyzed for nutrients, major inorganic ions, and pesticides. Twenty-two discrete suspended-sediment samples (10 West Oso Creek, 12 Oso Creek tributary) and 13 bacteria samples (eight West Oso Creek, five Oso Creek tributary) were collected and analyzed. These data were used to estimate, for selected constituents, rainfall deposition to and runoff loads and yields from the study subwatersheds. Quantities of fertilizers and pesticides applied in the subwatersheds were compared with quantities of nutrients and pesticides in rainfall and runoff. For the study period, total rainfall was greater than average. Most of the runoff at both subwatershed outlet sites occurred in response to a few specific storm periods. The West Oso Creek subwatershed produced more runoff during the study period than the Oso Creek tributary subwatershed, 10.83 inches compared with 7.28 inches. Runoff response was quicker and peak flows were higher in the West Oso Creek subwatershed than in the Oso Creek tributary subwatershed. Total nitrogen runoff yield for the 2-year study period averaged 2.61 pounds per acre per year from the West Oso Creek subwatershed and 0.966 pound per acre per year from the Oso Creek tributary subwatershed. Total phosphorus yields from the West Oso Creek and the Oso Creek tributary subwatersheds for the 2-year period were 0.776 and 0.498 pound per acre per year. Runoff yields of nitrogen and phosphorus were relatively small compared to inputs of nitrogen in fertilizer and rainfall deposition. Average annual runoff yield of total nitrogen (subwatersheds combined) represents about 2.4 percent of nitrogen applied as fertilizer and nitrogen entering the subwatersheds through rainfall deposition. Average annual runoff yield of total phosphorus (subwatersheds combined) represents about 4.4 percent of the phosphorus in applied fertilizer and rainfall deposition. Suspended-sediment yields from the West Oso Creek subwatershed were more than twice those from the Oso Creek tributary subwatershed. The average suspended-sediment yield from the West Oso Creek subwatershed was 582 pounds per acre per year. The average suspended-sediment yield from the Oso Creek tributary subwatershed was 257 pounds per acre per year. Twenty-two herbicides and eight insecticides were detected in runoff samples collected from the two subwatershed outlet sites. At the West Oso Creek site, 18 herbicides and four insecticides were detected, and at the Oso Creek tributary site, 17 herbicides and six insecticides. Seventeen pesticides were detected in only one sample at low concentrations (near the laboratory reporting level). Atrazine, atrazine degradation byproducts 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT) and 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine (OIET), glyphosate, and glyphosate byproduct aminomethylphosphonic acid (AMPA) were detected in all samples. Of all pesticides detected in runoff, the highest runoff yields were for glyphosate, 0.013 pound per acre per year for the West Oso Creek subwatershed and 0.001 pound per acre per year for the Oso Creek t

Growth of mature boreal Norway spruce was not affected by elevated [CO(2)] and/or air temperature unless nutrient availability was improved.

PubMed

Sigurdsson, Bjarni D; Medhurst, Jane L; Wallin, Göran; Eggertsson, Olafur; Linder, Sune

2013-11-01

The growth responses of mature Norway spruce (Picea abies (L.) Karst.) trees exposed to elevated [CO(2)] (CE; 670-700 ppm) and long-term optimized nutrient availability or elevated air temperature (TE; ±3.9 °C) were studied in situ in northern Sweden in two 3 year field experiments using 12 whole-tree chambers in ca. 40-year-old forest. The first experiment (Exp. I) studied the interactions between CE and nutrient availability and the second (Exp. II) between CE and TE. It should be noted that only air temperature was elevated in Exp. II, while soil temperature was maintained close to ambient. In Exp. I, CE significantly increased the mean annual height increment, stem volume and biomass increment during the treatment period (25, 28, and 22%, respectively) when nutrients were supplied. There was, however, no significant positive CE effect found at the low natural nutrient availability. In Exp. II, which was conducted at the natural site fertility, neither CE nor TE significantly affected height or stem increment. It is concluded that the low nutrient availability (mainly nitrogen) in the boreal forests is likely to restrict their response to the continuous rise in [CO(2)] and/or TE.

[Effects of different fertilization modes on vegetable growth, fertilizer nitrogen utilization, and nitrogen loss from vegetable field].

PubMed

Huang, Dong-feng; Wang, Guo; Li, Wei-hua; Qiu, Xiao-xuan

2009-03-01

A field experiment with Chinese cabbage, water spinach, and three-colored amaranth cropped three times in one year was conducted to study the effects of seven fertilization modes, i.e., none fertilization, basal application of chemical fertilizers, 1/2 basal application and 1/2 top-dressing of chemical fertilizers, basal application of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2 top-dressing of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2 top-dressing of chemical fertilizers and organic manure, and basal application of organic manure, on the plant height, yield, nitrogen accumulation, and fertilizer nitrogen utilization of the vegetables, and the loss of NO3- -N and NH4+ -N from vegetable field under natural rainfall condition. The results showed that comparing with none fertilization, the fertilization modes '1/2 basal application and 1/2 top-dressing of chemical fertilizers and organic manure' and 'basal application of chemical fertilizers and dicyandiamide' improved the agronomic properties of test vegetables, increased their yields by 103%-219% and 93%-226%, and nitrogen accumulation by 153% -216% and 231%-320%, respectively, and enhanced fertilizer nitrogen utilization rate. They also decreased the surface runoff loss of NO3- -N and NH4+ -N by 48.1% and 46.5%, respectively, compared with the mode 'basal application of chemical fertilizers', and hence, reduced the risk of agricultural non-point pollution. Therefore, these two fertilization modes could be popularized in vegetable production.

Soil-pit Method for Distribution and Leaching Loss of Nitrogen in Winter Wheat’s Soil, Weishan Irrigation District

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.

Nitrogen and phosphorus in streams of the Great Miami River Basin, Ohio, 1998-2000

USGS Publications Warehouse

Reutter, David C.

2003-01-01

Sources and loads of nitrogen and phosphorus in streams of the Great Miami River Basin were evaluated as part of the National Water-Quality Assessment program. Water samples were collected by the U.S. Geological Survey from October 1998 through September 2000 (water years 1999 and 2000) at five locations in Ohio on a routine schedule and additionally during selected high streamflows. Stillwater River near Union, Great Miami River near Vandalia, and Mad River near Eagle City were selected to represent predominantly agricultural areas upstream from the Dayton metropolitan area. Holes Creek near Kettering is in the Dayton metropolitan area and was selected to represent an urban area in the Great Miami River Basin. Great Miami River at Hamilton is downstream from the Dayton and Hamilton-Middletown metropolitan areas and was selected to represent mixed agricultural and urban land uses of the Great Miami River Basin. Inputs of nitrogen and phosphorus to streams from point and nonpoint sources were estimated for the three agricultural basins and for the Great Miami River Basin as a whole. Nutrient inputs from point sources were computed from the facilities that discharge one-half million gallons or more per day into streams of the Great Miami River Basin. Nonpoint-source inputs estimated in this report are atmospheric deposition and commercial-fertilizer and manure applications. Loads of ammonia, nitrate, total nitrogen, orthophosphate, and total phosphorus from the five sites were computed with the ESTIMATOR program. The computations show nitrate to be the primary component of instream nitrogen loads, and particulate phosphorus to be the primary component of instream phosphorus loads. The Mad River contributed the smallest loads of total nitrogen and total phosphorus to the study area upstream from Dayton, whereas the Upper Great Miami River (upstream from Vandalia) contributed the largest loads of total nitrogen and total phosphorus to the Great Miami River Basin upstream from Dayton. An evaluation of monthly mean loads shows that nutrient loads were highest during winter 1999 and lowest during the drought of summer and autumn 1999. During the 1999 drought, point sources were the primary contributors of nitrogen and phosphorus loads to most of the study area. Nonpoint sources, however, were the primary contributors of nitrogen and phosphorus loads during months of high streamflow. Nonpoint sources were also the primary contributors of nitrogen loads to the Mad River during the 1999 drought, owing to unusually large amounts of ground-water discharge to the stream. The Stillwater River Basin had the highest nutrient yields in the study area during months of high streamflow; however, the Mad River Basin had the highest yields of all nutrients except ammonia during the months of the 1999 drought. The high wet-weather yields in the Stillwater River Basin were caused by agricultural runoff, whereas high yields in the Mad River Basin during drought resulted from the large, sustained contribution of ground water to streamflow throughout the year. In the basins upstream from Dayton, an estimated 19 to 25 percent of the nonpoint source of nitrogen and 4 to 5 percent of the nonpoint source of phosphorus that was deposited or applied to the land was transported into streams.

Friction wear and auger analysis of iron implanted with 1.5-MeV nitrogen ions

NASA Technical Reports Server (NTRS)

Ferrante, J.; Jones, W. R., Jr.

1982-01-01

The effect of implantation of 1.5-MeV nitrogen ions on the friction and wear characteristics of pure iron sliding against steel was studied in a pin-on disk apparatus. An implantation dose of 5 x 10 to the 17th power ions/sq cm was used. Small reductions in initial and steady-state wear rates were observed for nitrogen-implanted iron riders as compared with unimplanted controls. Auger electron spectroscopy revealed a subsurface Gaussian nitrogen distribution with a maximum concentration of 15 at. % at a depth of 8 x 10 to the -7th m. A similar analysis within the wear scar of an implanted rider after 20 microns of wear yielded only background nitrogen concentration, thus giving no evidence for diffusion of nitrogen beyond the implanted range.

Using RNA-seq to Profile Gene Expression of Spikelet Development in Response to Temperature and Nitrogen during Meiosis in Rice (Oryza sativa L.).

PubMed

Yang, Jun; Chen, Xiaorong; Zhu, Changlan; Peng, Xiaosong; He, Xiaopeng; Fu, Junru; Ouyang, Linjuan; Bian, Jianmin; Hu, Lifang; Sun, Xiaotang; Xu, Jie; He, Haohua

2015-01-01

Rice reproductive development is sensitive to high temperature and soil nitrogen supply, both of which are predicted to be increased threats to rice crop yield. Rice spikelet development is a critical process that determines yield, yet little is known about the transcriptional regulation of rice spikelet development in response to the combination of heat stress and low nitrogen availability. Here, we profiled gene expression of rice spikelet development during meiosis under heat stress and different nitrogen levels using RNA-seq. We subjected plants to four treatments: 1) NN: normal nitrogen level (165 kg ha-1) with normal temperature (30°C); 2) HH: high nitrogen level (264 kg ha-1) with high temperature (37°C); 3) NH: normal nitrogen level and high temperature; and 4) HN: high nitrogen level and normal temperature. The de novo transcriptome assembly resulted in 52,250,482 clean reads aligned with 76,103 unigenes, which were then used to compare differentially expressed genes (DEGs) in the different treatments. Comparing gene expression in samples with the same nitrogen levels but different temperatures, we identified 70 temperature-responsive DEGs in normal nitrogen levels (NN vs NH) and 135 DEGs in high nitrogen levels (HN vs HH), with 27 overlapping DEGs. We identified 17 and seven nitrogen-responsive DEGs by comparing changes in nitrogen levels in lower temperature (NN vs HN) and higher temperature (NH vs HH), with one common DEG. The temperature-responsive genes were principally associated with cytochrome, heat shock protein, peroxidase, and ubiquitin, while the nitrogen-responsive genes were mainly involved in glutamine synthetase, amino acid transporter, pollen development, and plant hormone. Rice spikelet fertility was significantly reduced under high temperature, but less reduced under high-nitrogen treatment. In the high temperature treatments, we observed downregulation of genes involved in spikelet development, such as pollen tube growth, pollen maturation, especially sporopollenin biosynthetic process, and pollen exine formation. Moreover, we observed higher expression levels of the co-expressed DEGs in HN vs HH compared to NN vs NH. These included the six downregulated genes (one pollen maturation and five pollen exine formation genes), as well as the four upregulated DEGs in response to heat. This suggests that high-nitrogen treatment may enhance the gene expression levels to mitigate aspects of heat-stress. The spikelet genes identified in this study may play important roles in response to the combined effects of high temperature and high nitrogen, and may serve as candidates for crop improvement.

Is nitrogen the next carbon?

NASA Astrophysics Data System (ADS)

Battye, William; Aneja, Viney P.; Schlesinger, William H.

2017-09-01

Just as carbon fueled the Industrial Revolution, nitrogen has fueled an Agricultural Revolution. The use of synthetic nitrogen fertilizers and the cultivation of nitrogen-fixing crops both expanded exponentially during the last century, with most of the increase occurring after 1960. As a result, the current flux of reactive, or fixed, nitrogen compounds to the biosphere due to human activities is roughly equivalent to the total flux of fixed nitrogen from all natural sources, both on land masses and in the world's oceans. Natural fluxes of fixed nitrogen are subject to very large uncertainties, but anthropogenic production of reactive nitrogen has increased almost fivefold in the last 60 years, and this rapid increase in anthropogenic fixed nitrogen has removed any uncertainty on the relative importance of anthropogenic fluxes to the natural budget. The increased use of nitrogen has been critical for increased crop yields and protein production needed to keep pace with the growing world population. However, similar to carbon, the release of fixed nitrogen into the natural environment is linked to adverse consequences at local, regional, and global scales. Anthropogenic contributions of fixed nitrogen continue to grow relative to the natural budget, with uncertain consequences.

Nitrogen recycling from fuel-extracted algal biomass: residuals as the sole nitrogen source for culturing Scenedesmus acutus.

PubMed

Gu, Huiya; Nagle, Nick; Pienkos, Philip T; Posewitz, Matthew C

2015-05-01

In this study, the reuse of nitrogen from fuel-extracted algal residues was investigated. The alga Scenedesmus acutus was found to be able to assimilate nitrogen contained in amino acids, yeast extracts, and proteinaceous alga residuals. Moreover, these alternative nitrogen resources could replace nitrate in culturing media. The ability of S. acutus to utilize the nitrogen remaining in processed algal biomass was unique among the promising biofuel strains tested. This alga was leveraged in a recycling approach where nitrogen is recovered from algal biomass residuals that remain after lipids are extracted and carbohydrates are fermented to ethanol. The protein-rich residuals not only provided an effective nitrogen resource, but also contributed to a carbon "heterotrophic boost" in subsequent culturing, improving overall biomass and lipid yields relative to the control medium with only nitrate. Prior treatment of the algal residues with Diaion HP20 resin was required to remove compounds inhibitory to algal growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessing the spatial impact of climate on wheat productivity and the potential value of climate forecasts at a regional level

NASA Astrophysics Data System (ADS)

Wang, Enli; Xu, J.; Jiang, Q.; Austin, J.

2009-03-01

Quantification of the spatial impact of climate on crop productivity and the potential value of seasonal climate forecasts can effectively assist the strategic planning of crop layout and help to understand to what extent climate risk can be managed through responsive management strategies at a regional level. A simulation study was carried out to assess the climate impact on the performance of a dryland wheat-fallow system and the potential value of seasonal climate forecasts in nitrogen management in the Murray-Darling Basin (MDB) of Australia. Daily climate data (1889-2002) from 57 stations were used with the agricultural systems simulator (APSIM) to simulate wheat productivity and nitrogen requirement as affected by climate. On a good soil, simulated grain yield ranged from <2 t/ha in west inland to >7 t/ha in the east border regions. Optimal nitrogen rates ranged from <60 kgN/ha/yr to >200 kgN/ha/yr. Simulated gross margin was in the range of -20/ha to 700/ha, increasing eastwards. Wheat yield was closely related to rainfall in the growing season and the stored soil moisture at sowing time. The impact of stored soil moisture increased from southwest to northeast. Simulated annual deep drainage ranged from zero in western inland to >200 mm in the east. Nitrogen management, optimised based on ‘perfect’ knowledge of daily weather in the coming season, could add value of 26˜79/ha compared to management optimised based on historical climate, with the maximum occurring in central to western part of MDB. It would also reduce the nitrogen application by 5˜25 kgN/ha in the main cropping areas. Comparison of simulation results with the current land use mapping in MDB revealed that the western boundary of the current cropping zone approximated the isolines of 160 mm of growing season rainfall, 2.5t/ha of wheat grain yield, and 150/ha of gross margin in QLD and NSW. In VIC and SA, the 160-mm isohyets corresponded relatively lower simulated yield due to less stored soil water. Impacts of other factors like soil types were also discussed.

Effect of fiber source on cecal fermentation and nitrogen recycled through cecotrophy in rabbits.

PubMed

García, J; Carabaño, R; Pérez-Alba, L; de Blas, J C

2000-03-01

The influence of fiber source on fiber digestion in rabbits was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a fiber-free concentrate, based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix, to obtain diets containing at least 3% nitrogen and 5% starch. Daily soft feces excretion, and its NDF, and total and microbial nitrogen content were determined in 60 fattening rabbits (10 per diet). Seven days after the last cecotrophy control, the same animals were used to determine weight of stomach, cecum and their contents, and cecal fermentation traits (pH, VFA and ammonia concentrations, and buffer properties of cecal contents). Stepwise regression analysis showed a positive effect (P < .001) on soft feces excretion, total and microbial nitrogen concentrations in soft feces, cecal acidity, and total VFA in the cecum of dietary pectic constituents (2.9, 3.5, 2.5, .9, and 6.6%) and proportion of fine particles (< .315 mm) (1.8, .9, 1.3, .15, and .9%) per each increment of one percentage unit of the independent variables. Proportion of fine particles also increased weight of cecal contents (P < .001). Soft feces excretion and weight of stomach and of its contents increased (P < .001) by 5.2, 2.8, and 10.2% per each percentage unit increment of proportion of large particles (> 1.25 mm). Degree of lignification of NDF decreased total nitrogen concentration in soft feces and cecal VFA concentration (P < .001). Source of fiber affected cecal pH not only by its influence on the cecal concentrations of the final products of fermentation, but also through its effect on the pH of dry cecal contents (P < .001). The latter was negatively correlated with dietary proportion of fine particles, degree of lignification of NDF, and base-buffering capacity of dry cecal contents (r = -.52, -.37, and -.49, respectively). From these results, we conclude that pectic constituent concentration, degree of lignification of NDF, and particle size are the variables that best characterize the influence of the source of fiber on soft feces excretion and cecal fermentation traits in rabbits.

Maize yield response to nitrogen as influenced by spatio-temporal variations of soil-water-topography dynamics

USDA-ARS?s Scientific Manuscript database

Reducing N loss from agricultural lands and applying N fertilizer at rates that satisfy both economic and environmental objectives is critical for sustainable agricultural management. This study investigated spatial variability in maize yield response to N and its controlling factors along a typical...

International Space Station Increment-4/5 Microgravity Environment Summary Report

NASA Technical Reports Server (NTRS)

Jules, Kenol; Hrovat, Kenneth; Kelly, Eric; McPherson, Kevin; Reckart, Timothy

2003-01-01

This summary report presents the results of some of the processed acceleration data measured aboard the International Space Station during the period of December 2001 to December 2002. Unlike the past two ISS Increment reports, which were increment specific, this summary report covers two increments: Increments 4 and 5, hereafter referred to as Increment-4/5. Two accelerometer systems were used to measure the acceleration levels for the activities that took place during Increment-4/5. Due to time constraint and lack of precise timeline information regarding some payload operations and station activities, not a11 of the activities were analyzed for this report. The National Aeronautics and Space Administration sponsors the Microgravity Acceleration Measurement System and the Space Acceleration Microgravity System to support microgravity science experiments which require microgravity acceleration measurements. On April 19, 2001, both the Microgravity Acceleration Measurement System and the Space Acceleration Measurement System units were launched on STS-100 from the Kennedy Space Center for installation on the International Space Station. The Microgravity Acceleration Measurement System supports science experiments requiring quasi-steady acceleration measurements, while the Space Acceleration Measurement System unit supports experiments requiring vibratory acceleration measurement. The International Space Station Increment-4/5 reduced gravity environment analysis presented in this report uses acceleration data collected by both sets of accelerometer systems: The Microgravity Acceleration Measurement System, which consists of two sensors: the low-frequency Orbital Acceleration Research Experiment Sensor Subsystem and the higher frequency High Resolution Accelerometer Package. The low frequency sensor measures up to 1 Hz, but is routinely trimmean filtered to yield much lower frequency acceleration data up to 0.01 Hz. This filtered data can be mapped to arbitrary locations for characterizing the quasi-steady environment for payloads and the vehicle. The high frequency sensor is used to characterize the vibratory environment up to 100 Hz at a single measurement location. The Space Acceleration Measurement System, which deploys high frequency sensors, measures vibratory acceleration data in the range of 0.01 to 400 Hz at multiple measurement locations. This summary report presents analysis of some selected quasi-steady and vibratory activities measured by these accelerometers during Increment- 4/5 from December 2001 to December 2002.

Incremental Validity of Multidimensional Proficiency Scores from Diagnostic Classification Models: An Illustration for Elementary School Mathematics

ERIC Educational Resources Information Center

Kunina-Habenicht, Olga; Rupp, André A.; Wilhelm, Oliver

2017-01-01

Diagnostic classification models (DCMs) hold great potential for applications in summative and formative assessment by providing discrete multivariate proficiency scores that yield statistically driven classifications of students. Using data from a newly developed diagnostic arithmetic assessment that was administered to 2032 fourth-grade students…

State-dependent choice and ecological rationality.

PubMed

Nevai, Andrew L; Waite, Thomas A; Passino, Kevin M

2007-08-07

Decision makers who minimize costly errors should flexibly adjust the way they trade off competing demands, depending on their current state. We explore how state (amount of hoarded food) affects willingness to take extra predation risk to obtain larger food rewards, particularly in animals that may overemphasize safety. Assuming a sigmoid fitness function, we explore how a supplement in state influences this willingness trade danger for food energy. Above a threshold, the model predicts the supplement will weaken this willingness. Incremental increases in state in the deceleratory phase yield smaller fitness gains, so it pays to increase emphasis on safety after receiving a supplement. Below this threshold, the model makes the opposite prediction because incremental increases in state yield bigger fitness gains and so it pays to decrease emphasis on safety. We use the model to explain why hoarding gray jays (Perisoreus canadensis) were induced by an experimental subsidy to accept greater danger. This formerly puzzling finding makes sense if the jays' effective hoard was relatively small, due to theft and decomposition. We discuss adaptive state-dependent choice as a general explanation for apparently irrational behavior.

The Variation of Catalyst and Carrier Gas on Anisole Deoxygenation Reaction

NASA Astrophysics Data System (ADS)

Ariyani, D.; Dwi Nugrahaningtyas, Khoirina; Heraldy, E.

2018-03-01

This research aims to determine the best catalyst and carrier gas in anisole deoxygenation reaction. The reaction was carried out over a flow system with a variation of catalyst CoMo A (CoMo/USY reduction), CoMo B (CoMo/USY oxidation-reduction), and CoMo C (CoMo/ZAA oxidation-reduction). In addition, variation of carrier gas nitrogen and hydrogen was investigated. The result was analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). The deoxygenation anisole result showed that CoMo A catalyst with hydrogen as the carrier gas has the highest total product yield (50.72 %), intermediate product yield (38.49 % in phenol and 6.99 % in benzaldehyde), and deoxygenation yield (5.24 %). The CoMo C catalyst exhibited the most selective deoxygenation product. The nitrogen carrier gas with the CoMo C catalyst has the best selectivity of benzene product (93.92 %).

The Observed Response of Ozone Monitoring Instrument (OMI) NO2 Columns to NOx Emission Controls on Power Plants in the United States: 2005-2011

NASA Technical Reports Server (NTRS)

Duncan, Bryan N.; Yoshida, Yasuko; deFoy, Benjamin; Lamsal, Lok N.; Streets, David G.; Lu, Zifeng; Pickering, Kenneth E.; Krotkov, Nickolay A.

2013-01-01

We show that Aura Ozone Monitoring Instrument (OMI) nitrogen dioxide (NO2) tropospheric column data may be used to assess changes of the emissions of nitrogen oxides (NOx) from power plants in the United States, though careful interpretation of the data is necessary. There is a clear response for OMI NO2 data to NOx emission reductions from power plants associated with the implementation of mandated emission control devices (ECDs) over the OMI record (2005e2011). This response is scalar for all intents and purposes, whether the reduction is rapid or incremental over several years. However, it is variable among the power plants, even for those with the greatest absolute decrease in emissions. We document the primary causes of this variability, presenting case examples for specific power plants.

Field-scale electrolysis/ceramic membrane system for the treatment of sewage from decentralized small communities.

PubMed

Son, Dong-Jin; Kim, Woo-Yeol; Yun, Chan-Young; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

2017-07-05

The electrolysis process adopting copper electrodes and ceramic membrane with pore sizes of 0.1-0.2 μm were consisted to a system for the treatment of sewage from decentralized small communities. The system was operated under an HRT of 0.1 hour, voltage of 24 V, and TMP of 0.05 MPa. The system showed average removals of organics, nitrogen, phosphorus, and solids of up to 80%, 52%, 92%, and 100%, respectively. Removal of organics and nitrogen dramatically increased in proportion to increment of influent loading. Phosphorus and solids were remarkably eliminated by both electro-coagulation and membrane filtration. The residual particulate constituents could also be removed successfully through membrane process. A system composed of electrolysis process with ceramic membrane would be a compact, reliable, and flexible option for the treatment of sewage from decentralized small communities.

Global assessment of nitrogen losses and trade-offs with yields from major crop cultivations.

PubMed

Liu, Wenfeng; Yang, Hong; Liu, Junguo; Azevedo, Ligia B; Wang, Xiuying; Xu, Zongxue; Abbaspour, Karim C; Schulin, Rainer

2016-12-01

Agricultural application of reactive nitrogen (N) for fertilization is a cause of massive negative environmental problems on a global scale. However, spatially explicit and crop-specific information on global N losses into the environment and knowledge of trade-offs between N losses and crop yields are largely lacking. We use a crop growth model, Python-based Environmental Policy Integrated Climate (PEPIC), to determine global N losses from three major food crops: maize, rice, and wheat. Simulated total N losses into the environment (including water and atmosphere) are 44TgNyr -1 . Two thirds of these, or 29TgNyr -1 , are losses to water alone. Rice accounts for the highest N losses, followed by wheat and maize. The N loss intensity (NLI), defined as N losses per unit of yield, is used to address trade-offs between N losses and crop yields. The NLI presents high variation among different countries, indicating diverse N losses to produce the same amount of yields. Simulations of mitigation scenarios indicate that redistributing global N inputs and improving N management could significantly abate N losses and at the same time even increase yields without any additional total N inputs. Copyright © 2016 Elsevier B.V. All rights reserved.

Increasing ion and fusion yield in a dense plasma focus by combination of pre-ionization and heavy ion gas admixture

NASA Astrophysics Data System (ADS)

Farmanfarmaei, B.; Yousefi, H. R.; Salem, M. K.; Sari, A. H.

2018-04-01

The results of an experimental study of pre-ionization and heavy gas introduced into driven gas in a plasma focus device are reported. To achieve this purpose, we made use of two methods: first, the pre-ionization method by applying the shunt resistor and second, the admixture of heavy ions. We applied the different shunt resistors and found the optimum amount to be 200 MΩ at an optimum pressure of 0.5 Torr. Ion yield that was measured by array of Faraday cups and the energy of fast ions that was calculated by using the time-of-flight method were raised up to 22% and 45%, and the impurity caused by anode's erosion was reduced approximately by 67% in comparison to when there was no pre-ionization. Also, we have used the admixture of 5% argon ions with nitrogen (working gas) to improve the ion yield up to 45% in comparison with pure nitrogen. Finally, for the first time, we have utilized the combination of these methods together and have, consequently, reached the maximum ion yield and fusion yield. With this new method, ion yield raised up to 70% greater than that of the previous condition, i.e., without pre-ionization and heavy ion admixture.

Proteomic Analysis Revealed Nitrogen-mediated Metabolic, Developmental, and Hormonal Regulation of Maize (Zea mays L.) Ear Growth

PubMed Central

Li, Chunjian; Li, Xuexian

2012-01-01

Optimal nitrogen (N) supply is critical for achieving high grain yield of maize. It is well established that N deficiency significantly reduces grain yield and N oversupply reduces N use efficiency without significant yield increase. However, the underlying proteomic mechanism remains poorly understood. The present field study showed that N deficiency significantly reduced ear size and dry matter accumulation in the cob and grain, directly resulting in a significant decrease in grain yield. The N content, biomass accumulation, and proteomic variations were further analysed in young ears at the silking stage under different N regimes. N deficiency significantly reduced N content and biomass accumulation in young ears of maize plants. Proteomic analysis identified 47 proteins with significant differential accumulation in young ears under different N treatments. Eighteen proteins also responded to other abiotic and biotic stresses, suggesting that N nutritional imbalance triggered a general stress response. Importantly, 24 proteins are involved in regulation of hormonal metabolism and functions, ear development, and C/N metabolism in young ears, indicating profound impacts of N nutrition on ear growth and grain yield at the proteomic level. PMID:22936831

Carbon monoxide and methane adsorption of crude oil refinery using activated carbon from palm shells as biosorbent

NASA Astrophysics Data System (ADS)

Yuliusman; Afdhol, M. K.; Sanal, Alristo

2018-03-01

Carbon monoxide and methane gas are widely present in oil refineries. Off-potential gas is used as raw material for the petrochemical industry. In order for this off-gas to be utilized, carbon monoxide and methane must be removed from off-gas. This study aims to adsorb carbon monoxide and methane using activated carbon of palm shells and commercial activated carbon simultaneously. This research was conducted in 2 stages: 1) Preparation and characterization of activated carbon, 2) Carbon monoxide and methane adsorption test. The activation experiments using carbon dioxide at a flow rate of 150 ml/min yielded a surface area of 978.29 m2/g, Nitrogen at flow rate 150 ml/min yielded surface area 1241.48 m2/g, and carbon dioxide and nitrogen at a flow rate 200 ml/min yielded a surface area 300.37 m2/g. Adsorption of carbon monoxide and methane on activated carbon of palm shell systems yielded results in the amount of 0.5485 mg/g and 0.0649 mg/g and using commercial activated carbon yielded results in the amount of 0.5480 mg/g and 0.0650 mg/g

Effects of coal combustion byproduct encapsulated ammonium nitrate on wheat yield and uptake of nitrogen and metals

USDA-ARS?s Scientific Manuscript database

Nitrogen is an essential plant nutrient that is taken up in large quantity. Ammonium nitrate (AN) is used in agriculture as an N fertilizer, but it is also an ingredient in explosives. As a result of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City in April 1995, regulations o...

Effect of conservation practices on soil carbon and nitrogen accretion and crop yield in a corn production system in the southeastern coastal plain, USA

USDA-ARS?s Scientific Manuscript database

We implemented conservation farming practices (winter cover cropping plus strip tillage) for a non-irrigated corn production system in the southern coastal plain of Georgia, USA that had been previously been managed under a plow and harrow tillage regime. Total soil carbon and nitrogen were measure...

Do soil tests help forecast nitrogen response in first-year corn following alfalfa on fine-textured soils?

USDA-ARS?s Scientific Manuscript database

Improved methods of predicting grain yield response to fertilizer N for first-year corn (Zea mays L.) following alfalfa (Medicago sativa L.) on fine-textured soils are needed. Data from 21 site-years in the North Central Region were used to (i) determine how Illinois soil nitrogen test (ISNT) and pr...

Soil carbon management in large-scale Earth system modelling: implications for crop yields and nitrogen leaching

NASA Astrophysics Data System (ADS)

Olin, S.; Lindeskog, M.; Pugh, T. A. M.; Schurgers, G.; Wårlind, D.; Mishurov, M.; Zaehle, S.; Stocker, B. D.; Smith, B.; Arneth, A.

2015-06-01

We explore cropland management alternatives and the effect these can have on future C and N pools and fluxes using the land use-enabled dynamic vegetation model LPJ-GUESS. Simulated crop production, cropland carbon storage, carbon sequestration and nitrogen leaching from croplands are evaluated and discussed. Compared to the version of LPJ-GUESS that does not include land use dynamics, estimates of soil carbon stocks and nitrogen leaching from terrestrial to aquatic ecosystems were improved. We explore trade-offs between important ecosystem services that can be provided from agricultural fields such as crop yields, retention of nitrogen and carbon storage. These trade-offs are evaluated for current land use and climate and further explored for future conditions within the two future climate change scenarios, RCP 2.6 and 8.5. Our results show that the potential for carbon sequestration due to typical cropland management practices such as no-till and cover-crops proposed in literature is not realised, globally or over larger climatic regions. Our results highlight important considerations to be made when modelling C-N interactions in agricultural ecosystems under future environmental change, and the effects these have on terrestrial biogeochemical cycles.

Estimating total maximum daily loads with the Stochastic Empirical Loading and Dilution Model

USGS Publications Warehouse

Granato, Gregory; Jones, Susan Cheung

2017-01-01

The Massachusetts Department of Transportation (DOT) and the Rhode Island DOT are assessing and addressing roadway contributions to total maximum daily loads (TMDLs). Example analyses for total nitrogen, total phosphorus, suspended sediment, and total zinc in highway runoff were done by the U.S. Geological Survey in cooperation with FHWA to simulate long-term annual loads for TMDL analyses with the stochastic empirical loading and dilution model known as SELDM. Concentration statistics from 19 highway runoff monitoring sites in Massachusetts were used with precipitation statistics from 11 long-term monitoring sites to simulate long-term pavement yields (loads per unit area). Highway sites were stratified by traffic volume or surrounding land use to calculate concentration statistics for rural roads, low-volume highways, high-volume highways, and ultraurban highways. The median of the event mean concentration statistics in each traffic volume category was used to simulate annual yields from pavement for a 29- or 30-year period. Long-term average yields for total nitrogen, phosphorus, and zinc from rural roads are lower than yields from the other categories, but yields of sediment are higher than for the low-volume highways. The average yields of the selected water quality constituents from high-volume highways are 1.35 to 2.52 times the associated yields from low-volume highways. The average yields of the selected constituents from ultraurban highways are 1.52 to 3.46 times the associated yields from high-volume highways. Example simulations indicate that both concentration reduction and flow reduction by structural best management practices are crucial for reducing runoff yields.

Genetic Basis for Variation in Wheat Grain Yield in Response to Varying Nitrogen Application

PubMed Central

Mahjourimajd, Saba; Taylor, Julian; Sznajder, Beata; Timmins, Andy; Shahinnia, Fahimeh; Rengel, Zed; Khabaz-Saberi, Hossein; Kuchel, Haydn; Okamoto, Mamoru

2016-01-01

Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. Nitrogen fertilisers represent a significant production cost, in both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass production after establishment and showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation in NUE has been shown previously. Here we describe the genetic characterisation of NUE and identify genetic loci underlying N response under different N fertiliser regimes in a bread wheat population of doubled-haploid lines derived from a cross between two Australian genotypes (RAC875 × Kukri) bred for a similar production environment. NUE field trials were carried out at four sites in South Australia and two in Western Australia across three seasons. There was genotype-by-environment-by-treatment interaction across the sites and also good transgressive segregation for yield under different N supply in the population. We detected some significant Quantitative Trait Loci (QTL) associated with NUE and N response at different rates of N application across the sites and years. It was also possible to identify lines showing positive N response based on the rankings of their Best Linear Unbiased Predictions (BLUPs) within a trial. Dissecting the complexity of the N effect on yield through QTL analysis is a key step towards elucidating the molecular and physiological basis of NUE in wheat. PMID:27459317

Multi-omics analysis reveals regulators of the response to nitrogen limitation in Yarrowia lipolytica

DOE PAGES

Pomraning, Kyle R.; Kim, Young -Mo; Nicora, Carrie D.; ...

2016-02-25

Yarrowia lipolytica is an oleaginous ascomycete yeast that stores lipids in response to limitation of nitrogen. Furthermore, while the enzymatic pathways responsible for neutral lipid accumulation in Y. lipolytica are well characterized, regulation of these pathways has received little attention. We therefore sought to characterize the response to nitrogen limitation at system-wide levels, including the proteome, phosphoproteome and metabolome, to better understand how this organism regulates and controls lipid metabolism and to identify targets that may be manipulated to improve lipid yield.

Electrolytic Conductance of the Ternary System of Nitric Acid--Nitrogen Dioxide--Water at 32 deg F and Atmospheric Pressure

DTIC Science & Technology

1951-11-12

solutions of nitrogen dioxide in nitric acid where nitrosonium ions (NO+) and nitrate ions (NO-) have been identified (Cf. Ref. 4). The nitrogen...0.97 weight fraction nitric acid, hydrogen and nitrate ions are the predominant conducting species. In the range 0.97 to 1.00 weight fraction nitric...self-ionization to yield nitronium ions (NJ2) and nitratej2 ions (NO3) according to the expression 2HNO3--NO+ + NO- + H2 0 It is evident from this

Hydrazines and carbohydrazides produced from oxidized carbon in earth's primitive environment

NASA Technical Reports Server (NTRS)

Folsome, C. E.; Brittain, A.; Smith, A.; Chang, S.

1981-01-01

Whether abiological organic compounds can be formed from the interactions of energy sources with nitrogen, oxidized carbon and water is held to be of importance in geochemical models of the primordial earth atmosphere. It is reported that experiments using quenched spark discharges through molecular nitrogen on aqueous suspensions of CaCO3 and other reactants to simulate the hydrosphere/atmosphere interface yield hydrazine and carbohydrazine in significant but low yields. Such reactions in primitive aquatic environments may have supplied a pathway for chemical evolution and the origin of life, on a primitive earth in which fully oxidized states of carbon were available for the primary synthesis of organic matter.

Synthesis of Nitrogen- and Chlorine-Doped Graphene Quantum Dots for Cancer Cell Imaging.

PubMed

Nafiujjaman, Md; Joon, Hwang; Kwak, Kwang Soo; Lee, Yong-Kyu

2018-06-01

In this study, we synthesized high quantum yield nitrogen and chlorine-doped graphene quantum dots (Cl-GQDs-N) for cancer cell imaging using simple and high production yield hydrothermal method from low-cost fructose. Prepared Cl-GQDs-N are about 30 nm in diameter and these Cl-GQDs-N display powerful blue color photoluminescence under the 365 nm UV lamp. We have further investigated their optical performances under various conditions. In vitro study shows no toxicity effect in normal and cancer cells treated with Cl-GQDs-N. Finally, we believe that our synthesized Cl-GQDs-N will bring more application opportunities in the field of bioimaging, optoelectronics and beyond.

Sustainability versus yield in agricultural soils under various crop production practices - a microbial perspective

NASA Astrophysics Data System (ADS)

Pereg, Lily; Aldorri, Sind; McMillan, Mary

2017-04-01

Wheat and cotton are important food and cash crops often grown in rotation on black, grey and red clay soil, in Australia. The common practice of nitrogen and phosphate fertilizers have been solely in the form of agrochemicals, however, a few growers have incorporated manure or composted plant material into the soil before planting. While the cotton yield in studied farms was comparable, we found that the use of such organic amendments significantly enhanced the pool of nitrogen cycling genes, suggesting increased potential of soil microbial function as well as increased microbial metabolic diversity and abundance. Therefore, the regular use of organic amendments contributed to improved soil sustainability.

Responses of root physiological characteristics and yield of sweet potato to humic acid urea fertilizer

PubMed Central

Kou, Meng; Tang, Zhonghou; Zhang, Aijun; Li, Hongmin; Wei, Meng

2017-01-01

Humic acid (HA), not only promote the growth of crop roots, they can be combined with nitrogen (N) to increase fertilizer use efficiency and yield. However, the effects of HA urea fertilizer (HA-N) on root growth and yield of sweet potato has not been widely investigated. Xushu 28 was used as the experimental crop to investigate the effects of HA-N on root morphology, active oxygen metabolism and yield under field conditions. Results showed that nitrogen application alone was not beneficial for root growth and storage root formation during the early growth stage. HA-N significantly increased the dry weight of the root system, promoted differentiation from adventitious root to storage root, and increased the overall root activity, total root length, root diameter, root surface area, as well as root volume. HA-N thus increased the activity of superoxide dismutase (SOD), peroxidase (POD), and Catalase (CAT) as well as increasing the soluble protein content of roots and decreasing the malondialdehyde (MDA) content. HA-N significantly increased both the number of storage roots per plant increased by 14.01%, and the average fresh weight per storage root increased by 13.7%, while the yield was also obviously increased by 29.56%. In this study, HA-N increased yield through a synergistic increase of biological yield and harvest index. PMID:29253886

Active-Optical Sensors Using Red NDVI Compared to Red Edge NDVI for Prediction of Corn Grain Yield in North Dakota, U.S.A.

PubMed Central

Sharma, Lakesh K.; Bu, Honggang; Denton, Anne; Franzen, David W.

2015-01-01

Active-optical sensor readings from an N non-limiting area standard established within a farm field are used to predict yield in the standard. Lower yield predictions from sensor readings obtained from other parts of the field outside of the N non-limiting standard area indicate a need for supplemental N. Active-optical sensor algorithms for predicting corn (Zea mays, L.) yield to direct in-season nitrogen (N) fertilization in corn utilize red NDVI (normalized differential vegetative index). Use of red edge NDVI might improve corn yield prediction at later growth stages when corn leaves cover the inter-row space resulting in “saturation” of red NDVI readings. The purpose of this study was to determine whether the use of red edge NDVI in two active-optical sensors (GreenSeeker™ and Holland Scientific Crop Circle™) improved corn yield prediction. Nitrogen rate experiments were established at 15 sites in North Dakota (ND). Sensor readings were conducted at V6 and V12 corn. Red NDVI and red edge NDVI were similar in the relationship of readings with yield at V6. At V12, the red edge NDVI was superior to the red NDVI in most comparisons, indicating that it would be most useful in developing late-season N application algorithms. PMID:26540057

Active-Optical Sensors Using Red NDVI Compared to Red Edge NDVI for Prediction of Corn Grain Yield in North Dakota, U.S.A.

PubMed

Sharma, Lakesh K; Bu, Honggang; Denton, Anne; Franzen, David W

2015-11-02

Active-optical sensor readings from an N non-limiting area standard established within a farm field are used to predict yield in the standard. Lower yield predictions from sensor readings obtained from other parts of the field outside of the N non-limiting standard area indicate a need for supplemental N. Active-optical sensor algorithms for predicting corn (Zea mays, L.) yield to direct in-season nitrogen (N) fertilization in corn utilize red NDVI (normalized differential vegetative index). Use of red edge NDVI might improve corn yield prediction at later growth stages when corn leaves cover the inter-row space resulting in "saturation" of red NDVI readings. The purpose of this study was to determine whether the use of red edge NDVI in two active-optical sensors (GreenSeeker™ and Holland Scientific Crop Circle™) improved corn yield prediction. Nitrogen rate experiments were established at 15 sites in North Dakota (ND). Sensor readings were conducted at V6 and V12 corn. Red NDVI and red edge NDVI were similar in the relationship of readings with yield at V6. At V12, the red edge NDVI was superior to the red NDVI in most comparisons, indicating that it would be most useful in developing late-season N application algorithms.

Coordinated regulation of nitrogen supply mode and initial cell density for energy storage compounds production with economized nitrogen utilization in a marine microalga Isochrysis zhangjiangensis.

PubMed

Chi, Lei; Yao, Changhong; Cao, Xupeng; Xue, Song

2016-01-01

Lipids and carbohydrates are main energy storage compounds (ESC) of microalgae under stressed conditions and they are potential feedstock for biofuel production. Yet, the sustainable and commercially successful production of ESC in microalgae needs to consider nitrogen utilization efficiency. Here the impact of different initial cell densities (ICDs) on ESC accumulation in Isochrysis zhangjiangensis under two nitrogen supply modes (an initially equal concentration of nitrogen per-cell in the medium (N1) and an equal total concentration of nitrogen in the culture system (N2)) were investigated. The results demonstrated that the highest ESC yield (1.36gL(-1)) at N1, which included a maximal nitrogen supply in the cultivation system, and the highest ESC content (66.5%) and ESC productivity per mass of nitrogen (3.28gg(-1) (N) day(-1)) at N2, were all obtained under a high ICD of 8.0×10(6)cellsmL(-1). Therefore I. zhangjiangensis qualifies for ESC-enriched biomass production with economized nitrogen utilization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phosphorus and nitrogen concentrations and loads at Illinois River south of Siloam Springs, Arkansas, 1997-1999

USGS Publications Warehouse

Green, W. Reed; Haggard, Brian E.

2001-01-01

Water-quality sampling consisting of every other month (bimonthly) routine sampling and storm event sampling (six storms annually) is used to estimate annual phosphorus and nitrogen loads at Illinois River south of Siloam Springs, Arkansas. Hydrograph separation allowed assessment of base-flow and surfacerunoff nutrient relations and yield. Discharge and nutrient relations indicate that water quality at Illinois River south of Siloam Springs, Arkansas, is affected by both point and nonpoint sources of contamination. Base-flow phosphorus concentrations decreased with increasing base-flow discharge indicating the dilution of phosphorus in water from point sources. Nitrogen concentrations increased with increasing base-flow discharge, indicating a predominant ground-water source. Nitrogen concentrations at higher base-flow discharges often were greater than median concentrations reported for ground water (from wells and springs) in the Springfield Plateau aquifer. Total estimated phosphorus and nitrogen annual loads for calendar year 1997-1999 using the regression techniques presented in this paper (35 samples) were similar to estimated loads derived from integration techniques (1,033 samples). Flow-weighted nutrient concentrations and nutrient yields at the Illinois River site were about 10 to 100 times greater than national averages for undeveloped basins and at North Sylamore Creek and Cossatot River (considered to be undeveloped basins in Arkansas). Total phosphorus and soluble reactive phosphorus were greater than 10 times and total nitrogen and dissolved nitrite plus nitrate were greater than 10 to 100 times the national and regional averages for undeveloped basins. These results demonstrate the utility of a strategy whereby samples are collected every other month and during selected storm events annually, with use of regression models to estimate nutrient loads. Annual loads of phosphorus and nitrogen estimated using regression techniques could provide similar results to estimates using integration techniques, with much less investment.

A comparative study on phyllosphere nitrogen fixation by newly isolated Corynebacterium sp. & Flavobacterium sp. and their potentialities as biofertilizer.

PubMed

Giri, S; Pati, B R

2004-01-01

A number of nitrogen fixing bacteria has been isolated from forest phyllosphere on the basis of nitrogenase activity. Among them two best isolates are selected and identified as Corynebacterium sp. AN1 & Flavobacterium sp. TK2 able to reduce 88 and 132 n mol of acetylene (10(8)cells(-1)h(-1)) respectively. They were grown in large amount and sprayed on the phyllosphere of maize plants as a substitute for nitrogenous fertilizer. Marked improvements in growth and total nitrogen content of the plant have been observed by the application of these nitrogen-fixing bacteria. An average 30-37% increase in yield was obtained, which is nearer to chemical fertilizer treatment. Comparatively better effect was obtained by application of Flavobacterium sp.

[Mechanisms for the increased fertilizer nitrogen use efficiency of rice in wheat-rice rotation system under combined application of inorganic and organic fertilizers].

PubMed

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.

Overexpression of a glutamine synthetase gene affects growth and development in sorghum.

PubMed

Urriola, Jazmina; Rathore, Keerti S

2015-06-01

Nitrogen is a primary macronutrient in plants, and nitrogen fertilizers play a critical role in crop production and yield. In this study, we investigated the effects of overexpressing a glutamine synthetase (GS) gene on nitrogen metabolism, and plant growth and development in sorghum (Sorghum bicolor L., Moench). GS catalyzes the ATP dependent reaction between ammonia and glutamate to produce glutamine. A 1,071 bp long coding sequence of a sorghum cytosolic GS gene (Gln1) under the control of the maize ubiquitin (Ubq) promoter was introduced into sorghum immature embryos by Agrobacterium-mediated transformation. Progeny of the transformants exhibited higher accumulation of the Gln1 transcripts and up to 2.2-fold higher GS activity compared to the non-transgenic controls. When grown under optimal nitrogen conditions, these Gln1 transgenic lines showed greater tillering and up to 2.1-fold increase in shoot vegetative biomass. Interestingly, even under greenhouse conditions, we observed a seasonal component to both these parameters and the grain yield. Our results, showing that the growth and development of sorghum Gln1 transformants are also affected by N availability and other environmental factors, suggest complexity of the relationship between GS activity and plant growth and development. A better understanding of other control points and the ability to manipulate these will be needed to utilize the transgenic technology to improve nitrogen use efficiency of crop plants.

Temperature-Dependent Kinetic Model for Nitrogen-Limited Wine Fermentations▿

PubMed Central

Coleman, Matthew C.; Fish, Russell; Block, David E.

2007-01-01

A physical and mathematical model for wine fermentation kinetics was adapted to include the influence of temperature, perhaps the most critical factor influencing fermentation kinetics. The model was based on flask-scale white wine fermentations at different temperatures (11 to 35°C) and different initial concentrations of sugar (265 to 300 g/liter) and nitrogen (70 to 350 mg N/liter). The results show that fermentation temperature and inadequate levels of nitrogen will cause stuck or sluggish fermentations. Model parameters representing cell growth rate, sugar utilization rate, and the inactivation rate of cells in the presence of ethanol are highly temperature dependent. All other variables (yield coefficient of cell mass to utilized nitrogen, yield coefficient of ethanol to utilized sugar, Monod constant for nitrogen-limited growth, and Michaelis-Menten-type constant for sugar transport) were determined to vary insignificantly with temperature. The resulting mathematical model accurately predicts the observed wine fermentation kinetics with respect to different temperatures and different initial conditions, including data from fermentations not used for model development. This is the first wine fermentation model that accurately predicts a transition from sluggish to normal to stuck fermentations as temperature increases from 11 to 35°C. Furthermore, this comprehensive model provides insight into combined effects of time, temperature, and ethanol concentration on yeast (Saccharomyces cerevisiae) activity and physiology. PMID:17616615

Protection against salt toxicity in Azolla pinnata-Anabaena azollae symbiotic association by using combined-N sources.

PubMed

Mishra, A K; Singh, Satya S

2006-09-01

Protection from salt stress was observed in the terms of yield (fresh and dry weight, chlorophyll and protein) and nitrogenase activity. Azollapinnata appeared highly sensitive to 40 mM external NaCl stress. Fronds of Azolla unable to grow beyond a concentration of 30 mM NaCl and accordingly death was recorded at 40 mM NaCl on the 6th day of incubation. Yield was inhibited by various levels of NaCl (0, 10, 20 and 30 mM). Addition of combined-N to the growth medium protected the association partially from salt toxicity. Among the N-sources (NO3-, NH4+ and urea) tried, urea mitigated the salt-induced toxicity most efficiently. Reduction in nitrogenase activity was observed when intact Azolla was grown in nutrient medium either supplemented with different levels of NaCl or combined nitrogen. Only NO3- (5 mM) protected the enzymatic activity from salt toxicity while other concentrations of ammonium, nitrate and urea slowed down the salt-induced inhibition of enzyme activity in Azolla-Anabaena association. These results suggested that an optimum protection from salt stress could be obtained by using a combination of combined nitrogen sources. The reason for this protection might be due to the availability of combined nitrogen to the association, nitrogen is only available through the biological nitrogen fixation which is the most sensitive to salt stress.

Heterogeneous benefits of precision nitrogen management over the Midwestern US: evidence from 1,000 fields derived by satellite imagery and crop modeling

NASA Astrophysics Data System (ADS)

Jin, Z.; Archontoulis, S.; Lobell, D. B.

2017-12-01

The wise management of nitrogen (N) fertilizer is important for both economic and environmental considerations. The variable rate technology (VRT) that applies different rates of N fertilizer by fully taking account of the spatial heterogeneity within fields has gained popularity with the recent advent of high-resolution satellites and spectrometers, but its profitability is still uncertain given the dependence of corn-nitrogen responses to soil and climate. To our knowledge, the benefits of adopting VRT in the vast Midwestern US agricultural zones have only been assessed at a very limited number of fields based on labor-costing on-farm samplings. Here we present a study that integrates a range of geospatial tools and data to quantifying the economic benefit of VRT versus uniform N application over 1,000 randomly selected corn fields in the US Midwest. We employed the Google Earth Engine (GEE) and Landsat-5, 7 and 8 collections to derive 30m-resolution yield map for years 2007-2015, and used the multi-year averaged yields to characterize the yield variation and hence the management zones for each field and zone-specific yield goal. The yield goals as well as the Soil Survey Geographic Database (SSURGO) data were then used to calibrate the Agricultural Production Systems sIMulator (APSIM) model, which generated a range of variables such as yields, N balance and leaching. Our preliminary results showed that the calibrated APSIM model was able to capture about 60% of the variation in the satellite-based yield estimates, and more than 70% of the yield spread (i.e. maximum - minimum yield). Regardless of the overall environmental benefits of less N loss through leaching, the economic difference between adopting VRT and uniform application ranged from -50 to 200 per acre, with the majority lay between -10 and 40 per acre. Fields with a wider range of yield spread benefited more from adopting VRT, yet the conclusion varies upon weather, especially the precipitation. Our study confirmed that adopting VRT in the US Midwest was economically feasible under most cases, and highlighted the potential of using big-data platform to facilitate precision N management over a large scale. The methodology developed in this study can serve as a good foundation for other precision management applications over the world.

The application dosage of Azolla pinnata in fresh and powder form as organic fertilizer on soil chemical properties, growth and yield of rice plant

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.

Modelling climate change impacts on viticultural yield, phenology and stress conditions in Europe.

PubMed

Fraga, Helder; García de Cortázar Atauri, Iñaki; Malheiro, Aureliano C; Santos, João A

2016-11-01

Viticulture is a key socio-economic sector in Europe. Owing to the strong sensitivity of grapevines to atmospheric factors, climate change may represent an important challenge for this sector. This study analyses viticultural suitability, yield, phenology, and water and nitrogen stress indices in Europe, for present climates (1980-2005) and future (2041-2070) climate change scenarios (RCP4.5 and 8.5). The STICS crop model is coupled with climate, soil and terrain databases, also taking into account CO 2 physiological effects, and simulations are validated against observational data sets. A clear agreement between simulated and observed phenology, leaf area index, yield and water and nitrogen stress indices, including the spatial differences throughout Europe, is shown. The projected changes highlight an extension of the climatic suitability for grapevines up to 55°N, which may represent the emergence of new winemaking regions. Despite strong regional heterogeneity, mean phenological timings (budburst, flowering, veraison and harvest) are projected to undergo significant advancements (e.g. budburst/harvest can be >1 month earlier), with implications also in the corresponding phenophase intervals. Enhanced dryness throughout Europe is also projected, with severe water stress over several regions in southern regions (e.g. southern Iberia and Italy), locally reducing yield and leaf area. Increased atmospheric CO 2 partially offsets dryness effects, promoting yield and leaf area index increases in central/northern Europe. Future biomass changes may lead to modifications in nitrogen demands, with higher stress in northern/central Europe and weaker stress in southern Europe. These findings are critical decision support systems for stakeholders from the European winemaking sector. © 2016 John Wiley & Sons Ltd.

Biochar reduces yield-scaled emissions of reactive nitrogen gases from vegetable soils across China

NASA Astrophysics Data System (ADS)

Fan, Changhua; Chen, Hao; Li, Bo; Xiong, Zhengqin

2017-06-01

Biochar amendment to soil has been proposed as a strategy for sequestering carbon, mitigating climate change and enhancing crop productivity. However, few studies have compared the general effect of different feedstock-derived biochars on the various gaseous reactive nitrogen emissions (GNrEs) of N2O, NO and NH3 simultaneously across the typical vegetable soils in China. A greenhouse pot experiment with five consecutive vegetable crops was conducted to investigate the effects of two contrasting biochars, namely wheat straw biochar (Bw) and swine manure biochar (Bm) on GNrEs, vegetable yield and gaseous reactive nitrogen intensity (GNrI) in four typical soils which are representative of the intensive vegetable cropping systems across mainland China: an Acrisol from Hunan Province, an Anthrosol from Shanxi Province, a Cambisol from Shandong Province and a Phaeozem from Heilongjiang Province. Results showed that remarkable GNrE mitigation induced by biochar occurred in Anthrosol and Phaeozem, whereas enhancement of yield occurred in Cambisol and Phaeozem. Additionally, both biochars decreased GNrI through reducing N2O and NO emissions by 36.4-59.1 and 37.0-49.5 % for Bw (except for Cambisol), respectively, and by improving yield by 13.5-30.5 % for Bm (except for Acrisol and Anthrosol). Biochar amendments generally stimulated the NH3 emissions with greater enhancement from Bm than Bw. We can infer that the biochar's effects on the GNrEs and vegetable yield strongly depend on the attributes of the soil and biochar. Therefore, in order to achieve the maximum benefits under intensive greenhouse vegetable agriculture, both soil type and biochar characteristics should be seriously considered before conducting large-scale biochar applications.

The influence of different cultivation conditions on the metabolome of Fusarium oxysporum.

PubMed

Panagiotou, Gianni; Christakopoulos, Paul; Olsson, Lisbeth

2005-08-22

The two most widespread pentose sugars found in the biosphere are d-xylose and l-arabinose. They are both potential substrates for ethanol production. The purpose of this study was to better understand the redox constraints imposed to Fusarium oxysporum during utilization of pentoses. In order to increase ethanol yield and decrease by-product formation, nitrate was used as nitrogen source. The use of NADH, the cofactor in denitrification process when using nitrate as a nitrogen source, improved the ethanol yield on xylose to 0.89 mol mol(-1) compared to the ethanol yield achieved using ammonium as nitrogen source 0.44 mol mol(-1). The improved ethanol yield was followed by a 28% decrease in yield of the by-product xylitol. In order to investigate the metabolic pathway of arabinose and the metabolic limitations for the efficient ethanol production from this sugar, the extracellular and intracellular metabolite profiles were determined under aerobic and anaerobic cultivation conditions. The results of this study clearly show difficulties in channelling of glucose-1-P (G1P) to pentose phosphate pathway (PPP) and reduced NADPH regeneration, suggesting that NADPH becomes a limiting factor for arabinose conversion, resulting in excessive acetate production. Variations of the fungus intracellular amino and non-amino acid pool, under different culture conditions, were evaluated using principal component analysis (PCA). PCA projection of the metabolome data collected from F. oxysporum subjected to environmental perturbations succeeded to visualize different physiological states and the conclusions of this study were that the metabolite profile is unique according to: (1) the carbon source and (2) the oxygen supply, and to a lesser extent to the cultivation phase.

[Effects of phosphorus fertilization on yield of winter wheat and utilization of soil nitrogen].

PubMed

Xing, Dan; Li, Shu-wen; Xia, Bo; Wen, Hong-da

2015-02-01

In order to evaluate the threshold of phosphorus (P) application rate and improve the utilization efficiency of fertilizers in Baoding region of Hebei Province, a field experiment was conducted to examine the impacts of P fertilization on wheat yield, soil NO(3-)-N and nitrogen use efficiency. Results showed that, compared with the CK (P0), all treatments with P application (P1, 120 kg · hm(-2); P2, 240 kg · hm(-2) and P3, 480 kg · hm(-2)) increased the plant height, flag leaf areas and total leaf areas per plant of winter wheat, which was conducive to the accumulation of photosynthetic products. In addition, P application increased the spike number, kernels per spike and yield of winter wheat but slightly decreased the grain mass per 1000 seeds. Of the P-fertilized treatments, P2 had the highest wheat yield of 6102 kg · hm(-2), which was similar to P1 but significantly greater than those of P0 and P3. Furthermore, P fertilization reduced the NO(3-)-N content in top soil layer although the total accumulation of NO3- was still rather high. The N grain production efficiencies (GPE(N)) and N uptake efficiencies (UE(N)) of P1 and P2 were similar but greater than the other treatments. The use efficiency (UR(P)) , agronomic efficiency (AE(P)) and partial productivity of P fertilizer (PFP(P)) in P1 were significantly greater than P2 and P3. In conclusion, the P application rate of 120 kg · hm(-2) (P1) in this study could be an appropriate threshold in Baoding, Hebei, from the aspects of wheat yield, nitrogen and phosphate use efficiencies and accumulation of soil NO3-.

Production of biomass/energy crops on phosphatic clay soils in central Florida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stricker, J.A.; Prine, G.M.; Woodard, K.R.

1993-12-31

Phosphatic clay is a byproduct of phosphate mining. Presently more than 40,470 ha have been created, most in central Florida, and about 810 ha are being added each year. Phosphatic clays have high fertility and high water holding capacity, reducing fertilization costs and producing high yields without irrigation. Based on 10 years of research, scientists have selected tall annual-regenerating perennial C-4 grasses as having the greatest potential for biomass production in Florida. The purpose of this work was to determine the feasibility of growing these tall perennial grasses for biomass on phosphatic clay. Elephantgrass, sugarcane and energycane, and erianthus weremore » planted in duplicate replications on phosphatic clay soil in late August, 1986. yield was measured by one harvest in December or January each year for four years. Nitrogen fertilization included 112 kg ha{sup {minus}1} the first year followed by 134 kg ha{sup {minus}1} for the next three years. Nitrogen is the only supplemental nutrient needed to grow all tall grass crops on phosphatic clay. The average annual oven dry matter yield over the 4-yr period was 36.3 Mg ha{sup {minus}1} for PI 300086 elephantgrass, 45.2 for N51 elephantgrass, 42.5 for L79-1002 energycane, 49.0 for US72-1153 energycane, 49.7 for US78-1009 sugarcane, 52.2 for US56-9 sugarcane, 56.2 for CP72-1210 sugarcane, and 48.8 for 1K-7647 erianthus. More recent work has utilized domestic sewage sludge as a nitrogen source for the tall grasses. Preliminary sugar yields of selected sugarcane accessions & sweet sorghum were 4.7 Mg ha{sup {minus}1} for CP72-1210, 12.5 for US67-2022, 3.4 for US78-1009 and 1.3 Mg ha{sup {minus}1} for sweet sorghum. The high yields of the tall grasses grown on phosphatic clay with low inputs indicate a great potential for these crops as a source of renewable energy. A sustainable cropping system may be maintained by utilizing municipal sewage sludge as a nitrogen source with tall grasses on phosphatic clay.« less

Complex Physiological Response of Norway Spruce to Atmospheric Pollution - Decreased Carbon Isotope Discrimination and Unchanged Tree Biomass Increment.

PubMed

Čada, Vojtěch; Šantrůčková, Hana; Šantrůček, Jiří; Kubištová, Lenka; Seedre, Meelis; Svoboda, Miroslav

2016-01-01

Atmospheric pollution critically affects forest ecosystems around the world by directly impacting the assimilation apparatus of trees and indirectly by altering soil conditions, which subsequently also leads to changes in carbon cycling. To evaluate the extent of the physiological effect of moderate level sulfate and reactive nitrogen acidic deposition, we performed a retrospective dendrochronological analysis of several physiological parameters derived from periodic measurements of carbon stable isotope composition ((13)C discrimination, intercellular CO2 concentration and intrinsic water use efficiency) and annual diameter increments (tree biomass increment, its inter-annual variability and correlation with temperature, cloud cover, precipitation and Palmer drought severity index). The analysis was performed in two mountain Norway spruce (Picea abies) stands of the Bohemian Forest (Czech Republic, central Europe), where moderate levels of pollution peaked in the 1970s and 1980s and no evident impact on tree growth or link to mortality has been reported. The significant influence of pollution on trees was expressed most sensitively by a 1.88‰ reduction of carbon isotope discrimination (Δ(13)C). The effects of atmospheric pollution interacted with increasing atmospheric CO2 concentration and temperature. As a result, we observed no change in intercellular CO2 concentrations (Ci), an abrupt increase in water use efficiency (iWUE) and no change in biomass increment, which could also partly result from changes in carbon partitioning (e.g., from below- to above-ground). The biomass increment was significantly related to Δ(13)C on an individual tree level, but the relationship was lost during the pollution period. We suggest that this was caused by a shift from the dominant influence of the photosynthetic rate to stomatal conductance on Δ(13)C during the pollution period. Using biomass increment-climate correlation analyses, we did not identify any clear pollution-related change in water stress or photosynthetic limitation (since biomass increment did not become more sensitive to drought/precipitation or temperature/cloud cover, respectively). Therefore, we conclude that the direct effect of moderate pollution on stomatal conductance was likely the main driver of the observed physiological changes. This mechanism probably caused weakening of the spruce trees and increased sensitivity to other stressors.

Complex Physiological Response of Norway Spruce to Atmospheric Pollution – Decreased Carbon Isotope Discrimination and Unchanged Tree Biomass Increment

PubMed Central

Čada, Vojtěch; Šantrůčková, Hana; Šantrůček, Jiří; Kubištová, Lenka; Seedre, Meelis; Svoboda, Miroslav

2016-01-01

Atmospheric pollution critically affects forest ecosystems around the world by directly impacting the assimilation apparatus of trees and indirectly by altering soil conditions, which subsequently also leads to changes in carbon cycling. To evaluate the extent of the physiological effect of moderate level sulfate and reactive nitrogen acidic deposition, we performed a retrospective dendrochronological analysis of several physiological parameters derived from periodic measurements of carbon stable isotope composition (13C discrimination, intercellular CO2 concentration and intrinsic water use efficiency) and annual diameter increments (tree biomass increment, its inter-annual variability and correlation with temperature, cloud cover, precipitation and Palmer drought severity index). The analysis was performed in two mountain Norway spruce (Picea abies) stands of the Bohemian Forest (Czech Republic, central Europe), where moderate levels of pollution peaked in the 1970s and 1980s and no evident impact on tree growth or link to mortality has been reported. The significant influence of pollution on trees was expressed most sensitively by a 1.88‰ reduction of carbon isotope discrimination (Δ13C). The effects of atmospheric pollution interacted with increasing atmospheric CO2 concentration and temperature. As a result, we observed no change in intercellular CO2 concentrations (Ci), an abrupt increase in water use efficiency (iWUE) and no change in biomass increment, which could also partly result from changes in carbon partitioning (e.g., from below- to above-ground). The biomass increment was significantly related to Δ13C on an individual tree level, but the relationship was lost during the pollution period. We suggest that this was caused by a shift from the dominant influence of the photosynthetic rate to stomatal conductance on Δ13C during the pollution period. Using biomass increment-climate correlation analyses, we did not identify any clear pollution-related change in water stress or photosynthetic limitation (since biomass increment did not become more sensitive to drought/precipitation or temperature/cloud cover, respectively). Therefore, we conclude that the direct effect of moderate pollution on stomatal conductance was likely the main driver of the observed physiological changes. This mechanism probably caused weakening of the spruce trees and increased sensitivity to other stressors. PMID:27375659

Identification of technology options for reducing nitrogen pollution in cropping systems of Pujiang*

PubMed Central

Fang, Bin; Wang, Guang-huo; Van den berg, Marrit; Roetter, Reimund

2005-01-01

This work analyses the potential role of nitrogen pollution technology of crop systems of Pujiang, County in Eastern China’s Zhejiang Province, rice and vegetables are important cropping systems. We used a case study approach involving comparison of farmer practices and improved technologies. This approach allows assessing the impact of technology on pollution, is forward looking, and can yield information on the potential of on-the-shelf technology and provide opportunities for technology development. The approach particularly suits newly developed rice technologies with large potential of reducing nitrogen pollution and for future rice and vegetables technologies. The results showed that substantial reductions in nitrogen pollution are feasible for both types of crops. PMID:16187411

Identification of technology options for reducing nitrogen pollution in cropping systems of Pujiang.

PubMed

Fang, Bin; Wang, Guang-Huo; Van, Den Berg Marrit; Roetter, Reimund

2005-10-01

This work analyses the potential role of nitrogen pollution technology of crop systems of Pujiang, County in Eastern China's Zhejiang Province, rice and vegetables are important cropping systems. We used a case study approach involving comparison of farmer practices and improved technologies. This approach allows assessing the impact of technology on pollution, is forward looking, and can yield information on the potential of on-the-shelf technology and provide opportunities for technology development. The approach particularly suits newly developed rice technologies with large potential of reducing nitrogen pollution and for future rice and vegetables technologies. The results showed that substantial reductions in nitrogen pollution are feasible for both types of crops.

Hydrologic conditions and water quality of rainfall and storm runoff for two agricultural areas of the Oso Creek watershed, Nueces County, Texas, 2005-08

USGS Publications Warehouse

Ockerman, Darwin J.; Fernandez, Carlos J.

2010-01-01

The U.S. Geological Survey, in cooperation with the Texas State Soil and Water Conservation Board, Coastal Bend Bays and Estuaries Program, and Texas AgriLife Research and Extension Center at Corpus Christi, studied hydrologic conditions and water quality of rainfall and storm runoff of two primarily agricultural subwatersheds of the Oso Creek watershed in Nueces County, Texas. One area, the upper West Oso Creek subwatershed, is about 5,145 acres. The other area, a subwatershed drained by an unnamed tributary to Oso Creek (hereinafter, Oso Creek tributary), is about 5,287 acres. Rainfall and runoff (streamflow) were continuously monitored at the outlets of the two subwatersheds during the study period October 2005-September 2008. Seventeen rainfall samples were collected and analyzed for nutrients and major inorganic ions. Twenty-four composite runoff water-quality samples (12 at West Oso Creek, 12 at Oso Creek tributary) were collected and analyzed for nutrients, major inorganic ions, and pesticides. Twenty-six discrete suspended-sediment samples (12 West Oso Creek, 14 Oso Creek tributary) and 17 bacteria samples (10 West Oso Creek, 7 Oso Creek tributary) were collected and analyzed. These data were used to estimate, for selected constituents, rainfall deposition to and runoff loads and yields from the two subwatersheds. Quantities of fertilizers and pesticides applied in the two subwatersheds were compared with quantities of nutrients and pesticides in rainfall and runoff. For the study period, total rainfall was greater than average. Most of the runoff from the two subwatersheds occurred in response to a few specific storm periods. The West Oso Creek subwatershed produced more runoff during the study period than the Oso Creek tributary subwatershed, 13.95 inches compared with 9.45 inches. Runoff response was quicker and peak flows were higher in the West Oso Creek subwatershed than in the Oso Creek tributary subwatershed. Total nitrogen runoff yield for the 3-year study period averaged 2.62 pounds per acre per year from the West Oso Creek subwatershed and 0.839 pound per acre per year from the Oso Creek tributary subwatershed. Total phosphorus yields from the West Oso Creek and Oso Creek tributary subwatersheds for the 3-year period were 0.644 and 0.419 pound per acre per year, respectively. Runoff yields of nitrogen and phosphorus were relatively small compared to inputs of nitrogen in fertilizer and rainfall deposition. Average annual runoff yield of total nitrogen (subwatersheds combined) represents about 2.5 percent of nitrogen applied as fertilizer to cropland in the watershed and nitrogen entering the subwatersheds through rainfall deposition. Average annual runoff yield of total phosphorus (subwatersheds combined) represents about 4.0 percent of the phosphorus in applied fertilizer and rainfall deposition. Suspended-sediment yields from the West Oso Creek subwatershed were more than twice those from the Oso Creek tributary subwatershed. The average suspended-sediment yield from the West Oso Creek subwatershed was 522 pounds per acre per year and from the Oso Creek tributary subwatershed was 139 pounds per acre per year. Twenty-four herbicides and eight insecticides were detected in runoff samples collected at the two subwatershed outlets. At the West Oso Creek site, 19 herbicides and 4 insecticides were detected; at the Oso Creek tributary site, 18 herbicides and 6 insecticides were detected. Fourteen pesticides were detected in only one sample at low concentrations (near the laboratory reporting level). Atrazine and atrazine degradation byproduct 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT) were detected in all samples. Glyphosate and glyphosate byproduct aminomethylphosphonic acid (AMPA) were detected in all samples collected and analyzed during water years 2006-07 but were not included in analysis for samples collected in water year 2008. Of all pesticides detected in runoff, the highest runoff yields w

Over-Expression of a Tobacco Nitrate Reductase Gene in Wheat (Triticum aestivum L.) Increases Seed Protein Content and Weight without Augmenting Nitrogen Supplying

PubMed Central

Zhao, Xiao-Qiang; Nie, Xuan-Li; Xiao, Xing-Guo

2013-01-01

Heavy nitrogen (N) application to gain higher yield of wheat (Triticum aestivum L.) resulted in increased production cost and environment pollution. How to diminish the N supply without losing yield and/or quality remains a challenge. To meet the challenge, we integrated and expressed a tobacco nitrate reductase gene (NR) in transgenic wheat. The 35S-NR gene was transferred into two winter cultivars, “Nongda146” and “Jimai6358”, by Agrobacterium-mediation. Over-expression of the transgene remarkably enhanced T1 foliar NR activity and significantly augmented T2 seed protein content and 1000-grain weight in 63.8% and 68.1% of T1 offspring (total 67 individuals analyzed), respectively. Our results suggest that constitutive expression of foreign nitrate reductase gene(s) in wheat might improve nitrogen use efficiency and thus make it possible to increase seed protein content and weight without augmenting N supplying. PMID:24040315

Over-expression of a tobacco nitrate reductase gene in wheat (Triticum aestivum L.) increases seed protein content and weight without augmenting nitrogen supplying.

PubMed

Zhao, Xiao-Qiang; Nie, Xuan-Li; Xiao, Xing-Guo

2013-01-01

Heavy nitrogen (N) application to gain higher yield of wheat (Triticum aestivum L.) resulted in increased production cost and environment pollution. How to diminish the N supply without losing yield and/or quality remains a challenge. To meet the challenge, we integrated and expressed a tobacco nitrate reductase gene (NR) in transgenic wheat. The 35S-NR gene was transferred into two winter cultivars, "Nongda146" and "Jimai6358", by Agrobacterium-mediation. Over-expression of the transgene remarkably enhanced T1 foliar NR activity and significantly augmented T2 seed protein content and 1000-grain weight in 63.8% and 68.1% of T1 offspring (total 67 individuals analyzed), respectively. Our results suggest that constitutive expression of foreign nitrate reductase gene(s) in wheat might improve nitrogen use efficiency and thus make it possible to increase seed protein content and weight without augmenting N supplying.

Production of high docosahexaenoic acid by Schizochytrium sp. using low-cost raw materials from food industry.

PubMed

Song, Xiaojin; Zang, Xiaonan; Zhang, Xuecheng

2015-01-01

The low-cost substrates from food industry, including maize starch hydrolysate and soybean meal hydrolysate, were used to produce docosahexaenoic acid (DHA) by Schizochytrium limacinum OUC88. Glucose derived from maize starch hydrolysate was used as the carbon source and soybean meal hydrolysate as the nitrogen sources. In 10L bioreactor fermentation, by using the soybean meal hydrolysate as the main nitrogen source, the biomass of Schizochytrium limacinum OUC88 reached 85.27 g L(-1), and the yields of DHA was 20.7g L(-1). As a comparison, when yeast extract was used as the main nitrogen source, the yields of biomass and DHA were 68.93 g L(-1) and 13.3 g L(-1), respectively. From the results of this study, these hydrolysates can provide all the nutrients required for high-density cultivation of S. limacinum OUC88 and DHA production, that will improve the economical and competitive efficiency of commercial DHA production.

Highly Efficient Red-Emitting Carbon Dots with Gram-Scale Yield for Bioimaging.

PubMed

Ding, Hui; Wei, Ji-Shi; Zhong, Ning; Gao, Qing-Yu; Xiong, Huan-Ming

2017-11-07

Carbon dots (CDs) are a new class of photoluminescent (PL), biocompatible, environment-friendly, and low-cost carbon nanomaterials. Synthesis of highly efficient red-emitting carbon dots (R-CDs) on a gram scale is a great challenge at present, which heavily restricts the wide applications of CDs in the bioimaging field. Herein, R-CDs with a high quantum yield (QY) of 53% are produced on a gram scale by heating a formamide solution of citric acid and ethylenediamine. The as-prepared R-CDs have an average size of 4.1 nm and a nitrogen content of about 30%, with an excitation-independent emission at 627 nm. After detailed characterizations, such strong red fluorescence is ascribed to the contribution from the nitrogen- and oxygen-related surface states and the nitrogen-derived structures in the R-CD cores. Our R-CDs show good photostability and low cytotoxicity, and thus they are excellent red fluorescence probes for bioimaging both in vitro and in vivo.

Water regime-nitrogen fertilizer incorporation interaction: Field study on methane and nitrous oxide emissions from a rice agroecosystem in Harbin, China.

PubMed

Dong, Wenjun; Guo, Jia; Xu, Lijun; Song, Zhifeng; Zhang, Jun; Tang, Ao; Zhang, Xijuan; Leng, Chunxu; Liu, Youhong; Wang, Lianmin; Wang, Lizhi; Yu, Yang; Yang, Zhongliang; Yu, Yilei; Meng, Ying; Lai, Yongcai

2018-02-01

Water regime and nitrogen (N) fertilizer are two important factors impacting greenhouse gases (GHG) emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane (CH 4 ) emission compared with continuous flooding, however, the decrement was far lower than the global average level. The N 2 O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH 4 emissions at low level (75kgN/ha). But both CH 4 and N 2 O emissions were uninfluenced at the levels of 150kgN/ha and 225kgN/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150kgN/ha. From our results, we recommended that the intermittent irrigation and 150kgN/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields. Copyright © 2017. Published by Elsevier B.V.

Nutrient export from watersheds on Mt. Desert Island, maine, as a function of land use and fire history

USGS Publications Warehouse

Nielsen, M.G.; Kahl, J.S.

2007-01-01

A study of 13 small (less than 7.5 km2) watersheds on Mt. Desert Island, Maine, was conducted from January 1999 to September 2000 to determine nutrient export delivery to coastal waters around the island, and to determine whether a series of wildfires in 1947 have affected nutrient export in burned watersheds. Nutrient export (nitrate-nitrogen, total nitrogen, total phosphorus) was determined for each watershed during the study period, and was normalized by watershed area. The yield of nitrate-nitrogen (N) ranged from 10 to 140 kg/km2/year. Total N yield ranged from 42 to 250 kg/ km2/year. Total phosphorus (P) yield ranged from 1.4 to 7.9 kg/km2/year. Watersheds entirely within Acadia National Park (lacking human land-based nutrient sources) exported significantly less total N and total P than watersheds that were partly or entirely outside the park boundary. Nitrate-N export was not significantly different in these two groups of watersheds, perhaps because atmospheric deposition is a dominant source of nitrate in the study area. No relation was observed between burn history and nutrient export. Any effect of burn history may be masked by other landscape-level factors related to nutrient export. ?? Springer Science + Business Media B.V. 2007.

Nitrogen management challenges in major watersheds of South America

NASA Astrophysics Data System (ADS)

Bustamante, Mercedes M. C.; Martinelli, Luiz Antonio; Pérez, Tibisay; Rasse, Rafael; Ometto, Jean Pierre H. B.; Siqueira Pacheco, Felipe; Rafaela Machado Lins, Silvia; Marquina, Sorena

2015-06-01

Urbanization and land use changes alter the nitrogen (N) cycle, with critical consequences for continental freshwater resources, coastal zones, and human health. Sewage and poor watershed management lead to impoverishment of inland water resources and degradation of coastal zones. Here we review the N contents of rivers of the three most important watersheds in South America: the Amazon, La Plata, and Orinoco basins. To evaluate potential impacts on coastal zones, we also present data on small- and medium-sized Venezuelan watersheds that drain into the Caribbean Sea and are impacted by anthropogenic activities. Median concentrations of total dissolved nitrogen (TDN) were 325 μg L-1 and 275 μg L-1 in the Amazon and Orinoco basins, respectively, increasing to nearly 850 μg L-1 in La Plata Basin rivers and 2000 μg L-1 in small northern Venezuelan watersheds. The median TDN yield of Amazon Basin rivers (approximately 4 kg ha-1 yr-1) was larger than TDN yields of undisturbed rivers of the La Plata and Orinoco basins; however, TDN yields of polluted rivers were much higher than those of the Amazon and Orinoco rivers. Organic matter loads from natural and anthropogenic sources in rivers of South America strongly influence the N dynamics of this region.

Assessing fertilizer N placement on CH4 and N2O emissions in irrigated rice systems

USDA-ARS?s Scientific Manuscript database

Improved N fertilizer management practices can increase rice yields and mitigate global warming potential (GWP). While banding N has been shown to have positive effects on yield and nitrogen use efficiency (NUE), there is little information in how it affects greenhouse gas (GHG) emissions from flood...

Corn grain yield response to stover removal under variable nitrogen, irrigation, and carbon amendments

USDA-ARS?s Scientific Manuscript database

Demand for corn (Zea mays L.) stover either for livestock or cellulosic ethanol production have increased the importance of determining stover removal effects on biomass production. The objectives of this study was to evaluate yield response and N use from continuous stover removal under two irriga...

Enhanced electron yield from laser-driven wakefield acceleration in high-Z gas jets.

PubMed

Mirzaie, Mohammad; Hafz, Nasr A M; Li, Song; Liu, Feng; He, Fei; Cheng, Ya; Zhang, Jie

2015-10-01

An investigation of the electron beam yield (charge) form helium, nitrogen, and neon gas jet plasmas in a typical laser-plasma wakefield acceleration experiment is carried out. The charge measurement is made by imaging the electron beam intensity profile on a fluorescent screen into a charge coupled device which was cross-calibrated with an integrated current transformer. The dependence of electron beam charge on the laser and plasma conditions for the aforementioned gases are studied. We found that laser-driven wakefield acceleration in low Z-gas jet targets usually generates high-quality and well-collimated electron beams with modest yields at the level of 10-100 pC. On the other hand, filamentary electron beams which are observed from high-Z gases at higher densities reached much higher yields. Evidences for cluster formation were clearly observed in the nitrogen gas jet target, where we received the highest electron beam charge of ∼1.7 nC. Those intense electron beams will be beneficial for the applications on the generation of bright X-rays, gamma rays radiations, and energetic positrons via the bremsstrahlung or inverse-scattering processes.

Formulation of a minimal nutritional medium for enhanced lipid productivity in Chlorella sp. and Botryococcus sp. using response surface methodology.

PubMed

Vishwakarma, Rashi; Dhar, Dolly Wattal; Pabbi, Sunil

2018-03-01

Chlorella sp. MCC 7 and Botryococcus sp. MCC 31 were investigated to enable large-scale biodiesel production from minimal constituents in the growth medium. Response surface methodology (RSM) was used to maximise the biomass productivity and lipid yield using only nitrogen (N), phosphorus (P) and potassium (K) as urea, single super phosphate and muriate of potash. The optimum values were 0.42 g/L nitrogen; 0.14 g/L phosphorus and 0.22 g/L potassium for Chlorella sp.; and 0.46 g/L; 0.14 g/L and 0.25 g/L for Botryococcus sp. Lipid yield of 42% for Chlorella sp. and 52% in Botryococcus sp. was observed. An enhancement in lipid yield by approximately 55% for Chlorella sp. and 73% for Botryococcus sp. was registered as compared to original nutrient medium. Fourier transform infrared (FTIR) analysis of extracted lipids revealed characteristic bands for triglycerides. This study provided utilisation of a practicable nutrient recipe in the form of N, P, K input for enhanced lipid yield from the selected microalgal strains.

Response of a Circular Tunnel Through Rock to a Harmonic Rayleigh Wave

NASA Astrophysics Data System (ADS)

Kung, Chien-Lun; Wang, Tai-Tien; Chen, Cheng-Hsun; Huang, Tsan-Hwei

2018-02-01

A factor that combines tunnel depth and incident wavelength has been numerically determined to dominate the seismic responses of a tunnel in rocks that are subjected to harmonic P- and S-waves. This study applies the dynamic finite element method to investigate the seismic response of shallow overburden tunnels. Seismically induced stress increments in the lining of a circular tunnel that is subjected to an incident harmonic R-wave are examined. The determination of R-wave considers the dominant frequency of acceleration history of the 1999 Chi-Chi earthquake measured near the site with damage to two case tunnels at specifically shallow depth. An analysis reveals that the normalized seismically induced axial, shear and flexural stress increments in the lining of a tunnel reach their respective peaks at the depth h/ λ = 0.15, where the ground motion that is generated by an incident of R-wave has its maximum. The tunnel radius has a stronger effect on seismically induced stress increments than does tunnel depth. A greater tunnel radius yields higher normalized seismically induced axial stress increments and lower normalized seismically induced shear and flexural stress increments. The inertia of the thin overburden layer above the tunnel impedes the propagation of the wave and affects the motion of the ground around the tunnel. With an extremely shallow overburden, such an effect can change the envelope of the normalized seismically induced stress increments from one with a symmetric four-petal pattern into one with a non-symmetric three-petal pattern. The simulated results may partially elucidate the spatial distributions of cracks that were observed in the lining of the case tunnels.

[Nitrogen flow in Huizhou region].

PubMed

Ma, Xiaobo; Wang, Zhaoyin; Koenig, Albert; Deng, Jiaquan

2006-06-01

Eutrophication is a serious problem of water body pollution. By the method of material flow accounting, this paper studied the human activities- related nitrogen flow in the system of environment and anthroposphere in Huizhou region. The non-point source pollution was quantified by export coefficient method, and the domestic discharge was estimated by demand-supply method. The statistic and dynamic analyses based on the investigation data of 1998 showed that the major nitrogen flows in this region were river loads, fertilizer and feedstuff imports, atmospheric deposition, animal excretes' degradation and volatilization, and the processes relating to burning and other emissions. In 1998, about 40% of nitrogen was detained in the system, which could be accumulated and yield potential environmental problems. The nitrogen export in this region was mainly by rivers, accounted for about 57%. A comparison of Huizhou region with the Danube and Changjiang basins showed that the unit area nitrogen exports in these three regions were of the same magnitude, and the per capita nitrogen exports were comparable.

Cereal area and nitrogen use efficiency are drivers of future nitrogen fertilizer consumption.

PubMed

Dobermann, Achim; Cassman, Kenneth G

2005-09-01

At a global scale, cereal yields and fertilizer N consumption have increased in a near-linear fashion during the past 40 years and are highly correlated with one another. However, large differences exist in historical trends of N fertilizer usage and nitrogen use efficiency (NUE) among regions, countries, and crops. The reasons for these differences must be understood to estimate future N fertilizer requirements. Global nitrogen needs will depend on: (i) changes in cropped cereal area and the associated yield increases required to meet increasing cereal demand from population and income growth, and (ii) changes in NUE at the farm level. Our analysis indicates that the anticipated 38% increase in global cereal demand by 2025 can be met by a 30% increase in N use on cereals, provided that the steady decline in cereal harvest area is halted and the yield response to applied N can be increased by 20%. If losses of cereal cropping area continue at the rate of the past 20 years (-0.33% per year) and NUE cannot be increased substantially, a 60% increase in global N use on cereals would be required to meet cereal demand. Interventions to increase NUE and reduce N losses to the environment must be accomplished at the farm-or field-scale through a combination of improved technologies and carefully crafted local policies that contribute to the adoption of improved N management; uniform regional or national directives are unlikely to be effective at both sustaining yield increases and improving NUE. Examples from several countries show that increases in NUE at rates of 1% per year or more can be achieved if adequate investments are made in research and extension. Failure to arrest the decrease in cereal crop area and to improve NUE in the world's most important agricultural systems will likely cause severe damage to environmental services at local, regional, and global scales due to a large increase in reactive N load in the environment.

Cereal area and nitrogen use efficiency are drivers of future nitrogen fertilizer consumption.

PubMed

Dobermann, Achim; Cassman, Kenneth G

2005-12-01

At a global scale, cereal yields and fertilizer N consumption have increased in a near-linear fashion during the past 40 years and are highly correlated with one another. However, large differences exist in historical trends of N fertilizer usage and nitrogen use efficiency (NUE) among regions, countries, and crops. The reasons for these differences must be understood to estimate future N fertilizer requirements. Global nitrogen needs will depend on: (i) changes in cropped cereal area and the associated yield increases required to meet increasing cereal demand from population and income growth, and (ii) changes in NUE at the farm level. Our analysis indicates that the anticipated 38% increase in global cereal demand by 2025 can be met by a 30% increase in N use on cereals, provided that the steady decline in cereal harvest area is halted and the yield response to applied N can be increased by 20%. If losses of cereal cropping area continue at the rate of the past 20 years (-0.33% per year) and NUE cannot be increased substantially, a 60% increase in global N use on cereals would be required to meet cereal demand. Interventions to increase NUE and reduce N losses to the environment must be accomplished at the farm- or field-scale through a combination of improved technologies and carefully crafted local policies that contribute to the adoption of improved N management; uniform regional or national directives are unlikey to be effective at both sustaining yield increases and improving NUE. Examples from several countries show that increases in NUE at rates of 1% per year or more can be achieved if adequate investments are made in research and extension. Failure to arrest the decrease in cereal crop area and to improve NUE in the world's most important agricultural systems will likely cause severe damage to environmental services at local, regional, and global scales due to a large increase in reactive N load in the environment.

Surface-Water Quality and Nutrient Loads in the Nepaug Reservoir Watershed, Northwestern Connecticut, 1999-2001

USGS Publications Warehouse

Morrison, Jonathan; Colombo, Michael J.

2006-01-01

Water quality was characterized at three tributary watersheds to the Nepaug Reservoir-Nepaug River, Phelps Brook, and Clear Brook-from October 1998 through September 2001 to document existing water-quality conditions and evaluate potential future effects of the removal of sand and gravel from areas of the watershed. Some removal operations may include removal of vegetation and top soil and steepening of slopes. Routine water samples collected monthly in all three watersheds were analyzed for nutrients, organic carbon, major ions, and fecal indicator bacteria. Results of the analyses indicate that, in general, the water quality in all three tributary watersheds is good and meets standards established for drinking-water supplies for nitrate, but does not always meet contact-recreation standards for bacteria. Median concentrations of total nitrogen, total phosphorus, and total organic carbon were highest in the routine monthly samples from Phelps Brook and lowest from Clear Brook. Samples also were collected during selected storms to examine changes in concentrations of nutrients during periods of high streamflow. The maximum values measured for total nitrogen, total phosphorus, and total organic carbon were in storm samples from Clear Brook. The Nepaug River watershed delivered the largest loads of total nitrogen, total phosphorus, and total organic carbon to the reservoir. Yields of nutrients and organic carbon differed significantly from year to year and among the three watersheds. Yields of total nitrogen and total organic carbon were largest from Phelps Brook and smallest from Clear Brook. The yields of total phosphorus were largest from Nepaug River and smallest from Phelps Brook. In comparison to other watersheds in Connecticut, annual loads and yields from the three streams were lower than those of developed urban areas and comparable to those of other rural and forested basins. Delivery of nutrients and organic carbon to the reservoir took place mostly during the spring with the exception of those constituents delivered during Tropical Storm Floyd, a large fall storm.

Improvement of nitrogen utilization and soil properties by addition of a mineral soil conditioner: mechanism and performance.

PubMed

Yan, Xiaodan; Shi, Lin; Cai, Rumeng

2018-01-01

A mineral soil conditioner (MSC) composed of activated potash feldspar, gypsum, and calcium carbonate and containing an amount of available mineral nutrients, is shown to be effective for plant growth and acidic soil amelioration. In this study, a field test was conducted over four rice seasons by examining treatment with control check (CK), MSC, biological active carbon, and lime to investigate the nitrogen-use efficiency and mechanism of soil characteristic variations due to the desilicification and allitization of soil as well as the unrestrained use of nitrogen (N) fertilizer in recent years. Influences of MSC on the xylem sap intensity and mean rice yields were evaluated, and the soil type was also analyzed using the FactSage 6.1 Reaction, phase diagram, and Equilib modules. The results of the field trial showed that MSC application increased the xylem sap intensity and nitrogen export intensity by 37.33-39.85% and 31.40-51.20%, respectively. A significant increase (5.63-15.48%) in mean grain yields was achieved with MSC application over that with biological active carbon and lime application. The effects of MSC had a tendency to increase with time in the field experiment results, and grain yields increased after the initial application. The new formation of clay minerals exhibits a significant influence on [Formula: see text] fixation, especially for 2:1 phyllosilicates with illite, owing to the interlayers of the clay minerals. Our preliminary results showed that kaolinite, the main 1:1 phyllosilicate clay mineral in ferralsol, transformed to illite at room temperature as a consequence of the presence of H 4 SiO 4 and available K + supplied by MSC. This indicated that improving the soil quality combined with reducing N losses from soils is an efficient way to control non-point source pollution from agriculture without the risk of decreased in grain yield.

Targeting the right input data to improve crop modeling at global level

NASA Astrophysics Data System (ADS)

Adam, M.; Robertson, R.; Gbegbelegbe, S.; Jones, J. W.; Boote, K. J.; Asseng, S.

2012-12-01

Designed for location-specific simulations, the use of crop models at a global level raises important questions. Crop models are originally premised on small unit areas where environmental conditions and management practices are considered homogeneous. Specific information describing soils, climate, management, and crop characteristics are used in the calibration process. However, when scaling up for global application, we rely on information derived from geographical information systems and weather generators. To run crop models at broad, we use a modeling platform that assumes a uniformly generated grid cell as a unit area. Specific weather, specific soil and specific management practices for each crop are represented for each of the cell grids. Studies on the impacts of the uncertainties of weather information and climate change on crop yield at a global level have been carried out (Osborne et al, 2007, Nelson et al., 2010, van Bussel et al, 2011). Detailed information on soils and management practices at global level are very scarce but recognized to be of critical importance (Reidsma et al., 2009). Few attempts to assess the impact of their uncertainties on cropping systems performances can be found. The objectives of this study are (i) to determine sensitivities of a crop model to soil and management practices, inputs most relevant to low input rainfed cropping systems, and (ii) to define hotspots of sensitivity according to the input data. We ran DSSAT v4.5 globally (CERES-CROPSIM) to simulate wheat yields at 45arc-minute resolution. Cultivar parameters were calibrated and validated for different mega-environments (results not shown). The model was run for nitrogen-limited production systems. This setting was chosen as the most representative to simulate actual yield (especially for low-input rainfed agricultural systems) and assumes crop growth to be free of any pest and diseases damages. We conducted a sensitivity analysis on contrasting management practices, initial soil conditions, and soil characteristics information. Management practices were represented by planting date and the amount of fertilizer, initial conditions estimates for initial nitrogen, soil water, and stable soil carbon, and soil information is based on a simplified version of the WISE database, characterized by soil organic matter, texture and soil depth. We considered these factors as the most important determinants of nutrient supply to crops during their growing season. Our first global results demonstrate that the model is most sensitive to the initial conditions in terms of soil carbon and nitrogen (CN): wheat yields decreased by 45% when soil CN is null and increase by 15% when twice the soil CN content of the reference run is used. The yields did not appear to be very sensitive to initial soil water conditions, varying from 0% yield increase when initial soil water is set to wilting point to 6% yield increase when it was set to field capacity. They are slightly sensitive to nitrogen application: 8% yield decrease when no N is applied to 9% yield increase when 150 kg.ha-1 is applied. However, with closer examination of results, the model is more sensitive to nitrogen application than to initial soil CN content in Vietnam, Thailand and Japan compared to the rest of the world. More analyses per region and results on the planting dates and soil properties will be presented.

Evolution of US maize (Zea mays L.) root architectural and anatomical phenes over the past 100 years corresponds to increased tolerance of nitrogen stress

PubMed Central

York, Larry M.; Galindo-Castañeda, Tania; Schussler, Jeffrey R.; Lynch, Jonathan P.

2015-01-01

Increasing the nitrogen use efficiency of maize is an important goal for food security and agricultural sustainability. In the past 100 years, maize breeding has focused on yield and above-ground phenes. Over this period, maize cultivation has changed from low fertilizer inputs and low population densities to intensive fertilization and dense populations. The authors hypothesized that through indirect selection the maize root system has evolved phenotypes suited to more intense competition for nitrogen. Sixteen maize varieties representing commercially successful lines over the past century were planted at two nitrogen levels and three planting densities. Root systems of the most recent material were 7 º more shallow, had one less nodal root per whorl, had double the distance from nodal root emergence to lateral branching, and had 14% more metaxylem vessels, but total mextaxylem vessel area remained unchanged because individual metaxylem vessels had 12% less area. Plasticity was also observed in cortical phenes such as aerenchyma, which increased at greater population densities. Simulation modelling with SimRoot demonstrated that even these relatively small changes in root architecture and anatomy could increase maize shoot growth by 16% in a high density and high nitrogen environment. The authors concluded that evolution of maize root phenotypes over the past century is consistent with increasing nitrogen use efficiency. Introgression of more contrasting root phene states into the germplasm of elite maize and determination of the functional utility of these phene states in multiple agronomic conditions could contribute to future yield gains. PMID:25795737

Production mechanism of atomic nitrogen in atmospheric pressure pulsed corona discharge measured using two-photon absorption laser-induced fluorescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teramoto, Yoshiyuki; Ono, Ryo; Oda, Tetsuji

To study the production mechanism of atomic nitrogen, the temporal profile and spatial distribution of atomic nitrogen are measured in atmospheric pressure pulsed positive corona discharge using two-photon absorption laser-induced fluorescence. The absolute atomic nitrogen density in the streamer filaments is estimated from decay rate of atomic nitrogen in N{sub 2} discharge. The results indicate that the absolute atomic nitrogen density is approximately constant against discharge energy. When the discharge voltage is 21.5 kV, production yield of atomic nitrogen produced by an N{sub 2} discharge pulse is estimated to be 2.9 - 9.8 Multiplication-Sign 10{sup 13} atoms and the energymore » efficiency of atomic nitrogen production is estimated to be about 1.8 - 6.1 Multiplication-Sign 10{sup 16} atoms/J. The energy efficiency of atomic nitrogen production in N{sub 2} discharge is constant against the discharge energy, while that in N{sub 2}/O{sub 2} discharge increases with discharge energy. In the N{sub 2}/O{sub 2} discharge, two-step process of N{sub 2} dissociation plays significant role for atomic nitrogen production.« less

Improving rice models for more reliable prediction of responses of rice yield to CO2 and temperature elevaton

USDA-ARS?s Scientific Manuscript database

Materials and Methods The simulation exercise and model improvement were implemented in phase-wise. In the first modelling activities, the model sensitivities were evaluated to given CO2 concentrations varying from 360 to 720 'mol mol-1 at an interval of 90 'mol mol-1 and air temperature increments...

NONLINEAR AND FIBER OPTICS: Stimulated scattering of electromagnetic radiation in thermodynamic-nonequilibrium media

NASA Astrophysics Data System (ADS)

Blinov, N. A.; Zolotkov, V. N.; Lezin, A. Yu; Cheburkin, N. V.

1990-04-01

An analysis is made of transient stimulated scattering in a vibrationally nonequilibrium gas excited by a non-self-sustained discharge. A stability theory approach is used to describe the behavior of perturbation wave packets, yielding asymptotic expressions for the maximal increments of an instability of stimulated small-angle scattering by entropic and acoustic modes.

The effects of intensity on V̇O2 kinetics during incremental free swimming.

PubMed

de Jesus, Kelly; Sousa, Ana; de Jesus, Karla; Ribeiro, João; Machado, Leandro; Rodríguez, Ferran; Keskinen, Kari; Vilas-Boas, João Paulo; Fernandes, Ricardo J

2015-09-01

Swimming and training are carried out with wide variability in distances and intensities. However, oxygen uptake kinetics for the intensities seen in swimming has not been reported. The purpose of this study was to assess and compare the oxygen uptake kinetics throughout low-moderate to severe intensities during incremental swimming exercise. We hypothesized that the oxygen uptake kinetic parameters would be affected by swimming intensity. Twenty male trained swimmers completed an incremental protocol of seven 200-m crawl swims to exhaustion (0.05 m·s(-1) increments and 30-s intervals). Oxygen uptake was continuously measured by a portable gas analyzer connected to a respiratory snorkel and valve system. Oxygen uptake kinetics was assessed using a double exponential regression model that yielded both fast and slow components of the response of oxygen uptake to exercise. From low-moderate to severe swimming intensities changes occurred for the first and second oxygen uptake amplitudes (P ≤ 0.04), time constants (P = 0.01), and time delays (P ≤ 0.02). At the heavy and severe intensities, a notable oxygen uptake slow component (>255 mL·min(-1)) occurred in all swimmers. Oxygen uptake kinetics whilst swimming at different intensities offers relevant information regarding cardiorespiratory and metabolic stress that might be useful for appropriate performance diagnosis and training prescription.

Benefits of biochar, compost and biochar-compost for soil quality, maize yield and greenhouse gas emissions in a tropical agricultural soil.

PubMed

Agegnehu, Getachew; Bass, Adrian M; Nelson, Paul N; Bird, Michael I

2016-02-01

Soil quality decline represents a significant constraint on the productivity and sustainability of agriculture in the tropics. In this study, the influence of biochar, compost and mixtures of the two on soil fertility, maize yield and greenhouse gas (GHG) emissions was investigated in a tropical Ferralsol. The treatments were: 1) control with business as usual fertilizer (F); 2) 10 t ha(-1) biochar (B)+F; 3) 25 t ha(-1) compost (Com)+F; 4) 2.5 t ha(-1) B+25 t ha(-1) Com mixed on site+F; and 5) 25 t ha(-1) co-composted biochar-compost (COMBI)+F. Total aboveground biomass and maize yield were significantly improved relative to the control for all organic amendments, with increases in grain yield between 10 and 29%. Some plant parameters such as leaf chlorophyll were significantly increased by the organic treatments. Significant differences were observed among treatments for the δ(15)N and δ(13)C contents of kernels. Soil physicochemical properties including soil water content (SWC), total soil organic carbon (SOC), total nitrogen (N), available phosphorus (P), nitrate-nitrogen (NO3(-)N), ammonium-nitrogen (NH4(+)-N), exchangeable cations and cation exchange capacity (CEC) were significantly increased by the organic amendments. Maize grain yield was correlated positively with total biomass, leaf chlorophyll, foliar N and P content, SOC and SWC. Emissions of CO2 and N2O were higher from the organic-amended soils than from the fertilizer-only control. However, N2O emissions generally decreased over time for all treatments and emission from the biochar was lower compared to other treatments. Our study concludes that the biochar and biochar-compost-based soil management approaches can improve SOC, soil nutrient status and SWC, and maize yield and may help mitigate greenhouse gas emissions in certain systems. Copyright © 2015. Published by Elsevier B.V.

Specific and total N-nitrosamines formation potentials of nitrogenous micropollutants during chloramination.

PubMed

Piazzoli, Andrea; Breider, Florian; Aquillon, Caroline Gachet; Antonelli, Manuela; von Gunten, Urs

2018-05-15

N-nitrosamines are a group of potent human carcinogens that can be formed during oxidative treatment of drinking water and wastewater. Many tertiary and quaternary amines present in consumer products (e.g., pharmaceuticals, personal care and household products) are known to be N-nitrosodimethylamine (NDMA) precursors during chloramination, but the formation of other N-nitrosamines has been rarely studied. This study investigates the specific and total N-nitrosamine (TONO) formation potential (FP) of various precursors from nitrogen-containing micropollutants (chlorhexidine, metformin, benzalkonium chloride and cetyltrimethylammonium chloride) and tertiary and quaternary model amines (trimethyl amine, N,N-dimethylbutyl amine, N,N-dimethylbenzyl amine and tetramethyl ammonium). All the studied nitrogenous micropollutants displayed quantifiable TONO FP, with molar yields in the range 0.04-11.92%. However, the observed TONO pools constituted mostly of uncharacterized species, not included in US-EPA 8270 N-nitrosamines standard mix. Only the quaternary ammonium compound benzalkonium chloride showed quantifiable NDMA FP (0.56% molar yield), however, explaining only a minor fraction of the observed TONO FP. The studied model amines showed molar NDMA yields from 0.10% (trimethyl amine) to 5.05% (N,N-dimethylbenzyl amine), very similar to the molar TONO yields. The comparison of the FPs of micropollutants and model compounds showed that the presence of electron donating functional groups (such as a benzyl group) in tertiary and quaternary amine precursors leads to a higher formation of NDMA and uncharacterized N-nitrosamines, respectively. LC-qTOF screening of a list of proposed N-nitrosamine structures has enabled to identify a novel N-nitrosamine (N-nitroso-N-methyldodecylamine) from the chloramination of benzalkonium chloride. This finding supports the hypothesis that different functional groups in quaternary amines can act as leaving groups during chloramination and form differing N-nitrosamine structures at significant yield. Molar TONO yields determined for micropollutants were finally validated under experimental conditions closer to real water matrices, confirming their representativeness also for lower concentration ranges. Copyright © 2018 Elsevier Ltd. All rights reserved.

Curing preceramic polymers by exposure to nitrogen dioxide

NASA Technical Reports Server (NTRS)

Rabe, James A. (Inventor); Lipowitz, Jonathan (Inventor); Lu, Paul P. (Inventor)

1991-01-01

A rapid method of infusibilizing (curing) preceramic polymers comprising treatment said polymers with gaseous nitrogen dioxide. The infusibilized polymers may be pyrolyzed to temperatures in excess of about 800.degree. C. to yield ceramic materials with low oxygen content and, thus, good thermal stability. The methods are especially useful for the production of ceramic fibers and, more specifically, to the on-line production of ceramic fibers.

Stand Density Effects on Biomass Allocation Patterns and Subsequent Soil Nitrogen Demand

Treesearch

Christopher A. Dicus; Thomas J. Dean

1998-01-01

Growth and yield data from a loblolly pine plantation in southeastern Louisiana were obtained yearly from 1993 to 1996 on numbered trees within two stands initially planted on a 1.22- by 1.22-meter spacing, and two stands planted on a 2.44- by 2.44-meter spacing. Using allometric equations derived from a 1994 on-site destructive harvest, cited nitrogen...

Results from the Big Spring basin water quality monitoring and demonstration projects, Iowa, USA

USGS Publications Warehouse

Rowden, R.D.; Liu, H.; Libra, R.D.

2001-01-01

Agricultural practices, hydrology, and water quality of the 267-km2 Big Spring groundwater drainage basin in Clayton County, Iowa, have been monitored since 1981. Land use is agricultural; nitrate-nitrogen (-N) and herbicides are the resulting contaminants in groundwater and surface water. Ordovician Galena Group carbonate rocks comprise the main aquifer in the basin. Recharge to this karstic aquifer is by infiltration, augmented by sinkhole-captured runoff. Groundwater is discharged at Big Spring, where quantity and quality of the discharge are monitored. Monitoring has shown a threefold increase in groundwater nitrate-N concentrations from the 1960s to the early 1980s. The nitrate-N discharged from the basin typically is equivalent to over one-third of the nitrogen fertilizer applied, with larger losses during wetter years. Atrazine is present in groundwater all year; however, contaminant concentrations in the groundwater respond directly to recharge events, and unique chemical signatures of infiltration versus runoff recharge are detectable in the discharge from Big Spring. Education and demonstration efforts have reduced nitrogen fertilizer application rates by one-third since 1981. Relating declines in nitrate and pesticide concentrations to inputs of nitrogen fertilizer and pesticides at Big Spring is problematic. Annual recharge has varied five-fold during monitoring, overshadowing any water-quality improvements resulting from incrementally decreased inputs. ?? Springer-Verlag 2001.

Concentrations, loads, and yields of nutrients and suspended sediment in the South Pacolet, North Pacolet, and Pacolet Rivers, northern South Carolina and southwestern North Carolina, October 2005 to September 2009

USGS Publications Warehouse

Journey, Celeste A.; Caldwell, Andral W.; Feaster, Toby D.; Petkewich, Mattew D.; Bradley, Paul M.

2011-01-01

The U.S. Geological Survey, in cooperation with Spartanburg Water, evaluated the concentrations, loads, and yields of suspended sediment, dissolved ammonia, dissolved nitrate plus nitrite, total organic nitrogen, total nitrogen, dissolved orthophosphate, dissolved phosphorus, and total phosphorus at sites in the South Pacolet, North Pacolet, and Pacolet Rivers in northern South Carolina and southwestern North Carolina from October 1, 2005, to September 30, 2009 (water years 2006 to 2009). Nutrient and sediment loads and yields also were computed for the intervening subbasin of the Pacolet River not represented by the South and North Pacolet River Basins. Except for a few outliers, the majority of the measurements of total nitrogen concentrations were well below the U.S. Environmental Protection Agency recommended guideline of 0.69 milligram per liter for streams and rivers in the nutrient ecoregion IX, which includes the study area within the Pacolet River Basin. Dissolved orthophosphate, dissolved phosphorus, and total phosphorus concentrations were significantly lower at the South Pacolet River site compared to the North Pacolet and Pacolet River sites. About 90 percent of the total phosphorus concentrations at the South Pacolet River site were below the U.S. Environmental Protection Agency recommended guideline of 0.37 milligram per liter, and more than 75 percent of the total phosphorus concentrations at the North Pacolet and Pacolet River sites were above that guideline. At all sites, minimum annual nutrient loads for the estimation period were observed during water year 2008 when severe drought conditions were present. An estimated mean annual total nitrogen load of 37,770 kilograms per year and yield of 2.63 kilograms per hectare per year were determined for the South Pacolet River site for the estimation period. The North Pacolet River site had a mean annual total nitrogen load of 65,890 kilograms per year and yield of 2.19 kilograms per hectare per year. The Pacolet River had a mean annual total nitrogen load of 99,780 kilograms per year and yield of 1.82 kilograms per hectare per year. Mean annual total phosphorus loads of 2,576; 9,404; and 11,710 kilograms per year and yields of 0.180, 0.313, and 0.213 kilograms per hectare per year were estimated at the South Pacolet, North Pacolet, and Pacolet River sites, respectively. Annually, the intervening subbasin of the Pacolet River contributed negligible amounts of total nitrogen and total phosphorus loads, and large losses of dissolved nitrate plus nitrite and orthophosphate loads were determined for the subbasin. Biological (algal) uptake in the two reservoirs in this intervening area was considered the likely explanation for the loss of these constituents. Estimated mean annual suspended-sediment loads were 21,190,000; 9,895,000; and 6,547,000 kilograms per year at the South Pacolet, North Pacolet, and Pacolet River sites, respectively. In the intervening Pacolet River subbasin, computed annual suspended-sediment loads were consistently negative, indicating large percentage losses in annual suspended-sediment load. Sedimentation processes in the two reservoirs are the most likely explanations for these apparent losses. At all sites, the winter season tended to have the highest estimated seasonal dissolved orthophosphate and dissolved nitrate plus nitrite fluxes, and the summer and fall seasons tended to have the lowest fluxes. The reverse pattern, however, was observed in the intervening drainage area in the Pacolet River where the lowest fluxes of dissolved orthophosphate and nitrate plus nitrite occurred during the winter and spring seasons and the highest occurred during the summer and fall seasons. Synoptic samples were collected during a high-flow event in August 2009 at eight sites that represented shoreline and minor tributary drainages. The South Pacolet River site was identified as contributing greater than 80 percent of the cumulative nutrient and sediment l

Experimental Investigation of two-phase nitrogen Cryo transfer line

NASA Astrophysics Data System (ADS)

Singh, G. K.; Nimavat, H.; Panchal, R.; Garg, A.; Srikanth, GLN; Patel, K.; Shah, P.; Tanna, V. L.; Pradhan, S.

2017-02-01

A 6-m long liquid nitrogen based cryo transfer line has been designed, developed and tested at IPR. The test objectives include the thermo-hydraulic characteristics of Cryo transfer line under single phase as well as two phase flow conditions. It is always easy in experimentation to investigate the thermo-hydraulic parameters in case of single phase flow of cryogen but it is real challenge when one deals with the two phase flow of cryogen due to availibity of mass flow measurements (direct) under two phase flow conditions. Established models have been reported in the literature where one of the well-known model of Lockhart-Martenelli relationship has been used to determine the value of quality at the outlet of Cryo transfer line. Under homogenous flow conditions, by taking the ratio of the single-phase pressure drop and the two-phase pressure drop, we estimated the quality at the outlet. Based on these equations, vapor quality at the outlet of the transfer line was predicted at different heat loads. Experimental rresults shown that from inlet to outlet, there is a considerable increment in the pressure drop and vapour quality of the outlet depending upon heat load and mass flow rate of nitrogen flowing through the line.

Incremental sanitation improvement strategy: comparison of options for Hanoi, Vietnam.

PubMed

Harada, H; Matsui, S; Dong, N T; Shimizu, Y; Fujii, S

2010-01-01

Urban sanitation issues should be tackled strategically, and may be addressed effectively when sewage development is pursued in conjunction with complementary sanitation measures. Five sanitation improvement scenarios employing sewage, night-soil collection-and-treatment (NSCT) system, and/or septic-tank improvement by annual dislodging were analyzed from the perspective of COD loads, total nitrogen loads, and cost under the conditions found in Hanoi, Vietnam. Compared to the development of sewage alone, the scenario of developing NSCT systems in a complementary manner with sewage development was estimated to be the most effective for a rapid decrease of both COD and total nitrogen loads. However, it may be difficult in some cases to replace ordinary water-flush toilet by the micro-flush toilet that are used in NSCT systems. In this case, the scenario employing septic-tank improvement in conjunction with sewage development may be effective for a rapid decrease of COD in locations where septic tanks are widely used under poor maintenance conditions and nitrogen pollution is not serious compared to COD. It was calculated that the two scenarios above would respectively require cost increases of 16 and 22% over the sewage development scenario.

Production of polyhydroxybutyrate by the marine photosynthetic bacterium Rhodovulum sulfidophilum P5

NASA Astrophysics Data System (ADS)

Cai, Jinling; Wei, Ying; Zhao, Yupeng; Pan, Guanghua; Wang, Guangce

2012-07-01

The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation (8.10±0.09 g/L) and PHB production (1.11±0.13 g/L and 14.62%±2.2 of the cell dry weight) were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH{4/+}-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration (7.65±0.05 g/L) was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB (5.03±0.18 g/L and 66.93%±1.69% of the cell dry weight) was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation (8.77±0.58 g/L) and PHB production (6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight) was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield.

Variation in Virus Symptom Development and Root Architecture Attributes at the Onset of Storage Root Initiation in ‘Beauregard’ Sweetpotato Plants Grown with or without Nitrogen

PubMed Central

Villordon, Arthur Q.; Clark, Christopher A.

2014-01-01

It has been shown that virus infections, often symptomless, significantly limit sweetpotato productivity, especially in regions characterized by low input agricultural systems. In sweetpotatoes, the successful emergence and development of lateral roots (LRs), the main determinant of root architecture, determines the competency of adventitious roots to undergo storage root initiation. This study aimed to investigate the effect of some plant viruses on root architecture attributes during the onset of storage root initiation in ‘Beauregard’ sweetpotatoes that were grown with or without the presence of nitrogen. In two replicate experiments, virus-tested plants consistently failed to show visible symptoms at 20 days regardless of nitrogen treatment. In both experiments, the severity of symptom development among infected plants ranged from 25 to 118% when compared to the controls (virus tested plants grown in the presence of nitrogen). The presence of a complex of viruses (Sweet potato feathery mottle virus, Sweet potato virus G, Sweet potato virus C, and Sweet potato virus 2) was associated with 51% reduction in adventitious root number among plants grown without nitrogen. The effect of virus treatments on first order LR development depended on the presence or absence of nitrogen. In the presence of nitrogen, only plants infected with Sweet potato chlorotic stunt virus showed reductions in first order LR length, number, and density, which were decreased by 33%, 12%, and 11%, respectively, when compared to the controls. In the absence of nitrogen, virus tested and infected plants manifested significant reductions for all first order LR attributes. These results provide evidence that virus infection directly influences sweetpotato yield potential by reducing both the number of adventitious roots and LR development. These findings provide a framework for understanding how virus infection reduces sweetpotato yield and could lead to the development of novel strategies to mitigate virus effects on sweetpotato productivity. PMID:25243579

Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae.

PubMed

Milne, N; Luttik, M A H; Cueto Rojas, H F; Wahl, A; van Maris, A J A; Pronk, J T; Daran, J M

2015-07-01

In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing chemicals, uptake and assimilation of ammonium requires 1 ATP per incorporated NH3. Urea assimilation by this yeast is more energy efficient but still requires 0.5 ATP per NH3 produced. To decrease ATP costs for nitrogen assimilation, the S. cerevisiae gene encoding ATP-dependent urease (DUR1,2) was replaced by a Schizosaccharomyces pombe gene encoding ATP-independent urease (ure2), along with its accessory genes ureD, ureF and ureG. Since S. pombe ure2 is a Ni(2+)-dependent enzyme and Saccharomyces cerevisiae does not express native Ni(2+)-dependent enzymes, the S. pombe high-affinity nickel-transporter gene (nic1) was also expressed. Expression of the S. pombe genes into dur1,2Δ S. cerevisiae yielded an in vitro ATP-independent urease activity of 0.44±0.01 µmol min(-1) mg protein(-1) and restored growth on urea as sole nitrogen source. Functional expression of the Nic1 transporter was essential for growth on urea at low Ni(2+) concentrations. The maximum specific growth rates of the engineered strain on urea and ammonium were lower than those of a DUR1,2 reference strain. In glucose-limited chemostat cultures with urea as nitrogen source, the engineered strain exhibited an increased release of ammonia and reduced nitrogen content of the biomass. Our results indicate a new strategy for improving yeast-based production of nitrogen-containing chemicals and demonstrate that Ni(2+)-dependent enzymes can be functionally expressed in S. cerevisiae. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland

PubMed Central

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

[Effects of different nitrogen application rates on 15N-urea absorption, utilization, loss and fruit yield and quality of dwarf apple].

PubMed

Chen, Qian; Ding, Ning; Peng, Ling; Ge, Shun Feng; Jiang, Yuan Mao

2017-07-18

Seven-year-old 'Yanfu3'/M 26 /M. hupehensis Rehd. seedlings and 15 N trace technique were used to explore the characteristics of 15 N-urea absorption, utilization, loss and fruit yield and quality under different nitrogen application rates (N 100 , N 200 and N 300 ). The main results were as follows: the plant growth, 15 N absorption, utilization and loss differed significantly under different treatments. The plant leaf chlorophyll content (SPAD value), photosynthetic rate (P n ), total N content of leaves and the biomass, as well as the root-shoot ratio of N 200 treatment were obviously higher than the N 100 and N 300 treatments. Significant differences were observed in the 15 N derived from fertilizer (Ndff value) of different organs under different nitrogen application rates. The Ndff of fruits (flowers), leaves, one-year-old branch, and perennial branches in each measurement period was N 100 >N 200 ＞N 300 , while that of the roots at full-bloom and spring shoot growing slowly stage was N 100 >N 200 ＞N 300 , and in a trend of N 200 >N 100 ＞N 300 at autumn shoot growing stage, fruit rapid-swel-ling stage and fruit maturity stage. At fruit maturity stage, plant 15 N nitrogen utilization ratio of N 200 treatment was 23.6%, which was obviously higher than the N 100 (16.3%) and N 300 (14.4%) treatments, with the 15 N loss rate of 56.4%, obviously lower than the N 100 (60.6%) and N 300 (66.1%) treatments. There were significant differences among the treatments in fruit mass, yield per plant, soluble solid, fruit firmness, soluble sugar, titratable acids and sugar-acid ratio of different nitrogen rates, and the N 200 treatment showed the best performance, followed by the N 300 treatment, and then the N 100 treatment.