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Sample records for legume cover crops

  1. Zinc requirements of tropical legume cover crops

    USDA-ARS?s Scientific Manuscript database

    Tropical soils are deficient in essential plant nutrients, including zinc (Zn). Using cover crops in cropping systems is an important option to improve soil fertility for sustainable crop production. However, success of cover crops in highly weathered tropical infertile acid soils is greatly influen...

  2. Differential Soil Acidity Tolerance of Tropical Legume Cover Crops

    USDA-ARS?s Scientific Manuscript database

    In tropical regions, soil acidity and low soil fertility are the most important yield limiting factors for sustainable crop production. Using legume cover crops as mulch is an important strategy not only to protect the soil loss from erosion but also ameliorating soil fertility. Information is limit...

  3. Growth of tropical legume cover crops as influenced by nitrogen fertilization and Rhizobia

    USDA-ARS?s Scientific Manuscript database

    Tropical legume cover crops are important components in cropping systems due to their role in improving soil quality. Information is limited on the influence of nitrogen (N) fertilization on growth of tropical legume cover crops grown on Oxisols. A greenhouse experiment was conducted to evaluate the...

  4. Evaluation of tropical legume cover crops for copper use efficiency

    USDA-ARS?s Scientific Manuscript database

    Cover crops are important components of cropping systems due to their role in improving soil quality. Lack of adequate levels of soil micronutrients prevent the success of cover crops in highly weathered tropical soils. A greenhouse experiment was conducted with the objective to evaluate copper use ...

  5. Cover crop frequency and compost effects on a legume-rye cover crop during 8 years of organic vegetables

    USDA-ARS?s Scientific Manuscript database

    Organic matter inputs from compost or cover crops (CC) are important to maintain or improve soil quality, but their impact in high-value vegetable production systems are not well understood. Therefore, we evaluated the effects of CC frequency (every winter versus every 4th winter) and yard-waste co...

  6. Photosynthesis in tropical cover crop legumes influenced by irradiance, external carbon dioxide concentration and temperature

    USDA-ARS?s Scientific Manuscript database

    In plantation crops perennial tropical legumes are grown as understory plants, receive limited irradiance, and are subjected to elevated levels of CO2 and temperature. Independent short-term effects of photosynthetic photon flux density (PPFD), external carbon dioxide concentration [CO2] and temper...

  7. Cover crops and N credits

    USDA-ARS?s Scientific Manuscript database

    Cover crops often provide many short- and long-term benefits to cropping systems. Legume cover crops can significantly reduce the N fertilizer requirement of non-legume cash crops that follow. The objectives of this presentation were to: I) educate stakeholders about the potential benefits of cover ...

  8. Legume proportions, poultry litter, and tillage effects on cover crop decomposition

    USDA-ARS?s Scientific Manuscript database

    Hairy vetch (Vicia villosa Roth.)–cereal rye (Secale cereale L.) cover crop mixtures can provide N scavenging and N provisioning benefits in grain cropping systems. The objectives of this research were to determine, under field conditions, the effects of species proportions, tillage, and pelletized...

  9. Cover Crops

    USDA-ARS?s Scientific Manuscript database

    Cover crops are a beneficial tool for use in conservation tillage systems. Cover crop residues reduce soil erosion from water and wind, increase soil water availability for subsequent crops, enhance soil organic matter and biological activity, and can decrease labor and energy inputs. Cover crop...

  10. Abatement of nitrate pollution in groundwater and surface runoff from cropland using legume cover crops with no-till corn. Research report

    SciTech Connect

    Smith, M.S.; Frye, W.W.; Varco, J.J.

    1986-07-01

    Agricultural practices can have a significant impact on water quality. The effects of leguminous winter cover crops on leaching of nitrates from soil have been investigated in the project. Legume cover crops, by fixation of atmospheric N, can reduce the amount of fertilizer N required to produce summer grain crops. The methods initially used to evaluate cover crop effects on nitrate transport included suction probe lysimeters and measurement of nitrates in soil samples collected to a depth of 90 cm. These measurements demonstrated extreme spatial variability in nitrate distribution and water movement. Soil transformations of legume and fertilizer N sources were compared using labelled amendments. Early measurements show greater nitrate leaching with legume N due to the mulch effect reducing evaporative water removal.

  11. Growing cover crops to improve carbon sequestration

    USDA-ARS?s Scientific Manuscript database

    Different cover crops were grown and evaluated for improving carbon sequestration. The cover crops in the study include not only winter and summer types but also legumes and non-legumes, respectively. Winter legumes are white clover, bell beans, and purple vetch, and winter non-legumes are triticale...

  12. Cover Crops

    USDA-ARS?s Scientific Manuscript database

    Cover crops are great tools to improve soil quality and health, and great tools to increase carbon sequestration. They are nutrient management tools that can help scavenge nitrate, cycle nitrogen to the following crop, mine NO3 from groundwater, and increase nitrogen use efficiency of cropping syste...

  13. Crimped Cover Crop Legume Residue Effects on Sweet Corn (Zea mays L.) Yield in Puerto Rico

    USDA-ARS?s Scientific Manuscript database

    Crimped legume residue can control weeds and supply N for sweet corn production if biomass is sufficient. Three sweet corn (Zea mays L.) open pollinated variety “Suresweet 2011” plantings (April, 2013; July 2013; February 2014) were conducted on an Oxisol (very fine, kaolinitic, isohyperthermic and...

  14. Improving legumes for pasture, cover crops, living mulch, and green manure

    USDA-ARS?s Scientific Manuscript database

    With growing interest in alternative legumes for uses beyond hay, farmers are requesting options to meet their needs. This article explains two efforts in which the U.S. Dairy Forage Research Center is involved. The two efforts include: 1) kura clover seed production so producers have access to kura...

  15. Insects associated with winter legume cover crops in a sorghum for Bio-fuel and cotton rotation system

    USDA-ARS?s Scientific Manuscript database

    Use of novel crops for bio-fuel production requires evaluating the potential for sound ecological and economical implementation in a particular region. We examined the pest and generalist beneficial insect species associated with various winter cover crops (including narrowleaf lupin, white vetch, ...

  16. Winter cover crops influence Amaranthus palmeri establishment

    USDA-ARS?s Scientific Manuscript database

    Winter cover crops were evaluated for their effect on Palmer amaranth (PA) suppression in cotton production. Cover crops examined included rye and four winter legumes: narrow-leaf lupine, crimson clover, Austrian winter pea, and cahaba vetch. Each legume was evaluated alone and in a mixture with rye...

  17. 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...

  18. Cover crop water use

    USDA-ARS?s Scientific Manuscript database

    Cover crops are being widely promoted because of soil health benefits. However, semi-arid dryland production systems, chronically short of water for crop production, may not be able to profitably withstand the yield reduction that follows cover crops because of cover crop water use. Some studies sug...

  19. Cover crops for Alabama

    USDA-ARS?s Scientific Manuscript database

    Cover crops are grown to benefit the following crop as well as to improve the soil, but they are normally not intended for harvest. Selecting the right cover crops for farming operations can improve yields, soil and water conservation and quality, and economic productivity. Properly managed cover ...

  20. Legume crops phylogeny and genetic diversity for science and breeding

    USDA-ARS?s Scientific Manuscript database

    Economically, legumes (Fabaceae) represent the second most important family of crop plants after the grass family, Poaceae. Grain legumes account for 27% of world crop production and provide 33% of the dietary protein consumed by humans, while pasture and forage legumes provide vital part of animal ...

  1. Legumes can increase cadmium contamination in neighboring crops.

    PubMed

    Liu, Ling; Zhang, Qian; Hu, Liangliang; Tang, Jianjun; Xu, Ligen; Yang, Xiantian; Yong, Jean W H; Chen, Xin

    2012-01-01

    Legumes are widely used in many cropping systems because they share their nitrogen fixation products and phosphorus mobilization activities with their neighbors. In the current study, however, we showed that co-cultivation with legumes increased cadmium (Cd) contamination in the adjacent crops. Both field and mesocosm experiments indicated that legumes increased Cd levels in edible parts and shoots of four neighboring crops and five maize varieties tested, regardless of the Cd levels in the soil. This enhanced Cd accumulation in crops was attributed to root interactions that alter the rhizosphere environment. Co-cultivation with legumes reduced soil pH, which somewhat increased the exchangeable forms of Cd. Our results have demonstrated the inevitable increases in Cd levels of crops as a direct result of co-cultivation with legumes even under situations when these levels are below the permissible threshold. With this new revelation, we need to consider carefully the current cropping systems involving legumes and perhaps to re-design the current and future cropping systems in view of avoiding food contamination by Cd.

  2. Cover crops for enriching soil carbon and nitrogen under bioenergy sorghum

    USDA-ARS?s Scientific Manuscript database

    Soil carbon (C) and nitrogen (N) can be enriched with cover crops under agronomic crops, but little is known about their enrichment under bioenergy crops. Legume (hairy vetch [Vicia villosa Roth]), nonlegume (rye [Secaele cereale L.]), a mixture of legume and nonlegume (hairy vetch and rye) and a co...

  3. Molecular, Genetic and Agronomic Approaches to Utilizing Pulses as Cover Crops and Green Manure into Cropping Systems.

    PubMed

    Tani, Eleni; Abraham, Eleni; Chachalis, Demosthenis; Travlos, Ilias

    2017-06-05

    Cover crops constitute one of the most promising agronomic practices towards a more sustainable agriculture. Their beneficial effects on main crops, soil and environment are many and various, while risks and disadvantages may also appear. Several legumes show a high potential but further research is required in order to suggest the optimal legume cover crops for each case in terms of their productivity and ability to suppress weeds. The additional cost associated with cover crops should also be addressed and in this context the use of grain legumes such as cowpea, faba bean and pea could be of high interest. Some of the aspects of these grain legumes as far as their use as cover crops, their genetic diversity and their breeding using conventional and molecular approaches are discussed in the present review. The specific species seem to have a high potential for use as cover crops, especially if their noticeable genetic diversity is exploited and their breeding focuses on several desirable traits.

  4. Dietary fibre and fermentability characteristics of root crops and legumes.

    PubMed

    Mallillin, Aida C; Trinidad, Trinidad P; Raterta, Ruby; Dagbay, Kevin; Loyola, Anacleta S

    2008-09-01

    The dietary fibre and fermentability characteristics of local root crops and legumes were determined. Total, soluble and insoluble fibre were determined in six root crops (kamote, gabi, potato, tugi, ube, cassava) and ten legumes (mungbean, soyabean, peanut, pole sitao, cowpea, chickpea, green pea, lima bean, kidney bean and pigeon pea) using Association of Official Analytical Chemists methods. The dietary fibre from test foods was isolated and fermented in vitro using human faecal inoculum simulating conditions in the human colon. The SCFA, e.g. acetate, propionate, butyrate, produced after fibre fermentation was measured using HPLC. The dietary fibre content of root crops ranged from 4.6 to 13.5 g/100 g while legumes ranged from 20.9 to 46.9 g/100 g, suggesting that root crops and legumes are good sources of dietary fibre. Significant amounts of SCFA were produced after in vitro fermentation of the fibre isolate of both root crops and legumes. The best sources (as mmol/g fibre isolate) of acetate among the legumes were pole sitao (5.6 (sem 0.5)) and mungbean (5.3 (sem 0.1)) and among the root crops, tugi (2.5 (sem 0.4)) and cassava (2.4 (sem 0.1)); of propionate, kidney bean (7.2 (sem 1.5)) and pigeon pea (3.3 (sem 0.2)) for legumes, and tugi (1.8 (sem 0.2)) for root crops; and of butyrate, peanut (6.0 (sem 0.2)) and cowpea (5.4 (sem 0.2)) for legumes, and tugi (0.8 (sem 0.0)) and cassava (0.8 (sem 0.0)) for root crops. In conclusion, root crops and legumes are good sources of dietary fibre and produced SCFA after fibre fermentation, such as acetate, propionate and butyrate. SCFA production after in vitro fermentation can be estimated using human faecal inoculum and can be used to model the human colon.

  5. Hairy vetch seedbank persistence and implications for cover crop management

    USDA-ARS?s Scientific Manuscript database

    Hairy vetch (Vicia villosa Roth) is a fast growing, winter hardy annual legume that can produce shoot biomass levels upwards of 6500 kg ha-1. This cover crop is well suited for summer annual grain rotations, as it fixes considerable amounts of nitrogen, reduces erosion through rapid ground cover, an...

  6. Winter Cover Crops and Nitrous Oxide Emissions in Early Spring

    NASA Astrophysics Data System (ADS)

    Morris, C. K.; Walter, M. T.; Reiss, E. R.

    2015-12-01

    Winter cover crops mixtures can be used to manage greenhouse gas (GHG) emissions during critical periods such as spring thaw. Legumes are added to cover crops mixtures to increase crop productivity, but it is unknown if this effect decreases N2O emissions. In this project we investigate the relationship between biodiversity, productivity and GHG fluxes in cover crops varieties typically grown for soil heath in agricultural systems. Surface GHG emissions were measured with closed chambers beginning during snowmelt events and continuing until crops were tilled into the soil in early summer. We found that nitrous oxide emissions were reduced in cover cropped plots during the early spring thaw period when compared to bare soil. GHG emission reductions in agriculture can be achieved with proper selection of winter hardy cover crops.

  7. Midwest Cover Crops Field Guide

    USDA-ARS?s Scientific Manuscript database

    Producers who want to prevent soil erosion, improve nutrient cycling, sustain their soils, and protect/maintain the environment have been returning to a very old practice: planting cover crops. Cover crops are effective tools for reducing soil erosion and increasing nutrient recycling on farmlands, ...

  8. High plains cover crop research

    USDA-ARS?s Scientific Manuscript database

    Some recent statements have been made about the benefits of growing cover crops in mixtures as compared with single-species plantings of cover crops. Those stated benefits have included greatly reduced water use, enhanced soil microbiological activity, increased biomass productivity, and enhanced wa...

  9. Climate Impacts of Cover Crops

    NASA Astrophysics Data System (ADS)

    Lombardozzi, D.; Wieder, W. R.; Bonan, G. B.; Morris, C. K.; Grandy, S.

    2016-12-01

    Cover crops are planted in agricultural rotation with the intention of protecting soil rather than harvest. Cover crops have numerous environmental benefits that include preventing soil erosion, increasing soil fertility, and providing weed and pest control- among others. In addition to localized environmental benefits, cover crops can have important regional or global biogeochemical impacts by increasing soil organic carbon, changing emissions of greenhouse trace gases like nitrous oxide and methane, and reducing hydrologic nitrogen losses. Cover crops may additionally affect climate by changing biogeophysical processes, like albedo and latent heat flux, though these potential changes have not yet been evaluated. Here we use the coupled Community Atmosphere Model (CAM5) - Community Land Model (CLM4.5) to test how planting cover crops in the United States may change biogeophysical fluxes and climate. We present seasonal changes in albedo, heat fluxes, evaporative partitioning, radiation, and the resulting changes in temperature. Preliminary analyses show that during seasons when cover crops are planted, latent heat flux increases and albedo decreases, changing the evaporative fraction and surface temperatures. Understanding both the biogeophysical changes caused by planting cover crops in this study and the biogeochemical changes found in other studies will give a clearer picture of the overall impacts of cover crops on climate and atmospheric chemistry, informing how this land use strategy will impact climate in the future.

  10. UAV-based high-throughput phenotyping in legume crops

    NASA Astrophysics Data System (ADS)

    Sankaran, Sindhuja; Khot, Lav R.; Quirós, Juan; Vandemark, George J.; McGee, Rebecca J.

    2016-05-01

    In plant breeding, one of the biggest obstacles in genetic improvement is the lack of proven rapid methods for measuring plant responses in field conditions. Therefore, the major objective of this research was to evaluate the feasibility of utilizing high-throughput remote sensing technology for rapid measurement of phenotyping traits in legume crops. The plant responses of several chickpea and peas varieties to the environment were assessed with an unmanned aerial vehicle (UAV) integrated with multispectral imaging sensors. Our preliminary assessment showed that the vegetation indices are strongly correlated (p<0.05) with seed yield of legume crops. Results endorse the potential of UAS-based sensing technology to rapidly measure those phenotyping traits.

  11. Crop rotations that include legumes and reduced tillage improve the energy efficiency of crop production systems

    USDA-ARS?s Scientific Manuscript database

    Text: Modern crop production requires large inputs of energy and these inputs represent a substantial cost. Management practices such as crop rotation and choice of tillage practice influence the energy balance for a production system. Legumes support bacteria that are capable of fixing nitrogen (N)...

  12. Crop rotations that include legumes and reduced tillage improve the energy efficiency of crop production systems

    USDA-ARS?s Scientific Manuscript database

    Modern crop production requires large inputs of energy and these inputs represent a substantial cost. Management practices such as crop rotation and choice of tillage practice influence the energy balance for a production system. Legumes support bacteria that are capable of fixing nitrogen (N). This...

  13. Cover crop biomass harvest for bioenergy: implications for crop productivity

    USDA-ARS?s Scientific Manuscript database

    Winter cover crops, such as rye (Secale cereale), are usually used in conservation agriculture systems in the Southeast. Typically, the cover crop is terminated two to three weeks before planting the summer crop, with the cover biomass left on the soil surface as a mulch. However, these cover crops ...

  14. Trade-Offs between Economic and Environmental Impacts of Introducing Legumes into Cropping Systems

    PubMed Central

    Reckling, Moritz; Bergkvist, Göran; Watson, Christine A.; Stoddard, Frederick L.; Zander, Peter M.; Walker, Robin L.; Pristeri, Aurelio; Toncea, Ion; Bachinger, Johann

    2016-01-01

    Europe's agriculture is highly specialized, dependent on external inputs and responsible for negative environmental impacts. Legume crops are grown on less than 2% of the arable land and more than 70% of the demand for protein feed supplement is imported from overseas. The integration of legumes into cropping systems has the potential to contribute to the transition to a more resource-efficient agriculture and reduce the current protein deficit. Legume crops influence the production of other crops in the rotation making it difficult to evaluate the overall agronomic effects of legumes in cropping systems. A novel assessment framework was developed and applied in five case study regions across Europe with the objective of evaluating trade-offs between economic and environmental effects of integrating legumes into cropping systems. Legumes resulted in positive and negative impacts when integrated into various cropping systems across the case studies. On average, cropping systems with legumes reduced nitrous oxide emissions by 18 and 33% and N fertilizer use by 24 and 38% in arable and forage systems, respectively, compared to systems without legumes. Nitrate leaching was similar with and without legumes in arable systems and reduced by 22% in forage systems. However, grain legumes reduced gross margins in 3 of 5 regions. Forage legumes increased gross margins in 3 of 3 regions. Among the cropping systems with legumes, systems could be identified that had both relatively high economic returns and positive environmental impacts. Thus, increasing the cultivation of legumes could lead to economic competitive cropping systems and positive environmental impacts, but achieving this aim requires the development of novel management strategies informed by the involvement of advisors and farmers. PMID:27242870

  15. Using cover crops and cropping systems for nitrogen management

    USDA-ARS?s Scientific Manuscript database

    The reasons for using cover crops and optimized cropping sequences to manage nitrogen (N) are to maximize economic returns, improve soil quality and productivity, and minimize losses of N that might adversely impact environmental quality. Cover crops and cropping systems’ effects on N management are...

  16. Biomass potential of selected grass and legume crops

    SciTech Connect

    Cherney, J.H.; Johnson, K.D.; Volenec, J.J.; Greene, D.K. )

    1991-01-01

    Optimum management strategies for herbaceous biomass crops must be investigated concurrently with the development of cost-effective conversion processes. The objective of this paper is to evaluate the agronomic feasibility of several combinations of species and management systems for producing herbaceous biomass on sites ranging from good to marginal cropland in the Midwest region of the United States. Of the perennial grasses and legumes investigated, switchgrass showed the most potential as a biomass species. It requires minimum fertilizer inputs for high yield, is very persistent, and is effective in reducing soil erosion. Sorghum double-cropped with winter annual rye was very productive but required more inputs than switchgrass. Interseeding sorghum into perennial grasses was not a viable option, due to its great dependence on environmental variables. Plant composition varied greatly across species but was not greatly affected by environment or management treatmenst.

  17. Molecular, Genetic and Agronomic Approaches to Utilizing Pulses as Cover Crops and Green Manure into Cropping Systems

    PubMed Central

    Tani, Eleni; Abraham, Eleni; Chachalis, Demosthenis; Travlos, Ilias

    2017-01-01

    Cover crops constitute one of the most promising agronomic practices towards a more sustainable agriculture. Their beneficial effects on main crops, soil and environment are many and various, while risks and disadvantages may also appear. Several legumes show a high potential but further research is required in order to suggest the optimal legume cover crops for each case in terms of their productivity and ability to suppress weeds. The additional cost associated with cover crops should also be addressed and in this context the use of grain legumes such as cowpea, faba bean and pea could be of high interest. Some of the aspects of these grain legumes as far as their use as cover crops, their genetic diversity and their breeding using conventional and molecular approaches are discussed in the present review. The specific species seem to have a high potential for use as cover crops, especially if their noticeable genetic diversity is exploited and their breeding focuses on several desirable traits. PMID:28587254

  18. Selection of fungi by candidate cover crops

    USDA-ARS?s Scientific Manuscript database

    Diversified cropping systems that incorporate year-round ground cover, are known to maintain healthy soils. Information is available for producers regarding the benefits of specific cover crop species for soil fertility, weed and pest management. Even though it is widely recognized that cover crops ...

  19. Managing cover crops: an economic perspective

    USDA-ARS?s Scientific Manuscript database

    Common reasons given by producers as to why they do not adopt cover crops are related to economics: time, labor, and cost required for planting and managing cover crops. While many of the agronomic benefits of cover crops directly relate to economics, there are costs associated with adopting the pra...

  20. Registration of four winter-hardy faba bean germplasm lines for use in winter pulse and cover crop development

    USDA-ARS?s Scientific Manuscript database

    Faba bean (Vicia faba L.) is a versatile crop grown for food, feed, vegetable, or cover crop purposes in many countries. In response to the growing demand for winter annual legumes for cover crop development in the United States, we developed four winter-hardy faba bean germplasm lines, WH-1 (Reg. N...

  1. Cover crops support ecological intensification of arable cropping systems

    PubMed Central

    Wittwer, Raphaël A.; Dorn, Brigitte; Jossi, Werner; van der Heijden, Marcel G. A.

    2017-01-01

    A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the short-term effects of various cover crops on crop yield, nitrogen uptake, and weed infestation in four arable production systems (conventional cropping with intensive tillage and no-tillage; organic cropping with intensive tillage and reduced tillage). We hypothesized that cover cropping effects increase with decreasing management intensity. Our study demonstrated that cover crop effects on crop yield were highest in the organic system with reduced tillage (+24%), intermediate in the organic system with tillage (+13%) and in the conventional system with no tillage (+8%) and lowest in the conventional system with tillage (+2%). Our results indicate that cover crops are essential to maintaining a certain yield level when soil tillage intensity is reduced (e.g. under conservation agriculture), or when production is converted to organic agriculture. Thus, the inclusion of cover crops provides additional opportunities to increase the yield of lower intensity production systems and contribute to ecological intensification. PMID:28157197

  2. Cover crops support ecological intensification of arable cropping systems

    NASA Astrophysics Data System (ADS)

    Wittwer, Raphaël A.; Dorn, Brigitte; Jossi, Werner; van der Heijden, Marcel G. A.

    2017-02-01

    A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the short-term effects of various cover crops on crop yield, nitrogen uptake, and weed infestation in four arable production systems (conventional cropping with intensive tillage and no-tillage; organic cropping with intensive tillage and reduced tillage). We hypothesized that cover cropping effects increase with decreasing management intensity. Our study demonstrated that cover crop effects on crop yield were highest in the organic system with reduced tillage (+24%), intermediate in the organic system with tillage (+13%) and in the conventional system with no tillage (+8%) and lowest in the conventional system with tillage (+2%). Our results indicate that cover crops are essential to maintaining a certain yield level when soil tillage intensity is reduced (e.g. under conservation agriculture), or when production is converted to organic agriculture. Thus, the inclusion of cover crops provides additional opportunities to increase the yield of lower intensity production systems and contribute to ecological intensification.

  3. Timely precipitation drives cover crop outcomes

    USDA-ARS?s Scientific Manuscript database

    Cover crops can expand ecosystem services, though sound management recommendations for their use within semi-arid cropping systems is currently constrained by a lack of information. This study was conducted to determine agroecosystem responses to late-summer seeded cover crops under no-till managem...

  4. Roadmap to increased cover crop adoption

    USDA-ARS?s Scientific Manuscript database

    Cover crops are increasingly utilized by farmers and promoted by agronomists for the multiple benefits they contribute to soil and crop management systems. Yet, only a small percentage of cropland is planted to cover crops. In June of 2012, the National Wildlife Federation brought together 36 of the...

  5. Potential Uses of Wild Germplasms of Grain Legumes for Crop Improvement.

    PubMed

    Muñoz, Nacira; Liu, Ailin; Kan, Leo; Li, Man-Wah; Lam, Hon-Ming

    2017-02-04

    Challenged by population increase, climatic change, and soil deterioration, crop improvement is always a priority in securing food supplies. Although the production of grain legumes is in general lower than that of cereals, the nutritional value of grain legumes make them important components of food security. Nevertheless, limited by severe genetic bottlenecks during domestication and human selection, grain legumes, like other crops, have suffered from a loss of genetic diversity which is essential for providing genetic materials for crop improvement programs. Illustrated by whole-genome-sequencing, wild relatives of crops adapted to various environments were shown to maintain high genetic diversity. In this review, we focused on nine important grain legumes (soybean, peanut, pea, chickpea, common bean, lentil, cowpea, lupin, and pigeonpea) to discuss the potential uses of their wild relatives as genetic resources for crop breeding and improvement, and summarized the various genetic/genomic approaches adopted for these purposes.

  6. Potential Uses of Wild Germplasms of Grain Legumes for Crop Improvement

    PubMed Central

    Muñoz, Nacira; Liu, Ailin; Kan, Leo; Li, Man-Wah; Lam, Hon-Ming

    2017-01-01

    Challenged by population increase, climatic change, and soil deterioration, crop improvement is always a priority in securing food supplies. Although the production of grain legumes is in general lower than that of cereals, the nutritional value of grain legumes make them important components of food security. Nevertheless, limited by severe genetic bottlenecks during domestication and human selection, grain legumes, like other crops, have suffered from a loss of genetic diversity which is essential for providing genetic materials for crop improvement programs. Illustrated by whole-genome-sequencing, wild relatives of crops adapted to various environments were shown to maintain high genetic diversity. In this review, we focused on nine important grain legumes (soybean, peanut, pea, chickpea, common bean, lentil, cowpea, lupin, and pigeonpea) to discuss the potential uses of their wild relatives as genetic resources for crop breeding and improvement, and summarized the various genetic/genomic approaches adopted for these purposes. PMID:28165413

  7. A Comparative Nitrogen Balance and Productivity Analysis of Legume and Non-legume Supported Cropping Systems: The Potential Role of Biological Nitrogen Fixation.

    PubMed

    Iannetta, Pietro P M; Young, Mark; Bachinger, Johann; Bergkvist, Göran; Doltra, Jordi; Lopez-Bellido, Rafael J; Monti, Michele; Pappa, Valentini A; Reckling, Moritz; Topp, Cairistiona F E; Walker, Robin L; Rees, Robert M; Watson, Christine A; James, Euan K; Squire, Geoffrey R; Begg, Graham S

    2016-01-01

    The potential of biological nitrogen fixation (BNF) to provide sufficient N for production has encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertilizer, although few studies have systematically evaluated the effect of optimizing the balance between legumes and non N-fixing crops to optimize production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new legume-based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g., grains, forages and intercrops) across pedoclimatic regions of Europe. Mean BNF for different legume types ranged from 32 to 115 kg ha(-1) annually. Output in terms of total biomass (grain, forage, etc.) was 30% greater in non-legumes, which used N to produce dry matter more efficiently than legumes, whereas output of N was greater from legumes. When examined over the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years). BNF was lower when the legume fraction increased to 0.6-0.8, not because of any feature of the legume, but because the cropping systems in this range were dominated by mixtures of legume and non-legume forages to which inorganic N as fertilizer was normally applied. Forage (e.g., grass and clover), as opposed to grain crops in this range maintained high outputs of biomass and N. In conclusion, BNF through grain and forage legumes has the potential to generate major benefit in terms of reducing or dispensing with the need for mineral N without loss of total output.

  8. Use of Cover Crops in Hardwood Production

    Treesearch

    Randy Rentz

    2005-01-01

    Cover crops are as essential a practice in hardwood production as in pine production or any other nursery operation. Without proper cover crop rotation in a nursery plan, we open ourselves up to an array of problems: more diseases, wrong pH, more weeds, reduced fertility, and less downward percolation of soil moisture due, in part, to compaction....

  9. Hydrogen coupled CO2 fixation in legume cropping systems

    NASA Astrophysics Data System (ADS)

    Philpott, T.; Cen, Y.; Layzell, D. B.; Kyser, K.; Scott, N. A.

    2009-05-01

    Electron flow from oxidation of excess H2 released by root nodules was shown to contribute to microbial CO2 fixation in soybean crops. This discovery has important implications for carbon storage in soils used to grow legumes; however, further research is needed to understand the fate and turnover time of this H2-coupled CO2 fixation. Isotopic labeling of soil through incubation with 13CO2 was used to elucidate movement of sequestered carbon into soil carbon pools. Measurement of isotopic shifts was determined using Isotope Ratio Mass Spectrometry. Preliminary experiments have confirmed CO2 uptake through an isotopic shift (Δ13C -20.4 to -14.5 ‰) in 24 hour incubated soils labeled with 13CO2 (1% v/v, 99.5 Atom%) under elevated H2 concentration (6000 ppm). Other incubation experiments have confirmed the biotic nature of observed CO2 uptake by comparing isotopic shifts in oven dried and autoclaved soils to moist soil. Under an elevated H2 atmosphere, no significant isotopic shift was observed in dry and autoclaved soils whereas moist soil showed an isotopic shift of Δ13C -21.9 to 11.4 ‰ over 48 hours. Future experiments will involve longer incubations (7 days) and will be aimed at determining isotopic shifts within soil carbon pools. Samples will be incubated and fractionated into microbial biomass, light fraction carbon, and acid stable carbon and subsequent isotopic analysis will be carried out. This will help determine the distribution of H2- coupled fixed CO2 within soil carbon pools and the turnover time of sequestered carbon. This and further research may lead to modification of greenhouse gas coefficients for leguminous crops that includes a CO2 fixation component.

  10. A Comparative Nitrogen Balance and Productivity Analysis of Legume and Non-legume Supported Cropping Systems: The Potential Role of Biological Nitrogen Fixation

    PubMed Central

    Iannetta, Pietro P. M.; Young, Mark; Bachinger, Johann; Bergkvist, Göran; Doltra, Jordi; Lopez-Bellido, Rafael J.; Monti, Michele; Pappa, Valentini A.; Reckling, Moritz; Topp, Cairistiona F. E.; Walker, Robin L.; Rees, Robert M.; Watson, Christine A.; James, Euan K.; Squire, Geoffrey R.; Begg, Graham S.

    2016-01-01

    The potential of biological nitrogen fixation (BNF) to provide sufficient N for production has encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertilizer, although few studies have systematically evaluated the effect of optimizing the balance between legumes and non N-fixing crops to optimize production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new legume–based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g., grains, forages and intercrops) across pedoclimatic regions of Europe. Mean BNF for different legume types ranged from 32 to 115 kg ha−1 annually. Output in terms of total biomass (grain, forage, etc.) was 30% greater in non-legumes, which used N to produce dry matter more efficiently than legumes, whereas output of N was greater from legumes. When examined over the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years). BNF was lower when the legume fraction increased to 0.6–0.8, not because of any feature of the legume, but because the cropping systems in this range were dominated by mixtures of legume and non-legume forages to which inorganic N as fertilizer was normally applied. Forage (e.g., grass and clover), as opposed to grain crops in this range maintained high outputs of biomass and N. In conclusion, BNF through grain and forage legumes has the potential to generate major benefit in terms of reducing or dispensing with the need for mineral N without loss of total output. PMID:27917178

  11. Sunn hemp as a cover crop to reduce nitrogen inputs for winter wheat

    USDA-ARS?s Scientific Manuscript database

    The tropical legume sunn hemp (Crotalaria juncea L.) has the potential to perform as a beneficial cover crop in the southeastern United States due to its ability to accumulate large amounts of biomass and symbiotic nitrogen (N) in a short period of time during the summer months. Planting sunn hemp,...

  12. Utilization of sunn hemp for cover crops and weed control in temperate climates

    USDA-ARS?s Scientific Manuscript database

    The need to develop increasingly integrated pest management and sustainable food production systems has encouraged a greater interest to thoroughly evaluate effective utilization of cover crops in agricultural systems. Sunn hemp, a tropical legume that originated most likely from the Indo-Pakistani ...

  13. Organic supplemental nitrogen sources for field corn production following a hairy vetch cover crop

    USDA-ARS?s Scientific Manuscript database

    The combined use of legume cover crops and animal byproduct organic amendments could provide agronomic and environmental benefits to organic farmers by increasing corn grain yield while optimizing N and P inputs. To test this hypothesis we conducted a two-year field study and a laboratory soil incu...

  14. Starter fertilizer for managing cover crop-based organic rotational no-till corn yields

    USDA-ARS?s Scientific Manuscript database

    Weed control and N availability limit yield in organic corn production. Grass and legume cover crops are combined in mixtures to provide both weed and fertility management; however, additional fertility may be required to maximize corn yield. Research was conducted at Beltsville, MD, Kinston, NC, an...

  15. Effects of cover cropping on soil and rhizosphere microbial community structure in tomato production systems

    USDA-ARS?s Scientific Manuscript database

    Black polyethylene film is frequently used in vegetable farming systems to promote rapid warming of the soil in spring, conserve soil moisture, and suppress weeds. Alternative systems have been developed using cover cropping with legumes to provide a weed-suppressive mulch while also fixing nitrogen...

  16. Kenaf and cowpea as sugarcane cover crops

    USDA-ARS?s Scientific Manuscript database

    The use of cover crops during the fallow period prior to planting sugarcane has the potential to influence not only the following sugarcane crop, but the economics of the production system as a whole. Typically, a Louisiana sugarcane field is replanted every four years due to declining yields, and,...

  17. Increased Productivity of a Cover Crop Mixture Is Not Associated with Enhanced Agroecosystem Services

    PubMed Central

    Smith, Richard G.; Atwood, Lesley W.; Warren, Nicholas D.

    2014-01-01

    Cover crops provide a variety of important agroecological services within cropping systems. Typically these crops are grown as monocultures or simple graminoid-legume bicultures; however, ecological theory and empirical evidence suggest that agroecosystem services could be enhanced by growing cover crops in species-rich mixtures. We examined cover crop productivity, weed suppression, stability, and carryover effects to a subsequent cash crop in an experiment involving a five-species annual cover crop mixture and the component species grown as monocultures in SE New Hampshire, USA in 2011 and 2012. The mean land equivalent ratio (LER) for the mixture exceeded 1.0 in both years, indicating that the mixture over-yielded relative to the monocultures. Despite the apparent over-yielding in the mixture, we observed no enhancement in weed suppression, biomass stability, or productivity of a subsequent oat (Avena sativa L.) cash crop when compared to the best monoculture component crop. These data are some of the first to include application of the LER to an analysis of a cover crop mixture and contribute to the growing literature on the agroecological effects of cover crop diversity in cropping systems. PMID:24847902

  18. Increased productivity of a cover crop mixture is not associated with enhanced agroecosystem services.

    PubMed

    Smith, Richard G; Atwood, Lesley W; Warren, Nicholas D

    2014-01-01

    Cover crops provide a variety of important agroecological services within cropping systems. Typically these crops are grown as monocultures or simple graminoid-legume bicultures; however, ecological theory and empirical evidence suggest that agroecosystem services could be enhanced by growing cover crops in species-rich mixtures. We examined cover crop productivity, weed suppression, stability, and carryover effects to a subsequent cash crop in an experiment involving a five-species annual cover crop mixture and the component species grown as monocultures in SE New Hampshire, USA in 2011 and 2012. The mean land equivalent ratio (LER) for the mixture exceeded 1.0 in both years, indicating that the mixture over-yielded relative to the monocultures. Despite the apparent over-yielding in the mixture, we observed no enhancement in weed suppression, biomass stability, or productivity of a subsequent oat (Avena sativa L.) cash crop when compared to the best monoculture component crop. These data are some of the first to include application of the LER to an analysis of a cover crop mixture and contribute to the growing literature on the agroecological effects of cover crop diversity in cropping systems.

  19. Managing cover crops on strawberry furrow bottoms

    USDA-ARS?s Scientific Manuscript database

    Bare furrows in strawberry fields with plastic mulch covered beds can lead to lots of soil erosion and runoff during winter rainy periods. This article describes how growers can plant and manage cover crops in these furrows to minimize runoff and soil erosion. This is based on on-going research at...

  20. Patterns of crop cover under future climates.

    PubMed

    Porfirio, Luciana L; Newth, David; Harman, Ian N; Finnigan, John J; Cai, Yiyong

    2017-04-01

    We study changes in crop cover under future climate and socio-economic projections. This study is not only organised around the global and regional adaptation or vulnerability to climate change but also includes the influence of projected changes in socio-economic, technological and biophysical drivers, especially regional gross domestic product. The climatic data are obtained from simulations of RCP4.5 and 8.5 by four global circulation models/earth system models from 2000 to 2100. We use Random Forest, an empirical statistical model, to project the future crop cover. Our results show that, at the global scale, increases and decreases in crop cover cancel each other out. Crop cover in the Northern Hemisphere is projected to be impacted more by future climate than the in Southern Hemisphere because of the disparity in the warming rate and precipitation patterns between the two Hemispheres. We found that crop cover in temperate regions is projected to decrease more than in tropical regions. We identified regions of concern and opportunities for climate change adaptation and investment.

  1. Replacing fallow by cover crops: economic sustainability

    NASA Astrophysics Data System (ADS)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  2. Using cash cover crops to provide pollinator provisions

    USDA-ARS?s Scientific Manuscript database

    To date, the use of winter cover crops in MN and SD has been slow to be adopted. The short growing season and potential for late wet springs make cover crops risky to farmers with little economic return. The use of cash cover crops in this area offers the standard advantages of other cover crops, wi...

  3. Evaluating shade effects on crop productivity in sorghum-legume intercropping systems using support vector machines

    USDA-ARS?s Scientific Manuscript database

    Sorghum-legume intercropping has the potential to improve forage productivity, resource use efficiency, and forage quality under irrigation in the Southern High Plains of the United States. Crop production is conversion of solar radiation into biomass and solar radiation is wasted early in the seaso...

  4. Unique cover crops for Louisiana sugarcane

    USDA-ARS?s Scientific Manuscript database

    Louisiana sugarcane production practices provide a tremendous opportunity for the use of cover crops following the final sugarcane harvest in the fall of one year and prior to replanting sugarcane during the summer of the next year. A Louisiana sugarcane field is typically replanted every four years...

  5. A field-grown transgenic tomato line expressing higher levels of polyamines reveals legume cover crop mulch-specific perturbations in fruit phenotype at the levels of metabolite profiles, gene expression, and agronomic characteristics.

    PubMed

    Neelam, Anil; Cassol, Tatiana; Mehta, Roshni A; Abdul-Baki, Aref A; Sobolev, Anatoli P; Goyal, Ravinder K; Abbott, Judith; Segre, Anna L; Handa, Avtar K; Mattoo, Autar K

    2008-01-01

    Genetic modification of crop plants to introduce desirable traits such as nutritional enhancement, disease and pest resistance, and enhanced crop productivity is increasingly seen as a promising technology for sustainable agriculture and boosting food production in the world. Independently, cultural practices that utilize alternative agriculture strategies including organic cultivation subscribe to sustainable agriculture by limiting chemical usage and reduced tillage. How the two together affect fruit metabolism or plant growth in the field or whether they are compatible has not yet been tested. Fruit-specific yeast S-adenosylmethionine decarboxylase (ySAMdc) line 579HO, and a control line 556AZ were grown in leguminous hairy vetch (Vicia villosa Roth) (HV) mulch and conventional black polyethylene (BP) mulch, and their fruit analysed. Significant genotypexmulch-dependent interactions on fruit phenotype were exemplified by differential profiles of 20 fruit metabolites such as amino acids, sugars, and organic acids. Expression patterns of the ySAMdc transgene, and tomato SAMdc, E8, PEPC, and ICDHc genes were compared between the two lines as a function of growth on either BP or HV mulch. HV mulch significantly stimulated the accumulation of asparagine, glutamate, glutamine, choline, and citrate concomitant with a decrease in glucose in the 556AZ fruits during ripening as compared to BP. It enables a metabolic system in tomato somewhat akin to the one in higher polyamine-accumulating transgenic fruit that have higher phytonutrient content. Finally, synergism was found between HV mulch and transgenic tomato in up-regulating N:C indicator genes PEPC and ICDHc in the fruit.

  6. A field-grown transgenic tomato line expressing higher levels of polyamines reveals legume cover crop mulch-specific perturbations in fruit phenotype at the levels of metabolite profiles, gene expression, and agronomic characteristics

    PubMed Central

    Neelam, Anil; Cassol, Tatiana; Mehta, Roshni A.; Abdul-Baki, Aref A.; Sobolev, Anatoli P.; Goyal, Ravinder K.; Abbott, Judith; Segre, Anna L.; Handa, Avtar K.; Mattoo, Autar K.

    2008-01-01

    Genetic modification of crop plants to introduce desirable traits such as nutritional enhancement, disease and pest resistance, and enhanced crop productivity is increasingly seen as a promising technology for sustainable agriculture and boosting food production in the world. Independently, cultural practices that utilize alternative agriculture strategies including organic cultivation subscribe to sustainable agriculture by limiting chemical usage and reduced tillage. How the two together affect fruit metabolism or plant growth in the field or whether they are compatible has not yet been tested. Fruit-specific yeast S-adenosylmethionine decarboxylase (ySAMdc) line 579HO, and a control line 556AZ were grown in leguminous hairy vetch (Vicia villosa Roth) (HV) mulch and conventional black polyethylene (BP) mulch, and their fruit analysed. Significant genotype×mulch-dependent interactions on fruit phenotype were exemplified by differential profiles of 20 fruit metabolites such as amino acids, sugars, and organic acids. Expression patterns of the ySAMdc transgene, and tomato SAMdc, E8, PEPC, and ICDHc genes were compared between the two lines as a function of growth on either BP or HV mulch. HV mulch significantly stimulated the accumulation of asparagine, glutamate, glutamine, choline, and citrate concomitant with a decrease in glucose in the 556AZ fruits during ripening as compared to BP. It enables a metabolic system in tomato somewhat akin to the one in higher polyamine-accumulating transgenic fruit that have higher phytonutrient content. Finally, synergism was found between HV mulch and transgenic tomato in up-regulating N:C indicator genes PEPC and ICDHc in the fruit. PMID:18469323

  7. Contrasted nitrogen utilization in annual C 3 grass and legume crops: Physiological explorations and ecological considerations

    NASA Astrophysics Data System (ADS)

    Del Pozo, Alejandro; Garnier, Eric; Aronson, James

    2000-01-01

    Although it is well known that legumes have unusually high levels of nitrogen in both reproductive and vegetative organs, the physiological implications of this pattern have been poorly assessed. We conducted a literature survey and used data from two (unpublished) experiments on annual legumes and C 3 grasses in order to test whether these high nitrogen concentrations in legumes are correlated to high rates of carbon gain. Three different temporal/spatial scales were considered: full growing season/stand, days to month/whole plant and seconds/leaf. At the stand level, and for plants grown under both extratropical and tropical settings, biomass per unit organic-nitrogen was lower in legume than in grass crops. At a shorter time scale, the relative growth rate per unit plant nitrogen (`nitrogen productivity') was lower in faba bean ( Vicia faba var. minor cv. Tina) than in wheat ( Triticum aestivum cv. Alexandria), and this was confirmed in a comparison of two wild, circum-Mediterranean annuals - Medicago minima, a legume, and Bromus madritensis, a grass. Finally, at the leaf level, a synthesis of published data comparing soybean ( Glycine max) and rice ( Oryza sativa) on the one hand, and our own data on faba bean and wheat on the other hand, demonstrates that the photosynthetic rate per unit leaf nitrogen (the photosynthetic nitrogen use efficiency) is consistently lower in legumes than in grasses. These results demonstrate that, regardless of the scale considered and although the organic-nitrogen concentration in vegetative organs of legumes is higher than in grasses, this does not lead to higher rates of carbon gain in the former. Various physiological factors affecting the efficiency of nitrogen utilization at the three time scales considered are discussed. The suggestion is made that the ecological significance of the high nitrogen concentration in legumes may be related to a high nitrogen demand for high quality seed production at a time when nitrogen

  8. Fluorescence imaging to quantify crop residue cover

    NASA Technical Reports Server (NTRS)

    Daughtry, C. S. T.; Mcmurtrey, J. E., III; Chappelle, E. W.

    1994-01-01

    Crop residues, the portion of the crop left in the field after harvest, can be an important management factor in controlling soil erosion. Methods to quantify residue cover are needed that are rapid, accurate, and objective. Scenes with known amounts of crop residue were illuminated with long wave ultraviolet (UV) radiation and fluorescence images were recorded with an intensified video camera fitted with a 453 to 488 nm band pass filter. A light colored soil and a dark colored soil were used as background for the weathered soybean stems. Residue cover was determined by counting the proportion of the pixels in the image with fluorescence values greater than a threshold. Soil pixels had the lowest gray levels in the images. The values of the soybean residue pixels spanned nearly the full range of the 8-bit video data. Classification accuracies typically were within 3(absolute units) of measured cover values. Video imaging can provide an intuitive understanding of the fraction of the soil covered by residue.

  9. Differences in Crenate Broomrape Parasitism Dynamics on Three Legume Crops Using a Thermal Time Model

    PubMed Central

    Pérez-de-Luque, Alejandro; Flores, Fernando; Rubiales, Diego

    2016-01-01

    Root parasitic weeds are a major limiting production factor in a number of crops, and control is difficult. Genetic resistance and chemical control lead the fight, but without unequivocal success. Models that help to describe and even predict the evolution of parasitism underground are a valuable tool for herbicide applications, and even could help in breeding programs. Legumes are heavily affected by Orobanche crenata (crenate broomrape) in the Mediterranean basin. This work presents a descriptive model based on thermal time and correlating growing degree days (GDD) with the different developmental stages of the parasite. The model was developed in three different legume crops (faba bean, grass pea and lentil) attacked by crenate broomrape. The developmental stages of the parasite strongly correlated with the GDD and differences were found depending on the host crop. PMID:28018421

  10. Tuberous legumes: preliminary evaluation of tropical Australian and introduced species as fuel crops

    SciTech Connect

    Saxon, E.C.

    1981-04-01

    The evaluation of native and introduced legumes with starch-storing roots or tubers was undertaken to test whether plants traditionally collected as food by Australian aborigines might have a role in the development of crops for liquid fuel production (by fermentation of carbohydrates to ethanol). Tuberous-rooted legumes from overseas were planted at the Commonwealth Scientific and Industrial Research Organization, division of Tropical Crops and Pastures, Kimberley Research Station, Western Australia (15/sup 0/39'S, 128/sup 0/42'E) in December 1974, March 1978 and February 1979. Roots from the latter plantings were harvested in June 1979. Native plant material was collected during visits to aboriginal communities in the Kimberleys between April and June 1979. The native and introduced specimens were analyzed for fermentable carbohydrate and protein content. Several native plants appear more promising than introduced species as liquid fuel crops.

  11. Suppression of soilborne diseases of soybean with cover crops

    USDA-ARS?s Scientific Manuscript database

    Cover crops can foster the development of disease suppressive soils, and it has become common to use cover crops to manage soilborne diseases in high value crops. There is increasing interest in incorporating cover crops into agronomic systems in the Midwestern US for improving soil health. However,...

  12. Duck nesting in fields of undisturbed grass-legume cover

    USGS Publications Warehouse

    Duebbert, H.F.; Lokemoen, J.T.

    1976-01-01

    A study of dabbling duck (Anatinae) nesting was conducted during 1971-73 on nine 12- to 54-ha Cropland Adjustment Program fields in the prairie pothole region of north-central South Dakota. The tall, dense vegetation was comprised of introduced cool-season grasses and legumes, primarily smooth bromegrass (Bromus inermis), intermediate wheatgrass (Agropyron intermedium), and alfalfa. Complexes of temporary, seasonal, and semipermanent wetlands surrounded the fields at densities of 1.5-8.1 basins/km2 and areas of 9.4-17.2 ha/km2. Of the 620 nests studied, 38 percent were of blue-winged teal (Anas discors), 24 percent were of mallards (A. platyrhynchos), and 24 percent were of gadwalls (A. strepera). Densities of nests of all species averaged 67, 114, and 47 nests/km2 (3-yr av 77/km2). Calculated hatching rates were 69, 58, and 32 percent (av 56) for the 3 years. Hatchability of eggs in successful nests averaged 97.1 percent. Averages of 4.0, 6.2, and 1.2 ducklings were hatched per hectare in 1971, 1972, and 1973, respectively (3-yr av 3.7/ha).

  13. Control of plant virus diseases in cool-season grain legume crops.

    PubMed

    Makkouk, Khaled M; Kumari, Safaa G; van Leur, Joop A G; Jones, Roger A C

    2014-01-01

    Cool-season grain legume crops become infected with a wide range of viruses, many of which cause serious diseases and major yield losses. This review starts by discussing which viruses are important in the principal cool-season grain legume crops in different parts of the world, the losses they cause and their economic impacts in relation to control. It then describes the main types of control measures available: host resistance, phytosanitary measures, cultural measures, chemical control, and biological control. Examples are provided of successful deployment of the different types of measures to control virus epidemics in cool-season grain legume crops. Next it emphasizes the need for integrated approaches to control because single control measures used alone rarely suffice to adequately reduce virus-induced yield losses in these crops. Development of effective integrated disease management (IDM) strategies depends on an interdisciplinary team approach to (i) understand the ecological and climatic factors which lead to damaging virus epidemics and (ii) evaluate the effectiveness of individual control measures. In addition to using virus-resistant cultivars, other IDM components include sowing virus-tested seed stocks, selecting cultivars with low seed transmission rates, using diverse phytosanitary or cultural practices that minimize the virus source or reduce its spread, and using selective pesticides in an environmentally responsible way. The review finishes by briefly discussing the implications of climate change in increasing problems associated with control and the opportunities to control virus diseases more effectively through new technologies.

  14. THE ROLE OF CROP/POLLINATOR RELATIONSHIP IN BREEDING FOR POLLINATOR FRIENDLY LEGUME VARIETIES:FROM A BREEDING PERSPECTIVE

    USDA-ARS?s Scientific Manuscript database

    Breeders are encouraged to develop breeding approaches that strive to integrate food production into the healthy functioning of agro-ecosystems. In the case of legumes, this approach should preserve bee fauna by providing suitable floral resources within the crops themselves. In parallel, legume b...

  15. Environmental benefits of growing perennial legumes in cropping systems

    USDA-ARS?s Scientific Manuscript database

    Alfalfa offers several environmental benefits to farmers and society. Reduced nitrate leaching due to slower water flow and excellent nitrate removal are valuable in farm fields and at remediation sites. Improved N supply to following crops reduces energy use, economic costs, and greenhouse gas emis...

  16. Biomass and nitrogen accumulation of hairy vetch-cereal rye cover crop mixtures as influenced by species proportions

    USDA-ARS?s Scientific Manuscript database

    The performance and suitability of a legume-grass cover crop mixture for specific functions may be influenced by the proportions of each species in the mixture. The objectives of this study were to: 1) evaluate aboveground biomass and species biomass proportions at different hairy vetch (Vicia villo...

  17. Yields of Corn Silage Fertilized with Manure and Grown with Legume or Non-legume Companion Crops

    USDA-ARS?s Scientific Manuscript database

    In addition to reducing nitrate and soil losses, cover crops and living mulches could enhance corn silage yields. In a four-year study in southern Wisconsin, no-till corn was grown with herbicide-suppressed Kura-clover or with June-interseeded red clover followed by one year of clover production. Th...

  18. Estimation of runoff mitigation by morphologically different cover crop root systems

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Loiskandl, Willibald; Kaul, Hans-Peter; Himmelbauer, Margarita; Wei, Wei; Chen, Liding; Bodner, Gernot

    2016-07-01

    Hydrology is a major driver of biogeochemical processes underlying the distinct productivity of different biomes, including agricultural plantations. Understanding factors governing water fluxes in soil is therefore a key target for hydrological management. Our aim was to investigate changes in soil hydraulic conductivity driven by morphologically different root systems of cover crops and their impact on surface runoff. Root systems of twelve cover crop species were characterized and the corresponding hydraulic conductivity was measured by tension infiltrometry. Relations of root traits to Gardner's hydraulic conductivity function were determined and the impact on surface runoff was estimated using HYDRUS 2D. The species differed in both rooting density and root axes thickness, with legumes distinguished by coarser axes. Soil hydraulic conductivity was changed particularly in the plant row where roots are concentrated. Specific root length and median root radius were the best predictors for hydraulic conductivity changes. For an intensive rainfall simulation scenario up to 17% less rainfall was lost by surface runoff in case of the coarsely rooted legumes Melilotus officinalis and Lathyrus sativus, and the densely rooted Linum usitatissimum. Cover crops with coarse root axes and high rooting density enhance soil hydraulic conductivity and effectively reduce surface runoff. An appropriate functional root description can contribute to targeted cover crop selection for efficient runoff mitigation.

  19. A suggestion for planning cover crop mixtures: zones of occupancy

    USDA-ARS?s Scientific Manuscript database

    Producers may be able to improve the competitiveness of cover crop mixtures by selecting species to occupy zones in the cover crop canopy. This suggestion is based on a study where we compared four cover crop treatments, 1, 3, 6, and 9 species mixtures, for biomass production. Treatments were est...

  20. The potential of cover crops for improving soil function

    NASA Astrophysics Data System (ADS)

    Stoate, Chris; Crotty, Felicity

    2017-04-01

    Cover crops can be grown over the autumn and winter ensuring green cover throughout the year. They have been described as improving soil structure, reducing soil erosion and potentially even a form of grass weed control. These crops retain nutrients within the plant, potentially making them available for future crops, as well as increasing soil organic matter. Over the last three years, we have investigated how different cover crop regimes affect soil quality. Three separate experiments over each autumn/winter period have investigated how different cover crops affect soil biology, physics and chemistry, with each experiment building on the previous one. There have been significant effects of cover crops on soil structure, as well as significantly lower weed biomass and increased yields in the following crop - in comparison to bare stubble. For example, the effect of drilling the cover crops on soil structure in comparison to a bare stubble control that had not been driven on by machinery was quantified, and over the winter period the soil structure of the cover crop treatments changed, with compaction reduced in the cover crop treatments, whilst the bare stubble control remained unchanged. Weeds were found in significantly lower biomass in the cover crop mixes in comparison to the bare stubble control, and significantly lower weed biomass continued to be found in the following spring oat crop where the cover crops had been, indicating a weed suppressive effect that has a continued legacy in the following crop. The following spring oats have shown similar results in the last two years, with higher yields in the previous cover crop areas compared to the bare stubble controls. Overall, these results are indicating that cover crops have the potential to provide improvements to soil quality, reduce weeds and improve yields. We discuss the economic implications.

  1. The 4Rs for cover crops and other advances in cover crop management for environmental quality

    USDA-ARS?s Scientific Manuscript database

    Cover crops (CC) are universal tools that can be used to improve management practices to draw multiple benefits with increased sustainability across different continents (Dabney et al. 2001; Reeves 1994; Woodruff and Siddoway 1965; Frye et al. 1985; Holderbaum et al. 1990; Bilbro 1991; Langdale et a...

  2. Influence of cover crops on insect pests and predators in conservation tillage cotton.

    PubMed

    Tillman, Glynn; Schomberg, Harry; Phatak, Sharad; Mullinix, Benjamin; Lachnicht, Sharon; Timper, Patricia; Olson, Dawn

    2004-08-01

    In fall 2000, an on-farm sustainable agricultural research project was established for cotton, Gossypium hirsutum L., in Tift County, Georgia. The objective of our 2-yr research project was to determine the impact of several cover crops on pest and predator insects in cotton. The five cover crop treatments included 1) cereal rye, Secale cereale L., a standard grass cover crop; 2) crimson clover, Trifolium incarnatum L., a standard legume cover crop; 3) a legume mixture of balansa clover, Trifolium michelianum Savi; crimson clover; and hairy vetch, Vicia villosa Roth; 4) a legume mixture + rye combination; and 5) no cover crop in conventionally tilled fields. Three main groups or species of pests were collected in cover crops and cotton: 1) the heliothines Heliothis virescens (F.) and Helicoverpa zea (Boddie); 2) the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois); and 3) stink bugs. The main stink bugs collected were the southern green stink bug, Nezara viridula (L.); the brown stink bug, Euschistus servus (Say); and the green stink bug, Acrosternum hilare (Say). Cotton aphids, Aphis gossypii Glover, were collected only on cotton. For both years of the study, the heliothines were the only pests that exceeded their economic threshold in cotton, and the number of times this threshold was exceeded in cotton was higher in control cotton than in crimson clover and rye cotton. Heliothine predators and aphidophagous lady beetles occurred in cover crops and cotton during both years of the experiment. Geocoris punctipes (Say), Orius insidiosus (Say), and red imported fire ant, Solenopsis invicta Buren were relatively the most abundant heliothine predators observed. Lady beetles included the convergent lady beetle, Hippodamia convergens Guérin-Méneville; the sevenspotted lady beetle, Coccinella septempunctata L.; spotted lady beetle, Coleomegilla maculata (DeGeer); and the multicolored Asian lady beetle, Harmonia axyridis (Pallas). Density of G. punctipes was

  3. Genetics- and genomics-based interventions for nutritional enhancement of grain legume crops: status and outlook.

    PubMed

    Bohra, Abhishek; Sahrawat, Kanwar L; Kumar, Shiv; Joshi, Rohit; Parihar, Ashok K; Singh, Ummed; Singh, Deepak; Singh, Narendra P

    2015-05-01

    Meeting the food demands and ensuring nutritional security of the ever increasing global population in the face of degrading natural resource base and impending climate change is the biggest challenge of the twenty first century. The consequences of mineral/micronutrient deficiencies or the hidden hunger in the developing world are indeed alarming and need urgent attention. In addressing the problems associated with mineral/micronutrient deficiency, grain legumes as an integral component of the farming systems in the developing world have to play a crucial role. For resource-poor populations, a strategy based on selecting and/or developing grain legume cultivars with grains denser in micronutrients, by biofortification, seems the most appropriate and attractive approach to address the problem. This is evident from the on-going global research efforts on biofortification to provide nutrient-dense grains for use by the poorest of the poor in the developing countries. Towards this end, rapidly growing genomics technologies hold promise to hasten the progress of breeding nutritious legume crops. In conjunction with the myriad of expansions in genomics, advances in other 'omics' technologies particularly plant ionomics or ionome profiling open up novel opportunities to comprehensively examine the elemental composition and mineral networks of an organism in a rapid and cost-effective manner. These emerging technologies would effectively guide the scientific community to enrich the edible parts of grain legumes with bio-available minerals and enhancers/promoters. We believe that the application of these new-generation tools in turn would provide crop-based solutions to hidden hunger worldwide for achieving global nutritional security.

  4. Summary of cover crop effects on cotton production

    USDA-ARS?s Scientific Manuscript database

    Cover crop use in field crop research, especially cotton, dates back to Auburn University’s “Old Rotation”, the world’s oldest continuous cotton experiment, established in 1896. Despite the long history of cover crop research in the literature, meta-analytic methods have not been used to evaluate co...

  5. Cover Crop Chart: An Intuitive Educational Resource for Extension Professionals

    ERIC Educational Resources Information Center

    Liebig, Mark A.; Johnson, Holly; Archer, David; Hendrickson, John; Nichols, Kristine; Schmer, Marty; Tanaka, Don

    2013-01-01

    Interest in cover crops by agricultural producers has increased the need for information regarding the suitability of crops for addressing different production and natural resource goals. To help address this need, staff at the USDA-ARS Northern Great Plains Research Laboratory developed a decision aid called the Cover Crop Chart (CCC). Visually…

  6. Cover Crop Chart: An Intuitive Educational Resource for Extension Professionals

    ERIC Educational Resources Information Center

    Liebig, Mark A.; Johnson, Holly; Archer, David; Hendrickson, John; Nichols, Kristine; Schmer, Marty; Tanaka, Don

    2013-01-01

    Interest in cover crops by agricultural producers has increased the need for information regarding the suitability of crops for addressing different production and natural resource goals. To help address this need, staff at the USDA-ARS Northern Great Plains Research Laboratory developed a decision aid called the Cover Crop Chart (CCC). Visually…

  7. Remote sensing to monitor cover crop adoption in southeastern Pennsylvania

    USDA-ARS?s Scientific Manuscript database

    In the Chesapeake Bay watershed, winter cereal cover crops are often planted in rotation with summer crops to reduce the loss of nutrients and sediment from agricultural systems. Cover crops can also improve soil health, control weeds and pests, supplement forage needs, and support resilient croppin...

  8. 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

  9. 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.

  10. Establishment of three permanent cover crop seed mixtures in Hungarian vineyards

    NASA Astrophysics Data System (ADS)

    Miglécz, Tamas; Valkó, Orsolya; Donkó, Ádám; Deák, Balázs; Török, Péter; Kelemen, András; Drexler, Dóra; Tóthmérész, Béla

    2015-04-01

    In organic vineyard farming sowing high diversity cover crop seed mixtures offers a great opportunity to overcome high-priority problems mitigating vineyard cultivation, such as gain erosion control, save soil fertility, improve soil microbial activity and control weeds. Furthermore, we can also improve the biodiversity and ecosystem services of vineyards. Mainly non-native or low diversity seed mixtures are used for cover cropping containing some grass, grain or Fabaceae species. We studied vegetation development after sowing native high-diversity seed mixtures in four vineyards in an on farm field trial. We compared the effects of 4 treatments: (i) Biocont-Ecowin mixture (12 species), (ii) Fabaceae mixture (9 species), (iii) Grass-forb mixture (16 species) and control (no seed sowing). Study sites were located in Tokaj wine region, East Hungary. Seed mixtures were sown in March, 2012. After sowing, we recorded the percentage cover of vascular plant species in the end of June 2012, 2013 and 2014 in altogether 80 permanent plots. In the first year the establishment and weed control of Biocont-Ecowin and Legume seed mixture was the best. For the second year in inter-rows sown with Grass-herb and Legume seed mixtures we detected decreasing weed cover scores, while in inter-rows sown with Biocont-Ecowin seed mixture and in control inter-rows we detected higher weed cover scores. In the third year we still detected lower weed cover scores in inter-rows sown with Grass-forb and Legume seed mixtures, however on several sites we also detected decreasing cover of sown species. All sown species were detected in our plots during the time of the study, however some species were present only with low cover scores or only in a few plots. Out of the sown species Lotus corniculatus, Medicago lupulina, Plantago lanceolata, Trifolium repens, T. pratense and Coronilla varia established the most successfully, and had high cover scores on most sites even in the second and third year

  11. Effects of cover crop presence, cover crop species selection, and fungicide seed treatment on corn seedling growth

    USDA-ARS?s Scientific Manuscript database

    Cover crops offer erosion protection as well as soil and environmental quality benefits. However, they can occasionally have negative impacts on the yield of a following grain crop, which discourages broader adoption and adds substantial cost to the practice of cover cropping. We performed a series ...

  12. Hormonal regulation of reproductive growth under normal and heat-stress conditions in legume and other model crop species.

    PubMed

    Ozga, Jocelyn A; Kaur, Harleen; Savada, Raghavendra P; Reinecke, Dennis M

    2017-04-01

    Legume crops are grown throughout the world and provide an excellent food source of digestible protein and starch, as well as dietary fibre, vitamins, minerals, and flavonoids. Fruit and seeds from legumes are also an important source of vegetables for a well-balanced diet. A trend in elevated temperature as a result of climate change increases the risk of a heat stress-induced reduction in legume crop yield. High temperatures during the crop reproductive development phase are particularly detrimental to fruit/seed production because the growth and development of the reproductive tissues are sensitive to small changes in temperature. Hormones are signalling molecules that play important roles in a plant's ability to integrate different environmental inputs and modify their developmental processes to optimize growth, survival, and reproduction. This review focuses on the hormonal regulation of reproductive development and heat stress-induced alteration of this regulation during (i) pollination, (ii) early fruit set, and (iii) seed development that affects fruit/seed yield in legume and other model crops. Further understanding of hormone-regulated reproductive growth under non-stress and heat-stress conditions can aid in trait selection and the development of gene modification strategies and cultural practices to improve heat tolerance in legume crops contributing to improved food security. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Effects of Carbon and Cover Crop Residues on N2O and N2 Emissions

    NASA Astrophysics Data System (ADS)

    Burger, M.; Cooperman, Y.; Horwath, W. R.

    2016-12-01

    In Mediterranean climate, nitrous oxide emissions occurring with the first rainfall after the dry summer season can contribute up to 50% of agricultural systems' total annual emissions, but the drivers of these emissions have not been clearly identified, and there are only few measurements of atmospheric nitrogen (N2) production (denitrification) during these events. In lab incubations, we investigated N2O and N2 production, gross ammonification and nitrification, and microbial N immobilization with wet-up in soil from a vineyard that was previously fallow or where cover crop residue had been incorporated the previous spring. Before the first rainfall, we measured 120 mg dissolved organic carbon (DOC-C) kg-1 soil in the 0-5 cm layer of this vineyard, and after the rain 10 mg DOC-C kg-1, while nitrate levels before the rain were <5 mg N kg-1 in fallow and <10 mg N kg-1 in previously cover cropped soil. The N2O/N2 production was 2, 7, 9, and 86% in fallow, legume-grass mixture, rye, and legume cover cropped soil. The N2O/N2 ratio tended to increase with lower DOC (post-rain) levels in the soil. The results suggest that accumulated carbon in dry surface soil is the main driving factor of N2O and N2 emissions through denitrification with the first rainfall after prolonged dry periods.

  14. Breaking continuous potato cropping with legumes improves soil microbial communities, enzyme activities and tuber yield

    PubMed Central

    Qin, Shuhao; Yeboah, Stephen; Cao, Li; Zhang, Junlian; Shi, Shangli; Liu, Yuhui

    2017-01-01

    This study was conducted to explore the changes in soil microbial populations, enzyme activity, and tuber yield under the rotation sequences of Potato–Common vetch (P–C), Potato–Black medic (P–B) and Potato–Longdong alfalfa (P–L) in a semi–arid area of China. The study also determined the effects of continuous potato cropping (without legumes) on the above mentioned soil properties and yield. The number of bacteria increased significantly (p < 0.05) under P–B rotation by 78%, 85% and 83% in the 2, 4 and 7–year continuous cropping soils, respectively compared to P–C rotation. The highest fungi/bacteria ratio was found in P–C (0.218), followed by P–L (0.184) and then P–B (0.137) rotation over the different cropping years. In the continuous potato cropping soils, the greatest fungi/bacteria ratio was recorded in the 4–year (0.4067) and 7–year (0.4238) cropping soils and these were significantly higher than 1–year (0.3041), 2–year (0.2545) and 3–year (0.3030) cropping soils. Generally, actinomycetes numbers followed the trend P–L>P–C>P–B. The P–L rotation increased aerobic azotobacters in 2–year (by 26% and 18%) and 4–year (40% and 21%) continuous cropping soils compared to P–C and P–B rotation, respectively. Generally, the highest urease and alkaline phosphate activity, respectively, were observed in P–C (55.77 mg g–1) and (27.71 mg g–1), followed by P–B (50.72 mg mg–1) and (25.64 mg g–1) and then P–L (41.61 mg g–1) and (23.26 mg g–1) rotation. Soil urease, alkaline phosphatase and hydrogen peroxidase activities decreased with increasing years of continuous potato cropping. On average, the P–B rotation significantly increased (p <0.05) tuber yield by 19% and 18%, compared to P–C and P–L rotation respectively. P–L rotation also increased potato tuber yield compared to P–C, but the effect was lesser relative to P–B rotation. These results suggest that adopting potato–legume rotation

  15. Maize residue removal and cover crop effects on subsequent soybean crops

    USDA-ARS?s Scientific Manuscript database

    Residue removal and cover crop treatments often differentially affect cash crop yield across geographical regions. Objectives were to examine maize residue removal and cover crop treatment effects on soybean grain yield and seed components (moisture at harvest and mineral nutrients) near Brookings,...

  16. A Centralized Regional Database for Winter Cover Crops in Annual Cropping Systems

    USDA-ARS?s Scientific Manuscript database

    Winter cover crops have the potential to reduce erosion, minimize losses of nitrogen and phosphorus, and increase soil carbon in annual cropping systems in the Midwest. Public support, however, for incentives to farmers to adopt cover crops is minimal. Therefore, development of location-specific rec...

  17. Integrated crop-livestock systems and cover crop grazing in the Northern Great Plains

    USDA-ARS?s Scientific Manuscript database

    Integrating crops and livestock has been identified as an approach to sustainably intensify agricultural systems, increasing production while reducing the need for external inputs, building soil health, and increasing economic returns. Cover crops and grazing these cover crops are a natural fit with...

  18. Herbicide and cover crop residue integration in conservation tillage tomato

    USDA-ARS?s Scientific Manuscript database

    The increased adoption of conservation tillage in vegetable production requires more information on the role of various cover crops in weed control, tomato quality, and yield. Three conservation-tillage systems utilizing crimson clover, turnip, and cereal rye as winter cover crops were compared to a...

  19. Winter cover crops impact on corn production in semiarid regions

    USDA-ARS?s Scientific Manuscript database

    Cover crops have been proposed as a technique to increase soil health. This study examined the impact of winter brassica cover crop cocktails grown after wheat (Triticum aestivum) on corn yields; corn yield losses due to water and N stress; soil bacteria to fungi ratios; mycorrhizal markers; and ge...

  20. Termination of cover crops using rollers/crimpers

    USDA-ARS?s Scientific Manuscript database

    An integral component of conservation agriculture systems is the use of a high-residue winter cover crop; however, terminating cover crops is an addition expense and planting into high-residue can be a challenge. An experiment was conducted using black oat (Avena strigosa Schreb.), rye (Secale cere...

  1. Fertilizer effects on a winter cereal cover crop

    USDA-ARS?s Scientific Manuscript database

    Benefits associated with conservation tillage in the Southeast are improved by using a winter cereal cover crop. In general, cover crop benefits increase as biomass production is increased, but the infertile soils typically require additional N (inorganic or organic). Currently, limited informatio...

  2. Black oat cover crop management in watermelon production systems

    USDA-ARS?s Scientific Manuscript database

    Black oats (Avena strigosa Schreb.) were sown as a cover crop near Weslaco, Texas (Lat. 26 deg N) in Fall 2010. The cover crop was allowed to senesce naturally and was planted to watermelons in both the spring and in the fall of 2011. Watermelon transplants planted in the spring into mowed black o...

  3. Metal uptake via phosphate fertilizer and city sewage in cereal and legume crops in Pakistan.

    PubMed

    Murtaza, G; Javed, W; Hussain, A; Wahid, A; Murtaza, B; Owens, G

    2015-06-01

    Crop irrigation with heavy metal-contaminated effluents is increasingly common worldwide and necessitates management strategies for safe crop production on contaminated soils. This field study examined the phytoavailability of three metals (Cd, Cu, and Zn) in two cereal (wheat, maize) and legume (chickpea, mungbean) crops in response to the application of either phosphatic fertilizer or sewage-derived water irrigation over two successive years. Five fertilizer treatments, i.e. control, recommended nitrogen (N) applied alone and in combination of three levels of phosphorus (P), half, full and 1.5 times of recommended P designated as N0P0, N1P0, N1P0.5, N1P1.0, and N1P1.5, respectively. Tissue concentrations of Cd, Cu, Zn, and P were determined in various plant parts, i.e., root, straw, and grains. On the calcareous soils studied while maximum biomass production was obtained with application of P at half the recommended dose, the concentrations of metals in the crops generally decreased with increasing P levels. Tissue metal concentrations increased with the application of N alone. Translocation and accumulation of Zn and Cu were consistently higher than Cd. And the pattern of Cd accumulation differed among plant species; more Cd being accumulated by dicots than monocots, especially in their grains. The order of Cd accumulation in grains was maize > chickpea > mungbean > wheat. Mungbean and chickpea straws also had higher tissue Cd concentration above permissible limits. The two legume species behaved similarly, while cereal species differed from each other in their Cd accumulation. Metal ion concentrations were markedly higher in roots followed by straw and grains. Increasing soil-applied P also increased the extractable metal and P concentrations in the post-harvest soil. Despite a considerable addition of metals by P fertilizer, all levels of applied P effectively decreased metal phytoavailability in sewage-irrigated soils, and applying half of the

  4. Nitrous oxide emissions in cover crop-based corn production systems

    NASA Astrophysics Data System (ADS)

    Davis, Brian Wesley

    Nitrous oxide (N2O) is a potent greenhouse gas; the majority of N2O emissions are the result of agricultural management, particularly the application of N fertilizers to soils. The relationship of N2O emissions to varying sources of N (manures, mineral fertilizers, and cover crops) has not been well-evaluated. Here we discussed a novel methodology for estimating precipitation-induced pulses of N2O using flux measurements; results indicated that short-term intensive time-series sampling methods can adequately describe the magnitude of these pulses. We also evaluated the annual N2O emissions from corn-cover crop (Zea mays; cereal rye [Secale cereale], hairy vetch [Vicia villosa ], or biculture) production systems when fertilized with multiple rates of subsurface banded poultry litter, as compared with tillage incorporation or mineral fertilizer. N2O emissions increased exponentially with total N rate; tillage decreased emissions following cover crops with legume components, while the effect of mineral fertilizer was mixed across cover crops.

  5. Remote sensing to monitor cover crop adoption in southeastern Pennsylvania

    USGS Publications Warehouse

    Hively, Wells; Sjoerd Duiker,; Greg McCarty,; Prabhakara, Kusuma

    2015-01-01

    In the Chesapeake Bay Watershed, winter cereal cover crops are often planted in rotation with summer crops to reduce the loss of nutrients and sediment from agricultural systems. Cover crops can also improve soil health, control weeds and pests, supplement forage needs, and support resilient cropping systems. In southeastern Pennsylvania, cover crops can be successfully established following corn (Zea mays L.) silage harvest and are strongly promoted for use in this niche. They are also planted following corn grain, soybean (Glycine max L.), and vegetable harvest. In Pennsylvania, the use of winter cover crops for agricultural conservation has been supported through a combination of outreach, regulation, and incentives. On-farm implementation is thought to be increasing, but the actual extent of cover crops is not well quantified. Satellite imagery can be used to map green winter cover crop vegetation on agricultural fields and, when integrated with additional remote sensing data products, can be used to evaluate wintertime vegetative groundcover following specific summer crops. This study used Landsat and SPOT (System Probatoire d’ Observation de la Terre) satellite imagery, in combination with the USDA National Agricultural Statistics Service Cropland Data Layer, to evaluate the extent and amount of green wintertime vegetation on agricultural fields in four Pennsylvania counties (Berks, Lebanon, Lancaster, and York) from 2010 to 2013. In December of 2010, a windshield survey was conducted to collect baseline data on winter cover crop implementation, with particular focus on identifying corn harvested for silage (expected earlier harvest date and lower levels of crop residue), versus for grain (expected later harvest date and higher levels of crop residue). Satellite spectral indices were successfully used to detect both the amount of green vegetative groundcover and the amount of crop residue on the surveyed fields. Analysis of wintertime satellite imagery

  6. Potential of rice stubble as a reservoir of bradyrhizobial inoculum in rice-legume crop rotation.

    PubMed

    Piromyou, Pongdet; Greetatorn, Teerana; Teamtisong, Kamonluck; Tittabutr, Panlada; Boonkerd, Nantakorn; Teaumroong, Neung

    2017-09-15

    Bradyrhizobium encompasses a variety of bacteria that can live in symbiotic and endophytic associations with leguminous and non-leguminous plants such as rice. Therefore, it can be expected that rice endophytic bradyrhizobia can be applied in the rice-legume crop rotation system. Some endophytic bradyrhizobial strains were isolated from rice (Oryza sativa L.) tissues. The rice biomass could be enhanced when supplying KNO3, NH4NO3, or urea with bradyrhizobial strain inoculation, especially strain SUTN9-2. In contrast, the strains which suppressed rice growth were photosynthetic bradyrhizobia and also found to produce nitric oxide (NO) in the rice root. The expression of genes involved in NO production was conducted using qRT-PCR technique. The nirK gene expression level of SUT-PR48 with nitrate was higher than that of norB gene. In contrast, the inoculation of SUTN9-2 resulted in a lower expression of nirK gene when compared with norB gene. These results suggest that SUT-PR48 may accumulate NO more than SUTN9-2 does. Furthermore, the nifH expression of SUTN9-2 was induced in treatment without nitrogen supplementation in endophytic association with rice. The IAA and ACC deaminase produced in planta by SUTN9-2 were also detected. Enumeration of rice endophytic bradyrhizobia from rice tissues revealed that SUTN9-2 still persisted in rice tissues until rice-harvesting season. The mung bean (Vigna radiata) can be nodulated after rice stubbles were decomposed. Therefore, it is possible that rice stubbles can be used as inoculum in the rice-legume crop rotation system under both low- and high-organic matter soil condition.Importance This study shows that some rice endophytic bradyrhizobia could perform IAA production, and ACC deaminase activity together with nitrogen fixation ability during symbiosis inside rice tissues. These characteristics may play an important role in rice growth promotion by endophytic bradyrhizobium. However, the NO producing strains should be of

  7. Panel Discussion: Cover Crops Used at Vallonia Nursery, Indiana Division of Forestry

    Treesearch

    Robert Hawkins

    2005-01-01

    The use of cover crops is one essential step in management of nursery soils. Cover crops serve many different purposes within the soil. First, cover crops help in reducing erosion by stabilizing soil. Second, cover crops can be used as a visual guide to nutrient deficiencies in fields prior to sowing seedling crops. Most important, cover crops build organic matter,...

  8. Achievements and prospects of genomics-assisted breeding in three legume crops of the semi-arid tropics

    USDA-ARS?s Scientific Manuscript database

    Advances in sequencing and genotyping technologies have enabled generation of several thousand markers including SSRs, SNPs, DArTs, hundreds of thousands transcript reads and BAC-end sequences in chickpea, pigeonpea and groundnut, three major legume crops of the semi-arid tropics. Comprehensive tran...

  9. Legumes or nitrification inhibitors to reduce N2O emissions in subtropical cereal cropping systems? A simulation study

    USDA-ARS?s Scientific Manuscript database

    The DAYCENT biogeochemical model was used to investigate how the use of fertilisers coated with nitrification inhibitors and the introduction of legumes in the crop rotation can affect subtropical cereal production and N2O emissions. The model was validated using comprehensive multi-seasonal, high-f...

  10. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems

    PubMed Central

    Ladoni, Moslem; Kravchenko, Alexandra N.; Robertson, G. Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and NO3--N levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4–5 times during each growing season and analyzed for NO3--N and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3—N. Red clover cover crop increased NO3--N by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on NO3--N in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop agricultural systems. PMID:26600462

  11. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    PubMed

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop

  12. Soil Nitrogen Response to Coupling Cover Crops with Manure Injection

    USDA-ARS?s Scientific Manuscript database

    Coupling winter small grain cover crops (CC) with manure (M) application may increase retention of manure nitrogen (N) in corn-soybean cropping systems. The objective of this research was to quantify soil N changes after application of liquid swine M (Sus scrofa L.) at target N rates of 112, 224, an...

  13. Cover Crop Chart: An Outreach Tool for Agricultural Producers

    USDA-ARS?s Scientific Manuscript database

    Interest in cover crops by farmers and ranchers throughout the Northern Great Plains has increased the need for information on the suitability of a diverse portfolio of crops for different production and management resource goals. To help address this need, Northern Great Plains Research Laboratory...

  14. Potential use of phytocystatins in crop improvement, with a particular focus on legumes.

    PubMed

    Kunert, Karl J; van Wyk, Stefan G; Cullis, Christopher A; Vorster, Barend J; Foyer, Christine H

    2015-06-01

    Phytocystatins are a well-characterized class of naturally occurring protease inhibitors that function by preventing the catalysis of papain-like cysteine proteases. The action of cystatins in biotic stress resistance has been studied intensively, but relatively little is known about their functions in plant growth and defence responses to abiotic stresses, such as drought. Extreme weather events, such as drought and flooding, will have negative impacts on the yields of crop plants, particularly grain legumes. The concepts that changes in cellular protein content and composition are required for acclimation to different abiotic stresses, and that these adjustments are achieved through regulation of proteolysis, are widely accepted. However, the nature and regulation of the protein turnover machinery that underpins essential stress-induced cellular restructuring remain poorly characterized. Cysteine proteases are intrinsic to the genetic programmes that underpin plant development and senescence, but their functions in stress-induced senescence are not well defined. Transgenic plants including soybean that have been engineered to constitutively express phytocystatins show enhanced tolerance to a range of different abiotic stresses including drought, suggesting that manipulation of cysteine protease activities by altered phytocystatin expression in crop plants might be used to improve resilience and quality in the face of climate change.

  15. The Use of Cover Crops as Climate-Smart Management in Midwest Cropping Systems

    NASA Astrophysics Data System (ADS)

    Basche, A.; Miguez, F.; Archontoulis, S.; Kaspar, T.

    2014-12-01

    The observed trends in the Midwestern United States of increasing rainfall variability will likely continue into the future. Events such as individual days of heavy rain as well as seasons of floods and droughts have large impacts on agricultural productivity and the natural resource base that underpins it. Such events lead to increased soil erosion, decreased water quality and reduced corn and soybean yields. Winter cover crops offer the potential to buffer many of these impacts because they essentially double the time for a living plant to protect and improve the soil. However, at present, cover crops are infrequently utilized in the Midwest (representing 1-2% of row cropped land cover) in particular due to producer concerns over higher costs and management, limited time and winter growing conditions as well as the potential harm to corn yields. In order to expand their use, there is a need to quantify how cover crops impact Midwest cropping systems in the long term and namely to understand how to optimize the benefits of cover crops while minimizing their impacts on cash crops. We are working with APSIM, a cropping systems platform, to specifically quantify the long term future impacts of cover crop incorporation in corn-based cropping systems. In general, our regional analysis showed only minor changes to corn and soybean yields (<1% differences) when a cover crop was or was not included in the simulation. Further, a "bad spring" scenario (where every third year had an abnormally wet/cold spring and cover crop termination and planting cash crop were within one day) did not result in any major changes to cash crop yields. Through simulations we estimate an average increase of 4-9% organic matter improvement in the topsoil and an average decrease in soil erosion of 14-32% depending on cover crop planting date and growth. Our work is part of the Climate and Corn-based Cropping Systems Coordinated Agriculture Project (CSCAP), a collaboration of eleven Midwestern

  16. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    NASA Astrophysics Data System (ADS)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under

  17. Achievements and prospects of genomics-assisted breeding in three legume crops of the semi-arid tropics.

    PubMed

    Varshney, Rajeev K; Mohan, S Murali; Gaur, Pooran M; Gangarao, N V P R; Pandey, Manish K; Bohra, Abhishek; Sawargaonkar, Shrikant L; Chitikineni, Annapurna; Kimurto, Paul K; Janila, Pasupuleti; Saxena, K B; Fikre, Asnake; Sharma, Mamta; Rathore, Abhishek; Pratap, Aditya; Tripathi, Shailesh; Datta, Subhojit; Chaturvedi, S K; Mallikarjuna, Nalini; Anuradha, G; Babbar, Anita; Choudhary, Arbind K; Mhase, M B; Bharadwaj, Ch; Mannur, D M; Harer, P N; Guo, Baozhu; Liang, Xuanqiang; Nadarajan, N; Gowda, C L L

    2013-12-01

    Advances in next-generation sequencing and genotyping technologies have enabled generation of large-scale genomic resources such as molecular markers, transcript reads and BAC-end sequences (BESs) in chickpea, pigeonpea and groundnut, three major legume crops of the semi-arid tropics. Comprehensive transcriptome assemblies and genome sequences have either been developed or underway in these crops. Based on these resources, dense genetic maps, QTL maps as well as physical maps for these legume species have also been developed. As a result, these crops have graduated from 'orphan' or 'less-studied' crops to 'genomic resources rich' crops. This article summarizes the above-mentioned advances in genomics and genomics-assisted breeding applications in the form of marker-assisted selection (MAS) for hybrid purity assessment in pigeonpea; marker-assisted backcrossing (MABC) for introgressing QTL region for drought-tolerance related traits, Fusarium wilt (FW) resistance and Ascochyta blight (AB) resistance in chickpea; late leaf spot (LLS), leaf rust and nematode resistance in groundnut. We critically present the case of use of other modern breeding approaches like marker-assisted recurrent selection (MARS) and genomic selection (GS) to utilize the full potential of genomics-assisted breeding for developing superior cultivars with enhanced tolerance to various environmental stresses. In addition, this article recommends the use of advanced-backcross (AB-backcross) breeding and development of specialized populations such as multi-parents advanced generation intercross (MAGIC) for creating new variations that will help in developing superior lines with broadened genetic base. In summary, we propose the use of integrated genomics and breeding approach in these legume crops to enhance crop productivity in marginal environments ensuring food security in developing countries.

  18. Large-scale transcriptome analysis in chickpea (Cicer arietinum L.), an orphan legume crop of the semi-arid tropics of Asia and Africa

    USDA-ARS?s Scientific Manuscript database

    Chickpea (Cicer arietinum L.) is an important legume crop in the semi-arid regions of Asia and Africa. Gains in crop productivity have been low however, particularly due to biotic and abiotic stresses. To help enhance crop productivity using molecular breeding techniques, next generation sequencing ...

  19. Landmark Research in Legumes

    USDA-ARS?s Scientific Manuscript database

    Legumes are members of family Fabaceae or Leguminosae and include economically important grain legumes, oilseed crops, forage crops, shrubs and tropical or subtropical trees. Many legumes are rich source of quality protein for humans and animals and enrich the soil by producing their own nitrogen i...

  20. Draft genome sequence of pigeonpea (Cajanus cajan), an orphan legume crop of resource-poor farmers.

    PubMed

    Varshney, Rajeev K; Chen, Wenbin; Li, Yupeng; Bharti, Arvind K; Saxena, Rachit K; Schlueter, Jessica A; Donoghue, Mark T A; Azam, Sarwar; Fan, Guangyi; Whaley, Adam M; Farmer, Andrew D; Sheridan, Jaime; Iwata, Aiko; Tuteja, Reetu; Penmetsa, R Varma; Wu, Wei; Upadhyaya, Hari D; Yang, Shiaw-Pyng; Shah, Trushar; Saxena, K B; Michael, Todd; McCombie, W Richard; Yang, Bicheng; Zhang, Gengyun; Yang, Huanming; Wang, Jun; Spillane, Charles; Cook, Douglas R; May, Gregory D; Xu, Xun; Jackson, Scott A

    2011-11-06

    Pigeonpea is an important legume food crop grown primarily by smallholder farmers in many semi-arid tropical regions of the world. We used the Illumina next-generation sequencing platform to generate 237.2 Gb of sequence, which along with Sanger-based bacterial artificial chromosome end sequences and a genetic map, we assembled into scaffolds representing 72.7% (605.78 Mb) of the 833.07 Mb pigeonpea genome. Genome analysis predicted 48,680 genes for pigeonpea and also showed the potential role that certain gene families, for example, drought tolerance-related genes, have played throughout the domestication of pigeonpea and the evolution of its ancestors. Although we found a few segmental duplication events, we did not observe the recent genome-wide duplication events observed in soybean. This reference genome sequence will facilitate the identification of the genetic basis of agronomically important traits, and accelerate the development of improved pigeonpea varieties that could improve food security in many developing countries.

  1. Cover crops to improve soil health and pollinator habitat in nut orchards

    Treesearch

    Jerry. Van Sambeek

    2017-01-01

    Recently several national programs have been initiated calling for improving soil health and creating pollinator habitat using cover crops. Opportunities exist for nut growers to do both with the use of cover crops in our nut orchards. Because we can include perennial ground covers as cover crops, we have even more choices than landowners managing cover crops during...

  2. Effects of the legume Vigna unguiculata crop on carbon and nitrogen cycles

    NASA Astrophysics Data System (ADS)

    Sánchez-Navarro, Virginia; Zornoza, Raúl; Fernández, Juan; Faz Cano, Ángel

    2015-04-01

    In this study, we investigated the effects of a legume crop (Vigna unguiculata) on soil properties related to the carbon (C) and nitrogen (N) cycles, taking into account different management practices (conventional and organic) and two genotypes. The study was randomly designed in blocks with four replications, in plots of 10 m2. The crop cycle spanned from 29 May 2014 to 13 August 2014. We collected soil samples (0-30 cm) from each plot at the beginning and at the end of the cycle to measure soil total N, organic C, recalcitrant C, organic C labile fractions, microbial biomass C (MBC) and the enzyme activities β-glucosidase and β-glucosaminidase. We collected plant samples (seeds, pods, roots and stem/leaves) at two different maturity stages (fresh and dry pods) to assess the influence of management practices and genotype in the accumulation of N, as indicative of the content of proteins in the crop. In the final plant sampling, we also determined crop production. The results showed that no significant differences were observed between management practices and genotypes in any of the soil properties measured. However, total N, recalcitrant C, most labile C fraction, MBC and β-glucosidase increased at the final sampling compared to initial values. We observed that genotype had a significant effect on the concentration of the second fraction of labile C under organic management. N content in the different plant tissues was significantly higher in the intermediate sampling than in the final harvest, without significant differences between management practices and genotypes. We observed a significant positive correlation between N content in roots, seeds and pods. N content was always higher in seeds, indicating the high quantity of proteins in this crop. C content was significantly lower in stem/leaves than in the rest of tissues, without significant differences among them. No effect of management practice, maturity stage or genotype was observed with regard to C

  3. Tillage and cover cropping effects on soil properties and crop production in Illinois

    USDA-ARS?s Scientific Manuscript database

    Cover crops (CCs) have been heralded for their potential to improve soil properties, retain nutrients in the field, and increase subsequent crop yields yet support for these claims within the state of Illinois remains limited. We assessed the effects of integrating five sets of CCs into a corn-soybe...

  4. Cover crops effectiveness for soil erosion control in Sicilian vineyard

    NASA Astrophysics Data System (ADS)

    Gristina, L.; Novara, A.; Saladino, S.; Santoro, A.

    2009-04-01

    In vineyards, which are very common in Mediterranean area, cover crops are becoming increasingly used to reduce soil erosion. Cover crops reduce runoff by increasing infiltration and increasing roughness and then reducing the ovelandflow velocity. The aim of the present study was to quantify soil and water losses under different soil managements systems on vineyards. The study site was a Sauvignon blanc winegrape vineyard located in Southwestern Sicily. Vineyards were managed both traditionally (conventional tillage) and alternative management using cover crops: 1) Vicia faba ; 2) Vicia faba and Vicia sativa; 3) Trifolium subterraneum, Lolium perenne, Festuca rubra; 4)Trifolium subterraneum, Festuca rubra and Festuca ovina, 5) Triticum durum, 6) Triticum durum and Vicia sativa. To monitor water and sediment yield, a Gerlach trough was installed at each treatment on the vineyard inter-row, with the row vineyard used as a border (topographical border). Runoff was measured after each rainfall event (raingauge 0.2 mm accuracy) from November 2005 to April 2007. And sediments were measured after desiccation. The results show that runoff and erosion were reduced considerably under the treatments with Trifolium subterraneum, Lolium perenne, Festuca rubra and Trifolium subterraneum, Festuca rubra and Festuca ovina (treatments 3 and 4). The soil losses were reduced by 73% under treatment 4 compared to the tillage plot. Conventional tillage and alternative management using Vicia faba cover crop (treatment 1) result the most ineffective treatment to soil erosion. These results show that the use of a cover crop can be a simple soil and water conservation practice in Sicilian vineyards. Key words: soil erosion, cover crops, vineyard, Mediterranean area.

  5. 7 CFR 1437.502 - Coverage periods and fees for covered tropical crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Coverage periods and fees for covered tropical crops... CROP DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.502 Coverage periods and fees for covered tropical crops. (a) The crop year for all covered tropical crops is the...

  6. 7 CFR 1437.502 - Coverage periods and fees for covered tropical crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Coverage periods and fees for covered tropical crops... CROP DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.502 Coverage periods and fees for covered tropical crops. (a) The crop year for all covered tropical crops is the...

  7. 7 CFR 1437.502 - Coverage periods and fees for covered tropical crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Coverage periods and fees for covered tropical crops... CROP DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.502 Coverage periods and fees for covered tropical crops. (a) The crop year for all covered tropical crops is the...

  8. 7 CFR 1437.502 - Coverage periods and fees for covered tropical crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Coverage periods and fees for covered tropical crops... CROP DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.502 Coverage periods and fees for covered tropical crops. (a) The crop year for all covered tropical crops is the...

  9. 7 CFR 1437.502 - Coverage periods and fees for covered tropical crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Coverage periods and fees for covered tropical crops... CROP DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.502 Coverage periods and fees for covered tropical crops. (a) The crop year for all covered tropical crops is the...

  10. Using cash cover crops to provide pollinator provisions in the Upper Midwest

    USDA-ARS?s Scientific Manuscript database

    To date, the use of winter cover crops in MN and SD has been slow to be adopted. The short growing season and potential for late, wet springs make cover crops risky to farmers with little economic return. The use of cash cover crops in this area offers the standard advantages of other cover crops, w...

  11. COVER CROP SYSTEMS AFFECT WEED COMMUNITIES IN A CALIFORNIA VINEYARD

    USDA-ARS?s Scientific Manuscript database

    Vineyard weed communities were examined under four dormant season cover crop systems representative of those used in the north-coastal grape-growing region of California: no-till annuals (rose clover, soft brome, zorro fescue; ANoT), no-till perennials (blue wildrye, California brome, meadow barley,...

  12. Rolled cover crop mulches for organic corn and soybean production

    USDA-ARS?s Scientific Manuscript database

    Interest in cover crop mulches has increased out of both economic and soil conservation concerns. The number of tractor passes required to produce corn and a soybean organically is expensive and logistically challenging. Farmers currently use blind cultivators, such as a rotary hoe or flex-tine harr...

  13. Evaluation of organic cover crop termination methods: flame or fiction?

    USDA-ARS?s Scientific Manuscript database

    Use of winter cover crops is an integral component of organic vegetable systems. However, timely spring termination currently relies on tillage in most instances due to time constraints. Thus, the use of conservation practices in organic systems is usually disjointed with some tillage required betw...

  14. Assessment of spectral indicies for crop residue cover estimation

    USDA-ARS?s Scientific Manuscript database

    The quantification of surficial crop residue cover is important for assessing agricultural tillage practices, rangeland health, and brush fire hazards. The Cellulose Absorption Index (CAI) and the Shortwave Infrared Normalized Difference Residue Index (SINDRI) are two spectral indices that have show...

  15. Cover cropping impacts on arbuscular mycorrhizal fungi and soil aggregation

    USDA-ARS?s Scientific Manuscript database

    Cover crops are a management tool which can extend the period of time that a living plant is growing and conducting photosynthesis. This is critical for soil health, because most of the soil organisms, particularly the arbuscular mycorrhizal fungi, are limited by carbon. Research, on-farm, and demon...

  16. Modeling cover Crop Effectiveness on Maryland's Eastern Shore

    USDA-ARS?s Scientific Manuscript database

    Cover cropping has become a widely used conservation practice on Maryland’s Eastern shore. It is one of the main practices funded by the Maryland Department of Agriculture’s (MDA) Maryland Agricultural Water Quality Cost Share (MACS) program. The major benefits of this practice include reduction of ...

  17. Corn Belt Assessment of Cover Crop Management and Preferences

    USDA-ARS?s Scientific Manuscript database

    Surveying end-users about their use of technologies and preferences provides information for researchers and educators to develop relevant research and educational programs. A mail survey was sent to Corn Belt farmers during 2006 to quantify cover crop management and preferences. Results indicated t...

  18. Rye cover crop effects on soil quality in no-till corn silage-soybean cropping systems

    USDA-ARS?s Scientific Manuscript database

    Corn and soybean farmers in the upper Midwest are showing increasing interest in winter cover crops. Known benefits of winter cover crops include reductions in nutrient leaching, erosion prevention, and weed suppression; however, the effects of winter cover crops on soil quality in this region have ...

  19. Genetic resources in the USDA, ARS, PGRCU legume crop germplasm collections with phyto-pharmaceutical uses

    USDA-ARS?s Scientific Manuscript database

    Seventeen health functional legumes including butterfly pea (Clitoria ternatea L.), Indigofera cassioides Rottler ex DC., I. linnaei Ali, I. suffruticosa Mill., hyacinth bean [Lablab purpureus (L.) Sweet], velvetbean [Mucuna pruriens (L.) DC], jicama [Pachyrhizus erosus (L.) Urb.], winged bean [Psop...

  20. Aggregate distribution and associated organic carbon influenced by cover crops

    NASA Astrophysics Data System (ADS)

    Barquero, Irene; García-González, Irene; Benito, Marta; Gabriel, Jose Luis; Quemada, Miguel; Hontoria, Chiquinquirá

    2013-04-01

    Replacing fallow with cover crops during the non-cropping period seems to be a good alternative to diminish soil degradation by enhancing soil aggregation and increasing organic carbon. The aim of this study was to analyze the effect of replacing fallow by different winter cover crops (CC) on the aggregate distribution and C associated of an Haplic Calcisol. The study area was located in Central Spain, under semi-arid Mediterranean climate. A 4-year field trial was conducted using Barley (Hordeum vulgare L.) and Vetch (Vicia sativa L.) as CC during the intercropping period of maize (Zea mays L.) under irrigation. All treatments were equally irrigated and fertilized. Maize was directly sown over CC residues previously killed in early spring. Composite samples were collected at 0-5 and 5-20 cm depths in each treatment on autumn of 2010. Soil samples were separated by wet sieving into four aggregate-size classes: large macroaggregates ( >2000 µm); small macroaggregates (250-2000 µm); microaggregates (53-250 µm); and < 53 µm (silt + clay size). Organic carbon associated to each aggregate-size class was measured by Walkley-Black Method. Our preliminary results showed that the aggregate-size distribution was dominated by microaggregates (48-53%) and the <53 µm fraction (40-44%) resulting in a low mean weight diameter (MWD). Both cover crops increased aggregate size resulting in a higher MWD (0.28 mm) in comparison with fallow (0.20 mm) in the 0-5 cm layer. Barley showed a higher MWD than fallow also in 5-20 cm layer. Organic carbon concentrations in aggregate-size classes at top layer followed the order: large macroaggregates > small macroaggregates > microaggregates > silt + clay size. Treatments did not influence C concentration in aggregate-size classes. In conclusion, cover crops improved soil structure increasing the proportion of macroaggregates and MWD being Barley more effective than Vetch at subsurface layer.

  1. Comparison of species-rich cover crop mixtures in Hungarian vineyards

    NASA Astrophysics Data System (ADS)

    Donkó, Adam; Miglécz, Tamas; Valkó, Orsolya; Török, Peter; Deák, Balazs; Kelemen, Andras; Zanathy, Gabor; Drexler, Dora

    2014-05-01

    In case of vine growing, agricultural practices of the past decades - as mechanical cultivation on steep vineyard slopes - can endanger the soil of vineyards. Moreover, climate change scenarios predict heavier rainstorms, which can also promote the degradation of the soil. These are some of the reasons why sustainable floor management plays an increasingly important role in viticulture recently. The use of cover crops in the inter-row has a special importance, especially on steep slopes and in case of organic farming to provide conditions for environmental friendly soil management. Species-rich cover crop seed mixtures may help to prevent erosion and create easier cultivation circumstances. Furthermore they have a positive effect on soil structure, soil fertility and ecosystem functions. However, it is important to find suitable seed mixtures for specific production sites, consisting ideally of native species from local provenance, adapted to the local climate/vine region/vineyard. Requirements for suitable cover crop species are as follows: they should save the soil from erosion and also from compaction caused by the movement of workers and machines, they should not compete significantly with the grapevines, or influence produce quality. We started to develop and apply several species-rich cover crop seed mixtures in spring 2012. During the experiments, three cover crop seed mixtures (Biocont-Ecovin mixture, mixture of legumes, mixture of grasses and herbs) were compared in vineyards of the Tokaj and Szekszárd vine regions of Hungary. Each mixture was sown in three consecutive inter-rows at each experimental site (all together 10 sites). Besides botanical measurements, yield, must quality, and pruning weight was studied in every treatment. The botanical survey showed that the following species of the mixtures established successfully and prospered during the years 2012 and 2013: Coronilla varia, Lotus corniculatus, Medicago lupulina, Onobrychis viciifolia

  2. Cover crop effect on subsequent wheat yield and water use efficiency in the central great plains

    USDA-ARS?s Scientific Manuscript database

    Crop production systems in the water-limited environment of the semi-arid central Great Plains may not have potential to profitably use cover crops because of lowered subsequent wheat (Triticum asestivum L.) yields following the cover crop. Cover crop mixtures have reportedly shown less yield-reduci...

  3. Cover crops can affect subsequent wheat yield in the central great plains

    USDA-ARS?s Scientific Manuscript database

    Crop production systems in the water-limited environment of the semi-arid central Great Plains may not have potential to profitably use cover crops because of lowered subsequent wheat (Triticum asestivum L.) yields following the cover crop. Cover crop mixtures have reportedly shown less yield-reduci...

  4. The potential of climate change adjustment in crops: A synthesis

    USDA-ARS?s Scientific Manuscript database

    This chapter covers a study on various field crops like cereals, legumes, oil seeds, vegetables, cash crops, underutilized crops, and energy crops and their genetic adjustment to changing climates. More than 30 major field crops have been covered in different chapters of this book, which highlight h...

  5. Effects of rolling/crimping of cover crops on their termination, soil strength and moisture

    USDA-ARS?s Scientific Manuscript database

    Termination of cover crops in conservation systems has been accomplished by rolling down and crimping covers using rollers/crimpers. Three weeks after rolling is typically required to plant a cash crop into residue covers. A common method to speed-up a cover crop termination is application of herbic...

  6. Impact of cover crops on soil nitrate, crop yield and quality

    USDA-ARS?s Scientific Manuscript database

    There are multiple benefits of incorporating cover crops into current production systems including decreasing erosion, improving water infiltration, increasing soil organic matter and biological activity but in water limited areas caution should be utilized. A field study was established in the fal...

  7. Alfalfa interseeded into silage corn can serve as a cover crop and subsequent forage crop

    USDA-ARS?s Scientific Manuscript database

    Alfalfa (Medicago sativa) and corn (Zea mays) silage are commonly grown in rotation in dairy forage production systems throughout the northern regions of the USA. Alfalfa interseeded into silage corn could potentially serve two purposes: as a cover crop during the silage corn production year, and as...

  8. Summer legume 'green' nitrogen crops affect winter wheat forage in continuous rotations

    USDA-ARS?s Scientific Manuscript database

    Costs for inorganic nitrogen (N) fertilizers in the southern Great Plains (SGP) have increased in recent years with the rise in oil prices. In response, producers have become interested in the potential merits of using annual legumes as N sources. This study described the influence of two summer for...

  9. Cover crop termination timing is critical in organic rotational no-till systems

    USDA-ARS?s Scientific Manuscript database

    Cover crop-based rotational no-till enables organic farmers to reduce labor and build soil health. In these systems, cover crops are terminated with a roller-crimper and cash crops are direct-seeded into the mulch. A cropping system experiment was conducted at three locations in the Mid-Atlantic t...

  10. Cellulosic Biofuel Production with Winter Cover Crops: Yield and Nitrogen Implications

    USDA-ARS?s Scientific Manuscript database

    Interest in renewable energy sources derived from plant biomass is increasing. Growing cover crops after harvest of the primary crop has been proposed as a solution to producing cellulosic biomass on existing crop-producing land without reducing food-harvest potential. Growing cover crops is a recom...

  11. Cover crop impact on weed dynamics in an organic dry bean system

    USDA-ARS?s Scientific Manuscript database

    Cover crops have the potential to enhance crop rotations by increasing diversity and enriching agroecosystems. Weed suppression, nutrient provisoning, and enhancements to soil biota and structure are benefits of cover crops in cropping systems, including organic dry bean production. The late spring ...

  12. The potential for cereal rye cover crops to host corn seedling pathogens

    USDA-ARS?s Scientific Manuscript database

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil health and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects by growing two grass species in succession. Here, we show that rye cover crops host pathog...

  13. Cover crops in mixtures do not use water differently than single-species plantings

    USDA-ARS?s Scientific Manuscript database

    Some recent statements have been made about the benefits of growing cover crops in mixtures as compared with single-species plantings of cover crops. One of those stated benefits is greatly reduced water use by cover crops grown in mixtures. The objectives of this study were to characterize soil wat...

  14. Cover crop biomass production and water use in the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    The water-limited environment of the semi-arid central Great Plains may not have potential to produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater wate...

  15. Cover crop biomass production and water use in the central great plains under varying water availability

    USDA-ARS?s Scientific Manuscript database

    The water-limited environment of the semi-arid central Great Plains may not have potential to produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater wate...

  16. Living cover crops have immediate impacts on soil microbial community structure and function

    USDA-ARS?s Scientific Manuscript database

    Cover cropping is a widely promoted strategy to enhance soil health in agricultural systems. Despite a substantial body of literature demonstrating links between cover crops and soil biology, an important component of soil health, research evaluating how specific cover crop species influence soil mi...

  17. Effect of the different cover crops on the soil moisture in a Hungarian vineyard

    NASA Astrophysics Data System (ADS)

    Donkó, Ádám; Miglécz, Tamás; Valkó, Orsolya; Deák, Balázs; Kelemen, András; Török, Péter; Tóthmérész, Béla; Drexler, Dóra

    2017-04-01

    Since many years it is well known that the one-sided mechanical soil cultivation of vineyard inter-rows has many disadvantages. Growers can choose from alternative tillage technologies, such as the usage of green manure, or covering the inter-rows with straw mulch. Another possible technology is tto cover the inter-rows with species-rich seed mixtures. However, selection of the most suitable species is crucial; we have to take into consideration the age of the vines, and the specific characteristics of the vineyards involved. Species rich cover crop technology has many advantages: 1) it helps to prevent erosion and creates easier cultivation circumstances, 2) it has a positive effect on soil structure, soil fertility and ecosystem services, 3) we can create native mixtures from local provenance, adapted to the local climate/vine region/vineyard which enhances the nature conservation value of our site. But, they should not compete significantly with the grapevines, or negatively influence produce quality. In the year of 2012 we created, and started to study three different cover-crop mixtures in Hungarian wine regions under on-farm conditions: Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs. The results of the botanical surveys, yield and pruning weight were published in many papers and presentations before (e.g. Miglécz et al. 2015, Donkó et al. 2016). Besides the above measures, one key point of the effectiveness and sustainability of the living mulch vegetation is the level of soil moisture. That is why we started to investigate the soil moisture (vol %) of different treatments (Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs, coverage with Lolium perenne, and Control (spontaneous weed flora)) in at the Feind Winery in Balatonfőkajár (Hungary). The investigated variety is Welschriesling on loamy soil (Tihany Formation), planted in 2010. The seed mixtures were sown in the spring of 2013. We measured soil moisture

  18. Soil Water Improvements with the Long Term Use of a Winter Rye Cover Crop

    NASA Astrophysics Data System (ADS)

    Basche, A.; Kaspar, T.; Archontoulis, S.; Jaynes, D. B.; Sauer, T. J.; Parkin, T.; Miguez, F.

    2015-12-01

    The Midwestern United States, a region that produces one-third of maize and one-quarter of soybeans globally, is projected to experience increasing rainfall variability with future climate change. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding and runoff as well as drought-induced crop water stress. While some research indicates that a winter cover crop in a maize-soybean rotation increases soil water, producers continue to be concerned that water use by cover crops will reduce water for a following cash crop. We analyzed continuous in-field soil moisture measurements over from 2008-2014 at a Central Iowa research site that has included a winter rye cover crop in a maize-soybean rotation for thirteen years. This period of study included years in the top third of wettest years on record (2008, 2010, 2014) as well as years in the bottom third of driest years (2012, 2013). We found the cover crop treatment to have significantly higher soil water storage from 2012-2014 when compared to the no cover crop treatment and in most years greater soil water content later in the growing season when a cover crop was present. We further found that the winter rye cover crop significantly increased the field capacity water content and plant available water compared to the no cover crop treatment. Finally, in 2012 and 2013, we measured maize and soybean biomass every 2-3 weeks and did not see treatment differences in crop growth, leaf area or nitrogen uptake. Final crop yields were not statistically different between the cover and no cover crop treatment in any of the years of this analysis. This research indicates that the long-term use of a winter rye cover crop can improve soil water dynamics without sacrificing cash crop growth.

  19. Impacts of Cover Crops on Water and Nutrient Dynamics in Agroecosystems

    NASA Astrophysics Data System (ADS)

    Williard, K.; Swanberg, S.; Schoonover, J.

    2013-05-01

    Intensive cropping systems of corn (Zea Mays L.) and soybeans (Glycine max) are commonly leaky systems with respect to nitrogen (N). Reactive N outputs from agroecosystems can contribute to eutrophication and hypoxic zones in downstream water bodies and greenhouse gas (N2O) emissions. Incorporating cover crops into temperate agroecosystem rotations has been promoted as a tool to increase nitrogen use efficiency and thus limit reactive N outputs to the environment. Our objective was determine how cereal rye (Secale cereal L.) and annual ryegrass (Lolium multiflorum) cover crops impact nutrient and soil water dynamics in an intensive corn and soybean cropping rotation in central Illinois. Cover crops were planted in mid to late October and terminated in early April prior to corn or soybean planting. In the spring just prior to cover crop termination, soil moisture levels were lower in the cover crop plots compared to no cover plots. This can be a concern for the subsequent crop in relatively dry years, which the Midwestern United States experienced in 2012. No cover plots had greater nutrient leaching below the rooting zone compared to cover crop areas, as expected. The cover crops were likely scavenging nutrients during the fall and early spring and should provide nutrients to the subsequent crop via decomposition and mineralization of the cover crop residue. Over the long term, cover crop systems should produce greater inputs and cycling of carbon and N, increasing the productivity of crops due to the long-term accumulation of soil organic matter. This study demonstrates that there may be short term trade-offs in reduced soil moisture levels that should be considered alongside the long term nutrient scavenging and recycling benefits of cover crops.

  20. No-till Snap Bean performance and weed response following Cereal Rye and Vetch cover crops

    USDA-ARS?s Scientific Manuscript database

    Fall-planted cover crops offer many benefits including weed suppressive residues in spring sown crops when controlled and left on the soil surface. However, vegetable growers have been slow to adapt direct seeding (no-till) into cover crop residues. Field studies were conducted in 2009 and 2010 near...

  1. Managing cover crops in no-till organic systems using rolling technology

    USDA-ARS?s Scientific Manuscript database

    In recent years use of cover crops in no-till organic production systems without incorporating them into the soil has been steadily increasing. This increase is associated with important benefits from cover crops left on the soil surface which improve soil properties and enhance main crop growth. Ro...

  2. Organic and conventional farmers differ in their perspective on cover crop use and breeding

    USDA-ARS?s Scientific Manuscript database

    Cover crops play an important role in agricultural sustainability. Unlike commodity cash crops, however, there has been relatively little cover crop germplasm research and development. We conducted an online survey to evaluate a) the perspectives of organic and conventional farmers in the United Sta...

  3. Timing of glyphosate applications to wheat cover crops to reduce onion stunting caused by Rhizoctonia solani

    USDA-ARS?s Scientific Manuscript database

    Stunting caused by Rhizoctonia spp. is economically important in irrigated onion bulb crops in the semi-arid Columbia Basin of Oregon and Washington, where cereal winter cover crops commonly are planted the previous fall to prevent wind erosion of soil. The cover crop is killed with herbicide applic...

  4. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... 7 Agriculture 10 2010-01-01 2010-01-01 false Direct payment yields for covered commodities, except pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued...

  5. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... 7 Agriculture 10 2012-01-01 2012-01-01 false Direct payment yields for covered commodities, except pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued...

  6. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... 7 Agriculture 10 2014-01-01 2014-01-01 false Direct payment yields for covered commodities, except pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued...

  7. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... 7 Agriculture 10 2011-01-01 2011-01-01 false Direct payment yields for covered commodities, except pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued...

  8. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... 7 Agriculture 10 2013-01-01 2013-01-01 false Direct payment yields for covered commodities, except pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued...

  9. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... having a zero yield capability for the crop year involved for purposes of constructing a crop history... 7 Agriculture 10 2011-01-01 2011-01-01 false Notice of loss for covered tropical crops. 1437.504... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER...

  10. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... having a zero yield capability for the crop year involved for purposes of constructing a crop history... 7 Agriculture 10 2014-01-01 2014-01-01 false Notice of loss for covered tropical crops. 1437.504... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER...

  11. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... having a zero yield capability for the crop year involved for purposes of constructing a crop history... 7 Agriculture 10 2012-01-01 2012-01-01 false Notice of loss for covered tropical crops. 1437.504... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER...

  12. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... having a zero yield capability for the crop year involved for purposes of constructing a crop history... 7 Agriculture 10 2013-01-01 2013-01-01 false Notice of loss for covered tropical crops. 1437.504... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER...

  13. Agronomic responses to late-seeded cover crops in a semiarid region

    USDA-ARS?s Scientific Manuscript database

    Intensification of cropping systems in the Great Plains beyond annual cropping practices may be limited by inadequate precipitation, short growing seasons, and highly variable climatic conditions. Inclusion of cover crops in dryland cropping systems may serve as an effective intensification strateg...

  14. Management of Overwintering Cover Crops Influences Floral Resources and Visitation by Native Bees.

    PubMed

    Ellis, Katherine E; Barbercheck, Mary E

    2015-08-01

    The incorporation of cover crops into annual crop rotations is one practice that is used in the Mid-Atlantic United States to manage soil fertility, suppress weeds, and control erosion. Additionally, flowering cover crops have the potential to support beneficial insect communities, such as native bees. Because of the current declines in managed honey bee colonies, the conservation of native bee communities is critical to maintaining "free" pollination services. However, native bees are negatively affected by agricultural intensification and are also in decline across North America. We conducted two experiments to assess the potential of flowering cover crops to act as a conservation resource for native bees. We evaluated the effects of cover crop diversity and fall planting date on floral resource availability and visitation by native bees for overwintering flowering cover crop species commonly used in the Mid-Atlantic region. Cover crop species, crop rotation schedule, and plant diversity significantly influenced floral resource availability. Different cover crop species not only had different blooming phenologies and winter survival responses to planting date, but attracted unique bee communities. Flower density was the primary factor influencing frequency of bee visitation across cover crop diversity and fall planting date treatments. The results from these experiments will be useful for informing recommendations on the applied use of flowering cover crops for pollinator conservation purposes.

  15. Development of a global, gridded, and time-series crop yield dataset for four major cereal and legume crops

    NASA Astrophysics Data System (ADS)

    Iizumi, T.; Yokozawa, M.; Sakurai, G.

    2012-12-01

    Global, gridded crop yield data are essential to study impacts of climate variability and change on food production, atmosphere-soil-managed ecosystem carbon and nitrogen cycle at a global scale. However so far available data are limited to country, time-series data from the Food and Agriculture Organization (FAO) and global, gridded data in the circa 2000 from Monfreda et al. (2008). This necessitates an effort to develop a global, gridded, and time-series dataset. To that end we developed a 25-yr long (1982-2006) dataset with 1.125 x 1.125 grid size for maize, soybean, rice, and wheat by merging county statistics, FAO country statistics, and yield proxy from satellite products. Yield statistics were collected from agricultural agencies in 19 countries: those correspond to 58-95% of the global production in the 2000. The proportion for rice and wheat (58%) is less than those for maize (72%) and soybean (95%). Also net primary production (NPP) for that period was estimated crop by crop from the normalized differential vegetation index bi-monthly time series at 8-km resolution from the Global Inventory Modeling and Mapping Studies group, using the method of Los et al. (2000). When estimating yield from NPP, for each crop, we used the following six procedures: (1) for a given grid where an intended crop grows (evaluated from harvested area from Monfreda et al. (2008)), accumulate NPP time series for the whole growth period from Sacks et al. (2010), considering the temporal distribution of planting/harvesting date through an ensemble calculation of 100 different planting/harvesting date; (2) average over accumulated NPPs that locate within a given country and compute the ratio of a grid NPP against a country mean (this represents the spatial variation of yield); (3) multiply this ratio and country FAO yield year by year; (4) calculate correction coefficient that is a ratio between estimated grid yield in the 2000 and that from Monfreda et al. (2000); (5) repeat (1

  16. Limited Impact of a Fall-Seeded, Spring-Terminated Rye Cover Crop on Beneficial Arthropods.

    PubMed

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2017-03-03

    Cover crops are beneficial to agroecosystems because they decrease soil erosion and nutrient loss while increasing within-field plant diversity. Greater plant diversity within cropping systems can positively affect beneficial arthropod communities. We hypothesized that increasing plant diversity within annually rotated corn and soybean with the addition of a rye cover crop would positively affect the beneficial ground and canopy-dwelling communities compared with rotated corn and soybean grown without a cover crop. From 2011 through 2013, arthropod communities were measured at two locations in Iowa four times throughout each growing season. Pitfall traps were used to sample ground-dwelling arthropods within the corn and soybean plots and sweep nets were used to measure the beneficial arthropods in soybean canopies. Beneficial arthropods captured were identified to either class, order, or family. In both corn and soybean, community composition and total community activity density and abundance did not differ between plots that included the rye cover crop and plots without the rye cover crop. Most taxa did not significantly respond to the presence of the rye cover crop when analyzed individually, with the exceptions of Carabidae and Gryllidae sampled from soybean pitfall traps. Activity density of Carabidae was significantly greater in soybean plots that included a rye cover crop, while activity density of Gryllidae was significantly reduced in plots with the rye cover crop. Although a rye cover crop may be agronomically beneficial, there may be only limited effects on beneficial arthropods when added within an annual rotation of corn and soybean.

  17. Plant domestication versus crop evolution: a conceptual framework for cereals and grain legumes.

    PubMed

    Abbo, Shahal; Pinhasi van-Oss, Ruth; Gopher, Avi; Saranga, Yehoshua; Ofner, Itai; Peleg, Zvi

    2014-06-01

    'Domestication syndrome' (DS) denotes differences between domesticated plants and their wild progenitors. Crop plants are dynamic entities; hence, not all parameters distinguishing wild progenitors from cultigens resulted from domestication. In this opinion article, we refine the DS concept using agronomic, genetic, and archaeobotanical considerations by distinguishing crucial domestication traits from traits that probably evolved post-domestication in Near Eastern grain crops. We propose that only traits showing a clear domesticated-wild dimorphism represent the pristine domestication episode, whereas traits showing a phenotypic continuum between wild and domesticated gene pools mostly reflect post-domestication diversification. We propose that our approach may apply to other crop types and examine its implications for discussing the timeframe of plant domestication and for modern plant science and breeding.

  18. Cover crops do not increase C sequestration in production crops: evidence from 12 years of continuous measurements

    NASA Astrophysics Data System (ADS)

    Buysse, Pauline; Bodson, Bernard; Debacq, Alain; De Ligne, Anne; Heinesch, Bernard; Manise, Tanguy; Moureaux, Christine; Aubinet, Marc

    2017-04-01

    The numerous reports on carbon (C) loss from cropland soils have recently raised awareness on the climate change mitigation potential of these ecosystems, and on the necessity to improve C sequestration in these soils. Among the multiple solutions that are proposed, several field measurement and modelling studies reported that growing cover crops over fall and winter time could appear as an efficient solution. However, while the large majority of these studies are based on SOC stock inventories and very few information exists from the CO2 flux dynamics perspective. In the present work, we use the results from long-term (12 years) eddy-covariance measurements performed at the Lonzée Terrestrial Observatory (LTO, candidate ICOS site, Belgium) and focus on six intercrop periods managed with (3) and without (3) cover crops after winter wheat main crops, in order to compare their response to environmental factors and to investigate the impact of cover crops on Net Ecosystem Exchange (NEE). Our results showed that cumulated NEE was not significantly affected by the presence of cover crops. Indeed, while larger CO2 assimilation occurred during cover crop growth, this carbon gain was later lost by larger respiration rates due to larger crop residue amounts brought to the soil. As modelled by a Q10-like relationship, significantly larger R10 values were indeed observed during the three intercrop periods cultivated with cover crops. These CO2 flux-based results therefore tend to moderate the generally acknowledged positive impact of cover crops on net C sequestration by croplands. Our results indicate that the effect of growing cover crops on C sequestration could be less important than announced, at least at certain sites.

  19. Legume ground covers alter defoliation response of black walnut saplings to drought and anthracnose

    Treesearch

    J. W. Van Sambeek

    2003-01-01

    Growth and premature defoliation of black walnut saplings underplanted 5 or 6 years earlier with six different ground covers were quantified in response to a summer drought or anthracnose. Walnut saplings growing with ground covers of hairy vetch, crownvetch, and to a lesser extent sericea lespedeza continued to have more rapid height and diameter growth than saplings...

  20. Polarimetric Synthetic Aperture Radar data for Crop Cover Classification

    NASA Astrophysics Data System (ADS)

    Ramana, K. V.; Srikanth, P.; Deepika, U.; Sesha Sai, M. V. R.

    2014-11-01

    The interest in crop inventory through the use of microwave sensors is on the rise owing to need for accurate crop forecast and the availability of multi polarization data. Till recently, the temporal amplitude data has been used for crop discrimination as well as acreage estimation. With the availability of dual and quadpol data, the differential response of crop geometry at various crop growth stages to various polarizations is being exploited for discrimination and classification of crops. An attempt has been made in the current study with RISAT1 and Radarsat2 C-band single, dual, fully and hybrid polarimetric data for crop inventory. The single date hybrid polarimetric data gave comparable results to the three date single polarization data as well as with the single date fully polarimetric data for crops like rice and cotton.

  1. Cover crops to improve soil health and pollinator habitat in nut orchards: Part II

    Treesearch

    Jerry. Van Sambeek

    2017-01-01

    Integrating cover crops into a nut orchard can have some unique benefits and problems not found when used cover crops during the fallow period between cash crops. Studies show ground covers can reduce hardwood tree growth anywhere from a few percent to more than 70 percent in the case of tall fescue. This means if it takes 3 years to put on one inch of diameter growth...

  2. Assessing crop residue cover as scene moisture conditions change

    USDA-ARS?s Scientific Manuscript database

    Crop residue or plant litter is the portion of a crop left in the field after harvest. Crop residues on the soil surface provide a first line of defense against water and wind erosion and reduce the amounts of soil, nutrients, and pesticides that reach streams and rivers. Thus, quantification of cro...

  3. Cover crop root, shoot, and rhizodeposit contributions to soil carbon in a no- till corn bioenergy cropping system

    NASA Astrophysics Data System (ADS)

    Austin, E.; Grandy, S.; Wickings, K.; McDaniel, M. D.; Robertson, P.

    2016-12-01

    Crop residues are potential biofuel feedstocks, but residue removal may result in reduced soil carbon (C). The inclusion of a cover crop in a corn bioenergy system could provide additional biomass and as well as help to mitigate the negative effects of residue removal by adding belowground C to stable soil C pools. In a no-till continuous corn bioenergy system in the northern portion of the US corn belt, we used 13CO2 pulse labeling to trace C in a winter rye (secale cereale) cover crop into different soil C pools for two years following rye termination. Corn stover contributed 66 (another 163 was in harvested corn stover), corn roots 57, rye shoot 61, rye roots 59, and rye rhizodeposits 27 g C m-2 to soil C. Five months following cover crop termination, belowground cover crop inputs were three times more likely to remain in soil C pools and much of the root-derived C was in mineral- associated soil fractions. Our results underscore the importance of cover crop roots vs. shoots as a source of soil C. Belowground C inputs from winter cover crops could substantially offset short term stover removal in this system.

  4. Soil Organic Carbon Response to Cover Crop and Nitrogen Fertilization under Bioenergy Sorghum

    NASA Astrophysics Data System (ADS)

    Sainju, U. M.; Singh, H. P.; Singh, B. P.

    2015-12-01

    Removal of aboveground biomass for bioenergy/feedstock in bioenergy cropping systems may reduce soil C storage. Cover crop and N fertilization may provide additional crop residue C and sustain soil C storage compared with no cover crop and N fertilization. We evaluated the effect of four winter cover crops (control or no cover crop, cereal rye, hairy vetch, and hairy vetch/cereal rye mixture) and two N fertilization rates (0 and 90 kg N ha-1) on soil organic C (SOC) at 0-5, 5-15, and 15-30 cm depths under forage and sweet sorghums from 2010 to 2013 in Fort Valley, GA. Cover crop biomass yield and C content were greater with vetch/rye mixture than vetch or rye alone and the control, regardless of sorghum species. Soil organic C was greater with vetch/rye than rye at 0-5 and 15-30 cm in 2011 and 2013 and greater with vetch than rye at 5-15 cm in 2011 under forage sorghum. Under sweet sorghum, SOC was greater with cover crops than the control at 0-5 cm, but greater with vetch and the control than vetch/rye at 15-30 cm. The SOC increased at the rates of 0.30 Mg C ha-1 yr-1 at 0-5 cm for rye and the control to 1.44 Mg C ha-1 yr-1 at 15-30 cm for vetch/rye and the control from 2010 to 2013 under forage sorghum. Under sweet sorghum, SOC also increased linearly at all depths from 2010 to 2013, regardless of cover crops. Nitrogen fertilization had little effect on SOC. Cover crops increased soil C storage compared with no cover crop due to greater crop residue C returned to the soil under forage and sweet sorghum and hairy vetch/cereal rye mixture had greater C storage than other cover crops under forage sorghum.

  5. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    NASA Astrophysics Data System (ADS)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2014-12-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality at the watershed scale (~ 50 km2) and to identify critical source areas of high nitrate export. A physically based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data to simulate hydrological processes and agricultural nutrient cycling over the period of 1990-2000. To accurately simulate winter cover crop biomass in relation to growing conditions, a new approach was developed to further calibrate plant growth parameters that control the leaf area development curve using multitemporal satellite-based measurements of species-specific winter cover crop performance. Multiple SWAT scenarios were developed to obtain baseline information on nitrate loading without winter cover crops and to investigate how nitrate loading could change under different winter cover crop planting scenarios, including different species, planting dates, and implementation areas. The simulation results indicate that winter cover crops have a negligible impact on the water budget but significantly reduce nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading from agricultural lands was approximately 14 kg ha-1, but decreased to 4.6-10.1 kg ha-1 with cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was the most effective species, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of cover crops (~ 30

  6. Winter cover crops on processing tomato yield, quality, pest pressure, nitrogen availability, and profit margins

    PubMed Central

    Belfry, Kimberly D.; Trueman, Cheryl; Vyn, Richard J.; Loewen, Steven A.; Van Eerd, Laura L.

    2017-01-01

    Much of cover crop research to date focuses on key indicators of impact without considering the implications over multiple years, in the absence of a systems-based approach. To evaluate the effect of three years of autumn cover crops on subsequent processing tomato (Solanum lycopersicum L.) production in 2010 and 2011, a field split-split-plot factorial design trial with effects of cover crop type, urea ammonium nitrate fertilizer rate (0 or 140 kg N ha-1 preplant broadcast incorporated) and tomato cultivar (early vs. late) was conducted. The main plot factor, cover crop, included a no cover crop control, oat (Avena sativa L.), winter cereal rye (hereafter referred to as rye) (Secale cereale L.), oilseed radish (OSR) (Raphanus sativus L. var. oleiferus Metzg Stokes), and mix of OSR and rye (OSR + rye) treatments. Cover crop biomass of 0.5 to 2.8 and 1.7 to 3.1 Mg ha-1 was attained in early Oct. and the following early May, respectively. In general, OSR increased soil mineral N during cover crop growth and into the succeeding summer tomato growing season, while the remaining cover crops did not differ from the no cover crop control. The lack of a cover crop by N rate interaction in soil and plant N analyses at harvest suggests that growers may not need to modify N fertilizer rates to tomatoes based on cover crop type. Processing tomato fruit quality at harvest (rots, insect or disease damage, Agtron colour, pH, or natural tomato soluble solids (NTSS)) was not affected by cover crop type. In both years, marketable yield in the no cover crop treatment was lower or not statistically different than all planted cover crops. Partial profit margins over both years were 1320 $ ha-1 higher with OSR and $960 higher with oat compared to the no cover crop control. Thus, results from a systems-based approach suggest that the cover crops tested had no observed negative impact on processing tomato production and have the potential to increase marketable yield and profit margins

  7. Soil carbon sequestration via cover crops- A meta-analysis

    NASA Astrophysics Data System (ADS)

    Poeplau, Christopher; Don, Axel

    2014-05-01

    Agricultural soils are depleted in soil organic carbon (SOC) and have thus a huge potential to sequester SOC. This can primarily be achieved by increasing carbon inputs into the soil. Replacing winter fallows by cover crop cultivation for green manure has many benefits for the soil and forms an additional carbon input. An increase in carbon concentration has been reported in several studies worldwide. However, the effect on SOC stocks, as well as the influence of environmental parameters and management on SOC dynamics is not known. We therefore conducted a meta-analysis to investigate those issues. A total of 33 studies, comprising 47 sites and 147 plots were compiled. A pedotransfer function was used to estimate bulk densities and calculate SOC stocks. SOC stock change was found to be a linear function of time since introduction, with an annual sequestration rate of 0.32 Mg C ha-1 yr-1. Since no saturation was visible in the observations, we used the model RothC to estimate a new steady state level and the resulting total SOC stock change for an artificial "average cropland". The total average SOC stock change with an annual input of 1.87 Mg C ha-1 yr-1 was 16.76 Mg C ha-1 for the average soil depth of 22 cm. We estimated a potential global SOC sequestration of 0.12±0.03 Pg C yr-1, which would compensate for 8 % of the direct annual greenhouse gas emissions from agriculture.

  8. Summer cover crops and soil amendments to improve growth and nutrient uptake of okra

    SciTech Connect

    Wang, Q.R.; Li, Y.C.; Klassen, W.

    2006-04-15

    A pot experiment with summer cover crops and soil amendments was conducted in two consecutive years to elucidate the effects of these cover crops and soil amendments on 'Clemson Spineless 80' okra (Abelmoschus esculentus) yields and biomass production, and the uptake and distribution of soil nutrients and trace elements. The cover crops were sunn hemp (Crotalaria juncea), cowpea (Vigna unguiculata), velvetbean (Mucuna deeringiana), and sorghum sudan-grass (Sorghum bicolor x S. bicolor var. sudanense) with fallow as the control. The organic soil amendments were biosolids (sediment from wastewater plants), N-Viro Soil (a mixture of biosolids and coal ash), coal ash (a combustion by-product from power plants), co-compost (a mixture of 3 biosolids: 7 yard waste), and yard waste compost (mainly from leaves and branches of trees and shrubs, and grass clippings) with a soil-incorporated cover crop as the control. As a subsequent vegetable crop, okra was grown after the cover crops, alone or together with the organic soil amendments, had been incorporated. All of the cover crops, except sorghum sudangrass in 2002-03, significantly improved okra fruit yields and the total biomass production. Both cover crops and soil amendments can substantially improve nutrient uptake and distribution. The results suggest that cover crops and appropriate amounts of soil amendments can be used to improve soil fertility and okra yield without adverse environmental effects or risk of contamination of the fruit. Further field studies will be required to confirm these findings.

  9. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    NASA Astrophysics Data System (ADS)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2013-11-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991-2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha-1, but it decreased to 4.6-10.1 kg ha-1 with winter cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha-1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils and those

  10. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    USGS Publications Warehouse

    Yeo, In-Young; Lee, Sangchui; Sadeghi, Ali M.; Beeson, Peter C.; Hively, W. Dean; McCarty, Greg W.; Lang, Megan W.

    2013-01-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha−1, but it decreased to 4.6–10.1 kg ha−1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha−1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils

  11. Hardwood cover crops:can they enhance loblolly pine seedling production

    Treesearch

    Paul P. Kormanik; Shi-Jean S. Sung; T.L. Kormanik; Stanley J. Zarnoch

    1995-01-01

    It has been extremely difficult to obtain more than two loblolly pine (Pinus taeda L.) crops following even effective soil fumigation with methyl bromide in southern forest tree nurseries. The traditional agronomic cover crops such as sorghum and sudex, unless followed by fumigation, do not normally produce satisfactory loblolly pine seedling crops. Various species...

  12. Effects of soil composition and mineralogy on remote sensing of crop residue cover

    USDA-ARS?s Scientific Manuscript database

    The management of crop residues in agricultural fields influences soil erosion and soil carbon sequestration. Remote sensing methods can efficiently assess crop residue cover and tillaje intensity over many fields in a region. Although the reflectance spectra of soils and crop residues are often s...

  13. Combining Landsat-8 and WorldView-3 data to assess crop residue cover

    USDA-ARS?s Scientific Manuscript database

    Crop residues on the soil surface contribute to soil quality and form the first line defense against the erosive forces of water and wind. Quantifying crop residue cover on the soil surface after crops are planted is crucial for monitoring soil tillage intensity and assessing the extent of conserva...

  14. Evaluation of Cowpea Germplasm Lines Adapted for Use as a Cover Crop in the Southeastern US

    USDA-ARS?s Scientific Manuscript database

    Cowpeas (Vigna unguiculata) are desirable as a cover crop, because they are tolerant of heat, drought and poor soils, grow vigorously and compete well against weeds, and provide nitrogen for rotational crops. Cowpeas were grown extensively as a forage and green manure crop in the southeastern U.S. ...

  15. Impact of Cover Cropping and Landscape Positions on Nitrous Oxide Emissions in Northeastern Agroecosystems

    NASA Astrophysics Data System (ADS)

    Han, Z.; Walter, M. T.; Drinkwater, L. E.

    2015-12-01

    Studies investigating agricultural nitrous oxide (N2O) emissions tend to rely on plot-scale experiments. However, to understand the impacts of agricultural practices at a larger scale, it is essential to consider the variability of landscape characteristics along with management treatments. This study compared N2O emissions from a fertilizer-based, conventionally managed farm and an organically managed farm that uses legume cover crops as a primary nutrient source. The objective of the study was to assess how management regimes and slope positions interact to impact N2O emissions and soil characteristics. The field experiment was conducted in two adjacent grain farms in upstate New York that both have been under consistent management for 20 years. In the organic farm, red clover was frost-seeded into a winter grain (spelt), and then incorporated in the spring as a nutrient source for the subsequent corn plants. In contrast, the conventionally managed farm used inorganic fertilizer as the nutrient source. Gas measurement was conducted at two landscape positions at both farms: 1) shoulder and 2) toeslope positions. Comparable N2O emissions were found in the clover-corn phase in the organic site and the bare fallow-corn phase in the conventional site. The spelt-corn phase in the organic farm had the lowest N2O emissions. Soil nitrate concentration was the best predictor for seasonal average N2O emissions. The impact of landscape position on N2O emissions was only found in the conventional site, which was driven by higher denitrfication at toeslopes. In the organic farm, such effect was confounded by higher clover biomass at shoulder slopes. Our study shows that the impact of landscape characteristics on N2O emissions could differ across sites based on the complex interplay between environmental conditions and management.

  16. 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...

  17. Panel Discussion: Cover Crops Used at Georgia Forestry Commission Flint River and Walker Nurseries

    Treesearch

    Jeff Fields

    2005-01-01

    Flint River Nursery, located near Montezuma, Georgia, has used rye, wheat, brown top millet, and sorghum sudan grass for cover crops. Flint River has just begun to return to a summer cover crop situation. At Walker Nursery, located near Reidsville, Georgia, certified rye has been sown by the State Department of Corrections (DOC) for their harvesting, with a benefit to...

  18. Rye cover crop effects on direct and indirect nitrous oxide emissions

    USDA-ARS?s Scientific Manuscript database

    Winter cover crops can have a pronounced effect on N cycling in agricultural ecosystems. By reducing available soil mineral N during active growth and by providing a substrate for denitrifying bacteria after they are killed, cover crops can potentially influence soil N2O emissions. However, there ha...

  19. Effects of cover crops on soil quality: Selected chemical and biological parameters

    USDA-ARS?s Scientific Manuscript database

    Cover crops may improve soil physical, chemical, and biological properties and thus help improve land productivity. The objective of this study was to evaluate short-term changes (6, 9, and 12 weeks) in soil chemical and biological properties as influenced by cover crops for two different soils and...

  20. Growing Cover Crops Improve Biomass Accumulation and Carbon Sequestration: A Phytotron Study

    USDA-ARS?s Scientific Manuscript database

    Six of each winter and summer cover crops were grown in two soils, Krome gravelly loam soil (KGL), and Quincy fine sandy soil (QFS), in phytotrons at 3 temperatures (10/20, 15/25, 25/30 oC for winter/summer cover crops) to investigate their contributions for carbon (C) sequestration. The winter cove...

  1. Low-altitude aircraft imagery for assessment of winter cover-crop biomass and nitrogen content

    USDA-ARS?s Scientific Manuscript database

    Cover crops are planted during the autumn to reduce nitrogen inputs to the surface water system. The objective of this research is to determine a method to quickly assess the amount of nitrogen stored in the biomass before the cover crop is removed in the early spring. Two digital cameras were mo...

  2. Utilizing cover crop mulches to reduce tillage in organic systems in the southeastern USA

    USDA-ARS?s Scientific Manuscript database

    Organic sytems in the southeast offer unique challenges and solutions due to regional soil and climate characterized by highly weather soil types, high precipitation, and the capacity to grow cover crops in the winter. Recently high-residue cover crops and conservation tillage systems have increased...

  3. Utilizing Cover Crop Mulches to Reduce TIllage in Organic Systems in the Southeast

    USDA-ARS?s Scientific Manuscript database

    Cover crop roller-crimper trials have been conducted across the southeastern U.S. during the past decade. Regional climatic conditions make the system particularly attractive but also pose their own challenges. Winter annual cover crops productivity can exceed 8 Mg ha-1 (dry weight) for rye (Secale ...

  4. Effect of water content and organic carbon on remote sensing of crop residue cover

    USDA-ARS?s Scientific Manuscript database

    Crop residue cover is an important indicator of tillage method. Remote sensing of crop residue cover is an attractive and efficient method when compared with traditional ground-based methods, e.g., the line-point transect or windshield survey. A number of spectral indices have been devised for res...

  5. Ruminant Grazing of Cover Crops: Effects on Soil Properties and Agricultural Production

    ERIC Educational Resources Information Center

    Poffenbarger, Hanna

    2010-01-01

    Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops…

  6. Ruminant Grazing of Cover Crops: Effects on Soil Properties and Agricultural Production

    ERIC Educational Resources Information Center

    Poffenbarger, Hanna

    2010-01-01

    Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops…

  7. The effects of combined cover crop termination and planting in a cotton no-till system

    USDA-ARS?s Scientific Manuscript database

    One method to save resources while positively impacting the environment is combining agricultural field operations. In no-till systems, cover crop termination and cash crop planting can be performed simultaneously utilizing a tractor as a single power source. A no-till field experiment merging cover...

  8. A comparison of drill and broadcast methods for establishing cover crops on beds

    USDA-ARS?s Scientific Manuscript database

    Cover crops stands that are sufficiently dense soon after planting are more likely to suppress weeds, scavenge nutrients, and reduce erosion. Small-scale organic vegetable farmers often use broadcasting methods to establish cover crops but lack information on the most effective tool to incorporate ...

  9. Grazing winter rye cover crop in a cotton no-till system: yield and economics

    USDA-ARS?s Scientific Manuscript database

    Winter cover crop adoption in conservation management systems continues to be limited in the US but could be encouraged if establishment costs could be offset. A 4-yr field experiment was conducted near Watkinsville, Georgia in which a rye (Secale cereale L.) cover crop was either grazed by catt...

  10. Nitrate leaching from winter cereal cover crops using undisturbed soil-column lysimeters

    USDA-ARS?s Scientific Manuscript database

    Cover crops are important management practices for reducing nitrogen (N) leaching in the Chesapeake Bay watershed, which is under Total Maximum Daily Load restraints. Cool-season annual grasses such as barley, rye, or wheat are common cover crops, but studies are needed to directly compare field ni...

  11. Integrating choice of variety, soil amendments, and cover crops to optimize organic rice production

    USDA-ARS?s Scientific Manuscript database

    We have completed our first year of this project to determine the impact of winter cover crops, soil amendments, and rice varieties on organic rice production at Beaumont, TX. Two winter cover crops were established successfully and the amounts of dry biomass produced were 4,690 and 5,157 lb/acre f...

  12. US-1136, US-1137, and US-1138 Cowpea Germplasm Lines for Use as a Cover Crop

    USDA-ARS?s Scientific Manuscript database

    The adoption of sustainable and organic cultural practices in recent years has resulted in an increased use of cover crops. Cowpea (Vigna unguiculata L.) is an excellent warm season cover crop due to its tolerance of heat and drought stress, ability to grow well in sandy, poor, acidic soils, high b...

  13. Do cover crops increase or decrease nitrous oxide emissions? A meta-analysis

    USDA-ARS?s Scientific Manuscript database

    Few studies have examined the factors that affect the impact of cover crops on nitrous oxide emissions. A meta-analysis of the data obtained from twenty-six peer reviewed articles was conducted using the natural log of the nitrous oxide flux with a cover crop divided by the nitrous oxide flux withou...

  14. Forage radish winter cover crop suppresses winter annual weeds in fall and before corn planting

    USDA-ARS?s Scientific Manuscript database

    Forage radish (Raphanus sativus L. var. longipinnatus) is a new winter cover crop in the Mid-Atlantic region. The objective of this project was to characterize the repeatability, amount, and duration of weed suppression during and after a fall-planted forage radish cover crop and to quantify the sub...

  15. Effects of Cover Crops on Pratylenchus penetrans and the Nematode Community in Carrot Production

    PubMed Central

    Grabau, Zane J.; Zar Maung, Zin Thu; Noyes, D. Corey; Baas, Dean G.; Werling, Benjamin P.; Brainard, Daniel C.; Melakeberhan, Haddish

    2017-01-01

    Cover cropping is a common practice in U.S. Midwest carrot production for soil conservation, and may affect soil ecology and plant-parasitic nematodes—to which carrots are very susceptible. This study assessed the impact of cover crops—oats (Avena sativa), radish (Raphanus sativus) cv. Defender, rape (Brassica napus) cv. Dwarf Essex, and a mixture of oats and radish—on plant-parasitic nematodes and soil ecology based on the nematode community in Michigan carrot production systems. Research was conducted at two field sites where cover crops were grown in Fall 2014 preceding Summer 2015 carrot production. At Site 1, root-lesion (Pratylenchus penetrans) and stunt (Tylenchorhynchus sp.) nematodes were present at low population densities (less than 25 nematodes/100 cm3 soil), but were not significantly affected (P > 0.05) by cover crops. At Site 2, P. penetrans population densities were increased (P ≤ 0.05) by ‘Defender’ radish compared to other cover crops or fallow control during cover crop growth and midseason carrot production. At both sites, there were few short-term impacts of cover cropping on soil ecology based on the nematode community. At Site 1, only at carrot harvest, radish-oats mixture and ‘Dwarf Essex’ rape alone enriched the soil food web based on the enrichment index (P ≤ 0.05) while rape and radish increased structure index values. At Site 2, bacterivore abundance was increased by oats or radish cover crops compared to control, but only during carrot production. In general, cover crops did not affect the nematode community until nearly a year after cover crop growth suggesting that changes in the soil community following cover cropping may be gradual. PMID:28512383

  16. Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes.

    PubMed

    Bae, Jichul; Benoit, Diane L; Watson, Alan K

    2016-06-01

    In southern Québec, supplement roadside ground covers (i.e. Trifolium spp.) struggle to establish near edges of major roads and thus fail to assist turf recruitment. It creates empty niches vulnerable to weed establishment such as common ragweed (Ambrosia artemisiifolia). We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A growth chamber experiment was conducted to assess effects of metals (Zn, Pb, Ni, Cu, and Cd) on germination and seedling behaviors of roadside weed (A. artemisiifolia) and ground cover legumes (Coronilla varia, Lotus corniculatus, and Trifolium arvense). All metals inhibited T. arvense germination, but the effect was least on A. artemisiifolia. Low levels of Pb and Ni promoted germination initiation of A. artemisiifolia. Germination of L. corniculatus was not affected by Zn, Pb, and Ni, but inhibited by Cu and Cd. Germination of C. varia was decreased by Ni, Cu, and Cd and delayed by Zn and Pb. Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. artemisiifolia but highest in T. arvense when exposed to the metal treatments. L. corniculatus and C. varia seedlings survived when subjected to high levels of Zn, Pb, and Cd. In conclusion, the successful establishment of A. artemisiifolia along roadside edges can be associated with its greater tolerance of heavy metals. The findings also revealed that L. corniculatus is a potential candidate for supplement ground cover in metal-contaminated roadside edges in southern Québec, especially sites contaminated with Zn and Pb.

  17. Effect of date of termination of a winter cereal rye cover crop (Secale cereale) on corn seedling disease

    USDA-ARS?s Scientific Manuscript database

    Cover cropping is an expanding conservation practice that offers substantial benefits to soil protection, soil health, water quality, and potentially crop yields. Presently, winter cereals are the most widely used cover crops in the upper Midwest. However, winter cereal cover crops preceding corn, ...

  18. Single season effects of mixed-species cover crops on tomato health (cultivar Celebrity) in multi-state field trials

    USDA-ARS?s Scientific Manuscript database

    Cover crop use can help mitigate the deleterious effects of common cropping practices (e.g., tillage) and is, therefore, an important component of soil health maintenance. While known to be beneficial in the long term, the short-term effects of cover crops, specifically mixed-species cover crops in ...

  19. Effect of Winter Cover Crops on Nematode Population Levels in North Florida

    PubMed Central

    Wang, K.-H.; McSorley, R.; Gallaher, R. N.

    2004-01-01

    Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), lupine (Lupinus angustifolius), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). At the end of the corn crop in year 1, population densities of Meloidogyne incognita were lowest on corn following rye or oat (P ≤ 0.05), but no treatment differences were observed in year 2. Wheat was a good host to Paratrichodorus minor, whereas vetch was a poor host, but numbers of P. minor were not lower in vetch-planted plots after corn was grown. The second experiment used a split-plot design in which rye or lupine was planted into field plots with histories of five tropical cover crops: soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sorghum bicolor × S. sudanense), sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P ≤ 0.05) but not by the winter cover crops present at the time of sampling. Plots planted to sunn hemp in the fall maintained the lowest M. incognita and H. dihystera numbers. Results suggest that winter cover crops tested did not suppress plant-parasitic nematodes effectively. Planting tropical cover crops such as sunn hemp after corn in a triple-cropping system with winter cover crops may provide more versatile nematode management strategies in northern Florida. PMID:19262833

  20. Satellite Estimation of Fractional Cover in Several California Specialty Crops

    NASA Technical Reports Server (NTRS)

    Johnson, Lee; Cahn, Michael; Rosevelt, Carolyn; Guzman, Alberto; Farrara, Barry; Melton, Forrest S.

    2016-01-01

    Past research in California and elsewhere has revealed strong relationships between satellite NDVI, photosynthetically active vegetation fraction (Fc), and crop evapotranspiration (ETc). Estimation of ETc can support efficiency of irrigation practice, which enhances water security and may mitigate nitrate leaching. The U.C. Cooperative Extension previously developed the CropManage (CM) web application for evaluation of crop water requirement and irrigation scheduling for several high-value specialty crops. CM currently uses empirical equations to predict daily Fc as a function of crop type, planting date and expected harvest date. The Fc prediction is transformed to fraction of reference ET and combined with reference data from the California Irrigation Management Information System to estimate daily ETc. In the current study, atmospherically-corrected Landsat NDVI data were compared with in-situ Fc estimates on several crops in the Salinas Valley during 2011-2014. The satellite data were observed on day of ground collection or were linearly interpolated across no more than an 8-day revisit period. Results will be presented for lettuce, spinach, celery, broccoli, cauliflower, cabbage, peppers, and strawberry. An application programming interface (API) allows CM and other clients to automatically retrieve NDVI and associated data from NASA's Satellite Irrigation Management Support (SIMS) web service. The SIMS API allows for queries both by individual points or user-defined polygons, and provides data for individual days or annual timeseries. Updates to the CM web app will convert these NDVI data to Fc on a crop-specific basis. The satellite observations are expected to play a support role in Salinas Valley, and may eventually serve as a primary data source as CM is extended to crop systems or regions where Fc is less predictable.

  1. Satellite Estimation of Fractional Cover in Several California Specialty Crops

    NASA Astrophysics Data System (ADS)

    Johnson, L.; Cahn, M.; Rosevelt, C.; Guzman, A.; Lockhart, T.; Farrara, B.; Melton, F. S.

    2016-12-01

    Past research in California and elsewhere has revealed strong relationships between satellite NDVI, photosynthetically active vegetation fraction (Fc), and crop evapotranspiration (ETc). Estimation of ETc can support efficiency of irrigation practice, which enhances water security and may mitigate nitrate leaching. The U.C. Cooperative Extension previously developed the CropManage (CM) web application for evaluation of crop water requirement and irrigation scheduling for several high-value specialty crops. CM currently uses empirical equations to predict daily Fc as a function of crop type, planting date and expected harvest date. The Fc prediction is transformed to fraction of reference ET and combined with reference data from the California Irrigation Management Information System to estimate daily ETc. In the current study, atmospherically-corrected Landsat NDVI data were compared with in-situ Fc estimates on several crops in the Salinas Valley during 2011-2014. The satellite data were observed on day of ground collection or were linearly interpolated across no more than an 8-day revisit period. Results will be presented for lettuce, spinach, celery, broccoli, cauliflower, cabbage, peppers, and strawberry. An application programming interface (API) allows CM and other clients to automatically retrieve NDVI and associated data from NASA's Satellite Irrigation Management Support (SIMS) web service. The SIMS API allows for queries both by individual points or user-defined polygons, and provides data for individual days or annual timeseries. Updates to the CM web app will convert these NDVI data to Fc on a crop-specific basis. The satellite observations are expected to play a support role in Salinas Valley, and may eventually serve as a primary data source as CM is extended to crop systems or regions where Fc is less predictable.

  2. Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin.

    PubMed

    Maliki, Raphiou; Sinsin, Brice; Floquet, Anne; Cornet, Denis; Malezieux, Eric; Vernier, Philippe

    2016-01-01

    Traditional yam-based cropping systems (shifting cultivation, slash-and-burn, and short fallow) often result in deforestation and soil nutrient depletion. The objective of this study was to determine the impact of yam-based systems with herbaceous legumes on dry matter (DM) production (tubers, shoots), nutrients removed and recycled, and the soil fertility changes. We compared smallholders' traditional systems (1-year fallow of Andropogon gayanus-yam rotation, maize-yam rotation) with yam-based systems integrated herbaceous legumes (Aeschynomene histrix/maize intercropping-yam rotation, Mucuna pruriens/maize intercropping-yam rotation). The experiment was conducted during the 2002 and 2004 cropping seasons with 32 farmers, eight in each site. For each of them, a randomized complete block design with four treatments and four replicates was carried out using a partial nested model with five factors: Year, Replicate, Farmer, Site, and Treatment. Analysis of variance (ANOVA) using the general linear model (GLM) procedure was applied to the dry matter (DM) production (tubers, shoots), nutrient contribution to the systems, and soil properties at depths 0-10 and 10-20 cm. DM removed and recycled, total N, P, and K recycled or removed, and soil chemical properties (SOM, N, P, K, and pH water) were significantly improved on yam-based systems with legumes in comparison with traditional systems.

  3. Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin

    PubMed Central

    Sinsin, Brice; Floquet, Anne; Cornet, Denis; Malezieux, Eric; Vernier, Philippe

    2016-01-01

    Traditional yam-based cropping systems (shifting cultivation, slash-and-burn, and short fallow) often result in deforestation and soil nutrient depletion. The objective of this study was to determine the impact of yam-based systems with herbaceous legumes on dry matter (DM) production (tubers, shoots), nutrients removed and recycled, and the soil fertility changes. We compared smallholders' traditional systems (1-year fallow of Andropogon gayanus-yam rotation, maize-yam rotation) with yam-based systems integrated herbaceous legumes (Aeschynomene histrix/maize intercropping-yam rotation, Mucuna pruriens/maize intercropping-yam rotation). The experiment was conducted during the 2002 and 2004 cropping seasons with 32 farmers, eight in each site. For each of them, a randomized complete block design with four treatments and four replicates was carried out using a partial nested model with five factors: Year, Replicate, Farmer, Site, and Treatment. Analysis of variance (ANOVA) using the general linear model (GLM) procedure was applied to the dry matter (DM) production (tubers, shoots), nutrient contribution to the systems, and soil properties at depths 0–10 and 10–20 cm. DM removed and recycled, total N, P, and K recycled or removed, and soil chemical properties (SOM, N, P, K, and pH water) were significantly improved on yam-based systems with legumes in comparison with traditional systems. PMID:27446635

  4. Population dynamics of caterpillars on three cover crops before sowing cotton in Mato Grosso (Brazil).

    PubMed

    Silvie, P J; Menzel, C A; Mello, A; Coelho, A G

    2010-01-01

    Direct seeding mulch-based cropping systems under a preliminary cover crop such as millet are common in some areas of Brazil. Lepidopteran pests that damage cotton, soybean and maize crops can proliferate on cover crops, so preventive chemical treatments are necessary. Very little data is available on these pests on cover crops. This paper presents the dynamics of Spodoptera frugiperda, S. eridania, Mocis latipes and Diatraea saccharalis caterpillars monitored at Primavera do Leste, Mato Grosso state (Brazil) during the of 2005/2006 and 2006/2007 cropping seasons on four cover crops, i.e. finger millet (Eleusine coracana), pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolor) and ruzigrass (Brachiaria ruziziensis). The pests were visually counted on plants within a 1 m2 transect (wooden frame). Caterpillars were reared to facilitate identification of collected species and parasitoids. Many S. frugiperda caterpillars were observed on millet in 2005, with a maximum of 37 caterpillars/m2. On sorghum, we found 30 caterpillars/m2, or 0.83 caterpillars/plant. The Diatraea borer attacked sorghum later than the other pests. M. latipes was also observed on millet. The millet cover crop had to be dried for at least 1 month before direct drilling the main cotton crop in order to impede S. frugiperda infestations on cotton plantlets, thus avoiding the need for substantial resowing. The comparative methodological aspects are discussed.

  5. Draft genome sequence, and a sequence-defined genetic linkage map of the legume crop species Lupinus angustifolius L.

    PubMed

    Yang, Huaan; Tao, Ye; Zheng, Zequn; Zhang, Qisen; Zhou, Gaofeng; Sweetingham, Mark W; Howieson, John G; Li, Chengdao

    2013-01-01

    Lupin (Lupinus angustifolius L.) is the most recently domesticated crop in major agricultural cultivation. Its seeds are high in protein and dietary fibre, but low in oil and starch. Medical and dietetic studies have shown that consuming lupin-enriched food has significant health benefits. We report the draft assembly from a whole genome shotgun sequencing dataset for this legume species with 26.9x coverage of the genome, which is predicted to contain 57,807 genes. Analysis of the annotated genes with metabolic pathways provided a partial understanding of some key features of lupin, such as the amino acid profile of storage proteins in seeds. Furthermore, we applied the NGS-based RAD-sequencing technology to obtain 8,244 sequence-defined markers for anchoring the genomic sequences. A total of 4,214 scaffolds from the genome sequence assembly were aligned into the genetic map. The combination of the draft assembly and a sequence-defined genetic map made it possible to locate and study functional genes of agronomic interest. The identification of co-segregating SNP markers, scaffold sequences and gene annotation facilitated the identification of a candidate R gene associated with resistance to the major lupin disease anthracnose. We demonstrated that the combination of medium-depth genome sequencing and a high-density genetic linkage map by application of NGS technology is a cost-effective approach to generating genome sequence data and a large number of molecular markers to study the genomics, genetics and functional genes of lupin, and to apply them to molecular plant breeding. This strategy does not require prior genome knowledge, which potentiates its application to a wide range of non-model species.

  6. Draft Genome Sequence, and a Sequence-Defined Genetic Linkage Map of the Legume Crop Species Lupinus angustifolius L

    PubMed Central

    Zheng, Zequn; Zhang, Qisen; Zhou, Gaofeng; Sweetingham, Mark W.; Howieson, John G.; Li, Chengdao

    2013-01-01

    Lupin (Lupinus angustifolius L.) is the most recently domesticated crop in major agricultural cultivation. Its seeds are high in protein and dietary fibre, but low in oil and starch. Medical and dietetic studies have shown that consuming lupin-enriched food has significant health benefits. We report the draft assembly from a whole genome shotgun sequencing dataset for this legume species with 26.9x coverage of the genome, which is predicted to contain 57,807 genes. Analysis of the annotated genes with metabolic pathways provided a partial understanding of some key features of lupin, such as the amino acid profile of storage proteins in seeds. Furthermore, we applied the NGS-based RAD-sequencing technology to obtain 8,244 sequence-defined markers for anchoring the genomic sequences. A total of 4,214 scaffolds from the genome sequence assembly were aligned into the genetic map. The combination of the draft assembly and a sequence-defined genetic map made it possible to locate and study functional genes of agronomic interest. The identification of co-segregating SNP markers, scaffold sequences and gene annotation facilitated the identification of a candidate R gene associated with resistance to the major lupin disease anthracnose. We demonstrated that the combination of medium-depth genome sequencing and a high-density genetic linkage map by application of NGS technology is a cost-effective approach to generating genome sequence data and a large number of molecular markers to study the genomics, genetics and functional genes of lupin, and to apply them to molecular plant breeding. This strategy does not require prior genome knowledge, which potentiates its application to a wide range of non-model species. PMID:23734219

  7. Development of a remote sensing protocol for inventorying cover crop adoptions

    NASA Astrophysics Data System (ADS)

    Bermudez, Carolina

    The use of cover crops has been recognized as an agricultural management practice that can enhance soil quality, contribute to suppressing weeds, promote the recycling of nutrients, and provide many other benefits when incorporated in farming systems. Because cover crops can mitigate or prevent soil erosion and nutrient leaching, the positive impact of this conservation practice also has an effect beyond farm boundaries, by reducing the contamination of water bodies caused by agriculture. As a consequence, state and federal agencies have been trying to assess farmer's motivations and barriers for cover crop use, and have also intended to track their adoption as a means of assessing conservation practice implementation. Because remote sensing techniques can provide information over large areas, periodically, it can be useful for estimating cover cropped fields. A decision tree model approach was used in this study to develop sets of criteria for the identification of fields with cover crops, pastures and grasses, and stover, based on monthly NDVI values. The model had an overall accuracy of 82%, while the level of precision for cover crop detection was 76.9%. The results of this study demonstrate that remote sensing can be used successfully to identify the adoption of cover crops in agricultural fields based on monthly average NDVI values.

  8. USE OF COVER CROPS FOR WEED SUPPRESSION IN HAZELNUT (CORYLUS AVELLANA L.) IN TURKEY.

    PubMed

    Isik, D; Dok, M; Ak, K; Macit, I; Demir, Z; Mennan, H

    2014-01-01

    Weed management is critical in hazelnut (Corylus avellana) production. Weeds reduce nutrient availability, interfere with tree growth, and reduce hand-harvesting efficiency. Field experiments were conducted to test effects of cover crops as alternative weed management strategies in hazelnut. The cover crop treatments consisted of Trifolium repens L., Festuca rubra subsp. rubra L., Festuca arundinacea Schreb., Vicia villosa Roth. And Trifolium meneghinianum Celmand fallow with no cover crop. Control plots such as weedy control, herbicide control and mechanical control were added as reference plots. The lowest weed dry biomass was obtained from Vicia villosa plots, and there were no significant differences among all other cover crop treatments. The highest cover crop dry biomass was measured in the Trifolium meneghinianum plots. Regarding the effect of cover crops on hazelnut yields, the lowest yield was ob- tained from weedy control plots, while the highest yield was obtained from F. arundinacea plots. This research indicated that cover crops could be used as living mulch in integrated weed management programs to manage weeds in the hazelnut orchards.

  9. Brassica cover cropping for management of sheath blight of rice

    USDA-ARS?s Scientific Manuscript database

    Sheath blight, caused by Rhizoctonia solani, is the most important disease limiting rice production in Texas and other rice-producing states. The fungal pathogen survives between crops as soilborne sclerotia and mycelium in infected plant debris. These sclerotia and colonized plant debris float on t...

  10. Erosion control in orchards and vineyards by a new soil and cover crop management method

    NASA Astrophysics Data System (ADS)

    Hartl, Wilfried; Guettler, Hans; Auer, Karl; Erhart, Eva

    2016-04-01

    Cover crops are the basis for an erosion-free soil management in orchards and vineyards. The soil cover provided by the foliage and the intensive root formation counteract erosion. Cover crops provide the soil microfauna with fresh organic matter which improves soil structure and porosity. The water demand of cover crops, however, may pose problems for the water supply of the trees and vines in dry seasons. Therefore it is necessary to adjust the growth of the cover crops to the actual water conditions. In years with ample precipitation cover crops may be allowed lush vegetative growth till flowering and formation of seeds. In dry years, the growth of the cover crop must be restricted to stop the competition for water, sometimes even by cutting off the cover crop roots. The course of the weather is incalculable and rainfall may be very variable during the year, so it is sometimes necessary to adust the cover crop management several times a year. A new special equipment, which can perform all the tasks necessary for the flexible cover crop management has been developed together with the agricultural machinery manufacturers Bodenwerkstatt Ertl-Auer GmbH and Güttler GmbH. The GreenManager® device consists of three modules, namely a specific type of cultivator, a harrow and a prismatic roller with seeding equipment, which can be used separately or in combination. The GreenManager® can reduce cover crops by flattening the plants in the whole row middle, by bringing down the cover crops with the harrow, or by horizontally cutting the cover crop roots a few centimetres beneath the soil surface in the central part of the row middle or in the whole row middle. These measures reduce the water competition by cover crops without generating further losses of soil moisture through intensive soil cultivation. At the same time the risk of soil erosion is kept to a minimum, because the soil remains covered by dead plant biomass. In one passage the GreenManager® can direct

  11. Use and Performance of Cover Crops for Enhanced Carbon Sequestration and GHG Mitigation in Croplands

    NASA Astrophysics Data System (ADS)

    Osborne, B.; Saunders, M.; Helmy, M.; Lanigan, G.; Jones, M.; Nagy, M.; Walmsley, D.

    2009-04-01

    Traditionally cover crops have been used to reduce nitrogen leaching from croplands, although there is an increased realisation that they could contribute to an enhanced annual sequestration of carbon by providing vegetation cover during fallow periods. This will depend to a certain extent on the ability of the cover crop to photosynthesise during autumn/winter periods and, in turn, on the prevailing environmental conditions. A possible downside of the use of cover crops in terms of a full GHG balance is the potential losses associated with increases in trace gases such as nitrous oxide and methane due to alterations in soil physics or biogeochemistry and/or decomposition of material prior to crop growth in the spring. To address these issues we have examined the impact of a cover crop (mustard) on the GHG balance of a spring barley cropping system. We show that mustard can significantly improve the carbon balance but that this is constrained by freezing night temperatures, even under these mild climatic conditions, with a 27-54% reduction in photosynthetic performance, depending on year. The effect is dependent on the severity and duration of the freezing temperatures and was characterised by a slow recovery of photosynthetic performance after the freezing event. We also show that the cover crop has no impact on the losses of dissolved carbon. Preliminary results indicate that the cover crop does not significantly impact on trace gas emissions during autumn/winter, although there may be an effect during residue incorporation prior to tillage practices in the spring. Overall these results indicate the utility of using cover crops for GHG mitigation in arable agriculture and indicate that further research should be focussed on the choice of species for particular environmental conditions, including enhanced tolerance to, and recovery from, freezing night temperatures.

  12. Potential of carbon accumulation in no-till soils with intensive use and cover crops in southern Brazil.

    PubMed

    Amado, Telmo Jorge Carneiro; Bayer, Cimélio; Conceição, Paulo Cesar; Spagnollo, Evandro; de Campos, Ben-Hur Costa; da Veiga, Milton

    2006-01-01

    The area under no-till (NT) in Brazil reached 22 million ha in 2004-2005, of which approximately 45% was located in the southern states. From the 1970s to the mid-1980s, this region was a source of carbon dioxide to the atmosphere due to decrease of soil carbon (C) stocks and high consumption of fuel by intensive tillage. Since then, NT has partially restored the soil C lost and reduced the consumption of fossil fuels. To assess the potential of C accumulation in NT soils, four long-term experiments (7-19 yr) in subtropical soils (Paleudult, Paleudalf, and Hapludox) varying in soil texture (87-760 g kg(-1) of clay) in agroecologic southern Brazil zones (central region, northwest basaltic plateau in Rio Grande Sul, and west basaltic plateau in Santa Catarina) and with different cropping systems (soybean and maize) were investigated. The lability of soil organic matter (SOM) was calculated as the ratio of total organic carbon (TOC) to particulate organic carbon (POC), and the role of physical protection on stability of SOM was evaluated. In general, TOC and POC stocks in native grass correlated closely with clay content. Conversely, there was no clear effect of soil texture on C accumulation rates in NT soils, which ranged from 0.12 to 0.59 Mg ha(-1) yr(-1). The C accumulation was higher in NT than in conventional-till (CT) soils. The legume cover crops pigeon pea [Cajanus cajan (L.) Millsp] and velvet beans (Stizolobium cinereum Piper & Tracy) in NT maize cropping systems had the highest C accumulation rates (0.38-0.59 Mg ha(-1) yr(-1)). The intensive cropping systems also were effective in increasing the C accumulation rates in NT soils (0.25-0.34 Mg ha(-1) yr(-1)) when compared to the double-crop system used by farmers. These results stress the role of N fixation in improving the tropical and subtropical cropping systems. The physical protection of SOM within soil aggregates was an important mechanism of C accumulation in the sandy clay loam Paleudult under NT

  13. Multispectral determination of vegetative cover in corn crop canopy

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.

    1972-01-01

    The relationship between different amounts of vegetative ground cover and the energy reflected by corn canopies was investigated. Low altitude photography and an airborne multispectral scanner were used to measure this reflected energy. Field plots were laid out, representing four growth stages of corn. Two plot locations were chosen-on a very dark and a very light surface soil. Color and color infrared photographs were taken from a vertical distance of 10 m. Estimates of ground cover were made from these photographs and were related to field measurements of leaf area index. Ground cover could be predicted from leaf area index measurements by a second order equation. Microdensitometry and digitzation of the three separated dye layers of color infrared film showed that the near infrared dye layer is most valuable in ground cover determinations. Computer analysis of the digitized photography provided an accurate method of determining precent ground cover.

  14. Edible grain legumes

    USDA-ARS?s Scientific Manuscript database

    Edible grain legumes including dry bean, dry pea, chickpeas, and lentils, have served as important sources of protein for human diets for thousands of years. In the US, these crops are predominately produced for export markets. The objective of this study was to examine yield gains in these crops ov...

  15. Multispectral satellite mapping of crop residue cover and tillage intensity in Iowa

    USDA-ARS?s Scientific Manuscript database

    Accurate post-planting crop residue cover assessments are crucial for identifying dominant tillage practices across large geographic areas and evaluating effectiveness of Conservation Management Plans. Current assessment protocols are labor intensive, time consuming, and costly. We hypothesize that ...

  16. Replacing fallow with cover crops in a semiarid soil: effects on soil properties

    USDA-ARS?s Scientific Manuscript database

    Replacement of fallow in crop-fallow systems with cover crops (CCs) may improve soil properties. We assessed whether replacing fallow in no-till winter wheat (Triticum aestivum L.)-fallow with winter and spring CCs for five years reduced wind and water erosion, increased soil organic carbon (SOC), a...

  17. Coupling Cover Crops with Alternative Swine Manure Application Strategies: Manure-15N Tracer Studies

    USDA-ARS?s Scientific Manuscript database

    Integration of rye cover crops with alternative liquid swine (Sus scrofa L.) manure application strategies may enhance retention of manure N in corn (Zea mays L.) - soybean [Glycine max (L.) Merr] cropping systems. The objective of this study was to quantify uptake of manure derived-N by a rye (Seca...

  18. Steers grazing of a rye cover crop influences growth of rye and no-till cotton

    USDA-ARS?s Scientific Manuscript database

    Small grain cover crops offer opportunities for grazing but effects on following row crops are not well understood. From 1999 through 2008, stocker steers sequence grazed small grains in a 2-paddock rye-cotton-wheat-fallow- rye rotation. Treatments imposed on rye included 1) zero-grazing from 1999; ...

  19. The impact of fall cover crops on soil nitrate and corn growth

    USDA-ARS?s Scientific Manuscript database

    Incorporating cover crops into current production systems can have many beneficial impacts on the current cropping system including decreasing erosion, improving water infiltration, increasing soil organic matter and biological activity but in water limited areas caution should be utilized. A fiel...

  20. Effect of Seeding Rate and Planting Arrangement on Rye Cover Crop and Weed Growth

    USDA-ARS?s Scientific Manuscript database

    Weed growth in winter cover crops in warm climates may contribute to weed management costs in subsequent crops. A two year experiment was conducted on an organic vegetable farm in Salinas, California, to determine the impact of seeding rate and planting arrangement on rye (Secale cereale L. cv. Merc...

  1. Cover Crop and Liquid Manure Effects on Soil Quality Indicators in a Corn Silage System.

    USDA-ARS?s Scientific Manuscript database

    Due to a lack of surface residue and organic matter inputs, continuous corn (Zea mays L.) silage production is one of the most demanding cropping systems imposed on our soil resources. In this study, our objective was to determine if using cover/companion crops and/or applying low-solids liquid dair...

  2. Increasing diveristy of arbuscular mycorrhizal fungi in agroecosystems using specific cover crops

    USDA-ARS?s Scientific Manuscript database

    Fall-planted cover crops provide a plant host for obligate symbiotic arbuscular mycorrhizal fungi (AMF) during otherwise fallow periods and thus may increase AMF numbers in agroecosystems. Increased AMF numbers should increase mycorrhizal colonization of the subsequent cash crops, which has been li...

  3. Effects of a custom cover crop residue manager in a no-till cotton system

    USDA-ARS?s Scientific Manuscript database

    Cover crops are an important part of no-till conservation agriculture, and these crops must produce optimum biomass amounts to effectively protect the soil surface from erosion and runoff, conserve soil water, and provide a physical barrier against weeds. Because of the large amount of residue produ...

  4. Cover crop in Missouri: putting them to work on your farm

    USDA-ARS?s Scientific Manuscript database

    Sunlight powers agriculture and fortunately is free to all farmers. The challenge is harvesting as much sunlight as possible. With commodity crops that may only be in the field for 4 to 5 months, there are several months each year when fields are receiving untapped sunlight. Fortunately, cover crop...

  5. Epidemiology and integrated management of persistently transmitted aphid-borne viruses of legume and cereal crops in West Asia and North Africa.

    PubMed

    Makkouk, Khaled M; Kumari, Safaa G

    2009-05-01

    Cool-season food legumes (faba bean, lentil, chickpea and pea) and cereals (bread and durum wheat and barley) are the most important and widely cultivated crops in West Asia and North Africa (WANA), where they are the main source of carbohydrates and protein for the majority of the population. Persistently transmitted aphid-borne viruses pose a significant limitation to legume and cereal production worldwide. Surveys conducted in many countries in WANA during the last three decades established that the most important of these viruses are: Faba bean necrotic yellows virus (FBNYV: genus Nanovirus; family Nanoviridae), Bean leafroll virus (BLRV: genus Luteovirus; family Luteoviridae), Beet western yellows virus (BWYV: genus Polerovirus; family Luteoviridae), Soybean dwarf virus (SbDV: genus Luteovirus; family Luteoviridae) and Chickpea chlorotic stunt virus (CpCSV: genus Polerovirus; family Luteoviridae) which affect legume crops, and Barley yellow dwarf virus-PAV (BYDV-PAV: genus Luteovirus; family Luteoviridae), Barley yellow dwarf virus-MAV (BYDV-MAV: genus Luteovirus; family Luteoviridae) and Cereal yellow dwarf virus-RPV (CYDV-RPV: genus Polerovirus; family Luteoviridae) which affect cereal crops. Loss in yield caused by these viruses is usually high when infection occurs early in the growing season. Many aphid vector species for the above-mentioned viruses are reported to be prevalent in the WANA region. In addition, in this region many wild species (annual or perennial) were found infected with these viruses and may play an important role in their ecology and spread. Fast spread of these diseases was always associated with high aphid vector populations and activity. Although virus disease management can be achieved by combining several control measures, development of resistant genotypes is undoubtedly one of the most appropriate control methods. Over the last three decades barley and wheat genotypes resistant to BYDV, faba bean genotypes resistant to BLRV, and

  6. Nitrate Leaching from Winter Cereal Cover Crops Using Undisturbed Soil-Column Lysimeters.

    PubMed

    Meisinger, John J; Ricigliano, Kristin A

    2017-05-01

    Cover crops are important management practices for reducing nitrogen (N) leaching, especially in the Chesapeake Bay watershed, which is under total maximum daily load (TMDL) restraints. Winter cereals are common cool-season crops in the Bay watershed, but studies have not directly compared nitrate-N (NO-N) leaching losses from these species. A 3-yr cover crop lysimeter study was conducted in Beltsville, MD, to directly compare NO-N leaching from a commonly grown cultivar of barley ( L.), rye ( L.), and wheat ( L.), along with a no-cover control, using eight tension-drained undisturbed soil column lysimeters in a completely randomized design with two replicates. The lysimeters were configured to exclude runoff and to estimate NO-N leaching and flow-weighted NO-N concentration (FWNC). The temporal pattern of NO-N leaching showed a consistent highly significant ( < 0.001) effect of lower NO-N leaching with cover crops compared with no cover but showed only small and periodically significant ( < 0.05) effects among the cultivars of barley, rye, and wheat covers. Nitrate-N leaching was more affected by the quantity of establishment-season (mid-October to mid-December) precipitation than by cover crop species. For example, compared with no cover, winter cereal covers reduced NO-N leaching 95% in a dry year and 50% in wet years, with corresponding reductions in FWNC of 92 and 43%, respectively. These results are important for scientists, nutrient managers, and policymakers because they directly compare NO-N leaching from winter cereal covers and expand knowledge for developing management practices for winter cereals that can improve water quality and increase N efficiency in cropping systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Effects of a Cover Crop on Splash Dispersal of Colletotrichum acutatum Conidia.

    PubMed

    Ntahimpera, N; Ellis, M A; Wilson, L L; Madden, L V

    1998-06-01

    ABSTRACT A rain simulator, with generated rains of 11 and 30 mm/h, was used to determine the effect of a cover crop or intercrop on the splash dispersal of Colletotrichum acutatum conidia. Dispersal through sudangrass, which can be used as a 'living mulch', was tested at two planting densities (140 or 280 kg/ha) and two heights (5 and 20 cm) and compared with a control consisting of a bare soil. Dispersal of C. acutatum conidia was assessed by counting colonies formed from spore-bearing splash droplets deposited in sheltered petri plates containing a selective medium. Both a cover crop and rain intensity significantly affected splash dispersal as measured by the interpolated total number of colonies (denoted by Sigma) from 0 to 72 cm from the inoculum source and in a time span of 61 min of generated rain (P < 0.001). However, there was no significant interaction of cover crop and intensity (P > 0.90). Dispersal with a 30-mm/h rain was higher than dispersal with a 11-mm/h rain, and presence of a cover crop significantly reduced dispersal compared with bare soil (P < 0.001). Of the treatments with sudangrass, cover crop planting density did not affect dispersal overall, but there was greater spore dispersal with the taller sudangrass at the higher planting density, due in part to the higher rate of water splashing with the tall grass compared with the short grass. Spore deposition in the petri plates could be functionally related to distance and time using a diffusion-type model, and parameter estimates could be used to explain the effects of cover crop on Sigma. Although the relationship between cover crop properties and splash dispersal is complex, results show the potential beneficial effects of the cover crop on disease management.

  8. Watershed-Scale Cover Crops Reduce Nutrient Export From Agricultural Landscapes.

    NASA Astrophysics Data System (ADS)

    Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Trentman, M. T.; Royer, T. V.; Prior, K.

    2016-12-01

    The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter Midwestern agricultural streams, which degrades both local and downstream water quality, resulting in algal blooms and subsequent hypoxic "dead zones" far from the nutrient source. We are quantifying the benefits of watershed-scale conservation practices that may reduce nutrient runoff from adjacent farm fields. Specifically, research is lacking on whether the planting of winter cover crops in watersheds currently dominated by row-crop agriculture can significantly reduce nutrient inputs to adjacent streams. Since 2013, farmers have planted cover crops on 70% of croppable acres in the Shatto Ditch Watershed (IN), and "saturation level" implementation of this conservation practice has been sustained for 3 years. Every 14 days, we have quantified nutrient loss from fields by sampling nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel throughout the watershed. Cover crops improved stream water quality by reducing dissolved inorganic nutrients exported downstream; nitrate-N and DRP concentrations and fluxes were significantly lower in tiles draining fields with cover crops compared to those without. Annual watershed nutrient export also decreased, and reductions in N and P loss ( 30-40%) exceeded what we expected based on only a 6-10% reduction in runoff due to increased watershed water holding capacity. We are also exploring the processes responsible for increased nutrient retention, where they are occurring (terrestrial vs. aquatic) and when (baseflow vs. storms). For example, whole-stream metabolism also responded to cover crop planting, showing reduced variation in primary production and respiration in years after watershed-scale planting of cover crops. In summary, widespread land cover change, through cover crop planting, can

  9. Biomass production of 12 winter cereal cover crop cultivars and their effect on subsequent no-till corn yield

    USDA-ARS?s Scientific Manuscript database

    Cover crops can improve the sustainability and resilience of corn and soybean production systems. However, there have been isolated reports of corn yield reductions following winter rye cover crops. Although there are many possible causes of corn yield reductions following winter cereal cover crops,...

  10. Microbial community structure and abundance in the rhizosphere and bulk soil of a tomato cropping system that includes cover crops

    USDA-ARS?s Scientific Manuscript database

    In this report we use Terminal Restriction Fragment Length Polymorphisms (TRFLP) in a tomato production system to “finger printing” the soil microbial community structure with Phylum specific primer sets. Factors influencing the soil microbes are a cover crop of Hairy Vetch (Vicia villosa) or Rye (...

  11. Root characteristics of cover crops and their erosion-reducing potential during concentrated runoff

    NASA Astrophysics Data System (ADS)

    de Baets, S.; Poesen, J.

    2009-04-01

    In the loam region in central Belgium, a lot of research has been conducted on the effects of cover crops for preventing splash and interrill erosion and on their nutrient pumping effectiveness. As this is a very effective erosion and environment conservation technique, planting cover crops during the winter season is widely applied in the loess belt. Most of these cover crops freeze at the beginning of the winter period. Consequently, the above-ground biomass becomes less effective in protecting the soil from water erosion. Apart from the effects of the above-ground biomass in protecting the soil against raindrop impacts and reducing flow velocities by the retarding effects of their stems, plant roots also play an important role in improving soil strength. Previous research showed that roots contribute to a large extent to the resistance of topsoils against concentrated flow erosion. Unfortunately, information on root properties of common cover crops (e.g. Sinapis alba, Phacelia tanacetifoli, Lolium perenne, Avena sativa, Secale cereale, Raphanus sativus subsp. oleiferus) is very scarce. Therefore, root density distribution with depth and their erosion-reducing effects during concentrated flow erosion were assessed by conducting root auger measurements and concentrated flow experiments at the end of the growth period (December). The preliminary results indicate that the studied cover crops are not equally effective in preventing soil loss by concentrated flow erosion at the end of the growing season. Cover crops with thick roots, such as Sinapis alba and Raphanus sativus subsp. oleiferus are less effective than cover crops with fine-branched roots such as Phacelia tanacetifoli, Lolium perenne (Ryegrass), Avena sativa (Oats) and Secale cereale (Rye) in preventing soil losses by concentrated flow erosion. These results enable soil managers to select the most suitable crops and maximize soil protection.

  12. WRKY domain-encoding genes of a crop legume chickpea (Cicer arietinum): comparative analysis with Medicago truncatula WRKY family and characterization of group-III gene(s)

    PubMed Central

    Kumar, Kamal; Srivastava, Vikas; Purayannur, Savithri; Kaladhar, V. Chandra; Cheruvu, Purnima Jaiswal; Verma, Praveen Kumar

    2016-01-01

    The WRKY genes have been identified as important transcriptional modulators predominantly during the environmental stresses, but they also play critical role at various stages of plant life cycle. We report the identification of WRKY domain (WD)-encoding genes from galegoid clade legumes chickpea (Cicer arietinum L.) and barrel medic (Medicago truncatula). In total, 78 and 98 WD-encoding genes were found in chickpea and barrel medic, respectively. Comparative analysis suggests the presence of both conserved and unique WRKYs, and expansion of WRKY family in M. truncatula primarily by tandem duplication. Exclusively found in galegoid legumes, CaWRKY16 and its orthologues encode for a novel protein having a transmembrane and partial Exo70 domains flanking a group-III WD. Genomic region of galegoids, having CaWRKY16, is more dynamic when compared with millettioids. In onion cells, fused CaWRKY16-EYFP showed punctate fluorescent signals in cytoplasm. The chickpea WRKY group-III genes were further characterized for their transcript level modulation during pathogenic stress and treatments of abscisic acid, jasmonic acid, and salicylic acid (SA) by real-time PCR. Differential regulation of genes was observed during Ascochyta rabiei infection and SA treatment. Characterization of A. rabiei and SA inducible gene CaWRKY50 showed that it localizes to plant nucleus, binds to W-box, and have a C-terminal transactivation domain. Overexpression of CaWRKY50 in tobacco plants resulted in early flowering and senescence. The in-depth comparative account presented here for two legume WRKY genes will be of great utility in hastening functional characterization of crop legume WRKYs and will also help in characterization of Exo70Js. PMID:27060167

  13. WRKY domain-encoding genes of a crop legume chickpea (Cicer arietinum): comparative analysis with Medicago truncatula WRKY family and characterization of group-III gene(s).

    PubMed

    Kumar, Kamal; Srivastava, Vikas; Purayannur, Savithri; Kaladhar, V Chandra; Cheruvu, Purnima Jaiswal; Verma, Praveen Kumar

    2016-06-01

    The WRKY genes have been identified as important transcriptional modulators predominantly during the environmental stresses, but they also play critical role at various stages of plant life cycle. We report the identification of WRKY domain (WD)-encoding genes from galegoid clade legumes chickpea (Cicer arietinum L.) and barrel medic (Medicago truncatula). In total, 78 and 98 WD-encoding genes were found in chickpea and barrel medic, respectively. Comparative analysis suggests the presence of both conserved and unique WRKYs, and expansion of WRKY family in M. truncatula primarily by tandem duplication. Exclusively found in galegoid legumes, CaWRKY16 and its orthologues encode for a novel protein having a transmembrane and partial Exo70 domains flanking a group-III WD. Genomic region of galegoids, having CaWRKY16, is more dynamic when compared with millettioids. In onion cells, fused CaWRKY16-EYFP showed punctate fluorescent signals in cytoplasm. The chickpea WRKY group-III genes were further characterized for their transcript level modulation during pathogenic stress and treatments of abscisic acid, jasmonic acid, and salicylic acid (SA) by real-time PCR. Differential regulation of genes was observed during Ascochyta rabiei infection and SA treatment. Characterization of A. rabiei and SA inducible gene CaWRKY50 showed that it localizes to plant nucleus, binds to W-box, and have a C-terminal transactivation domain. Overexpression of CaWRKY50 in tobacco plants resulted in early flowering and senescence. The in-depth comparative account presented here for two legume WRKY genes will be of great utility in hastening functional characterization of crop legume WRKYs and will also help in characterization of Exo70Js. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  14. Cover crop water quality benefits in intensive production

    USDA-ARS?s Scientific Manuscript database

    Fresh market tomatoes are typically grown in in raised beds covered in polyethylene mulch with bare-soil furrows between the beds. Field experiments were conducted over five years to examine two alternative management strategies. In side-by-side comparison with the traditional management practice, t...

  15. Mapping crop ground cover using airborne multispectral digital imagery

    USDA-ARS?s Scientific Manuscript database

    Empirical relationships between remotely sensed vegetation indices and density information, such as leaf area index or ground cover (GC), are commonly used to derive spatial information in many precision farming operations. In this study, we modified an existing methodology that does not depend on e...

  16. Impact of cover crops and tillage on porosity of podzolic soil

    NASA Astrophysics Data System (ADS)

    Błażewicz-Woźniak, M.; Konopiñski, M.

    2013-09-01

    The aim of the study was to determine the influence of cover crops biomass, mixed with the soil on different dates and with the use of different tools in field conditions. The cover crop biomass had a beneficial influence on the total porosity of the 0-20 cm layer of the soil after winter. The highest porosity was achievedwith cover crops of buckwheat, phacelia and mustard, the lowest with rye. During the vegetation period the highest porosity of soil was observed in the ridges. Among the remaining non-ploughing cultivations, pre-winter use of stubble cultivator proved to have a beneficial influence on the soil porosity, providing results comparable to those achieved in conventional tillage. The differential porosity of the soil was modified not only by the catch crops and the cultivation methods applied, but also by the sample collection dates, and it did change during the vegetation period. The highest content of macropores after winter was observed for the phacelia cover crop, and the lowest in the case of cultivation without any cover crops. Pre-winter tillage with the use of a stubble cultivator increased the amount of macropores in soil in spring, and caused the biggest participation of mesopores as compared with other non-ploughing cultivation treatments of the soil. The smallest amount of mesopores was found in the ridges.

  17. Monitoring cover crops using radar remote sensing in southern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Shang, J.; Huang, X.; Liu, J.; Wang, J.

    2016-12-01

    Information on agricultural land surface conditions is important for developing best land management practices to maintain the overall health of the fields. The climate condition supports one harvest per year for the majority of the field crops in Canada, with a relative short growing season between May and September. During the non-growing-season months (October to the following April), many fields are traditionally left bare. In more recent year, there has been an increased interest in planting cover crops. Benefits of cover crops include boosting soil organic matters, preventing soil from erosion, retaining soil moisture, and reducing surface runoff hence protecting water quality. Optical remote sensing technology has been exploited for monitoring cover crops. However limitations inherent to optical sensors such as cloud interference and signal saturation (when leaf area index is above 2.5) impeded its operational application. Radar remote sensing on the other hand is not hindered by unfavorable weather conditions, and the signal continues to be sensitive to crop growth beyond the saturation point of optical sensors. It offers a viable means for capturing timely information on field surface conditions (with or without crop cover) or crop development status. This research investigated the potential of using multi-temporal RADARSAT-2 C-band synthetic aperture radar (SAR) data collected in 2015 over multiple fields of winter wheat, corn and soybean crops in southern Ontario, Canada, to retrieve information on the presence of cover crops and their growth status. Encouraging results have been obtained. This presentation will report the methodology developed and the results obtained.

  18. Cover crops increase foraging activity of omnivorous predators in seed patches and facilitate weed biological control

    USDA-ARS?s Scientific Manuscript database

    Omnivores are important consumers of both weed seeds and insect pests, and habitat provisions like cover crops are suggested to promote their ecosystem services in agricultural systems. However, few studies establish direct links between cover, food, and pest suppression because they are entangled a...

  19. Soil erosion control, plant diversity, and arthropod communities under heterogeneous cover crops in an olive orchard.

    PubMed

    Gómez, José Alfonso; Campos, Mercedes; Guzmán, Gema; Castillo-Llanque, Franco; Vanwalleghem, Tom; Lora, Ángel; Giráldez, Juan V

    2017-01-30

    A 3-year experiment compared in an olive orchard the effect of different cover crops' composition on runoff, water erosion, diversity of annual plants, and arthropod communities which could provide an alternative to conventional management based on tillage (CT). The cover crops evaluated were a seeded homogeneous grass (GC), a seeded mix of ten different species (MCseeded), and a non-seeded cover by vegetation naturally present at the farm after 20 years of mowing (MCnatural). The results suggest that heterogeneous cover crops can provide a viable alternative to homogeneous ones in olives, providing similar benefits in reducing runoff and soil losses compared to management based on bare soil. The reduction in soil loss was particularly large: 46.7 in CT to 6.5 and 7.9 t ha(-1) year(-1) in GC and MCseeded, respectively. The heterogeneous cover crops resulted in greater diversity of plant species and a modification of the arthropod communities with an increased number of predators for pests. The reduction of the cost of implanting heterogeneous cover crops, improvement of the seeding techniques, and selection of species included in the mixes require additional research to promote the use of this practice which can deliver enhanced environmental benefits.

  20. THE ROLE OF CROP/POLLINATOR RELATIONSHIP UNDERSTANDING IN BREEDING FOR POLLINATOR-FRIENDLY LEGUME VARIETIES; FROM A BREEDING PERSPECTIVE

    USDA-ARS?s Scientific Manuscript database

    Following the reports of the decline in solitary and social bees, breeders are encouraged to develop a breeding approach that strives to integrate food production into the healthy functioning of the agro-ecosystems. In the particular case of legumes, this approach should preserve bee fauna by provi...

  1. Genepool of Wild Populations of Forage and Grain Legume Crops of Northwest and Central Regions of Russia

    USDA-ARS?s Scientific Manuscript database

    An international plant collection expedition to the northwest and central regions of Russia was undertaken in 2007 to collect seed of wild-growing perennial grass and legume species that have potential for forage and turf applications. These collections are of interest in breeding and selection pro...

  2. Intercropping Cover Crops with Pineapple for the Management of Rotylenchulus reniformis

    PubMed Central

    Wang, K.-H.; Sipes, B. S.; Schmitt, D. P.

    2003-01-01

    Effect of cover crops intercropped with pineapple (Ananas comosus) on Rotylenchulus reniformis population densities and activity of nematode-trapping fungi (NTF) were evaluated in two cycles of cover crop and pineapple. Sunn hemp (Crotalaria juncea), rapeseed (Brassica napus), African marigold (Tagetes erecta), or weeds were intercropped with pineapples. Beds planted with sunn hemp or rapeseed had lower population densities of R. reniformis than African marigold, weeds, or pineapple plots during cover crop growth, and the subsequent pineapple-growing periods. Rapeseed was a good host to Meloidogyne javanica and resulted in high population densities of M. javanica in the subsequent pineapple crop. Fireweed (Erigeron canadensis) occurred commonly and was a good host to R. reniformis. Bacterivorous nematode population densities increased (P ≤ 0.05) most in sunn hemp, especially early after planting. Nematode-trapping fungi required a long period to develop measurable population densities. Population densities of NTF were higher in cover crops than weeds or pineapples during the first crop cycle (P < 0.05). Although pineapple produced heavier fruits following sunn hemp than in the other treatments (P < 0.05), commercial yields were not different among rapeseed, weed, and sunn hemp treatments. PMID:19265973

  3. Cover cropping alters the diet of arthropods in a banana plantation: a metabarcoding approach.

    PubMed

    Mollot, Gregory; Duyck, Pierre-François; Lefeuvre, Pierre; Lescourret, Françoise; Martin, Jean-François; Piry, Sylvain; Canard, Elsa; Tixier, Philippe

    2014-01-01

    Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey.

  4. Cover Cropping Alters the Diet of Arthropods in a Banana Plantation: A Metabarcoding Approach

    PubMed Central

    Mollot, Gregory; Duyck, Pierre-François; Lefeuvre, Pierre; Lescourret, Françoise; Martin, Jean-François; Piry, Sylvain; Canard, Elsa; Tixier, Philippe

    2014-01-01

    Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey. PMID:24695585

  5. Structure of bacterial communities in soil following cover crop and organic fertilizer incorporation.

    PubMed

    Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

    2016-11-01

    Incorporation of organic material into soils is an important element of organic farming practices that can affect the composition of the soil bacterial communities that carry out nutrient cycling and other functions crucial to crop health and growth. We conducted a field experiment to determine the effects of cover crops and fertilizers on bacterial community structure in agricultural soils under long-term organic management. Illumina sequencing of 16S rDNA revealed diverse communities comprising 45 bacterial phyla in corn rhizosphere and bulk field soil. Community structure was most affected by location and by the rhizosphere effect, followed by sampling time and amendment treatment. These effects were associated with soil physicochemical properties, including pH, moisture, organic matter, and nutrient levels. Treatment differences were apparent in bulk and rhizosphere soils at the time of peak corn growth in the season following cover crop and fertilizer application. Cover crop and fertilizer treatments tended to lower alpha diversity in early season samples. However, winter rye, oilseed radish, and buckwheat cover crop treatments increased alpha diversity in some later season samples compared to a no-amendment control. Fertilizer treatments and some cover crops decreased relative abundance of members of the ammonia-oxidizing family Nitrosomonadaceae. Pelleted poultry manure and Sustane® (a commercial fertilizer) decreased the relative abundance of Rhizobiales. Our data point to a need for future research exploring how (1) cover crops influence bacterial community structure and functions, (2) these effects differ with biomass composition and quantity, and (3) existing soil conditions and microbial community composition influence how soil microbial populations respond to agricultural management practices.

  6. The Effect of Marigolds (Tagetes spp.) and Other Cover Crops on Pratylenchus penetrans and on Following Potato Crops.

    PubMed

    Kimpinski, J; Arsenault, W J; Gallant, C E; Sanderson, J B

    2000-12-01

    Root-lesion nematodes (primarily Pratylenchus penetrans) were monitored in two marigold cultivars (Tagetes tenuifolia cv. Nemakill and cv. Nemanon), annual ryegrass (Lolium multiflorum cv. Lemtal), red clover (Trifolium pratense cv. Florex), and soybean (Glycine max cv. Proteus), and in the following potato (Solanum tuberosum cv. Superior) crop during three growth sequences. Meadow fescue (Festuca elatior cv. Miner) and bee plant (Phacelia tanacetifolia cv. Gipha) were added to the trial in the second year. Black-eyed Susan (Rudbeckia hirta, unidentified cv.) and two additional marigold cultivars (T. patula ssp. nana, unidentified cv., and T. erecta cv. Crackerjack) were included in the final sequence. Population levels of root-lesion nematodes were consistently lower under marigolds compared to the other cover crops tested. Correspondingly, average potato tuber yields were significantly higher (8-14%) when potato followed marigolds. The highest levels of root-lesion nematodes occurred under red clover and soybean, and the average potato tuber yields were lowest following these crops.

  7. Cover crop mulches influence biological control of the imported cabbageworm (Pieris rapae L., Lepidoptera: Pieridae) in cabbage

    USDA-ARS?s Scientific Manuscript database

    Increasing structural complexity within crop fields can provide a way to manipulate pest abundance and biological control in agroecosystems. Here, we examine the effect of cover crop mulches in cabbage on the structure and function of an insect food web, investigating the role of cover crop species,...

  8. Short-term soil responses to late-seeded cover crops in a semi-arid environment

    USDA-ARS?s Scientific Manuscript database

    Cover crops can expand ecosystem services, though sound management recommendations for their use within semi-arid cropping systems is currently constrained by a lack of information. This study was conducted to determine agroecosystem responses to late-summer seeded cover crops under no-till managem...

  9. Large-scale transcriptome analysis in chickpea (Cicer arietinum L.), an orphan legume crop of the semi-arid tropics of Asia and Africa

    PubMed Central

    Hiremath, Pavana J; Farmer, Andrew; Cannon, Steven B; Woodward, Jimmy; Kudapa, Himabindu; Tuteja, Reetu; Kumar, Ashish; BhanuPrakash, Amindala; Mulaosmanovic, Benjamin; Gujaria, Neha; Krishnamurthy, Laxmanan; Gaur, Pooran M; KaviKishor, Polavarapu B; Shah, Trushar; Srinivasan, Ramamurthy; Lohse, Marc; Xiao, Yongli; Town, Christopher D; Cook, Douglas R; May, Gregory D; Varshney, Rajeev K

    2011-01-01

    Chickpea (Cicer arietinum L.) is an important legume crop in the semi-arid regions of Asia and Africa. Gains in crop productivity have been low however, particularly because of biotic and abiotic stresses. To help enhance crop productivity using molecular breeding techniques, next generation sequencing technologies such as Roche/454 and Illumina/Solexa were used to determine the sequence of most gene transcripts and to identify drought-responsive genes and gene-based molecular markers. A total of 103 215 tentative unique sequences (TUSs) have been produced from 435 018 Roche/454 reads and 21 491 Sanger expressed sequence tags (ESTs). Putative functions were determined for 49 437 (47.8%) of the TUSs, and gene ontology assignments were determined for 20 634 (41.7%) of the TUSs. Comparison of the chickpea TUSs with the Medicago truncatula genome assembly (Mt 3.5.1 build) resulted in 42 141 aligned TUSs with putative gene structures (including 39 281 predicted intron/splice junctions). Alignment of ∼37 million Illumina/Solexa tags generated from drought-challenged root tissues of two chickpea genotypes against the TUSs identified 44 639 differentially expressed TUSs. The TUSs were also used to identify a diverse set of markers, including 728 simple sequence repeats (SSRs), 495 single nucleotide polymorphisms (SNPs), 387 conserved orthologous sequence (COS) markers, and 2088 intron-spanning region (ISR) markers. This resource will be useful for basic and applied research for genome analysis and crop improvement in chickpea. PMID:21615673

  10. Does grazing of cover crops impact biologically active soil C and N fractions under inversion and no tillage management

    USDA-ARS?s Scientific Manuscript database

    Cover crops are a key component of conservation cropping systems. They can also be a key component of integrated crop-livestock systems by offering high-quality forage during short periods between cash crops. The impact of cattle grazing on biologically active soil C and N fractions has not receiv...

  11. Salt and N leaching and soil accumulation due to cover cropping practices

    NASA Astrophysics Data System (ADS)

    Gabriel, J. L.; Quemada, M.

    2012-04-01

    Nitrate leaching beyond the root zone can increase water contamination hazards and decrease crop available N. Cover crops used in spite of fallow are an alternative to reduce nitrate contamination in the vadose zone, because reducing drainage and soil mineral N accumulation. Cover crops can improve important characteristics in irrigated land as water retention capacity or soil aggregate stability. However, increasing evapotranspiration and consequent drainage below the root system reduction, could lead to soil salt accumulation. Salinity affects more than 80 million ha of arable land in many areas of the world, and one of the principal causes for yield reduction and even land degradation in the Mediterranean region. Few studies dealt with both problems at the same time. Therefore, it is necessary a long-term evaluation of the potential effect on soil salinity and nitrate leaching, in order to ensure that potential disadvantages that could originate from soil salt accumulation are compensated with all advantages of cover cropping. A study of the soil salinity and nitrate leaching was conducted during 4 years in a semiarid irrigated agricultural area of Central Spain. Three treatments were studied during the intercropping period of maize (Zea mays L.): barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and fallow. Cover crops were killed in March allowing seeding of maize of the entire trial in April, and all treatments were irrigated and fertilised following the same procedure. Before sowing, and after harvesting maize and cover crops, soil salt and nitrate accumulation was determined along the soil profile. Soil analysis was conducted at six depths every 0.20 m in each plot in samples from four 0 to 1.2-m depth holes dug. The electrical conductivity of the saturated paste extract and soil mineral nitrogen was measured in each soil sample. A numerical model based on the Richards water balance equation was applied in order to calculate drainage at 1.2 m depth

  12. Managing soil nitrate with cover crops and buffer strips in Sicilian vineyards

    NASA Astrophysics Data System (ADS)

    Novara, A.; Gristina, L.; Guaitoli, F.; Santoro, A.; Cerdà, A.

    2013-08-01

    When soil nitrate levels are low, plants suffer nitrogen (N) deficiency but when the levels are excessive, soil nitrates can pollute surface and subsurface waters. Strategies to reduce the nitrate pollution are necessary to reach a sustainable use of resources such as soil, water and plant. Buffer strips and cover crops can contribute to the management of soil nitrates, but little is known of their effectiveness in semiarid vineyards plantations. The research was carried out in the south coast of Sicily (Italy) to evaluate nitrate trends in a vineyard managed both conventionally and using two different cover crops (Triticum durum and Vicia sativa cover crop). A 10 m-wide buffer strip was seeded with Lolium perenne at the bottom of the vineyard. Soil nitrate was measured monthly and nitrate movement was monitored by application of a 15N tracer to a narrow strip between the bottom of vineyard and the buffer and non-buffer strips. Lolium perenne biomass yield in the buffer strips and its isotopic nitrogen content were monitored. Vicia sativa cover crop management contributed with an excess of nitrogen, and the soil management determined the nitrogen content at the buffer areas. A 6 m buffer strip reduced the nitrate by 42% with and by 46% with a 9 m buffer strip. Thanks to catch crops, farmers can manage the N content and its distribution into the soil over the year, can reduced fertilizer wastage and reduce N pollution of surface and groundwater.

  13. Effect of cover crops on greenhouse gas emissions in an irrigated field under integrated soil fertility management

    NASA Astrophysics Data System (ADS)

    Guardia, Guillermo; Abalos, Diego; García-Marco, Sonia; Quemada, Miguel; Alonso-Ayuso, María; Cárdenas, Laura M.; Dixon, Elizabeth R.; Vallejo, Antonio

    2016-09-01

    Agronomical and environmental benefits are associated with replacing winter fallow by cover crops (CCs). Yet, the effect of this practice on nitrous oxide (N2O) emissions remains poorly understood. In this context, a field experiment was carried out under Mediterranean conditions to evaluate the effect of replacing the traditional winter fallow (F) by vetch (Vicia sativa L.; V) or barley (Hordeum vulgare L.; B) on greenhouse gas (GHG) emissions during the intercrop and the maize (Zea mays L.) cropping period. The maize was fertilized following integrated soil fertility management (ISFM) criteria. Maize nitrogen (N) uptake, soil mineral N concentrations, soil temperature and moisture, dissolved organic carbon (DOC) and GHG fluxes were measured during the experiment. Our management (adjusted N synthetic rates due to ISFM) and pedo-climatic conditions resulted in low cumulative N2O emissions (0.57 to 0.75 kg N2O-N ha-1 yr-1), yield-scaled N2O emissions (3-6 g N2O-N kg aboveground N uptake-1) and N surplus (31 to 56 kg N ha-1) for all treatments. Although CCs increased N2O emissions during the intercrop period compared to F (1.6 and 2.6 times in B and V, respectively), the ISFM resulted in similar cumulative emissions for the CCs and F at the end of the maize cropping period. The higher C : N ratio of the B residue led to a greater proportion of N2O losses from the synthetic fertilizer in these plots when compared to V. No significant differences were observed in CH4 and CO2 fluxes at the end of the experiment. This study shows that the use of both legume and nonlegume CCs combined with ISFM could provide, in addition to the advantages reported in previous studies, an opportunity to maximize agronomic efficiency (lowering synthetic N requirements for the subsequent cash crop) without increasing cumulative or yield-scaled N2O losses.

  14. Legume Information System (LegumeInfo.org): a key component of a set of federated data resources for the legume family

    USDA-ARS?s Scientific Manuscript database

    The Legume Information System (LIS), at http://legumeinfo.org, is a genomic data portal (GDP) for the legume family. LIS provides access to genetic and genomic information for major crop and model legumes. With more than two-dozen domesticated legume species, there are numerous specialists working o...

  15. Evaluation of native bees as pollinators of cucurbit crops under floating row covers.

    PubMed

    Minter, Logan M; Bessin, Ricardo T

    2014-10-01

    Production of cucurbit crops presents growers with numerous challenges. Several severe pests and diseases can be managed through the use of rotation, trap cropping, mechanical barriers, such as row covers, and chemical applications. However, considerations must also be made for pollinating insects, as adequate pollination affects the quantity and quality of fruit. Insecticides may negatively affect pollinators; a concern enhanced in recent years due to losses in managed Apis melifera L. colonies. Row covers can be used in place of chemical control before pollination, but when removed, pests have access to fields along with the pollinators. If pollination services of native bees could be harnessed for use under continuous row covers, both concerns could be balanced for growers. The potential of two bee species which specialize on cucurbit flowers, Peponapis pruinosa Say and Xenoglossa strenua Cresson, were assessed under continuous row covers, employed over acorn squash. Experimental treatments included plots with either naturally or artificially introduced bees under row covers and control plots with row covers either permanently removed at crop flowering, or employed continuously with no added pollinating insects. Pests in plots with permanently removed row covers were managed using standard practices used in certified organic production. Marketable yields from plots inoculated with bees were indistinguishable from those produced under standard practices, indicating this system would provide adequate yields to growers without time and monetary inputs of insecticide applications. Additionally, application of this technique was investigated for muskmelon production and discussed along with considerations for farm management.

  16. A comparative analysis of transcriptomic, biochemical, and physiological responses to elevated ozone identifies species-specific mechanisms of resilience in legume crops

    PubMed Central

    Yendrek, Craig R.; Koester, Robert P.

    2015-01-01

    Current concentrations of tropospheric ozone ([O3]) pollution negatively impact plant metabolism, which can result in decreased crop yields. Interspecific variation in the physiological response of plants to elevated [O3] exists; however, the underlying cellular responses explaining species-specific differences are largely unknown. Here, a physiological screen has been performed on multiple varieties of legume species. Three varieties of garden pea (Pisum sativum L.) were resilient to elevated [O3]. Garden pea showed no change in photosynthetic capacity or leaf longevity when exposed to elevated [O3], in contrast to varieties of soybean (Glycine max (L.) Merr.) and common bean (Phaseolus vulgaris L.). Global transcriptomic and targeted biochemical analyses were then done to examine the mechanistic differences in legume responses to elevated [O3]. In all three species, there was an O3-mediated reduction in specific leaf weight and total non-structural carbohydrate content, as well as increased abundance of respiration-related transcripts. Differences specific to garden pea included a pronounced increase in the abundance of GLUTATHIONE REDUCTASE transcript, as well as greater contents of foliar glutathione, apoplastic ascorbate, and sucrose in elevated [O3]. These results suggest that garden pea may have had greater capacity for detoxification, which prevented net losses in CO2 fixation in an elevated [O3] environment. PMID:26324463

  17. A comparative analysis of transcriptomic, biochemical, and physiological responses to elevated ozone identifies species-specific mechanisms of resilience in legume crops.

    PubMed

    Yendrek, Craig R; Koester, Robert P; Ainsworth, Elizabeth A

    2015-12-01

    Current concentrations of tropospheric ozone ([O3]) pollution negatively impact plant metabolism, which can result in decreased crop yields. Interspecific variation in the physiological response of plants to elevated [O3] exists; however, the underlying cellular responses explaining species-specific differences are largely unknown. Here, a physiological screen has been performed on multiple varieties of legume species. Three varieties of garden pea (Pisum sativum L.) were resilient to elevated [O3]. Garden pea showed no change in photosynthetic capacity or leaf longevity when exposed to elevated [O3], in contrast to varieties of soybean (Glycine max (L.) Merr.) and common bean (Phaseolus vulgaris L.). Global transcriptomic and targeted biochemical analyses were then done to examine the mechanistic differences in legume responses to elevated [O3]. In all three species, there was an O3-mediated reduction in specific leaf weight and total non-structural carbohydrate content, as well as increased abundance of respiration-related transcripts. Differences specific to garden pea included a pronounced increase in the abundance of GLUTATHIONE REDUCTASE transcript, as well as greater contents of foliar glutathione, apoplastic ascorbate, and sucrose in elevated [O3]. These results suggest that garden pea may have had greater capacity for detoxification, which prevented net losses in CO2 fixation in an elevated [O3] environment. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  18. Cover crops effect on farm benefits and nitrate leaching: linking economic and environmental analysis

    NASA Astrophysics Data System (ADS)

    Gabriel, José Luis; Vanclooster, Marnik; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Introducing cover crops interspersed with intensively fertilized crops in rotation has the potential to reduce nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of the technique is still limited because growing CC could lead to extra costs for the farm in three different forms: direct, indirect, and opportunity costs. Environmental studies are complex, and evaluating the indicators that are representative of the environmental impact of an agricultural system is a complicated task that is conducted by specialized groups and methodologies. Multidisciplinary studies may help to develop reliable approaches that would contribute to choosing the best agricultural strategies based on linking economic and environmental benefits. This study evaluates barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo) as cover crops between maize, leaving the residue in the ground or selling it for animal feeding, and compares the economic and environmental results with respect to a typical maize-fallow rotation. Nitrate leaching for different weather conditions was calculated using the mechanistic-deterministic WAVE model, using the Richards equation parameterised with a conceptual model for the soil hydraulic properties for describing the water flow in the vadose zone, combined with field observed data. The economic impact was evaluated through stochastic (Monte-Carlo) simulation models of farms' profits using probability distribution functions of maize yield and cover crop biomass developed fitted with data collected from various field trials (during more than 5 years) and probability distribution functions of maize and different cover crop forage prices fitted from statistical sources. Stochastic dominance relationships are obtained to rank the most profitable strategies from a farm financial perspective

  19. Greenhouse Gas Emissions Increase Following the Termination of a Perennial Legume Phase of an Annual Crop Rotation within the Red River Valley, Manitoba

    NASA Astrophysics Data System (ADS)

    Hanis, K. L.; Tenuta, M.; Amiro, B. D.; Glenn, A. J.; Maas, S.; Gervais, M.

    2013-12-01

    Perennial legume forages may have the potential to increase soil carbon sequestration and decrease nitrous oxide (N2O) emissions to the atmosphere when introduced into annual cropping systems. However, little is known about what short-term effect the return to annual cropping following termination of perennial legume forage would have on carbon dioxide (CO2) and N2O emissions. Furthermore, there are few quantitative measurements about this impact on the Canadian Prairies. A long-term field experiment to continuously measure CO2 and N2O fluxes was established at the Trace Gas Manitoba (TGAS-MAN) Long Term Greenhouse Gas Monitoring Site at Glenlea, Manitoba using the flux gradient micrometeorlogical technique with a tunable diode laser analyzer. The soil is poorly drained clay in the Red River Valley. The field experiment consisted of four 4-hectare plots planted to corn in 2006 and faba bean in 2007. In 2008, grass-alfalfa forage was introduced to two plots (annual - perennial) and grown until 2011 whereas the other two plots (annual) were planted to annual crops: spring wheat, rapeseed, barley and spring wheat in 2008, 2009, 2010 and 2011, respectively. In late September of 2011 the grass-alfalfa forage was killed and in 2012 all four plots were planted with corn. Termination of the grass-alfalfa forage resulted in greater fall CO2 emissions in 2011, greater spring melt CO2 emissions and net annual N2O emissions in 2012 from the annual-perennial plots when compared to the annual plots. Over seven crop years (2006-2012), the annual - perennial system increased carbon uptake by 3.4 Mg C ha-1 and reduced N2O emissions by 3.0 Mg CO2-eq ha-1 compared to the annual system. However after accounting for harvest removals both the annual and annual-perennial systems were net carbon sources of 5.7 and 2.5 Mg C ha-1 and net GHG sources of 38 and 24 Mg CO2-eq ha-1 respectively. We are currently following the long-term impacts of inclusion of perennial forages in an annual

  20. Brassica cover crops for nitrogen retention in the Mid-Atlantic coastal plain.

    PubMed

    Dean, Jill E; Weil, Ray R

    2009-01-01

    Brassica cover crops are new to the mid-Atlantic region, and limited information is available on their N uptake capabilities for effective N conservation. Forage radish (Raphanus sativus L. cv. Daikon), oilseed radish (Raphanus sativus L. cv. Adagio), and rape (Brassica napus L. cv. Dwarf Essex) were compared with rye (Secale cereale L. cv. Wheeler), a popular cover crop in the region, with regard to N uptake ability and potential to decrease N leaching at two sites in Maryland. Plants were harvested in fall and spring for dry matter and N analysis. Soil samples from 0 cm to 105 to 180 cm depth were obtained in fall and spring for NH(4)-N and NO(3)-N analyses. Ceramic cup tension lysimeters were installed at depths of 75 to 120 cm to monitor NO(3)-N in soil pore water. Averaged across 3 site-years, forage radish and rape shoots had greater dry matter production and captured more N in fall than rye shoots. Compared with a weedy fallow control, rape and rye caused similar decreases in soil NO(3)-N in fall and spring throughout the sampled profile. Cover crops had no effect on soil NH(4)-N. During the spring on coarse textured soil, pore water NO(3)-N concentrations in freeze-killed Brassica (radish) plots were greater than in control and overwintering Brassica (rape) and rye plots. On fine textured soil, all cover crops provided a similar decrease in pore water NO(3)-N concentration compared with control. On coarse textured soils, freeze-killed Brassica cover crops should be followed by an early-planted spring main crop.

  1. Effect of a Terminated Cover Crop and Aldicarb on Cotton Yield and Meloidogyne incognita Population Density.

    PubMed

    Wheeler, T A; Leser, J F; Keeling, J W; Mullinix, B

    2008-06-01

    Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log(10) (J2 + 1)/500 cm(3) soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log(10)(J2 + 1)/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18 degrees C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10 degrees C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty.

  2. How are arbuscular mycorrhizal associations related to maize growth performance during short-term cover crop rotation?

    PubMed

    Higo, Masao; Takahashi, Yuichi; Gunji, Kento; Isobe, Katsunori

    2017-07-31

    Better cover crop management options aiming to maximize the benefits of arbuscular mycorrhizal fungi (AMF) to subsequent crops are largely unknown. We investigated the impact of cover crop management methods on maize growth performance and assemblages of AMF colonizing maize roots in a field trial. The cover crop treatments comprised Italian ryegrass, wheat, brown mustard and fallow in rotation with maize. The diversity of AMF communities among cover crops used for maize management was significantly influenced by the cover crop and time course. Cover crops did not affect grain yield and aboveground biomass of subsequent maize but affected early growth. A structural equation model indicated that the root colonization, AMF diversity and maize phosphorus uptake had direct strong positive effects on yield performance. AMF variables and maize performance were related directly or indirectly to maize grain yield, whereas root colonization had a positive effect on maize performance. AMF may be an essential factor that determines the success of cover crop rotational systems. Encouraging AMF associations can potentially benefit cover cropping systems. Therefore, it is imperative to consider AMF associations and crop phenology when making management decisions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

    NASA Astrophysics Data System (ADS)

    Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla

    2015-10-01

    For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

  4. From model to crop: functional analysis of a STAY-GREEN gene in the model legume Medicago truncatula and effective use of the gene for alfalfa improvement.

    PubMed

    Zhou, Chuanen; Han, Lu; Pislariu, Catalina; Nakashima, Jin; Fu, Chunxiang; Jiang, Qingzhen; Quan, Li; Blancaflor, Elison B; Tang, Yuhong; Bouton, Joseph H; Udvardi, Michael; Xia, Guangmin; Wang, Zeng-Yu

    2011-11-01

    Medicago truncatula has been developed into a model legume. Its close relative alfalfa (Medicago sativa) is the most widely grown forage legume crop in the United States. By screening a large population of M. truncatula mutants tagged with the transposable element of tobacco (Nicotiana tabacum) cell type1 (Tnt1), we identified a mutant line (NF2089) that maintained green leaves and showed green anthers, central carpels, mature pods, and seeds during senescence. Genetic and molecular analyses revealed that the mutation was caused by Tnt1 insertion in a STAY-GREEN (MtSGR) gene. Transcript profiling analysis of the mutant showed that loss of the MtSGR function affected the expression of a large number of genes involved in different biological processes. Further analyses revealed that SGR is implicated in nodule development and senescence. MtSGR expression was detected across all nodule developmental zones and was higher in the senescence zone. The number of young nodules on the mutant roots was higher than in the wild type. Expression levels of several nodule senescence markers were reduced in the sgr mutant. Based on the MtSGR sequence, an alfalfa SGR gene (MsSGR) was cloned, and transgenic alfalfa lines were produced by RNA interference. Silencing of MsSGR led to the production of stay-green transgenic alfalfa. This beneficial trait offers the opportunity to produce premium alfalfa hay with a more greenish appearance. In addition, most of the transgenic alfalfa lines retained more than 50% of chlorophylls during senescence and had increased crude protein content. This study illustrates the effective use of knowledge gained from a model system for the genetic improvement of an important commercial crop.

  5. Cover crop, soil amendments, and variety effects on organic rice production in Texas

    USDA-ARS?s Scientific Manuscript database

    The major challenges in organic rice production include optimization of nutrient utilization, weed management, and variety selection. In this study, we tested the effects of two soil amendment products, two fertilizer rates, and three cover cropping systems (clover, ryegrass, and fallow) on organic ...

  6. Replacing fallow with cover crops in a semiarid soil:Effects on soil properties

    USDA-ARS?s Scientific Manuscript database

    Replacement of fallow in crop–fallow systems with cover crops (CCs) may improve soil properties. We assessed whether replacing fallow in no-till winter wheat (Triticum aestivum L.)–fallow with winter and spring CCs for 5 years reduced wind and water erosion, increased soil organic carbon (SOC), and ...

  7. Sunn Hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions

    USDA-ARS?s Scientific Manuscript database

    Plantings of sunn hemp as a cover crop have been experimentally shown to improve soil health, reduce plant-parasitic nematodes, and increase nematode-antagonistic microorganisms. However, these studies have been largely conducted in tropical and subtropical regions. To investigate the impacts of sun...

  8. Managing soil nitrate with cover crops and buffer strips in Sicilian vineyards

    NASA Astrophysics Data System (ADS)

    Novara, A.; Gristina, L.; Guaitoli, F.; Santoro, A.; Cerdà, A.

    2013-04-01

    When soil nitrate levels are inadequate, plants suffer nitrogen deficiency but when the levels are excessive, nitrates (NO3-N) can pollute surface and subsurface waters. Strategies to reduce the nitrate pollution are necessary to reach a sustainable use of resources such as soil, water and plant. Buffer strips and cover crops can contribute to the management of soil nitrates, but little is known of their effectiveness in semiarid vineyards plantations. The experimental site, a 10 m wide and 80 m long area at the bottom of a vineyard was selected in Sicily. The soil between vine rows and upslope of the buffer strip (seeded with Lolium perenne) and non-buffer strips (control) was managed conventionally and with one of two cover crops (Triticum durum and Vicia sativa cover crop). Soil nitrate was measured monthly and nitrate movement was monitored by application of a 15N tracer to a narrow strip between the bottom of vineyard and the buffer and non-buffer strips. L. perenne biomass yield in the buffer strips and its isotopic nitrogen content were monitored. V. sativa cover crop management contribute with an excess of nitrogen, and the soil management determined the nitrogen content at the buffer areas. A 6 m buffer strip reduce the nitrate by 42% with and by 46% with a 9 m buffer strip.

  9. Peanut performance and weed management in a high residue cover crop system

    USDA-ARS?s Scientific Manuscript database

    Previous research indicates conservation tillage is a viable option for successful peanut production, but more study is needed to help understand interactions between cover crop residues and peanut production. Specifically, additional information is needed about the effects of varying levels of c...

  10. Cover crops alter phosphorus soil fractions and organic matter accumulation in a Peruvian cacao agroforestry system

    USDA-ARS?s Scientific Manuscript database

    In many tropical soils, excessive weathering of primary minerals confounded by intense agricultural production has resulted in the depletion of organic matter and plant available forms of phosphorus (P). Long-term growth of cover crops in tropical agroforestry systems have been shown to influence nu...

  11. Cover Crop Effects on Nitrous Oxide Emission from a Manure-Treated Mollisol

    USDA-ARS?s Scientific Manuscript database

    Agriculture contributes 40% to 60% of the total annual N2O emissions to the atmosphere. Development of management practices to reduce these emissions would have a significant impact on greenhouse gas levels. Non-leguminous cover crops are efficient scavengers of residual soil NO3, thereby reducing l...

  12. Rye cover crop effects on nitrous oxide emissions from a corn-soybean system

    USDA-ARS?s Scientific Manuscript database

    Agricultural activities are a major source nitrous oxide emitted to the atmosphere. Development of management practices to reduce these emissions is needed. Non-leguminous cover crops are efficient scavengers of residual soil nitrate, but their effects on nitrous oxide emissions have not been well d...

  13. New roller/crimper concepts for mechanical termination of cover crops in conservaton agriculture

    USDA-ARS?s Scientific Manuscript database

    Rollers/crimpers have been used in conservation agriculture to terminate cover crops, however, excessive vibration generated by the original straight-bar roller design has delayed adoption of this technology in the United States. To avoid excessive vibration, producers generally reduce operating spe...

  14. New roller concepts for mechanical terminating cover crops in conservation agriculture in the southern United States

    USDA-ARS?s Scientific Manuscript database

    Rollers may provide a viable option to herbicides for terminating cover crops; however, excessive vibration generated by rollers and transferred to tractors hinders adoption of this technology in the US. To avoid excessive vibration, producers must limit their operational speed, which increases time...

  15. Rhizosphere microorganisms affected by soil solarization and cover cropping in Capsicum annuum and Phaseolus lunatus agroecosystems

    USDA-ARS?s Scientific Manuscript database

    Field experiments were conducted to evaluate the effects of soil solarization or cover cropping on bell pepper (Capsicum annuum) and lima bean (Phaseolus lunatus, L.) rhizosphere microorganisms. In Experiment I, flat surface solarization (FSS), raised bed solarization (RBS), cowpea (Vigna unguiculat...

  16. Impact of five cover crop green manures and Actinovate on Fusarium Wilt of watermelon

    USDA-ARS?s Scientific Manuscript database

    Triploid watermelon cultivars are grown on more than 2,023 ha in Maryland and in Delaware. Triploid watermelons have little host resistance to Fusarium wilt of watermelon (Fusarium oxysporum f. sp. niveum). The effects of four different fall-planted cover crops that were tilled in the spring as gree...

  17. Long-term effects of compost and cover crops on soil phosphorus in two California agroecosystems

    USDA-ARS?s Scientific Manuscript database

    Inefficient P use in agriculture results in soil P accumulation and losses to surrounding ecosystems, highlighting the need to reduce external inputs and use them more efficiently. Composts reduce the need for mineral fertilizers by recycling P from wastes at the regional scale, whereas cover crops ...

  18. A time-efficient scooping method to prepare cover crop seed for cone planters.

    USDA-ARS?s Scientific Manuscript database

    Cone planters (CP) uniformly distribute seed over research plots, however, preparing seed for CP by weighing is time-consuming. This study evaluated the effect of seed preparation method (scooping with a calibrated cup versus weighing) on population density of monoculture cover crops planted at sev...

  19. Cover crops in the upper midwestern United States: Simulated effect on nitrate leaching with artificial drainage

    USDA-ARS?s Scientific Manuscript database

    Fall-planted winter cover crops are an agricultural management practice with multiple benefits that includes reducing nitrate losses from artificially drained fields. While the practice is commonly used in the southern and eastern U.S., little is known about its efficacy in Midwestern states where a...

  20. Can leguminous cover crops partially replace nitrogen fertilization in Mississippi delta cotton production

    USDA-ARS?s Scientific Manuscript database

    Petroleum prices impacts cotton (Gossypium hirsutum L.) N fertilization cost. A 3-year field study was conducted on a Dundee silt loam to assess the interactions of leguminous cover crops [none, Austrian winter field pea (Pisum sativum L.) or hairy vetch (Vicia villosa Roth] and N fertilization rate...

  1. Mechanism of disease suppression of Fusarium wilt of watermelon by cover crop green manures

    USDA-ARS?s Scientific Manuscript database

    A fall planted Vicia villosa cover crop incorporated in spring as a green manure can suppress Fusarium wilt [Fusarium oxysporum f. sp. niveum (FON)] of watermelon in Maryland and Delaware. Experiments were conducted to determine whether the mechanism of this suppression was general or specific, and ...

  2. Response of representative cover crops to aluminum toxicity, phosphorus deprivation, and organic amendment

    USDA-ARS?s Scientific Manuscript database

    This study aimed to: a) determine the effect of P depletion and presence of Al on root and shoot growth of representative cover crops, and on their nutrient uptake; b) characterize the composition of root exudation under P and Al stress in nutrient solution; c) evaluate the ability of aqueous extrac...

  3. Hyperspectral remote sensing estimation of crop residue cover: Soil mineralogy, surface conditions, and their effects

    USDA-ARS?s Scientific Manuscript database

    Conservation tillage practices can enhance soil organic carbon content (SOC), improve soil structure, and reduce erosion. However, direct assessment of tillage practice for monitoring SOC change over large regions is difficult. Remote sensing of crop residue cover (CRC) can help assess tillage pra...

  4. Cover crops alter the soil microbial community and increase potato tuber yield and quality

    USDA-ARS?s Scientific Manuscript database

    An on-going study at a commercial farm operation in the San Luis Valley, CO is examining the effect of various summer cover crops (mustard, canola, sorghum-sudangrass, and a wet fallow control) on potato tuber yield and quality. In four of the five years, potato tuber yield and quality has shown si...

  5. Cover crop effects on soil microbial communities and enzyme activity in semiarid agroecosystems

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to compare a fallow-winter wheat (Triticum aestivum L.) rotation to several cover crop-winter wheat rotations under dryland and irrigated conditions in the semiarid US High Plains. We carried out a study that included two sites (Sidney, NE, and Akron, CO), and three s...

  6. Multiple rolling/crimping effects on termination of two summer cover crops in a conservation system

    USDA-ARS?s Scientific Manuscript database

    A field experiment was initiated in the 2015 growing season at the USDA-NSDL to determine the effectiveness of a prototype two-stage roller/crimper in mechanical termination of two summer cover crops intended for organic systems. The experiment was a randomized complete block design with four replic...

  7. Multiple microbial activity-based measures reflect effects of cover cropping and tillage on soils

    USDA-ARS?s Scientific Manuscript database

    Agricultural producers, conservation professionals, and policy makers are eager to learn of soil analytical techniques and data that document improvement in soil health by agricultural practices such as no-till and incorporation of cover crops. However, there is considerable uncertainty within the r...

  8. Fall cover crops boost soil arbuscular mycorrhizal fungi which can lead to reduced inputs

    USDA-ARS?s Scientific Manuscript database

    Fall cover crops provide multiple benefits to producers. These benefits include pathogen and pest protection, drought protection, weed control, reduced soil erosion, nutrient acquisition and retention, increased soil organic matter, and conservation of soil water by improvement of soil structure th...

  9. Soil Persistence of Metarhizium anisopliae Applied to Manage Sugarbeet Root Maggot in a Cover Crop Microenvironment

    USDA-ARS?s Scientific Manuscript database

    The sugarbeet root maggot, Tetanops myopaeformis (Röder), is a major insect pest of sugarbeet, Beta vulgaris L., in North Dakota, Minnesota, and Idaho. Three field trials using the insect pathogen Metarhizium anisopliae (Metch.) Sorok. ATCC 62176 in conjunction with cover crops were conducted in 200...

  10. Soil microbial communities under cacao agroforestry and cover crop systems in Peru

    USDA-ARS?s Scientific Manuscript database

    Cacao (Theobroma cacao) trees are grown in tropical regions worldwide for chocolate production. We studied the effects of agroforestry management systems and cover cropping on soil microbial communities under cacao in two different replicated field experiments in Peru. Two agroforestry systems, Imp...

  11. Fuzzy Multi Attributive Comparison of Roller Designs used to Terminate a Cover Crop

    USDA-ARS?s Scientific Manuscript database

    Cover crops are a vital part of conservation tillage systems, but they have to be managed appropriately to get their full benefits. These benefits include weed pressure reduction caused by alleopathy, improving soil properties due to mulch effects and increased soil organic matter. In recent years,...

  12. Effects of organic fertilization and cover crops on organic pepper production

    USDA-ARS?s Scientific Manuscript database

    The requirement for certified organic vegetable producers to implement a soil-building plan has led to the development of soil fertility systems based on combinations of organic fertilizers and cover crops. In order to determine optimal soil fertility combinations, conventional and organic bell pepp...

  13. Time interval between cover crop termination and planting influences corn seedling disease, plant growth, and yield

    USDA-ARS?s Scientific Manuscript database

    Experiments were established in controlled and field environment to evaluate the effect of time intervals between cereal rye cover crop termination and corn planting on corn seedling disease, corn growth, and grain yield in 2014 and 2015. Rye termination dates ranged from 25 days before planting (DB...

  14. US-1136, US-1137, and US-1138 cowpea lines for cover crop use

    USDA-ARS?s Scientific Manuscript database

    Following five years of field evaluation, three cowpea populations were selected as best adapted for use as a cover crop. A pure line selection procedure was used to develop genetically uniform lines from the segregating populations. Field evaluations demonstrated that the lines grow rapidly for u...

  15. The mechanism for weed suppression by a forage radish cover crop

    USDA-ARS?s Scientific Manuscript database

    In the Mid-Atlantic region, forage radish (Raphanus sativus L. var. longipinnatus) winter cover crops planted prior to 1 September suppress winter annual weeds from fall until early April. Little is known about the mechanism of this weed suppression. Published research reports suggest that allelopat...

  16. Reduction in metolachlor and degradate concentrations in shallow groundwater through cover crop use.

    PubMed

    White, Paul M; Potter, Thomas L; Bosch, David D; Joo, Hyun; Schaffer, Bruce; Muñoz-Carpena, Rafael

    2009-10-28

    Pesticide use during crop production has the potential to adversely impact groundwater quality. In southern Florida, climatic and hydrogeologic conditions and agronomic practices indicate that contamination risks are high. In the current study, dissipation of the widely used herbicide, metolachlor, and levels of the compound and selected degradates in shallow groundwater beneath six 0.15-ha plots in sweet corn (Zea mays) production were evaluated over a two-year period. During fallow periods (May to October), plots were either left bare or cover cropped with sunn hemp (Crotalaria juncea L.). Metolachlor was broadcast applied at label recommended rates prior to planting sweet corn each year. Groundwater monitoring wells hydraulically upgradient and downgradient, and within each plot were sampled biweekly. Results showed that metolachlor dissipation was rapid, as evidenced by the detection of relatively high levels of the metolachlor ethane sulfonic degradate (MESA) in groundwater beneath plots and a rapid metolachlor DT(50) (9-14 days) in a companion laboratory soil incubation. Other degradates detected included hydroxymetolachlor in soil and in groundwater metolachlor oxanilic acid (MOA) and a product tentatively identified as 2-chloro-N-(2-acetyl-6-methylphenyl-N-(2-methoxy-1-methylethyl) acetamide, a photo-oxidation product. Metolachlor and MESA levels, up to 16 and 2.4 times higher in groundwater beneath the noncover cropped plots when compared to those of the cover cropped plots, indicate that cover cropping results in more rapid dissipation and/or reduced leaching. The study demonstrated that integration of cover crops into agronomic systems in the region may yield water quality benefits by reducing herbicide inputs to groundwater.

  17. Crop acquisition of phosphorus, iron and zinc from soil in cereal/legume intercropping systems: a critical review

    PubMed Central

    Xue, Yanfang; Xia, Haiyong; Christie, Peter; Zhang, Zheng; Li, Long; Tang, Caixian

    2016-01-01

    Background Phosphorus (P), iron (Fe) and zinc (Zn) are essential elements for plant growth and development, but their availability in soil is often limited. Intercropping contributes to increased P, Fe and Zn uptake and thereby increases yield and improves grain nutritional quality and ultimately human health. A better understanding of how intercropping leads to increased plant P, Fe and Zn availability will help to improve P-fertilizer-use efficiency and agronomic Fe and Zn biofortification. Scope This review synthesizes the literature on how intercropping of legumes with cereals increases acquisition of P, Fe and Zn from soil and recapitulates what is known about root-to-shoot nutrient translocation, plant-internal nutrient remobilization and allocation to grains. Conclusions Direct interspecific facilitation in intercropping involves below-ground processes in which cereals increase Fe and Zn bioavailability while companion legumes benefit. This has been demonstrated and verified using isotopic nutrient tracing and molecular analysis. The same methodological approaches and field studies should be used to explore direct interspecific P facilitation. Both niche complementarity and interspecific facilitation contribute to increased P acquisition in intercropping. Niche complementarity may also contribute to increased Fe and Zn acquisition, an aspect poorly understood. Interspecific mobilization and uptake facilitation of sparingly soluble P, Fe and Zn from soil, however, are not the only determinants of the concentrations of P, Fe and Zn in grains. Grain yield and nutrient translocation from roots to shoots further influence the concentrations of these nutrients in grains. PMID:26749590

  18. Large-scale transcriptome analysis in chickpea (Cicer arietinum L.), an orphan legume crop of the semi-arid tropics of Asia and Africa.

    PubMed

    Hiremath, Pavana J; Farmer, Andrew; Cannon, Steven B; Woodward, Jimmy; Kudapa, Himabindu; Tuteja, Reetu; Kumar, Ashish; Bhanuprakash, Amindala; Mulaosmanovic, Benjamin; Gujaria, Neha; Krishnamurthy, Laxmanan; Gaur, Pooran M; Kavikishor, Polavarapu B; Shah, Trushar; Srinivasan, Ramamurthy; Lohse, Marc; Xiao, Yongli; Town, Christopher D; Cook, Douglas R; May, Gregory D; Varshney, Rajeev K

    2011-10-01

    Chickpea (Cicer arietinum L.) is an important legume crop in the semi-arid regions of Asia and Africa. Gains in crop productivity have been low however, particularly because of biotic and abiotic stresses. To help enhance crop productivity using molecular breeding techniques, next generation sequencing technologies such as Roche/454 and Illumina/Solexa were used to determine the sequence of most gene transcripts and to identify drought-responsive genes and gene-based molecular markers. A total of 103,215 tentative unique sequences (TUSs) have been produced from 435,018 Roche/454 reads and 21,491 Sanger expressed sequence tags (ESTs). Putative functions were determined for 49,437 (47.8%) of the TUSs, and gene ontology assignments were determined for 20,634 (41.7%) of the TUSs. Comparison of the chickpea TUSs with the Medicago truncatula genome assembly (Mt 3.5.1 build) resulted in 42,141 aligned TUSs with putative gene structures (including 39,281 predicted intron/splice junctions). Alignment of ∼37 million Illumina/Solexa tags generated from drought-challenged root tissues of two chickpea genotypes against the TUSs identified 44,639 differentially expressed TUSs. The TUSs were also used to identify a diverse set of markers, including 728 simple sequence repeats (SSRs), 495 single nucleotide polymorphisms (SNPs), 387 conserved orthologous sequence (COS) markers, and 2088 intron-spanning region (ISR) markers. This resource will be useful for basic and applied research for genome analysis and crop improvement in chickpea. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd. No claim to original US government works.

  19. Summer cover crops reduce atrazine leaching to shallow groundwater in southern Florida.

    PubMed

    Potter, Thomas L; Bosch, David D; Joo, Hyun; Schaffer, Bruce; Muñoz-Carpena, Rafael

    2007-01-01

    At Florida's southeastern tip, sweet corn (Zea Mays) is grown commercially during winter months. Most fields are treated with atrazine (6-chloro-N-ethyl-N'-[1-methylethyl]-1,3,5-triazine-2,4-diamine). Hydrogeologic conditions indicate a potential for shallow groundwater contamination. This was investigated by measuring the parent compound and three degradates--DEA (6-chloro-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine), DIA (6-chloro-N-ethyl)-1,3,5-triazine-2,4-diamine, and HA (6-hydroxy-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine)--in water samples collected beneath sweet corn plots treated annually with the herbicide. During the study, a potential mitigation measure (i.e., the use of a cover crop, Sunn Hemp [Crotalaria juncea L.], during summer fallow periods followed by chopping and turning the crop into soil before planting the next crop) was evaluated. Over 3.5 yr and production of four corn crops, groundwater monitoring indicated leaching of atrazine, DIA, and DEA, with DEA accounting for more than half of all residues in most samples. Predominance of DEA, which increased after the second atrazine application, was interpreted as an indication of rapid and extensive atrazine degradation in soil and indicated that an adapted community of atrazine degrading organisms had developed. A companion laboratory study found a sixfold increase in atrazine degradation rate in soil after three applications. Groundwater data also revealed that atrazine and degradates concentrations were significantly lower in samples collected beneath cover crop plots when compared with concentrations below fallow plots. Together, these findings demonstrated a relatively small although potentially significant risk for leaching of atrazine and its dealkylated degradates to groundwater and that the use of a cover crop like Sunn Hemp during summer months may be an effective mitigation measure.

  20. Strip-tilled cover cropping for managing nematodes, soil mesoarthropods, and weeds in a bitter melon agroecosystem.

    PubMed

    Marahatta, Sharadchandra P; Wang, Koon-Hui; Sipes, Brent S; Hooks, Cerruti R R

    2010-06-01

    A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled strips; the experiment was conducted twice (Season I and II). Strip-tilled cover cropping with SH prolonged M. incognita suppression in Season I but not in Season II where suppression was counteracted with enhanced crop growth. Sunn hemp also consistently enhanced bacterivorous and fungivorous nematode population densities prior to cash crop planting, prolonged enhancement of the Enrichment Index towards the end of both cash crop cycles, and increased numbers of soil mesoarthropods. Strip-tilled cover cropping of SH followed by clipping of the living mulch as surface mulch also reduced broadleaf weed populations up to 3 to 4 weeks after cash crop planting. However, SH failed to reduce soil disturbance as indicated by the Structure Index. Marigold suppressed M. incognita efficiently when planted immediately following a M. incognita-susceptible crop, but did not enhance beneficial soil mesofauna including free-living nematodes and soil mesoarthropods. Strip-tilled cover cropping of MG reduced broadleaf weed populations prior to cash crop planting in Season II, but this weed suppression did not last beyond the initial cash crop cycle.

  1. Effectiveness of Different Herbicide Applicators Mounted on a Roller/Crimper for Accelerated Rye Cover Crop Termination

    USDA-ARS?s Scientific Manuscript database

    Under ideal weather conditions and weed free, a cash crop can be planted 3 weeks after rolling a mature cereal rye winter cover crop without using herbicides. However, cloudy and wet weather can delay the rolling and/or desiccation of rye thereby delaying cash crop planting which can reduce yield. O...

  2. Earthworm populations are affected from Long-Term Crop Sequences and Bio-Covers under No-Tillage

    USDA-ARS?s Scientific Manuscript database

    Earthworms are crucial for improving soil biophysical properties in cropping systems. Consequently, effects of cropping rotation and bio-covers were assessed on earthworm populations under no-tillage sites. Main effects of 6 different cropping sequences [corn (Zea mays), cotton (Gossypium hirsutum),...

  3. Strip-tilled Cover Cropping for Managing Nematodes, Soil Mesoarthropods, and Weeds in a Bitter Melon Agroecosystem

    PubMed Central

    Wang, Koon-Hui; Sipes, Brent S.; Hooks, Cerruti R.R.

    2010-01-01

    A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled strips; the experiment was conducted twice (Season I and II). Strip-tilled cover cropping with SH prolonged M. incognita suppression in Season I but not in Season II where suppression was counteracted with enhanced crop growth. Sunn hemp also consistently enhanced bacterivorous and fungivorous nematode population densities prior to cash crop planting, prolonged enhancement of the Enrichment Index towards the end of both cash crop cycles, and increased numbers of soil mesoarthropods. Strip-tilled cover cropping of SH followed by clipping of the living mulch as surface mulch also reduced broadleaf weed populations up to 3 to 4 weeks after cash crop planting. However, SH failed to reduce soil disturbance as indicated by the Structure Index. Marigold suppressed M. incognita efficiently when planted immediately following a M. incognita-susceptible crop, but did not enhance beneficial soil mesofauna including free-living nematodes and soil mesoarthropods. Strip-tilled cover cropping of MG reduced broadleaf weed populations prior to cash crop planting in Season II, but this weed suppression did not last beyond the initial cash crop cycle. PMID:22736847

  4. The Effect of Marigolds (Tagetes spp.) and Other Cover Crops on Pratylenchus penetrans and on Following Potato Crops

    PubMed Central

    Kimpinski, J.; Arsenault, W. J.; Gallant, C. E.; Sanderson, J. B.

    2000-01-01

    Root-lesion nematodes (primarily Pratylenchus penetrans) were monitored in two marigold cultivars (Tagetes tenuifolia cv. Nemakill and cv. Nemanon), annual ryegrass (Lolium multiflorum cv. Lemtal), red clover (Trifolium pratense cv. Florex), and soybean (Glycine max cv. Proteus), and in the following potato (Solanum tuberosum cv. Superior) crop during three growth sequences. Meadow fescue (Festuca elatior cv. Miner) and bee plant (Phacelia tanacetifolia cv. Gipha) were added to the trial in the second year. Black-eyed Susan (Rudbeckia hirta, unidentified cv.) and two additional marigold cultivars (T. patula ssp. nana, unidentified cv., and T. erecta cv. Crackerjack) were included in the final sequence. Population levels of root-lesion nematodes were consistently lower under marigolds compared to the other cover crops tested. Correspondingly, average potato tuber yields were significantly higher (8-14%) when potato followed marigolds. The highest levels of root-lesion nematodes occurred under red clover and soybean, and the average potato tuber yields were lowest following these crops. PMID:19271006

  5. Cover crop mulch and weed management influence arthropod communities in strip-tilled cabbage.

    PubMed

    Bryant, Alexandria; Brainard, Daniel C; Haramoto, Erin R; Szendrei, Zsofia

    2013-04-01

    Cover crop mulch and weeds create habitat complexity in agricultural fields that may influence arthropods. Under strip-tillage systems, planting rows are tilled and preestablished cover crops can remain between rows. In field experiments conducted in Michigan in 2010 and 2011, a preestablished oat (Avena sativa L.) cover crop was allowed to grow between rows of strip-tilled cabbage and killed at 0, 9-14, or 21-27 d after transplanting (DAT). The effects of herbicide intensity and oat kill date on arthropods, weeds, and crop yield were examined. Two levels of herbicide intensity (low or high) were used to manipulate habitat vegetational complexity, with low weed management intensity resulting in more weeds, particularly in 2010. Oat kill date manipulated the amount of cover crop mulch on the soil surface. Later oat kill dates were associated with higher natural enemy abundance. Reduced herbicide intensity was associated with (1) lower abundance of several key cabbage (Brassica oleraceae L.) pests, and (2) greater abundance of important natural enemy species. Habitats with both later oat kill dates and reduced herbicide intensity contained (1) fewer herbivores with chewing feeding guilds and more specialized diet breadths, and (2) greater abundance of active hunting natural enemies. Oats reduced cabbage yield when oat kill was delayed past 9-14 DAT. Yields were reduced under low herbicide intensity treatments in 2010 when weed pressure was greatest. We suspect that increased habitat complexity associated with oat mulches and reduced herbicide intensity enhances biological control in cabbage, although caution should be taken to avoid reducing yields or enhancing hyperparasitism.

  6. Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.

    PubMed

    Drury, C F; Tan, C S; Welacky, T W; Reynolds, W D; Zhang, T Q; Oloya, T O; McLaughlin, N B; Gaynor, J D

    2014-03-01

    Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Effect of water content and organic carbon on remote sensing of crop residue cover

    NASA Astrophysics Data System (ADS)

    Serbin, G.; Hunt, E. R., Jr.; Daughtry, C. S. T.; McCarty, G. W.; Brown, D. J.; Doraiswamy, P. C.

    2009-04-01

    Crop residue cover is an important indicator of tillage method. Remote sensing of crop residue cover is an attractive and efficient method when compared with traditional ground-based methods, e.g., the line-point transect or windshield survey. A number of spectral indices have been devised for residue cover estimation. Of these, the most effective are those in the shortwave infrared portion of the spectrum, situated between 1950 and 2500 nm. These indices include the hyperspectral Cellulose Absorption Index (CAI), and advanced multispectral indices, i.e., the Lignin-Cellulose Absorption (LCA) index and the Shortwave Infrared Normalized Difference Residue Index (SINDRI), which were devised for the NASA Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor. Spectra of numerous soils from U.S. Corn Belt (Indiana and Iowa) were acquired under wetness conditions varying from saturation to oven-dry conditions. The behavior of soil reflectance with water content was also dependent on the soil organic carbon content (SOC) of the soils, and the location of the spectral bands relative to significant water absorptions. High-SOC soils showed the least change in spectral index values with increase in soil water content. Low-SOC soils, on the other hand, showed measurable difference. For CAI, low-SOC soils show an initial decrease in index value followed by an increase, due to the way that water content affects CAI spectral bands. Crop residue CAI values decrease with water content. For LCA, water content increases decrease crop residue index values and increase them for soils, resulting in decreased contrast. SINDRI is also affected by SOC and water content. As such, spatial information on the distribution of surface soil water content and SOC, when used in a geographic information system (GIS), will improve the accuracy of remotely-sensed crop residue cover estimates.

  8. Soil oribatid mite communities under three species of legumes in an ultisol in Brazil.

    PubMed

    Badejo, M Adetola; Espindola, Jose Antonio Azevedo; Guerra, Jose Guilherme Marinho; De Aquino, Adriana Maria; Correa, Maria Elizabeth Fernandes

    2002-01-01

    Oribatid mite densities in the topsoil and their activity at the soil surface were monitored under three species of perennial legume cover crops namely, Arachis pintoi, Macroptilium atropupureum and Pueraria phaseoloides, grass (Panicum maximum) and bare plots on three occasions in 1998 and 1999 in a derived savanna zone in Brazil. Both densities and activity at the soil surface were higher in the early but cool dry season in April 1998 than in the early wet but warm season in November 1998 and 1999. Three taxonomic groups of macropyline oribatid mites, namely Nothrus, Archegozetes and Masthermannia as well as a brachypyline taxon, Scheloribates were suggested as possible indicators of effect of legumes on soil biota because their populations increased under the legumes and/or the irresidues. Nothrus in particular increased in abundance more than any other taxon in the presence of residues of A. pintoi. Each legume supported a unique oribatid mite community in terms of species composition and relative abundance. The large numbers of Archegozeres trapped from all the legume and grass plots in April and November 1998 were also attributed to highly conducive conditions provided by the vegetation cover and their residues. The results suggest that the oribatid mite community of the study area was numerically stable as the peak populations of different species were not synchronized. Many taxonomic groups of pycnonotic brachypyline mites were absent. Legume cover crops, especially A. pintoi, and their residues have potential in restoring oribatid mite populations to precultivation levels.

  9. Crop acquisition of phosphorus, iron and zinc from soil in cereal/legume intercropping systems: a critical review.

    PubMed

    Xue, Yanfang; Xia, Haiyong; Christie, Peter; Zhang, Zheng; Li, Long; Tang, Caixian

    2016-03-01

    Phosphorus (P), iron (Fe) and zinc (Zn) are essential elements for plant growth and development, but their availability in soil is often limited. Intercropping contributes to increased P, Fe and Zn uptake and thereby increases yield and improves grain nutritional quality and ultimately human health. A better understanding of how intercropping leads to increased plant P, Fe and Zn availability will help to improve P-fertilizer-use efficiency and agronomic Fe and Zn biofortification. This review synthesizes the literature on how intercropping of legumes with cereals increases acquisition of P, Fe and Zn from soil and recapitulates what is known about root-to-shoot nutrient translocation, plant-internal nutrient remobilization and allocation to grains. Direct interspecific facilitation in intercropping involves below-ground processes in which cereals increase Fe and Zn bioavailability while companion legumes benefit. This has been demonstrated and verified using isotopic nutrient tracing and molecular analysis. The same methodological approaches and field studies should be used to explore direct interspecific P facilitation. Both niche complementarity and interspecific facilitation contribute to increased P acquisition in intercropping. Niche complementarity may also contribute to increased Fe and Zn acquisition, an aspect poorly understood. Interspecific mobilization and uptake facilitation of sparingly soluble P, Fe and Zn from soil, however, are not the only determinants of the concentrations of P, Fe and Zn in grains. Grain yield and nutrient translocation from roots to shoots further influence the concentrations of these nutrients in grains. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Effects of recurrent rolling/crimping operations on cover crop termination, soil moisture, and soil strength for conservation organic systems

    USDA-ARS?s Scientific Manuscript database

    Rolling/crimping technology has been utilized to mechanically terminate cover crops in conservation agriculture. In the southeastern United States, to eliminate competition for valuable soil moisture, three weeks are typically required after rolling to plant a cash crop into the desiccated cover cro...

  11. Establishment of five cover crops and total soil nutrient extraction in a humid tropical soil in the Peruvian Amazon

    USDA-ARS?s Scientific Manuscript database

    In order to evaluate the establishment of five cover crops and their potential to increase soil fertility through nutrient extraction, an experiment was installed in the Research Station of Choclino, San Martin, Peru. Five cover crops were planted: Arachis pintoi Krapov. & W.C. Greg, Calopogonium m...

  12. Evaluating the relationship between biomass, percent groundcover and remote sensing indices across six winter cover crop fields in Maryland

    USDA-ARS?s Scientific Manuscript database

    Planting cover crops is an effective method to reduce both nitrogen leaching and sedimentation into waterways. Winter cover crops are planted post-harvest on corn and soybean fields to scavenge residual nitrogen that remains in the soil, and to meet soil erosion guidelines, providing positive water...

  13. Effect of roller/crimper designs in terminating rye cover crop in small-scale conservation systems

    USDA-ARS?s Scientific Manuscript database

    In recent years, use of cover crops in no-till organic production systems has steadily increased. When cover crops are terminated at an appropriate growth stage, the unincorporated residue mulch protects the soil from erosion, runoff, soil compaction, and weed pressure, and conserves soil water. In ...

  14. A powered roller/crimper for walk-behind tractors to terminate cover crops in conservation agriculture

    USDA-ARS?s Scientific Manuscript database

    Roller/crimper implements have been used in large conservation farming systems to terminate cover crops near maturity and flatten them down to create a mulch through which cash crops can be planted directly into the cover residue. On small farms, tractors are usually small and less powerful relative...

  15. Cover crop management influences residue biomass and subsequent weed suppression in a conservation agriculture corn and cotton rotation

    USDA-ARS?s Scientific Manuscript database

    Use of winter cover crops is an integral component of conservation systems in corn and cotton. However, data concerning cover management and subsequent residue and weed biomass is needed. Field experiments were conducted from autumn of 2003 through cash crop harvest in 2006 at the Alabama Agricultur...

  16. Effects of cover crops on the microbial community and its ability to suppress disease and acquire nutrients

    USDA-ARS?s Scientific Manuscript database

    Cover crops are able to provide a field with a microbial biomass that is able perform important ecological functions for that field. Studies show that cover crops are able to increase soil microbial biomass, suppress disease and weeds, and improve soil and water quality. Siderophores are an importan...

  17. Macronutrients use efficiency and changes in chemical properties of an oxisol as influenced by phosphorus fertilization and tropical cover crops

    USDA-ARS?s Scientific Manuscript database

    Cover crops are important components of copping systems due to their beneficial effects on soil physical, chemical and biological properties. A green house experiment was conducted to evaluate influence of phosphorus (P) fertilization on nutrient use efficiency of 14 tropical cover crops. The P leve...

  18. Interactions between allelochemicals and the microbial community affect weed suppression following cover crop residue incorporation into soil

    USDA-ARS?s Scientific Manuscript database

    The objective of this study is to understand how soil microorganisms interact with cover crop-derived allelochemicals to suppress weed germination and growth following cover crop residue incorporation. We conducted a time series experiment by crossing sterilized and non-sterilized soil with four dif...

  19. Can cover crop and manure maintain or improve soil properties after stover removal from irrigated no-till corn?

    USDA-ARS?s Scientific Manuscript database

    Addition of cover crops and animal manure following corn (Zea mays L.) stover removal for expanded uses may mitigate negative soil property effects of stover removal. We studied the short-term (3 yr) cumulative impacts of stover removal with and without winter rye (Secale cereale L.) cover crop or a...

  20. Cover crop management practices-implications for early season weed control in conservation tillage corn cotton rotation

    USDA-ARS?s Scientific Manuscript database

    Use of the winter cover crops is an integral component of the conservation systems in corn (Zea mays L.) and cotton (Gossypium hirsutum L.). A field experiment was initiated in 2004 to evaluate weed suppression provided by winter cover crops in a conservation tillage corn and cotton rotation. Rotati...

  1. Influence of the nature and age of cover crop residues on the sorption of three pesticides

    NASA Astrophysics Data System (ADS)

    Cassigneul, Ana; Alletto, Lionel; Chuette, Delphine; Le Gac, Anne-Laure; Hatier, Jules; Etievant, Veronique; Bergheaud, Valérie; Baumberger, Stéphanie; Méchin, Valérie; Justes, Eric; Benoit, Pierre

    2013-04-01

    In agricultural fields, soil and water quality preservation is strongly influenced by pesticides use and behavior. To limit the environmental impacts of agricultural activities, best management practices such as the use of cover crops are encouraged. Cover crops during the fallow period were found to be efficient in reducing nitrate leaching, controlling soil erosion, improving soil organic content and enhancing soil biological activity. This technique was also found to modify soil water dynamics in the following crop. According to these effects, modifications on pesticide behavior in soil, such as sorption, degradation and transport, are expected (Alletto et al., 2012 ; 2013). In this study, the impact of the nature and level of decomposition of cover crop was studied on the sorption characteristics of three pesticides. These pesticides differed in their physicochemical characteristics (hydrophobicity, solubility, persistence) and were two herbicides, S-metolachlor and glyphosate, which are largely used in maize production and predominantly found as pollutants in water; and one fungicide, epoxiconazole. Correlations between pesticide sorption and physicochemical characteristics of the cover crop residues were studied. Residues of oat, turnip rape, red clover and phacelia were collected in March 2011 and incubated at 28°C and at the water holding capacity during 0, 6, 28 or 56 days. For each date, adsorption of the three radiolabeled pesticides was measured in batch on the different cover crop residues, and their biochemical composition (Van Soest fractionation), hydrophobicity (contact angle measurement) and C/N ratio were determined. Results showed that the adsorption of the pesticides differed significantly according to (i) the pesticide, (ii) the nature of cover crop, (iii) the decomposition level of the cover crop and the interaction cover crop x decomposition time. Epoxiconazole was the most adsorbed molecule, with Kd values ranging from 161 ± 30 L/Kg (oat

  2. Tillage, cover-crop residue management, and irrigation incorporation impact on fomesafen runoff.

    PubMed

    Potter, Thomas L; Truman, Clint C; Webster, Theodore M; Bosch, David D; Strickland, Timothy C

    2011-07-27

    Intensive glyphosate use has contributed to the evolution and occurrence of glyphosate-resistant weeds that threaten production of many crops. Sustained use of this highly valued herbicide requires rotation and/or substitution of herbicides with different modes of action. Cotton growers have shown considerable interest in the protoporphyrinogen oxidase inhibitor, fomesafen. Following registration for cotton in 2008, use has increased rapidly. Environmental fate data in major use areas are needed to appropriately evaluate risks. Field-based rainfall simulation was used to evaluate fomesafen runoff potential with and without irrigation incorporation in a conventional tillage system (CT) and when conservation tillage (CsT) was practiced with and without cover crop residue rolling. Without irrigation incorporation, relatively high runoff, about 5% of applied, was measured from the CT system, indicating that this compound may present a runoff risk. Runoff was reduced by >50% when the herbicide was irrigation incorporated after application or when used with a CsT system. Data indicate that these practices should be implemented whenever possible to reduce fomesafen runoff risk. Results also raised concerns about leaching and potential groundwater contamination and crop injury due to rapid washoff from cover crop residues in CsT systems. Further work is needed to address these concerns.

  3. The effects of cover crop on weed control in collard (Brassica olerecea var acephala) and lettuce (Lactuca sativa L.).

    PubMed

    Mennan, H; Ngouajio, M; Isik, D; Kose, B; Kaya, E

    2006-01-01

    Leafy vegetables are not very competitive and weed interference can cause considerable yield losses in collard (Brassica olerecea var acephala) and lettuce (Lactuca sativa L.). Currently there are no pre or post emergence herbicides registered for weed control in these vegetables in Turkey. For this reason, alternative weed control strategies need to be developed. Cover crop residue could represent an alternative method of weed management in these crops. Field studies were conducted in 2004 at the Black Sea Agricultural Research Institute experimental field in Samsun, Turkey. The cover crop treatments consisted of Sorghum bicolor (L.) Moench, Sorghum vulgare Pers., Vicia villosa L., Amaranthus cruentus L., Pisum sativum L. and the bare ground with no cover crop. All cover crops were seeded by hand and incorporated into the soil on 11 May, 2004. Each plot was 10 m2 (2 x 5 m) and arranged in a randomized complete block design with four replications. All cover crops were incorporated into the soil by discing on 1 September 2004 at flowering stage of the cover crops. Broadleaved weed species were dominant in the experimental area. Most cover crops established well and S. bicolor biomass was the highest. The number of weed species emerging in all treatments was different at 14 DAD (days after desiccation). Similar results were observed at 28 and 56 DAD. Treatments with Vicia villosa residues had fewer weed species and lower total weed densities than other treatments.

  4. Crop Ground Cover Fraction and Canopy Chlorophyll Content Mapping using RapidEye imagery

    NASA Astrophysics Data System (ADS)

    Zillmann, E.; Schonert, M.; Lilienthal, H.; Siegmann, B.; Jarmer, T.; Rosso, P.; Weichelt, T.

    2015-04-01

    Remote sensing is a suitable tool for estimating the spatial variability of crop canopy characteristics, such as canopy chlorophyll content (CCC) and green ground cover (GGC%), which are often used for crop productivity analysis and site-specific crop management. Empirical relationships exist between different vegetation indices (VI) and CCC and GGC% that allow spatial estimation of canopy characteristics from remote sensing imagery. However, the use of VIs is not suitable for an operational production of CCC and GGC% maps due to the limited transferability of derived empirical relationships to other regions. Thus, the operational value of crop status maps derived from remotely sensed data would be much higher if there was no need for reparametrization of the approach for different situations. This paper reports on the suitability of high-resolution RapidEye data for estimating crop development status of winter wheat over the growing season, and demonstrates two different approaches for mapping CCC and GGC%, which do not rely on empirical relationships. The final CCC map represents relative differences in CCC, which can be quickly calibrated to field specific conditions using SPAD chlorophyll meter readings at a few points. The prediction model is capable of predicting SPAD readings with an average accuracy of 77%. The GGC% map provides absolute values at any point in the field. A high R2 value of 80% was obtained for the relationship between estimated and observed GGC%. The mean absolute error for each of the two acquisition dates was 5.3% and 8.7%, respectively.

  5. Management of Rotylenchulus reniformis in Pineapple, Ananas comosus, by Intercycle Cover Crops

    PubMed Central

    Wang, K.-H.; Sipes, B. S.; Schmitt, D. P.

    2002-01-01

    The effects of intercycle cover crops on Rotylenchulus reniformis population densities in pineapple were evaluated in one greenhouse and two field experiments. In the greenhouse, Crotalaria juncea, Brassica napus, and Tagetes erecta were planted for 3 months and then incorporated. These treatments were compared to weedy fallow with or without 1,3-dichloropropene (1,3-D) in three soils (Makawao fallow, Wahiawa fallow, and Wahiawa pineapple) naturally infested with R. reniformis. All cover crop incorporation suppressed R. reniformis numbers in cowpea more than did the weedy treatment in the Makawao (P < 0.05) but not in the Wahiawa soils. Crotalaria juncea treatment increased bacterivorous nematodes and nematode-trapping fungal population densities more than the other treatments in Makawao fallow and Wahiawa pineapple-planted soils. The field trials included the same plants as well as Sinapis alba. Treatments with Crotalaria juncea and 1,3-D maintained lower R. reniformis population densities on pineapple longer than other cover crops or weedy fallow treatments. Crotalaria juncea could have suppressed R. reniformis because it is a poor host and because it enhances nematode-trapping fungi when incorporated into soil. Treatment with 1,3-D reduced microbial activities but produced the greatest pineapple yield. PMID:19265916

  6. Management of Rotylenchulus reniformis in pineapple, Ananas comosus, by intercycle cover crops.

    PubMed

    Wang, K-H; Sipes, B S; Schmitt, D P

    2002-06-01

    The effects of intercycle cover crops on Rotylenchulus reniformis population densities in pineapple were evaluated in one greenhouse and two field experiments. In the greenhouse, Crotalaria juncea, Brassica napus, and Tagetes erecta were planted for 3 months and then incorporated. These treatments were compared to weedy fallow with or without 1,3-dichloropropene (1,3-D) in three soils (Makawao fallow, Wahiawa fallow, and Wahiawa pineapple) naturally infested with R. reniformis. All cover crop incorporation suppressed R. reniformis numbers in cowpea more than did the weedy treatment in the Makawao (P < 0.05) but not in the Wahiawa soils. Crotalaria juncea treatment increased bacterivorous nematodes and nematode-trapping fungal population densities more than the other treatments in Makawao fallow and Wahiawa pineapple-planted soils. The field trials included the same plants as well as Sinapis alba. Treatments with Crotalaria juncea and 1,3-D maintained lower R. reniformis population densities on pineapple longer than other cover crops or weedy fallow treatments. Crotalaria juncea could have suppressed R. reniformis because it is a poor host and because it enhances nematode-trapping fungi when incorporated into soil. Treatment with 1,3-D reduced microbial activities but produced the greatest pineapple yield.

  7. Effect of cover crops management in aggregate stability of a vineyard in Central Spain.

    NASA Astrophysics Data System (ADS)

    Ruiz-Colmenero, Marta; Bienes, Ramon; Marques, Maria-Jose

    2010-05-01

    Our research focuses in cover crop treatments used to avoid soil degradation in hillsides. The soil-plant interaction can influence the soil structure. In this study we pay special attention to the soil aggregates in a hillside vineyard (average slope of 14%), under Mediterranean semiarid climatic conditions (average annual temperature 14°C, annual rainfall around 400 mm), in the South East of Madrid located at an altitude of 800 masl. The soil classification according to USDA (2006) is Calcic Haploxeralf. Its particle size yields 58% sand, 18% silt and 24% clay, so that according to USDA classification it is a sandy clay loam soil. The bulk density of the first 10 cm of topsoil is 1.2 g cm-3 and its real density is 2.4 g cm-3. It has low organic matter content: 1.3 ± 0.1% (Walkley and Black, 1934). Three treatments were tested: i) traditional tillage ii) soil covered by Brachypodium distachyon allowing self-sowing, and iii) soil covered by Secale cereale, mown in early spring. In each treatment the aggregate stability was measured. These cover crops were established in a 2m wide strip at the center of the rows. We have collected samples of soil for each treatment along 2 years and we analyzed the aggregates, trying to find changes in their stability. Aggregates of 4 to 4.75 mm diameter were selected by dry sieving. The stability was measured with Drop-test: CND and TDI (Imeson and Vis, 1984). An improvement in the stability of aggregates was observed after two years of cover crop treatment. There are significant differences among the treatments analyzed with Kolmogorov-Smirnov test, being Brachypodium distachyon the treatment with more stable aggregates, it is necessary a mean higher than 8 drops to disintegrate every aggregate completely. Organic carbon was also measured by Loss on Ignition method (Schulte and Hopkins, 1996). This method can lead to an overestimation of the organic matter in soil samples but is considered suitable for aggregates. Again, those

  8. Economy of fertilizer nitrogen through organic sources in rain-fed rice-legume cropping systems in West Bengal, India.

    PubMed

    Puste, A M; Bandyopadhyay, S; Das, D K

    2001-12-11

    Field experiments were conducted at a farmers" plot adjacent to the Regional Research Station, red and laterite zone, Sub-center Sekhampur (Birbhum district) of West Bengal, India, situated 23 degrees 24' N latitude, 87 degrees 24' E longitude, to study the effect of different bio- and organic sources of nutrients instead of total fertilizer N in terms of crop productivity in the sequence and building up of soil fertility. During the wet seasons of 1997 and 1998, 12 combinations of bio- and organic sources (crop residues, well decomposed cow dung, dhanicha as green manure) were substituted for 25-50% of N fertilizer applied on transplanted rice (Cv. IR 36). Subsequently, during the winters of 1997-1998 and 1998-1999, leguminous pulse crops like lentil (Lens culinaris [L.] Medic.), gram ( Cicer arietinum L.) and lathyrus (Lathyrus sativus L.) were grown with and without inoculation of Rhizobium. Results revealed that the application of inorganic N in combination with organic sources exhibited a significant increase in rice yield (3.60-3.84 t ha(-1) ) compared to the yield from sole application of N (3.19-3.26 t ha(-1) ). The study showed that about 25% of total applied N was saved without significant yield reduction with simultaneous improvement of soil physical properties (pH, organic matter, available N, P, K, and CEC). Seed yield of pulses (lentil, gram, and lathyrus) were more pronounced in the treatment inoculated with Rhizobium, with a saving of 42.6-48.4 kg N ha(-1). Therefore, the results suggest that the combined application of inorganic and organic N sources in a 75:25 ratio is a superior N-management practice with regards to crop yields as well as improvement of soil fertility.

  9. ROLE OF ALLELOPATHY IN THE STIMULATORY AND INHIBITORY EFFECTS OF HAIRY VETCH COVER CROP RESIDUE IN NO-TILLAGE SUSTAINABLE PRODUCTION SYSTEMS

    USDA-ARS?s Scientific Manuscript database

    Cover crops can provide multiple benefits to sustainable cropping systems including building soil organic matter, controlling soil and nutrient losses from fields, moderating radiation and moisture exchange, releasing nutrients for subsequent crops, and suppressing weed and pest populations. Many o...

  10. Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil.

    PubMed

    Wang, Qing-Ren; Li, Yun-Cong; Klassen, Waldemar

    2003-11-01

    The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome very gravelly loam soil subjected to these treatments. The control consisted of Krome soil without any amendment. The loading rate was 205 g pot(-1) for each amendment (equivalent to 50 t ha(-1) of the dry weight), and the amounts of the cover crops incorporated into the soil in the pot were those that had been grown in it. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO3-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments. The leguminous cover crop, sunn hemp, returned into the soil, increased the leachate NO3-N and inorganic P concentration significantly compared with the non-legume, sorghum sudangrass. The results suggest that at heavy loading rates of soil amendments, leaching of NO3- could be a significant concern by application of biosolids. Leaching of inorganic P can be increased significantly by both co-compost and biosolids, but decreased by coal ash and N-viro soil by virtue of improved adsorption. The leguminous cover crop

  11. Ambient and elevated carbon dioxide on growth, physiological and nutrient uptake parameters of perennial leguminous cover crops under low light intensities

    USDA-ARS?s Scientific Manuscript database

    Adaptability and optimum growth of cover crops in plantation crops is affected by the inherent nature of the cover crop species and the light intensity at canopy levels. Globally concentrations of atmospheric CO2 are increasing and this creates higher photosynthesis and nutrient demand by crops as l...

  12. Effects of green manure cover crops on Spodoptera litura (Lepidoptera: Noctuidae) populations.

    PubMed

    Tuan, Shu-Jen; Li, Nian-Jhen; Yeh, Chih-Chun; Tang, Li-Cheng; Chi, Hsin

    2014-06-01

    Spodoptera litura (F.) is an important pest of numerous agro-economic crops, including green manure cover crops. In Taiwan, sesbania (Sesbanin roxburghii Merr.), sunn hemp (Crotalaria juncea L.), and rapeseed (Brassicae campestris L. variety chinensis) are the most popular green manure crops; sesbania and sunn hemp are commonly planted in warm seasons, whereas rapeseed is grown in the winter. In this study, life-table data for S. litura reared on these three green manures were collected to evaluate their roles as refuges of this pest. The net reproductive rate, intrinsic rate of increase, and finite rate of increase of S. litura were the highest when reared on sesbania (1428.1 offspring, 0.2327 d(-1), 1.2621 d(-1)), followed by sunn hemp (778.4 offspring, 0.2070 d(-1), 1.2300 d(-1)) and rapeseed (737.6 offspring, 0.2040 d(-1), 1.2263 d(-1)). The high growth rates on these green manure crops show that they can serve as potential breeding sites for S. litura. Population projection demonstrated the rapid growth of S. litura on sesbania, sunn hemp, and rapeseed as well. Because most growers have traditionally ignored pest management in green manure fields, the mass emergence of S. litura in these fields may cause unexpected infestations in nearby vegetable, corn, and peanut crops. This study shows that the use of green manures as sources of nutrients should be critically reassessed and an area-wide pest management program should be instituted by taking the population of S. litura in green manure fields into consideration.

  13. Linking the planting of cover crops to soil and water nutrient dynamics in Shatto Ditch Watershed, IN

    NASA Astrophysics Data System (ADS)

    Christopher, S. F.; Tank, J. L.; Hanrahan, B. R.; Mahl, U. H.; Huang, K.

    2013-12-01

    Tile drainage systems are common in the Midwest, and facilitate the transfer of excess inorganic nitrogen (N) and phosphorus (P) from agricultural soils to adjacent streams. These non-point sources contribute to elevated nutrient loads to tributaries in the Mississippi River Basin, which have been linked to widespread hypoxia and associated ecological and economic problems in the Gulf of Mexico. In agricultural areas dominated by row-crops, the planting of cover crops after the cash crop has been harvested offers a potential mechanism to reduce nutrient leaching from fields to tile drains in the off-season. In general, cover crops retain nutrients on fields and increase soil organic matter (SOM) content after they are harvested. The planting of cover crops also promotes immobilization of soil N and reduction in losses of dissolved P from soils due to reduced erosion, resulting in significantly less leaching to surface waters through tile drains. As part of a demonstration project in the Shatto Ditch Watershed, located in the Tippecanoe River Basin, IN, we are testing whether the planting of cover crops will influence soil nutrient and organic matter, and how cover crops alter the dynamics of nutrient leaching from tile drains. We have been sampling tile drain outflows on a twice-monthly sampling regime and have been measuring dissolved inorganic N and P concentrations in tile water since November 2012. During Spring 2013, tile drain nitrate concentrations sampled synoptically throughout the watershed ranged from 2.6 - 38.9 mg NO3- L -1 (mean = 17.2 +/- 1.6 mg NO3- L -1) with the lowest concentrations coming from fields planted in cover crops (range = 2.6 - 19.0 mg NO3- L -1, mean = 9.7 +/- 1.5 mg NO3- L -1). In contrast, soluble reactive phosphorus (SRP) concentrations were much lower in tile drain water and ranged from 7.5 - 182.7 μg L-1 (mean = 24.5 +/- 5.0 μg L-1 SRP) and preliminary data suggest that there were no differences between fields with and without

  14. Evaluating a core germplasm collection of the cover crop hairy vetch for use in sustainable farming systems

    USDA-ARS?s Scientific Manuscript database

    Understanding linkage between genotype and agronomically important phenotypes (early flowering, hard seed and winter hardiness) will facilitate cultivar selection and inform breeding programs concerned with the cover crop hairy vetch (Vicia villosa). . We used molecular and biochemical techniques to...

  15. Effects of cover crop management and planting operations on cotton establishment and yield in a no-till system

    USDA-ARS?s Scientific Manuscript database

    One method to save resources while positively impacting the environment is combining agricultural field operations. In no-till systems, for example, termination of cover crops and planting of the cash crop can be performed simultaneously utilizing a tractor as a single power source. A no-till field ...

  16. Conservation tillage issues: cover crop-based organic rotational no-till grain production in the mid-atlantic region

    USDA-ARS?s Scientific Manuscript database

    Organic producers in the mid-Atlantic region are interested in reducing tillage, labor, and time requirements for grain production. Cover crop-based organic rotational no-till grain production is one approach to accomplishing these goals. Advancements in a system for planting crops into a mat of cov...

  17. Effects of Tillage, Rotation and Cover Crop on the Physical Properties of a Silt-Loam Soil

    NASA Astrophysics Data System (ADS)

    Haruna, Samuel Idoko; Nkongolo, Nsalambi Vakanda

    2015-04-01

    Soil and crop management practices can affect the physical properties and have a direct impact on soil sustainability and crop performance. The objective of this study was to investigate how soil physical properties were affected by three years of tillage, cover crop and crop rotation treatments in a corn and soybean field. The study was conducted on a Waldron siltyloam soil at Lincoln University of Missouri. Soil physical properties studied were soil bulk density, volumetric and gravimetric water contents, volumetric air content, total pore space, air-filled and water-filled pore space, gas diffusion coefficient and pore tortuosity factor. Results showed significant interactions (p<0.05) between cover crop and crop rotation for bulk density, gravimetric and total pore space in 2013. In addition, cover crop also significantly interacted (p<0.05) with tillage for bulk density and total pore space. All soil physical properties studied were significantly affected by the depth of sampling (p<0.0001), except for bulk density, the pore tortuosity factor and total pore space in 2012, and gravimetric and volumetric in 2013. Overall, soil physical properties were significantly affected by the treatments, with the effects changing from one year to another. Addition of a cover crop improved soil physical properties better in rotation than in monoculture.

  18. Long term tillage, cover crop and fertilization effects on microbial community structure and activity: Implications on soil quality

    USDA-ARS?s Scientific Manuscript database

    Reduced tillage, cover crops and fertilization are associated with greater microbial biomass and activity that are linked to improvements in soil quality, but their impacts vary widely with climate, soils and cropping systems. This study aimed to characterize the impact of long term (31 years) tilla...

  19. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne

    USDA-ARS?s Scientific Manuscript database

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disin...

  20. Effects of cover crops with potential for use in anaerobic soil disinfestation (asd) on reproduction of meloidogyne spp.

    USDA-ARS?s Scientific Manuscript database

    Several cover crops were assessed for their susceptibility to invasion and galling by three species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on their potential for use as the organic amendment component in anaerobic soil disinfestation (AS...

  1. Improved growth and nutrient status of an oat cover crop in sod-based versus conventional peanut-cotton rotations

    USDA-ARS?s Scientific Manuscript database

    Nitrogen (N) leaching from agricultural soils is a major concern in the southeastern USA. A winter cover crop following the summer crop rotation is essential for controlling N leaching and soil run-off, thereby improving sustainable development. Rotation of peanut (Arachis hypogea L.) and cotton (Go...

  2. Nutrient cycling potential of camelina (Camelina sativa L. Crantz.) as a cover crop in the US Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Berti, Marisol; Samarappuli, Dulan

    2017-04-01

    Camelina [Camelina sativa (L.) Crantz.] is an industrial oilseed crop in the Brassicaceae family with multiple uses. Currently, camelina is not used as a cover crop, but it has the potential to be used as such in maize-soybean-wheat cropping systems. The objectives of this study were to determine the agronomic performance and nutrient scavenging potential of winter camelina in comparison with other common cover crops. Experiments were conducted in Fargo, ND in 2015 and 2016, and in Prosper, ND in 2015. The experimental design was a randomized complete block design with a split-plot arrangement with three replicates. The main plot was the sowing date and the subplot were camelina cultivars as well as other common cover crops in the area. Sowing dates were targeted to 15 August and September 1, although the final dates varied slightly each year. Biomass yield, N content of the biomass N uptake and P uptake was evaluated. Winter camelina N and P uptake ranged between 21 and 30.5 kg N ha-1 and 3.4 to 5.3 kg P ha-1. The nutrient scavenging potential of winter camelina was similar to other cover crops although slightly lower than turnip (Brassica rapa L.), radish (Raphanus sativus L.), and rape (Brassica napus L.) cultivars which had significantly higher P uptake than winter camelina and the other cover crops in the study. An evaluation of spring regrowth and cover indicated that only rye, winter camelina, and pennycress (Thlaspi arvense L.) survived the winter, although a few plants of triticale (x Trticosecale Witt.) and rape were found on a few plots. Because of the high variability on the plots there were no significant differences among the surviving cover crops on soil coverage. The soil coverage for rye cultivars was 25 and 35% and for camelina cv. Bison was 27%.In 2016, biomass yield was not significant for sowing date, cultivars, or their interaction. Winter camelina cultivars biomass yield fluctuated between 1.15 and 2.33 Mg dry matter ha-1 on the first sowing

  3. The Effect of Conservation Tillage and Cover Crop Residue on Beneficial Arthropods and Weed Seed Predation in Acorn Squash.

    PubMed

    Quinn, N F; Brainard, D C; Szendrei, Z

    2016-10-15

    Conservation tillage combined with cover crops or mulching may enhance natural enemy activity in agroecosystems by reducing soil disturbance and increasing habitat structural complexity. In particular, weed seed predation can increase with vegetation cover and reduced tillage, indicating that mulches may improve the quality of the habitat for weed seed foraging. The purpose of this study was to quantify the effects of tillage and mulching for conservation biological control in cucurbit fields. The effects of mulch and reduced tillage on arthropods and rates of weed seed loss from arenas were examined in field trials on sandy soils in 2014 and 2015. Experimental factors included tillage and cover crop, each with two levels: strip-tillage or full-tillage, and cover crop mulch (rye residue) or no cover crop mulch (unmulched). Arthropod abundance on the crop foliage was not affected by tillage or cover crops. Contrary to expectations, epigeal natural enemies of insects and rates of weed seed removal either did not respond to treatments or were greater in full-tilled plots and plots without mulch. Our study demonstrates the potential importance of weed seed predators in reducing weed seedbanks in vegetable agroecosystems, and suggests that early-season tillage may not be detrimental to epigeal predator assemblages.

  4. The Effect of Conservation Tillage and Cover Crop Residue on Beneficial Arthropods and Weed Seed Predation in Acorn Squash.

    PubMed

    Quinn, N F; Brainard, D C; Szendrei, Z

    2016-12-01

    Conservation tillage combined with cover crops or mulching may enhance natural enemy activity in agroecosystems by reducing soil disturbance and increasing habitat structural complexity. In particular, weed seed predation can increase with vegetation cover and reduced tillage, indicating that mulches may improve the quality of the habitat for weed seed foraging. The purpose of this study was to quantify the effects of tillage and mulching for conservation biological control in cucurbit fields. The effects of mulch and reduced tillage on arthropods and rates of weed seed loss from arenas were examined in field trials on sandy soils in 2014 and 2015. Experimental factors included tillage and cover crop, each with two levels: strip-tillage or full-tillage, and cover crop mulch (rye residue) or no cover crop mulch (unmulched). Arthropod abundance on the crop foliage was not affected by tillage or cover crops. Contrary to expectations, epigeal natural enemies of insects and rates of weed seed removal either did not respond to treatments or were greater in full-tilled plots and plots without mulch. Our study demonstrates the potential importance of weed seed predators in reducing weed seedbanks in vegetable agroecosystems, and suggests that early-season tillage may not be detrimental to epigeal predator assemblages. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Impact of vetch cover crop on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia

    NASA Astrophysics Data System (ADS)

    Demelash, Nigus; Klik, Andreas; Holzmann, Hubert; Ziadat, Feras; Strohmeier, Stefan; Bayu, Wondimu; Zucca, Claudio; Abera, Atikilt

    2016-04-01

    Cover crops improve the sustainability and quality of both natural system and agro ecosystem. In Gumara-Maksegnit watershed which is located in Lake Tana basin, farmers usually use fallow during the rainy season for the preceding chickpea production system. The fallowing period can lead to soil erosion and nutrient losses. A field experiment was conducted during growing seasons 2014 and 2015 to evaluate the effect of cover crops on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia. The plot experiment contained four treatments arranged in Randomized Complete Block Design with three replications: 1) Control plot (Farmers' practice: fallowing- without cover crop), 2) Chickpea planted with Di-ammonium phosphate (DAP) fertilizer with 46 k ha-1 P2O5 and 23 k ha-1 nitrogen after harvesting vetch cover crop, 3) Chick pea planted with vetch cover crop incorporated with the soil as green manure without fertilizer, 4) Chick pea planted with vetch cover crop and incorporated with the soil as green manure and with 23 k ha-1 P2O5 and 12.5 k ha-1 nitrogen. Each plot with an area of 36 m² was equipped with a runoff monitoring system. Vetch (Vicia sativa L.) was planted as cover crop at the onset of the rain in June and used as green manure. The results of the experiment showed statistically significant (P < 0.05) differences on the number of pods per plant, above ground biomass and grain yield of chick pea. However, there was no statistically significant difference (P > 0.05) on average plant height, average number of branches and hundred seed weight. Similarly, the results indicated that cover crop has a clear impact on runoff volume and sediment loss. Plots with vetch cover crop reduce the average runoff by 65% and the average soil loss decreased from 15.7 in the bare land plot to 8.6 t ha-1 with plots covered by vetch. In general, this result reveales that the cover crops, especially vetch, can be used to improve chickpea grain yield

  6. Liming can decrease legume crop yield and leaf gas exchange by enhancing root to shoot ABA signalling.

    PubMed

    Rothwell, Shane A; Elphinstone, E David; Dodd, Ian C

    2015-04-01

    To meet future requirements for food production, sustainable intensive agricultural systems need to optimize nutrient availability to maximize yield, traditionally achieved by maintaining soil pH within an optimal range (6-6.5) by applying lime (calcium carbonate). However, a field trial that applied recommended liming rates to a sandy loam soil (increasing soil pH from 5.5 to 6.2) decreased pod yield of field bean (Vicia faba L. cv. Fuego) by ~30%. Subsequent pot trials, with liming that raised soil pH to 6.3-6.7, reduced stomatal conductance (g(s)) by 63, 26, and 59% in V. faba, bean (Phaseolus vulgaris), and pea (Pisum sativum), respectively. Furthermore, liming reduced shoot dry biomass by 16-24% in these species. Ionomic analysis of root xylem sap and leaf tissue revealed a decrease in phosphorus concentration that was correlated with decreased g(s): both reductions were partially reversed by adding superphosphate fertilizer. Further analysis of pea suggests that leaf gas exchange was reduced by a systemic increase (roots, xylem sap, and leaves) in the phytohormone abscisic acid (ABA) in response to lime-induced suboptimal plant phosphorus concentrations. Supplying synthetic ABA via the transpiration stream to detached pea leaves, at the same xylem sap concentrations induced by liming, decreased transpiration. Furthermore, the g(s) of the ABA-deficient mutant pea wilty was unresponsive to liming, apparently confirming that ABA mediates some responses to low phosphorus availability caused by liming. This research provides a detailed mechanistic understanding of the physiological processes by which lime application can limit crop yields, and questions the suitability of current liming recommendations.

  7. Liming can decrease legume crop yield and leaf gas exchange by enhancing root to shoot ABA signalling

    PubMed Central

    Rothwell, Shane A.; Elphinstone, E. David; Dodd, Ian C.

    2015-01-01

    To meet future requirements for food production, sustainable intensive agricultural systems need to optimize nutrient availability to maximize yield, traditionally achieved by maintaining soil pH within an optimal range (6–6.5) by applying lime (calcium carbonate). However, a field trial that applied recommended liming rates to a sandy loam soil (increasing soil pH from 5.5 to 6.2) decreased pod yield of field bean (Vicia faba L. cv. Fuego) by ~30%. Subsequent pot trials, with liming that raised soil pH to 6.3–6.7, reduced stomatal conductance (g s) by 63, 26, and 59% in V. faba, bean (Phaseolus vulgaris), and pea (Pisum sativum), respectively. Furthermore, liming reduced shoot dry biomass by 16–24% in these species. Ionomic analysis of root xylem sap and leaf tissue revealed a decrease in phosphorus concentration that was correlated with decreased g s: both reductions were partially reversed by adding superphosphate fertilizer. Further analysis of pea suggests that leaf gas exchange was reduced by a systemic increase (roots, xylem sap, and leaves) in the phytohormone abscisic acid (ABA) in response to lime-induced suboptimal plant phosphorus concentrations. Supplying synthetic ABA via the transpiration stream to detached pea leaves, at the same xylem sap concentrations induced by liming, decreased transpiration. Furthermore, the g s of the ABA-deficient mutant pea wilty was unresponsive to liming, apparently confirming that ABA mediates some responses to low phosphorus availability caused by liming. This research provides a detailed mechanistic understanding of the physiological processes by which lime application can limit crop yields, and questions the suitability of current liming recommendations. PMID:25740925

  8. Sunn Hemp Cover Cropping and Organic Fertilizer Effects on the Nematode Community Under Temperate Growing Conditions

    PubMed Central

    Hinds, Jermaine; Wang, Koon-Hui; Marahatta, Sharadchandra P.; Meyer, Susan L. F.; Hooks, Cerruti R. R.

    2013-01-01

    Field experiments were conducted in Maryland to investigate the influence of sunn hemp cover cropping in conjunction with organic and synthetic fertilizers on the nematode community in a zucchini cropping system. Two field treatments, zucchini planted into a sunn hemp living and surface mulch (SH) and zucchini planted into bare-ground (BG) were established during three field seasons from 2009 to 2011. In 2009, although SH slightly increased nematode richness compared with BG by the first harvest (P < 0.10), it reduced nematode diversity and enrichment indices (P < 0.01 and P < 0.10, respectively) and increased the channel index (P < 0.01) compared to BG at the final harvest. This suggests a negative impact of SH on nematode community structure. The experiment was modified in 2010 and 2011 where the SH and BG main plots were further split into two subplots to investigate the added influence of an organic vs. synthetic fertilizer. In 2010, when used as a living and surface mulch in a no-till system, SH increased bacterivorous, fungivorous, and total nematodes (P < 0.05) by the final zucchini harvest, but fertilizer type did not influence nematode community structure. In 2011, when incorporated into the soil before zucchini planting, SH increased the abundance of bacterivorous and fungivorous nematodes early in the cropping season. SH increased species richness also at the end of the season (P < 0.05). Fertilizer application did not appear to influence nematodes early in the season. However, in late season, organic fertilizers increased enrichment and structure indices and decreased channel index by the end of the zucchini cropping cycle. PMID:24379485

  9. Sunn hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions.

    PubMed

    Hinds, Jermaine; Wang, Koon-Hui; Marahatta, Sharadchandra P; Meyer, Susan L F; Hooks, Cerruti R R

    2013-12-01

    Field experiments were conducted in Maryland to investigate the influence of sunn hemp cover cropping in conjunction with organic and synthetic fertilizers on the nematode community in a zucchini cropping system. Two field treatments, zucchini planted into a sunn hemp living and surface mulch (SH) and zucchini planted into bare-ground (BG) were established during three field seasons from 2009 to 2011. In 2009, although SH slightly increased nematode richness compared with BG by the first harvest (P < 0.10), it reduced nematode diversity and enrichment indices (P < 0.01 and P < 0.10, respectively) and increased the channel index (P < 0.01) compared to BG at the final harvest. This suggests a negative impact of SH on nematode community structure. The experiment was modified in 2010 and 2011 where the SH and BG main plots were further split into two subplots to investigate the added influence of an organic vs. synthetic fertilizer. In 2010, when used as a living and surface mulch in a no-till system, SH increased bacterivorous, fungivorous, and total nematodes (P < 0.05) by the final zucchini harvest, but fertilizer type did not influence nematode community structure. In 2011, when incorporated into the soil before zucchini planting, SH increased the abundance of bacterivorous and fungivorous nematodes early in the cropping season. SH increased species richness also at the end of the season (P < 0.05). Fertilizer application did not appear to influence nematodes early in the season. However, in late season, organic fertilizers increased enrichment and structure indices and decreased channel index by the end of the zucchini cropping cycle.

  10. Utilization of summer legumes as bioenergy feedstocks

    USDA-ARS?s Scientific Manuscript database

    Sunn hemp (Crotolaria juncea), is a fast growing, high biomass yielding tropical legume that may be a possible southeastern bioenergy crop. When comparing this legume to a commonly grown summer legume—cowpeas (Vigna unguiculata), sunn hemp was superior in biomass yield and subsequent energy yield. S...

  11. Crop and cattle production responses to tillage and cover crop management in an integrated crop-livestock system in the southeastern USA

    USDA-ARS?s Scientific Manuscript database

    Integrated crop-livestock systems can help achieve greater environmental quality from disparate crop and livestock systems by recycling nutrients and taking advantage of synergies between systems. We investigated crop and animal production responses in integrated crop-livestock systems with two typ...

  12. The Kill Date as a Management Tool for Cover Cropping Success

    PubMed Central

    Alonso-Ayuso, María; Gabriel, José Luis; Quemada, Miguel

    2014-01-01

    Integrating cover crops (CC) in rotations provides multiple ecological services, but it must be ensured that management does not increase pre-emptive competition with the subsequent crop. This experiment was conducted to study the effect of kill date on: (i) CC growth and N content; (ii) the chemical composition of residues; (iii) soil inorganic N and potentially mineralizable N; and (iv) soil water content. Treatments were fallow and a CC mixture of barley (Hordeum vulgare L.) and vetch (Vicia sativa L.) sown in October and killed on two different dates in spring. Above-ground biomass and chemical composition of CC were determined at harvest, and ground cover was monitored based on digital image analysis. Soil mineral N was determined before sowing and after killing the CC, and potentially mineralizable N was measured by aerobic incubation at the end of the experiment. Soil water content was monitored daily to a depth of 1.1 m using capacitance sensors. Under the present conditions of high N availability, delaying kill date increased barley above-ground biomass and N uptake from deep soil layers; little differences were observed in vetch. Postponing kill date increased the C/N ratio and the fiber content of plant residues. Ground cover reached >80% by the first kill date (∼1250°C days). Kill date was a means to control soil inorganic N by balancing the N retained in the residue and soil, and showed promise for mitigating N losses. The early kill date decreased the risk of water and N pre-emptive competition by reducing soil depletion, preserving rain harvested between kill dates and allowing more time for N release in spring. The soil potentially mineralizable N was enhanced by the CC and kill date delay. Therefore kill date is a crucial management variable for maximizing the CC benefits in agricultural systems. PMID:25296333

  13. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in Grassland establishment

    USGS Publications Warehouse

    Milchunas, D.G.; Vandever, M.W.; Ball, L.O.; Hyberg, S.

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat-fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area of

  14. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

    USGS Publications Warehouse

    Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area

  15. Influence of cover crops and crop residue treatment on soil organic carbon stocks evaluated in Swedish long-term field experiments

    NASA Astrophysics Data System (ADS)

    Poeplau, Christopher; Bolinder, Martin A.; Börjesson, Gunnar; Kätterer, Thomas

    2015-04-01

    Soil organic carbon (SOC) stocks in agricultural soils are strongly controlled by management. In this study we quantified the effect of cover crops and crop residue management on SOC stocks in Swedish long-term experiments. Eight pairs of cover crop (undersown ryegrass) vs. no cover crop were investigated in Swedish long-term field experiments (16 to 24 years). Yields of the main crop were not affected by the cover crop. Cover crops significantly increased SOC stocks, with a mean carbon sequestration rate in all experiments (excluding one) of 0.32±0.29 Mg C ha-1 yr-1. Interestingly, this sequestration is similar to that estimated for a U.S.experiment, where ryegrass growth is much less temperature- and light-limited than under Swedish conditions. This sequestration rate is also the same as that recently reported for many other cover crops in a global meta-analysis but less than SOC changes in ley-dominated rotations which under Nordic conditions were shown to accumulate in average 0.5 Mg C ha-1 yr-1 more carbon compared to exclusively annual cropping systems. Thus, originally introduced in agricultural rotations to reduce nitrate leaching, cover crops are also an effective practice to increase SOC stocks, even at relatively high latitudes. The effect of crop residue treatment was studied in 16 pairs of straw incorporated (SI) vs. straw removed (SR) treatments in six Swedish long-term field experiments. Data series on SOC with 5-28 sampling dates during 27-53 years were analysed using ICBM, a dynamic SOC model. At five out of six sites, the humification coefficient for straw (hlitter; the fraction of straw C that is entering the slow C pool) was much smaller (0-0.09) than the ICBM default h-value for plant material estimated in previous studies (0.125). The derived hlitter-values and thus the stabilization of straw-derived carbon increased significantly with clay content. For an Italian site (with five pairs of SI vs. SR) that was used for model validation we found

  16. Legume information system (LegumeInfo.org): a key component of a set of federated data resources for the legume family

    PubMed Central

    Dash, Sudhansu; Campbell, Jacqueline D.; Cannon, Ethalinda K.S.; Cleary, Alan M.; Huang, Wei; Kalberer, Scott R.; Karingula, Vijay; Rice, Alex G.; Singh, Jugpreet; Umale, Pooja E.; Weeks, Nathan T.; Wilkey, Andrew P.; Farmer, Andrew D.; Cannon, Steven B.

    2016-01-01

    Legume Information System (LIS), at http://legumeinfo.org, is a genomic data portal (GDP) for the legume family. LIS provides access to genetic and genomic information for major crop and model legumes. With more than two-dozen domesticated legume species, there are numerous specialists working on particular species, and also numerous GDPs for these species. LIS has been redesigned in the last three years both to better integrate data sets across the crop and model legumes, and to better accommodate specialized GDPs that serve particular legume species. To integrate data sets, LIS provides genome and map viewers, holds synteny mappings among all sequenced legume species and provides a set of gene families to allow traversal among orthologous and paralogous sequences across the legumes. To better accommodate other specialized GDPs, LIS uses open-source GMOD components where possible, and advocates use of common data templates, formats, schemas and interfaces so that data collected by one legume research community are accessible across all legume GDPs, through similar interfaces and using common APIs. This federated model for the legumes is managed as part of the ‘Legume Federation’ project (accessible via http://legumefederation.org), which can be thought of as an umbrella project encompassing LIS and other legume GDPs. PMID:26546515

  17. Crop residues of the contiguous United States: Balancing feedstock and soil needs with conservation tillage, cover crops, and biochar

    USDA-ARS?s Scientific Manuscript database

    Crop residues are among the cellulosic feedstocks expected to provide renewable energy. The availability of crop species and residue availability varies across the United States. Estimates of harvestable residues must consider all the residues produced during the entire rotation. Inclusion of fallow...

  18. Unique and conserved features of floral evocation in legumes.

    PubMed

    Liew, Lim Chee; Singh, Mohan B; Bhalla, Prem L

    2014-08-01

    Legumes, with their unique ability to fix atmospheric nitrogen, play a vital role in ensuring future food security and mitigating the effects of climate change because they use less fossil energy and produce less greenhouse gases compared with N-fertilized systems. Grain legumes are second only to cereal crops as a source of human and animal food, and they contribute approximately one third of the protein consumed by the human population. The productivity of seed crops, such as grain legumes, is dependent on flowering. Despite the genetic variation and importance of flowering in legume production, studies of the molecular pathways that control flowering in legumes are limited. Recent advances in genomics have revealed that legume flowering pathways are divergent from those of such model species as Arabidopsis thaliana. Here, we discuss the current understanding of flowering time regulation in legumes and highlight the unique and conserved features of floral evocation in legumes.

  19. Cover crops influence soil microorganisms and phytoextraction of copper from a moderately contaminated vineyard.

    PubMed

    Mackie, K A; Schmidt, H P; Müller, T; Kandeler, E

    2014-12-01

    We investigated the ability of summer (Avena sativa [oat], Trifolium incarnatum [crimson clover], Chenopodium [goosefoot]) and winter (Vicia villosa [hairy vetch], Secale Cereale L. [Rye], Brassica napus L. partim [rape]) cover crops, including a mixed species treatment, to extract copper from an organic vineyard soil in situ and the microbial communities that may support it. Clover had the highest copper content (14.3mgCukg(-1) DM). However, it was the amount of total biomass production that determined which species was most effective at overall copper removal per hectare. The winter crop rye produced significantly higher amounts of biomass (3532kgDMha(-1)) and, therefore, removed significantly higher amounts of copper (14,920mgCuha(-1)), despite less accumulation of copper in plant shoots. The maximum annual removal rate, a summation of best performing summer and winter crops, would be 0.033kgCuha(-1)y(-1). Due to this low annual extraction efficiency, which is less than the 6kgCuha(-1)y(-1) permitted for application, phytoextraction cannot be recommended as a general method of copper extraction from vineyards. Copper concentration did not influence aboveground or belowground properties, as indicated by sampling at two distances from the grapevine row with different soil copper concentrations. Soil microorganisms may have become tolerant to the copper levels at this site. Microbial biomass and soil enzyme activities (arylsulfatase and phosphatase) were instead driven by seasonal fluxes of resource pools. Gram+ bacteria were associated with high soil moisture, while fungi seemed to be driven by extractable carbon, which was linked to high plant biomass. There was no microbial group associated with the increased phytoextraction of copper. Moreover, treatment did not influence the abundance, activity or community structure of soil microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Conversion to No-Till Improves Maize Nitrogen Use Efficiency in a Continuous Cover Cropping System.

    PubMed

    Habbib, Hazzar; Verzeaux, Julien; Nivelle, Elodie; Roger, David; Lacoux, Jérôme; Catterou, Manuella; Hirel, Bertrand; Dubois, Frédéric; Tétu, Thierry

    2016-01-01

    A two-year experiment was conducted in the field to measure the combined impact of tilling and N fertilization on various agronomic traits related to nitrogen (N) use efficiency and to grain yield in maize cultivated in the presence of a cover crop. Four years after conversion to no-till, a significant increase in N use efficiency N harvest index, N remobilization and N remobilization efficiency was observed both under no and high N fertilization conditions. Moreover, we observed that grain yield and grain N content were higher under no-till conditions only when N fertilizers were applied. Thus, agronomic practices based on continuous no-till appear to be a promising for increasing N use efficiency in maize.

  1. Conversion to No-Till Improves Maize Nitrogen Use Efficiency in a Continuous Cover Cropping System

    PubMed Central

    Habbib, Hazzar; Verzeaux, Julien; Nivelle, Elodie; Roger, David; Lacoux, Jérôme; Catterou, Manuella; Hirel, Bertrand; Dubois, Frédéric; Tétu, Thierry

    2016-01-01

    A two-year experiment was conducted in the field to measure the combined impact of tilling and N fertilization on various agronomic traits related to nitrogen (N) use efficiency and to grain yield in maize cultivated in the presence of a cover crop. Four years after conversion to no-till, a significant increase in N use efficiency N harvest index, N remobilization and N remobilization efficiency was observed both under no and high N fertilization conditions. Moreover, we observed that grain yield and grain N content were higher under no-till conditions only when N fertilizers were applied. Thus, agronomic practices based on continuous no-till appear to be a promising for increasing N use efficiency in maize. PMID:27711154

  2. Simulating long-term impacts of cover crops and climate change on crop production and environmental outcomes in the midwestern United States

    USDA-ARS?s Scientific Manuscript database

    It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize-soybean rotation offers mul...

  3. A sustainable legume biomass energy farming system

    SciTech Connect

    Neathery, J.; Rubel, A.; Stencel, J.; Collins, M.

    1996-12-31

    Before environmentally sensitive areas are converted to biomass energy production, the production, the potential for sustainability of such systems must be assessed. The focus has been on woody or grass crops because of their high potential yields; however, yield sustainability is dependent on the application of fertilizer and lining materials, which in turn contribute to large costs. Growing legumes or mixtures of legumes with grasses could lower or alleviate the need for nitrate fertilizers. The incorporation of legumes into energy cropping systems could: (1) add soil organic matter; (2) introduce biologically fixed N; (3) improve soil structure and texture; (4) reduce soil erosion; (5) reduce production costs; and (6) decrease nitrate run-off in surface waters. Through the {open_quotes}rotation effect{close_quotes}, legumes cause increases in yield of subsequent non-legume crops beyond that accounted for by biologically-fixed N alone. In this paper, we describe a biomass energy system combining legume and grass biomass energy with fertilizer production from these same materials. Preliminary agronomic and engineering assessments for this type of biomass system are presented. The technologies needed to integrate nitrate production with legume energy farming and energy production through legume energy conversion are identified.

  4. Seeding date affects fall growth of winter canola (Brassica napus L. ‘Baldur’) and its performance as a winter cover crop in central Iowa

    USDA-ARS?s Scientific Manuscript database

    In recent years, interest has increased in finding non-grass cover crop species that could be planted after soybean (Glycine max (L) Merr.) and before corn (Zea mays L.) in Iowa crop rotations. In this study, we investigate the use of winter canola (Brassica napus L.) as an alternative cover crop fo...

  5. Cover-crops - improvement of soil fertility and provision of biomass

    NASA Astrophysics Data System (ADS)

    Kirchmeyr, Franz; Szerencsits, Manfred

    2017-04-01

    Besides climate change, erosion, inadequate crop rotation and intensive tillage may turn arable land into marginal land. On the other hand, reclamation approaches which include arable farming methods may result only in short-term success if they do not consider their effects on humus content and erosion. Additionally, effective reclamation will also have to address the growing need for food production besides biomass provision. Therefore, we investigated if cover or catch crops (CC) may accomplish both goals: Improve soil quality and humus content even if CC-biomass is used for biogas production. Humus content and soil fertility: In comparison to complete fallow in a crop rotation with silage maize and cereals the humus balance can be improved from -50 to +280 kg humus carbon (C) ha-1 year-1 through additional CC (4.5 t DM ha-1) used for biogas production and an equivalent amount of digestate returned to the field. With a CC-yield of 2.5 t DM ha-1 the humus balance results in 220 kg C ha-1 year-1. It is still slightly higher if the same CC remains on the field as green manure (170 kg C ha-1 year-1). Additionally it is important to consider that 20 - 50 % of the assimilated carbon can be found in the plant roots and that roots and root exudates as well as CC harvest residues provide fresh organic matter for soil life. Furthermore, biomass production of cover crops was considerably higher, if they were used for biogas production because of earlier cultivation and later harvest than mulching. Erosion control: The risk of erosion can be reduced by approx. 50 % in comparison to complete fallow if CC with 2.5 t DM ha-1 remain on the field as green manure. A comparable reduction can be achieved, if CC with 4.5 t DM ha-1 are harvested for biogas production. Because of better weed suppression, tilth and soil structure of CC with higher biomass, it is more likely to apply conservation tillage and avoid ploughing. Without ploughing a CC with 4.5 t DM ha-1 used for biogas the

  6. Cover crops as a gateway to greater conservation in Iowa?: Integrating crop models, field trials, economics and farmer perspectives regarding soil resilience in light of climate change

    NASA Astrophysics Data System (ADS)

    Roesch-McNally, G. E.; Basche, A.; Tyndall, J.; Arbuckle, J. G.; Miguez, F.; Bowman, T.

    2014-12-01

    Scientists predict a number of climate changes for the US Midwest with expected declines in crop productivity as well as eco-hydrological impacts. More frequent extreme rain events particularly in the spring may well increase saturated soils thus complicating agronomic interests and also exacerbate watershed scale impairments (e.g., sediment, nutrient loss). In order to build more resilient production systems in light of climate change, farmers will increasingly need to implement conservation practices (singularly or more likely in combination) that enable farmers to manage profitable businesses yet mitigate consequential environmental impacts that have both in-field and off-farm implications. Cover crops are empirically known to promote many aspects of soil and water health yet even the most aggressive recent estimates show that only 1-2% of the total acreage in Iowa have been planted to cover crops. In order to better understand why farmers are reluctant to adopt cover crops across Iowa we combined agronomic and financial data from long-term field trials, working farm trials and model simulations so as to present comprehensive data-driven information to farmers in focus group discussions in order to understand existing barriers, perceived benefits and responses to the information presented. Four focus groups (n=29) were conducted across Iowa in four geographic regions. Focus group discussions help explore the nuance of farmers' responses to modeling outputs and their real-life agronomic realities, thus shedding light on the social and psychological barriers with cover crop utilization. Among the key insights gained, comprehensive data-driven research can influence farmer perspectives on potential cover crop impacts to cash crop yields, experienced costs are potentially quite variable, and having field/farm benefits articulated in economic terms are extremely important when farmers weigh the opportunity costs associated with adopting new practices. Our work

  7. Effects of Cover Crop Species and Season on Population Dynamics of Escherichia coli and Listeria innocua in Soil

    PubMed Central

    Reed-Jones, Neiunna L.; Marine, Sasha Cahn; Everts, Kathryne L.

    2016-01-01

    Cover crops provide several ecosystem services, but their impact on enteric bacterial survival remains unexplored. The influence of cover cropping on foodborne pathogen indicator bacteria was assessed in five cover crop/green manure systems: cereal rye, hairy vetch, crimson clover, hairy vetch-rye and crimson clover-rye mixtures, and bare ground. Cover crop plots were inoculated with Escherichia coli and Listeria innocua in the fall of 2013 and 2014 and tilled into the soil in the spring to form green manure. Soil samples were collected and the bacteria enumerated. Time was a factor for all bacterial populations studied in all fields (P < 0.001). E. coli levels declined when soil temperatures dipped to <5°C and were detected only sporadically the following spring. L. innocua diminished somewhat but persisted, independently of season. In an organic field, the cover crop was a factor for E. coli in year 1 (P = 0.004) and for L. innocua in year 2 (P = 0.011). In year 1, E. coli levels were highest in the rye and hairy vetch-rye plots. In year 2, L. innocua levels were higher in hairy vetch-rye (P = 0.01) and hairy vetch (P = 0.03) plots than in the rye plot. Bacterial populations grew (P < 0.05) or remained the same 4 weeks after green manure incorporation, although initial reductions in L. innocua numbers were observed after tilling (P < 0.05). Green manure type was a factor only for L. innocua abundance in a transitional field (P < 0.05). Overall, the impacts of cover crops/green manures on bacterial population dynamics in soil varied, being influenced by bacterial species, time from inoculation, soil temperature, rainfall, and tillage; this reveals the need for long-term studies. PMID:26729724

  8. Effects of Cover Crop Species and Season on Population Dynamics of Escherichia coli and Listeria innocua in Soil.

    PubMed

    Reed-Jones, Neiunna L; Marine, Sasha Cahn; Everts, Kathryne L; Micallef, Shirley A

    2016-01-04

    Cover crops provide several ecosystem services, but their impact on enteric bacterial survival remains unexplored. The influence of cover cropping on foodborne pathogen indicator bacteria was assessed in five cover crop/green manure systems: cereal rye, hairy vetch, crimson clover, hairy vetch-rye and crimson clover-rye mixtures, and bare ground. Cover crop plots were inoculated with Escherichia coli and Listeria innocua in the fall of 2013 and 2014 and tilled into the soil in the spring to form green manure. Soil samples were collected and the bacteria enumerated. Time was a factor for all bacterial populations studied in all fields (P < 0.001). E. coli levels declined when soil temperatures dipped to <5°C and were detected only sporadically the following spring. L. innocua diminished somewhat but persisted, independently of season. In an organic field, the cover crop was a factor for E. coli in year 1 (P = 0.004) and for L. innocua in year 2 (P = 0.011). In year 1, E. coli levels were highest in the rye and hairy vetch-rye plots. In year 2, L. innocua levels were higher in hairy vetch-rye (P = 0.01) and hairy vetch (P = 0.03) plots than in the rye plot. Bacterial populations grew (P < 0.05) or remained the same 4 weeks after green manure incorporation, although initial reductions in L. innocua numbers were observed after tilling (P < 0.05). Green manure type was a factor only for L. innocua abundance in a transitional field (P < 0.05). Overall, the impacts of cover crops/green manures on bacterial population dynamics in soil varied, being influenced by bacterial species, time from inoculation, soil temperature, rainfall, and tillage; this reveals the need for long-term studies. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. Impact of climate change on water balance components in Mediterranean rainfed olive orchards under tillage or cover crop soil management

    NASA Astrophysics Data System (ADS)

    Rodríguez-Carretero, María Teresa; Lorite, Ignacio J.; Ruiz-Ramos, Margarita; Dosio, Alessandro; Gómez, José A.

    2013-04-01

    The rainfed olive orchards in Southern Spain constitute the main socioeconomic system of the Mediterranean Spanish agriculture. These systems have an elevated level of complexity and require the accurate characterization of crop, climate and soil components for a correct management. It is common the inclusion of cover crops (usually winter cereals or natural cover) intercalated between the olive rows in order to reduce water erosion. Saving limited available water requires specific management, mowing or killing these cover crops in early spring. Thus, under the semi-arid conditions in Southern Spain the management of the cover crops in rainfed olive orchards is essential to avoid a severe impact to the olive orchards yield through depletion of soil water. In order to characterize this agricultural system, a complete water balance model has been developed, calibrated and validated for the semi-arid conditions of Southern Spain, called WABOL (Abazi et al., 2013). In this complex and fragile system, the climate change constitutes a huge threat for its sustainability, currently limited by the availability of water resources, and its forecasted reduction for Mediterranean environments in Southern Spain. The objective of this study was to simulate the impact of climate change on the different components of the water balance in these representative double cropping systems: transpiration of the olive orchard and cover crop, runoff, deep percolation and soil water content. Four climatic scenarios from the FP6 European Project ENSEMBLES were first bias corrected for temperatures and precipitation (Dosio and Paruolo, 2011; Dosio et al., 2012) and, subsequently, used as inputs for the WABOL model for five olive orchard fields located in Southern Spain under different conditions of crop, climate, soils and management, in order to consider as much as possible of the variability detected in the Spanish olive orchards. The first results indicate the significant effect of the cover

  10. The use of cover crops to increase soil organic carbon in Mediterranean vineyards

    NASA Astrophysics Data System (ADS)

    García-Díaz, Andrés; Bienes Allas, Ramón; Sastre Rodriguez, Blanca

    2016-04-01

    In Central Spain the vineyards are commonly managed with conventional tillage (CT) to remove water and nutrient competition between the spontaneous vegetation and the vine plants. The continuous tillage promotes high mineralization rates resulting in soils with low organic matter content and prone to erosion. Consequently the increase of soil organic carbon (SOC) in Mediterranean soils has been a main concern in the last years. It is necessary to carry out different soil managements to enhance soil fertility and reduce erosion through the increase of SOC. The aim of this study was to assess the capacity of cover crops (CC) to increase SOC in vineyards in Mediterranean climate. The experiment consisted in four vineyards in four different locations (different type of soil and microclimate), in the same region, to analyze the influence of CC on different conditions. A seeded CC (Brachypodium distachyon L. P. Beauv) and spontaneous vegetation were performed to compare to CT. The Brachypodium distachyon cover was seeded in December, 2012. We analyzed the organic carbon content and bulk density after three agronomy seasons. The samples were taken in the summer of 2015 at the depth of 0-5 cm. The bulk density of Brachypodium distachyon was 1.42 t•m-3, which was statistically significant comparing to both CT (1.33 t•m-3) and spontaneous vegetation (1.34 t•m-3). The SOC percentage of CT, Brachypodium distachyon and spontaneous vegetation was 0.82, 0.96 and 1.10 respectively. Only spontaneous vegetation showed statistically significant differences compared to CT. The results were highly variable depending on the vineyard. The spontaneous vegetation was the most effective CC increasing SOC with an average of 2 t•ha-1 more than CT in three agronomy seasons. These results point out the different efficiency of CC and the high influence of local conditions on SOC increase.

  11. Effect of Sorghum-Sudangrass and Velvetbean Cover Crops on Plant-Parasitic Nematodes Associated with Potato Production in Florida

    PubMed Central

    Crow, W. T.; Weingartner, D. P.; Dickson, D. W.; McSorley, R.

    2001-01-01

    In a 3-year field study, population densities of Belonolaimus longicaudatus and other plant-parasitic nematodes and crop yields were compared between potato (Solanum tuberosum) cropping systems where either sorghum-sudangrass (Sorghum bicolor × S. arundinaceum) or velvetbean (Mucuna pruriens) was grown as a summer cover crop. Population densities of B. longicaudatus, Paratrichodorus minor, Tylenchorhynchus sp., and Mesocriconema sp. increased on sorghum-sudangrass. Population densities of P. minor and Mesocriconema sp. increased on velvetbean. Sorghum-sudangrass increased population densities of B. longicaudatus and Mesocriconema sp. on a subsequent potato crop compared to velvetbean. Potato yields following velvetbean were not greater than following sorghum-sudangrass despite reductions in population densities of B. longicaudatus. PMID:19265888

  12. Impact of Reduced Tillage and Cover Cropping on the Greenhouse Gas Budget of a Maize/Soybean Rotation Ecosystem

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to evaluate the impact of an alternative management scenario (reduced tillage and cover cropping) on ecosystem respiration and N2O and CH4 exchange in a maize (Zea mays L)/soybean (Glycine max L.) rotation agroecosystem in north-central Minnesota. The control treatmen...

  13. Overcoming weed management challenges in cover crop-based organic rotational no-till soybean production in the Eastern US

    USDA-ARS?s Scientific Manuscript database

    Cover crop-based, organic rotational no-till soybean production has been gaining traction in the Eastern region of the United States because of the ability of this new system to enhance soil conservation, reduce labor requirements, and decrease diesel fuel use compared to traditional organic product...

  14. Cover crops in the upper midwestern United States: Potential adoption and reduction of nitrate leaching in the Mississippi River Basin

    USDA-ARS?s Scientific Manuscript database

    Nitrate losses from agricultural lands in the Midwest flow into the Mississippi River Basin (MRB) and contribute significantly to hypoxia in the Gulf of Mexico. Previous work has shown that cover crops can reduce loadings, but adoption rates are low, and the potential impact is currently unknown. Th...

  15. Effects of terminating cover crops with rolling/crimping and herbicides in a cotton no-till system

    USDA-ARS?s Scientific Manuscript database

    In fall of 2008, a field experiment was initiated in central Alabama to study the effects of rolling/crimping and different herbicides with different application rates on cover crops termination rates, cotton population and yield. Results from 2009 and 2010 growing seasons are presented. A roller/cr...

  16. Expression of allelopathy in the soil environment: Soil concentration and activity of benzoxazinoid compounds released by rye cover crop residue

    USDA-ARS?s Scientific Manuscript database

    The activity of allelopathic compounds is often reduced in the soil environment where processes involving release from donor plant material, soil adsorption and degradation, and uptake by receptor plants naturally result in complex interactions. Rye (Secale cereale L.) cover crops are known to supp...

  17. Allelopathic influence of a wheat or rye cover crop on growth and yield of no-till cotton

    USDA-ARS?s Scientific Manuscript database

    TECHNICAL ABSTRACT No-till planting cotton into small grain cover crops has many benefits including reducing soil erosion and allelopathic suppression of weeds. It is suggested that the potentials of allelopathy on cotton plants. Nevertheless, little is known about the actual effects of alleloche...

  18. Soil chemistry affects revegetation establishment with and without cover crops in northern mixed grass prairie after energy development

    USDA-ARS?s Scientific Manuscript database

    We measured rangeland health and perennial grass establishment in twelve interim reclamations as part of oil extraction activity. Sites at Ft. Berthold Indian Reservation in North Dakota were planted with two different perennial grass mixes, with and without an oat cover crop in late summer/fall of ...

  19. Cover crops and tillage in a mature Merlot vineyard affect yields and cluster weight but not nutrition

    USDA-ARS?s Scientific Manuscript database

    Permanent cover crops are commonly used in vineyard floor management because of their beneficial effects to soil and vine health, but studies evaluating their competitive effects on vines have been conducted primarily in non-irrigated vineyards. Future air quality regulations could mandate the use o...

  20. Cover crop residue and organic mulches provide weed control during limited-input no-till collard production

    USDA-ARS?s Scientific Manuscript database

    Limited input producers may adopt no-till production if sufficient weed suppression can be achieved. High-biomass producing cover crops used in conjunction with organic mulches may provide sufficient weed control in no-till vegetable production. Our objective was to quantify weed suppression from a ...

  1. High Biomass Cover Crops and Organic Mulch Effects on Soil Moisture and Weed Distribution during Collard Production.

    USDA-ARS?s Scientific Manuscript database

    Traditional organic vegetable production relies on tillage for weed suppression, but organic producers may be likely to adopt no-till if sufficient weed suppression can be achieved. A combination of high residue cover crops with in situ organic mulches may provide vegetable growers with multiple be...

  2. Cover crop residue and organic mulches provide weed control during limited-input no-till collard production

    USDA-ARS?s Scientific Manuscript database

    Limited input producers may adopt no-till if sufficient weed suppression can be achieved. High-biomass producing cover crops used in conjunction with organic mulches may provide sufficient weed control in no-till vegetable production. Our objective was to quantify weed suppression from a summer co...

  3. Black oat cover crop management effects on soil temperature and biological properties on a Mollisol in Texas, USA

    USDA-ARS?s Scientific Manuscript database

    This field experiment was conducted to evaluate effects of mowing (no mowing, flail mowing, or sickle mowing) management of a black oat (Avena strigosa [Schreb.]) cover crop on soil microenvironmental conditions and on microbial biomass, dissolved organic C (DOC), soil inorganic N, resin-extractable...

  4. Linking a Germplasm Collection of the Cover Crop Hairy Vetch (Vicia villosa Roth) to Traits Related to Improved Nitrogen Fixation

    USDA-ARS?s Scientific Manuscript database

    Hairy vetch is used as a leguminous cover crop throughout the United States providing important ecosystem services in agro-ecosystems (Abdul-Baki et al., 2002; Mohler and Teasdale, 1993; Puget and Drinkwater, 2001; Seo et al., 2006; Stute and Posner, 1995). Many traits found in hairy vetch have pro...

  5. Cultural strategies for managing weeds and soil moisture in cover crop based no-till soybean production

    USDA-ARS?s Scientific Manuscript database

    A four site-year study was conducted in North Carolina to evaluate the effects of soybean planting timing and row spacing on soil moisture, weed density, soybean lodging, and yield in a cover crop-based no-till organic soybean production system. Soybean planting timing included roll-kill/planting a...

  6. Cover crops impact on excess rainfall and soil erosion rates in orchards and potato fields, Israel

    NASA Astrophysics Data System (ADS)

    Egozi, Roey; Gil, Eshel

    2015-04-01

    Bare soil and high drainage densities are common characteristics of intensive agriculture land. The couplings of these characteristics lead to high runoff and eroded soil volumes leaving the field or the orchard via the local drainage system into the fluvial system. This process increase flood risk due to massive deposition of the coarse fraction of the eroded soil and therefore reduces channel capacity to discharge the increase volumes of concentrated runoff. As a result drainage basin authorities are forced to invest large amount of money in maintaining and enlarging the drainage network. However this approach is un-sustainable. On the other hand, implementing cover crops (CC) and modification to current agricultural practices over the contributing area of the watershed seems to have more benefits and provide sustainable solution. A multi-disciplinary approach applied in commercial potatoes fields and orchards that utilize the benefit of CC shows great success as means of soil and water conservation and weed disinfestation without reduction in the yield, its quality or its profitability. The results indicate that it is possible to grow potatoes and citrus trees under CC with no reduction in yield or nutrient uptake, with more than 95% reduction in soil loss and more than 60% in runoff volumes and peak discharges.

  7. Modeled Impacts of Cover Crops and Vegetative Barriers on Corn Stover Availability and Soil Quality

    SciTech Connect

    Ian J. Bonner; David J. Muth Jr.; Joshua B. Koch; Douglas L. Karlen

    2014-06-01

    Environmentally benign, economically viable, and socially acceptable agronomic strategies are needed to launch a sustainable lignocellulosic biofuel industry. Our objective was to demonstrate a landscape planning process that can ensure adequate supplies of corn (Zea mays L.) stover feedstock while protecting and improving soil quality. The Landscape Environmental Assessment Framework (LEAF) was used to develop land use strategies that were then scaled up for five U.S. Corn Belt states (Nebraska, Iowa, Illinois, Indiana, and Minnesota) to illustrate the impact that could be achieved. Our results show an annual sustainable stover supply of 194 million Mg without exceeding soil erosion T values or depleting soil organic carbon [i.e., soil conditioning index (SCI)?>?0] when no-till, winter cover crop, and vegetative barriers were incorporated into the landscape. A second, more rigorous conservation target was set to enhance soil quality while sustainably harvesting stover. By requiring erosion to be <1/2 T and the SCI-organic matter (OM) subfactor to be >?0, the annual sustainable quantity of harvestable stover dropped to148 million Mg. Examining removal rates by state and soil resource showed that soil capability class and slope generally determined the effectiveness of the three conservation practices and the resulting sustainable harvest rate. This emphasizes that sustainable biomass harvest must be based on subfield management decisions to ensure soil resources are conserved or enhanced, while providing sufficient biomass feedstock to support the economic growth of bioenergy enterprises.

  8. Evaluation of the metal phytoextraction potential of crop legumes. Regulation of the expression of O-acetylserine (thiol)lyase under metal stress.

    PubMed

    Pajuelo, E; Carrasco, J A; Romero, L C; Chamber, M A; Gotor, C

    2007-09-01

    The metal phytoextraction potential of three legumes belonging to different genera has been studied under greenhouse conditions. Legumes accumulate As and metals mainly in roots, although translocation to shoot is observed. Alfalfa did accumulate the highest concentrations of As and metals in shoots and aerial biomass was less affected by the toxic elements, indicating its good behaviour in phytoextraction. Clover accumulated less metal, but showed larger biomass. EDTA addition enhanced Pb phytoextraction up to levels similar to those described for plants proposed in phytoremediation. The regulation of O-acetylserine (thiol)lyase from legumes under metal stress has been analysed to test the possibility of establishing a possible correlation between the expression of OASTL in the presence of the metals and the metal accumulation in legume plant tissues. Cd and Pb(EDTA) produce the strongest increases of OASTL activity, with the higher enhancement seen in roots, in parallel with the higher metal accumulation. Arsenic produced an increase of root enzyme activity, whereas Cu produced a decrease, mainly in shoots. Western blots using antibodies against an A. THALIANA cytosolic OAS-TL recognised up to five protein bands in crude extracts from LOTUS and clover. A low molecular weight isoform of 32 kDa was induced in the presence of Cd and Pb. A partial RT-PCR sequence from clover has been obtained, showing 86 - 97 % identity with other described OASTLs. The PCR fragment has been used to analyse OASTL mRNA levels of legumes under metal stress. OASTL transcripts were increased by As, Cd, and Pb, especially in roots, where metal accumulation was maximal, while Cu produced a decrease in the transcript levels.

  9. Neglecting legumes has compromised human health and sustainable food production.

    PubMed

    Foyer, Christine H; Lam, Hon-Ming; Nguyen, Henry T; Siddique, Kadambot H M; Varshney, Rajeev K; Colmer, Timothy D; Cowling, Wallace; Bramley, Helen; Mori, Trevor A; Hodgson, Jonathan M; Cooper, James W; Miller, Anthony J; Kunert, Karl; Vorster, Juan; Cullis, Christopher; Ozga, Jocelyn A; Wahlqvist, Mark L; Liang, Yan; Shou, Huixia; Shi, Kai; Yu, Jingquan; Fodor, Nandor; Kaiser, Brent N; Wong, Fuk-Ling; Valliyodan, Babu; Considine, Michael J

    2016-08-02

    The United Nations declared 2016 as the International Year of Pulses (grain legumes) under the banner 'nutritious seeds for a sustainable future'. A second green revolution is required to ensure food and nutritional security in the face of global climate change. Grain legumes provide an unparalleled solution to this problem because of their inherent capacity for symbiotic atmospheric nitrogen fixation, which provides economically sustainable advantages for farming. In addition, a legume-rich diet has health benefits for humans and livestock alike. However, grain legumes form only a minor part of most current human diets, and legume crops are greatly under-used. Food security and soil fertility could be significantly improved by greater grain legume usage and increased improvement of a range of grain legumes. The current lack of coordinated focus on grain legumes has compromised human health, nutritional security and sustainable food production.

  10. Estimating variability in grain legume yields across Europe and the Americas

    NASA Astrophysics Data System (ADS)

    Cernay, Charles; Ben-Ari, Tamara; Pelzer, Elise; Meynard, Jean-Marc; Makowski, David

    2015-06-01

    Grain legume production in Europe has recently come under scrutiny. Although legume crops are often promoted to provide environmental services, European farmers tend to turn to non-legume crops. It is assumed that high variability in legume yields explains this aversion, but so far this hypothesis has not been tested. Here, we estimate the variability of major grain legume and non-legume yields in Europe and the Americas from yield time series over 1961-2013. Results show that grain legume yields are significantly more variable than non-legume yields in Europe. These differences are smaller in the Americas. Our results are robust at the level of the statistical methods. In all regions, crops with high yield variability are allocated to less than 1% of cultivated areas. Although the expansion of grain legumes in Europe may be hindered by high yield variability, some species display risk levels compatible with the development of specialized supply chains.

  11. Estimating variability in grain legume yields across Europe and the Americas.

    PubMed

    Cernay, Charles; Ben-Ari, Tamara; Pelzer, Elise; Meynard, Jean-Marc; Makowski, David

    2015-06-08

    Grain legume production in Europe has recently come under scrutiny. Although legume crops are often promoted to provide environmental services, European farmers tend to turn to non-legume crops. It is assumed that high variability in legume yields explains this aversion, but so far this hypothesis has not been tested. Here, we estimate the variability of major grain legume and non-legume yields in Europe and the Americas from yield time series over 1961-2013. Results show that grain legume yields are significantly more variable than non-legume yields in Europe. These differences are smaller in the Americas. Our results are robust at the level of the statistical methods. In all regions, crops with high yield variability are allocated to less than 1% of cultivated areas. Although the expansion of grain legumes in Europe may be hindered by high yield variability, some species display risk levels compatible with the development of specialized supply chains.

  12. Estimating variability in grain legume yields across Europe and the Americas

    PubMed Central

    Cernay, Charles; Ben-Ari, Tamara; Pelzer, Elise; Meynard, Jean-Marc; Makowski, David

    2015-01-01

    Grain legume production in Europe has recently come under scrutiny. Although legume crops are often promoted to provide environmental services, European farmers tend to turn to non-legume crops. It is assumed that high variability in legume yields explains this aversion, but so far this hypothesis has not been tested. Here, we estimate the variability of major grain legume and non-legume yields in Europe and the Americas from yield time series over 1961–2013. Results show that grain legume yields are significantly more variable than non-legume yields in Europe. These differences are smaller in the Americas. Our results are robust at the level of the statistical methods. In all regions, crops with high yield variability are allocated to less than 1% of cultivated areas. Although the expansion of grain legumes in Europe may be hindered by high yield variability, some species display risk levels compatible with the development of specialized supply chains. PMID:26054055

  13. Unlocking the potential of orphan legumes.

    PubMed

    Cullis, Christopher; Kunert, Karl J

    2016-12-21

    Orphan, or underutilized, legumes are domesticated legumes with useful properties, but with less importance than major world crops due to use and supply constraints. However, they play a significant role in many developing countries, providing food security and nutrition to consumers, as well as income to resource-poor farmers. They have been largely neglected by both researchers and industry due to their limited economic importance in the global market. Orphan legumes are better adapted than the major legume crops to extreme soil and climatic conditions, with high tolerance to abiotic environmental stresses such as drought. As a stress response they can also produce compounds with pharmaceutical value. Orphan legumes are therefore a likely source of important traits for introduction into major crops to aid in combating the stresses associated with global climate change. Modern large-scale genomics techniques are now being applied to many of these previously understudied crops, with the first successes reported in the genomics area. However, greater investment of resources and manpower are necessary if the potential of orphan legumes is to be unlocked and applied in the future.

  14. Influence of cover crop and intercrop systems on Bemisia argentifolli (Hemiptera: Aleyrodidae) infestation and associated squash silverleaf disorder in zucchini.

    PubMed

    Manandhar, Roshan; Hooks, Cerruti R R; Wright, Mark G

    2009-04-01

    Field experiments were conducted to evaluate the effects of cover cropping and intercropping on population densities of silverleaf whitefly, Bemisia argentifolli Bellow and Perring, and the incidence of squash silverleaf disorder (SSL) in zucchini, Cucurbita pepo L., in Oahu, HI. Two cover crops, buckwheat (BW), Fagopyrum esculentum Moench, and white clover (WC), Trifolium repens L., or sunn hemp (SH), Crotolaria juncea L., and an intercropped vegetable, okra, Abelmonchus esculentus L., were evaluated during the 2003, 2005, and 2006 growing seasons, respectively. Population densities of whiteflies and SSL severity varied during the three field experiments. In 2003, the severity of SSL and percentage of leaves displaying symptoms were significantly lower on zucchini plants in WC than BW plots throughout the crops' growth cycle. Additionally, the percentage of leaves per plant displaying SSL symptoms was significantly greater in bare-ground (BG) compared with the pooled BW and WC treatments on each inspection date. In 2005, zucchini intercropped with okra had lower numbers of adult whiteflies and resulted in significantly lower severity of SSL than pooled BW and WC treatments. During 2006, zucchini grown with SH had significantly lower numbers of all whitefly stages (i.e., egg, immature, and adult) and less SSL severity symptoms than BW. Despite these differences in whitefly numbers and SSL severity, marketable yields were not significantly lower in BW compared with WC or SH treatment plots during the study. The mechanisms underlying these results and the feasibility of using cover crops and intercrops to manage B. argentifolli and SSL are discussed.

  15. Effects of land cover change on moisture availability and potential crop yield in the world’s breadbaskets

    NASA Astrophysics Data System (ADS)

    Bagley, Justin E.; Desai, Ankur R.; Dirmeyer, Paul A.; Foley, Jonathan A.

    2012-03-01

    The majority of the world’s food production capability is inextricably tied to global precipitation patterns. Changes in moisture availability—whether from changes in climate from anthropogenic greenhouse gas emissions or those induced by land cover change (LCC)—can have profound impacts on food production. In this study, we examined the patterns of evaporative sources that contribute to moisture availability over five major global food producing regions (breadbaskets), and the potential for land cover change to influence these moisture sources by altering surface evapotranspiration. For a range of LCC scenarios we estimated the impact of altered surface fluxes on crop moisture availability and potential yield using a simplified linear hydrologic model and a state-of-the-art ecosystem and crop model. All the breadbasket regions were found to be susceptible to reductions in moisture owing to perturbations in evaporative source (ES) from LCC, with reductions in moisture availability ranging from 7 to 17% leading to potential crop yield reductions of 1-17%, which are magnitudes comparable to the changes anticipated with greenhouse warming. The sensitivity of these reductions in potential crop yield to varying magnitudes of LCC was not consistent among regions. Two variables explained most of these differences: the first was the magnitude of the potential moisture availability change, with regions exhibiting greater reductions in moisture availability also tending to exhibit greater changes in potential yield; the second was the soil moisture within crop root zones. Regions with mean growing season soil moisture fractions of saturation >0.5 typically had reduced impacts on potential crop yield. Our results indicate the existence of LCC thresholds that have the capability to create moisture shortages adversely affecting crop yields in major food producing regions, which could lead to future food supply disruptions in the absence of increased irrigation or other

  16. Prioritisation of native legume species for further evaluation as potential forage crops in water-limited agricultural systems in South Africa.

    PubMed

    Müller, Francuois L; Raitt, Lincoln M; Chimphango, Samson B M; Samuels, M Igshaan; Cupido, Clement F; Boatwright, J Stephen; Knight, Richard; Trytsman, Marike

    2017-09-19

    In the face of climate change, identification of forage species suitable for dryland farming under low rainfall conditions in South Africa is needed. Currently, there are only a limited number of forage species suitable for dryland farming under such conditions. The objective of this study was to identify and prioritise native legume species that could potentially be used in dryland farming systems in water-limited agro-ecosystems in South Africa. Using a combination of ecological niche modelling techniques, plant functional traits, and indigenous knowledge, 18 perennial herbaceous or stem-woody legume species were prioritised for further evaluation as potential fodder species within water-limited agricultural areas. These species will be evaluated further for their forage quality and their ability to survive and produce enough biomass under water limitation and poor edaphic conditions.

  17. Weed Flora and Dormant-season cover crops have no effects on arbuscular mycorrhizae of grapevine

    USDA-ARS?s Scientific Manuscript database

    We tested the hypotheses that mycorrhizal colonization of a perennial crop increases with a high frequency of mycorrhizal hosts within the plant community, and that a high diversity of mycorrhizal hosts is associated with a high diversity of arbuscular mycorrhizal fungi (AMF) on the perennial crop. ...

  18. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... maximize that production. That is, harvesting and other production activities for the plants in the ground... basis of measurement, as applicable, of the crop from which production could be achieved existing on the... zero, as applicable, of production harvested, before or after the disaster, from those crop...

  19. Soil water improvements with the long-term use of a winter rye cover crop

    USDA-ARS?s Scientific Manuscript database

    The Midwestern United States is projected to experience increasing rainfall variability. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding as well as drought-induced crop water stress. While some ...

  20. Planting date impacts on soil water management, plant growth, and weeds in cover-crop-based no-till corn production

    USDA-ARS?s Scientific Manuscript database

    Low input and organic farmers are increasingly utilizing cover crop mulches in maize production. Many farmers are delaying planting corn into these high residue environments to allow greater growth of the cover crop to maximize nitrogen fixation and improve mechanical termination with roller crimpe...

  1. Organic weed conrol and cover crop residue integration impacts on weed control, quality, and yield and economics in conservation tillage tomato - A case study

    USDA-ARS?s Scientific Manuscript database

    The increased use of conservation tillage in vegetable production requires more information be developed on the role of cover crops in weed control, tomato quality and yield. Three conservation-tillage systems utilizing crimson clover, brassica and cereal rye as winter cover crops were compared to ...

  2. A functional characterisation of a wide range of cover crop species: growth and nitrogen acquisition rates, leaf traits and ecological strategies.

    PubMed

    Tribouillois, Hélène; Fort, Florian; Cruz, Pablo; Charles, Raphaël; Flores, Olivier; Garnier, Eric; Justes, Eric

    2015-01-01

    Cover crops can produce ecosystem services during the fallow period, as reducing nitrate leaching and producing green manure. Crop growth rate (CGR) and crop nitrogen acquisition rate (CNR) can be used as two indicators of the ability of cover crops to produce these services in agrosystems. We used leaf functional traits to characterise the growth strategies of 36 cover crops as an approach to assess their ability to grow and acquire N rapidly. We measured specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (LNC) and leaf area (LA) and we evaluated their relevance to characterise CGR and CNR. Cover crop species were positioned along the Leaf Economics Spectrum (LES), the SLA-LDMC plane, and the CSR triangle of plant strategies. LA was positively correlated with CGR and CNR, while LDMC was negatively correlated with CNR. All cover crops could be classified as resource-acquisitive species from their relative position on the LES and the SLA-LDMC plane. Most cover crops were located along the Competition/Ruderality axis in the CSR triangle. In particular, Brassicaceae species were classified as very competitive, which was consistent with their high CGR and CNR. Leaf functional traits, especially LA and LDMC, allowed to differentiate some cover crops strategies related to their ability to grow and acquire N. LDMC was lower and LNC was higher in cover crop than in wild species, pointing to an efficient acquisitive syndrome in the former, corresponding to the high resource availability found in agrosystems. Combining several leaf traits explained approximately half of the CGR and CNR variances, which might be considered insufficient to precisely characterise and rank cover crop species for agronomic purposes. We hypothesised that may be the consequence of domestication process, which has reduced the range of plant strategies and modified the leaf trait syndrome in cultivated species.

  3. A Functional Characterisation of a Wide Range of Cover Crop Species: Growth and Nitrogen Acquisition Rates, Leaf Traits and Ecological Strategies

    PubMed Central

    Tribouillois, Hélène; Fort, Florian; Cruz, Pablo; Charles, Raphaël; Flores, Olivier; Garnier, Eric; Justes, Eric

    2015-01-01

    Cover crops can produce ecosystem services during the fallow period, as reducing nitrate leaching and producing green manure. Crop growth rate (CGR) and crop nitrogen acquisition rate (CNR) can be used as two indicators of the ability of cover crops to produce these services in agrosystems. We used leaf functional traits to characterise the growth strategies of 36 cover crops as an approach to assess their ability to grow and acquire N rapidly. We measured specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (LNC) and leaf area (LA) and we evaluated their relevance to characterise CGR and CNR. Cover crop species were positioned along the Leaf Economics Spectrum (LES), the SLA-LDMC plane, and the CSR triangle of plant strategies. LA was positively correlated with CGR and CNR, while LDMC was negatively correlated with CNR. All cover crops could be classified as resource-acquisitive species from their relative position on the LES and the SLA-LDMC plane. Most cover crops were located along the Competition/Ruderality axis in the CSR triangle. In particular, Brassicaceae species were classified as very competitive, which was consistent with their high CGR and CNR. Leaf functional traits, especially LA and LDMC, allowed to differentiate some cover crops strategies related to their ability to grow and acquire N. LDMC was lower and LNC was higher in cover crop than in wild species, pointing to an efficient acquisitive syndrome in the former, corresponding to the high resource availability found in agrosystems. Combining several leaf traits explained approximately half of the CGR and CNR variances, which might be considered insufficient to precisely characterise and rank cover crop species for agronomic purposes. We hypothesised that may be the consequence of domestication process, which has reduced the range of plant strategies and modified the leaf trait syndrome in cultivated species. PMID:25789485

  4. Sensitivity of crop cover to climate variability: insights from two Indian agro-ecoregions.

    PubMed

    Mondal, Pinki; Jain, Meha; DeFries, Ruth S; Galford, Gillian L; Small, Christopher

    2015-01-15

    Crop productivity in India varies greatly with inter-annual climate variability and is highly dependent on monsoon rainfall and temperature. The sensitivity of yields to future climate variability varies with crop type, access to irrigation and other biophysical and socio-economic factors. To better understand sensitivities to future climate, this study focuses on agro-ecological subregions in Central and Western India that span a range of crops, irrigation, biophysical conditions and socioeconomic characteristics. Climate variability is derived from remotely-sensed data products, Tropical Rainfall Measuring Mission (TRMM - precipitation) and Moderate Resolution Imaging Spectroradiometer (MODIS - temperature). We examined green-leaf phenologies as proxy for crop productivity using the MODIS Enhanced Vegetation Index (EVI) from 2000 to 2012. Using both monsoon and winter growing seasons, we assessed phenological sensitivity to inter-annual variability in precipitation and temperature patterns. Inter-annual EVI phenology anomalies ranged from -25% to 25%, with some highly anomalous values up to 200%. Monsoon crop phenology in the Central India site is highly sensitive to climate, especially the timing of the start and end of the monsoon and intensity of precipitation. In the Western India site, monsoon crop phenology is less sensitive to precipitation variability, yet shows considerable fluctuations in monsoon crop productivity across the years. Temperature is critically important for winter productivity across a range of crop and management types, such that irrigation might not provide a sufficient buffer against projected temperature increases. Better access to weather information and usage of climate-resilient crop types would play pivotal role in maintaining future productivity. Effective strategies to adapt to projected climate changes in the coming decades would also need to be tailored to regional biophysical and socio-economic conditions. Copyright © 2014

  5. Effects of Winter Cover Crops Straws Incorporation on CH4 and N2O Emission from Double-Cropping Paddy Fields in Southern China

    PubMed Central

    Tang, Hai-Ming; Xiao, Xiao-Ping; Tang, Wen-Guang; Wang, Ke; Sun, Ji-Min; Li, Wei-Yan; Yang, Guang-Li

    2014-01-01

    Residue management in cropping systems is believed to improve soil quality. However, the effects of residue management on methane (CH4) and nitrous oxide (N2O) emissions from paddy field in Southern China have not been well researched. The emissions of CH4 and N2O were investigated in double cropping rice (Oryza sativa L.) systems with straw returning of different winter cover crops by using the static chamber-gas chromatography technique. A randomized block experiment with three replications was established in 2004 in Hunan Province, China, including rice–rice–ryegrass (Lolium multiflorum L.) (Ry-R-R), rice–rice–Chinese milk vetch (Astragalus sinicus L.) (Mv-R-R) and rice–rice with winter fallow (Fa-R-R). The results showed that straw returning of winter crops significantly increased the CH4 emission during both rice growing seasons when compared with Fa-R-R. Ry-R-R plots had the largest CH4 emissions during the early rice growing season with 14.235 and 15.906 g m−2 in 2012 and 2013, respectively, when Ry-R-R plots had the largest CH4 emission during the later rice growing season with 35.673 and 38.606 g m−2 in 2012 and 2013, respectively. The Ry-R-R and Mv-R-R also had larger N2O emissions than Fa-R-R in both rice seasons. When compared to Fa-R-R, total N2O emissions in the early rice growing season were increased by 0.05 g m−2 in Ry-R-R and 0.063 g m−2 in Mv-R-R in 2012, and by 0.058 g m−2 in Ry-R-R and 0.068 g m−2 in Mv-R-R in 2013, respectively. Similar result were obtained in the late rice growing season, and the total N2O emissions were increased by 0.104 g m−2 in Ry-R-R and 0.073 g m−2 in Mv-R-R in 2012, and by 0.108 g m−2 in Ry-R-R and 0.076 g m−2 in Mv-R-R in 2013, respectively. The global warming potentials (GWPs) from paddy fields were ranked as Ry-R-R>Mv-R-R>Fa-R-R. As a result, straw returning of winter cover crops has significant effects on increase of CH4 and N2O emission from paddy field in double cropping rice system

  6. Effects of winter cover crops straws incorporation on CH4 and N2O emission from double-cropping paddy fields in southern China.

    PubMed

    Tang, Hai-Ming; Xiao, Xiao-Ping; Tang, Wen-Guang; Wang, Ke; Sun, Ji-Min; Li, Wei-Yan; Yang, Guang-Li

    2014-01-01

    Residue management in cropping systems is believed to improve soil quality. However, the effects of residue management on methane (CH4) and nitrous oxide (N2O) emissions from paddy field in Southern China have not been well researched. The emissions of CH4 and N2O were investigated in double cropping rice (Oryza sativa L.) systems with straw returning of different winter cover crops by using the static chamber-gas chromatography technique. A randomized block experiment with three replications was established in 2004 in Hunan Province, China, including rice-rice-ryegrass (Lolium multiflorum L.) (Ry-R-R), rice-rice-Chinese milk vetch (Astragalus sinicus L.) (Mv-R-R) and rice-rice with winter fallow (Fa-R-R). The results showed that straw returning of winter crops significantly increased the CH4 emission during both rice growing seasons when compared with Fa-R-R. Ry-R-R plots had the largest CH4 emissions during the early rice growing season with 14.235 and 15.906 g m(-2) in 2012 and 2013, respectively, when Ry-R-R plots had the largest CH4 emission during the later rice growing season with 35.673 and 38.606 g m(-2) in 2012 and 2013, respectively. The Ry-R-R and Mv-R-R also had larger N2O emissions than Fa-R-R in both rice seasons. When compared to Fa-R-R, total N2O emissions in the early rice growing season were increased by 0.05 g m(-2) in Ry-R-R and 0.063 g m(-2) in Mv-R-R in 2012, and by 0.058 g m(-2) in Ry-R-R and 0.068 g m(-2) in Mv-R-R in 2013, respectively. Similar result were obtained in the late rice growing season, and the total N2O emissions were increased by 0.104 g m(-2) in Ry-R-R and 0.073 g m(-2) in Mv-R-R in 2012, and by 0.108 g m(-2) in Ry-R-R and 0.076 g m(-2) in Mv-R-R in 2013, respectively. The global warming potentials (GWPs) from paddy fields were ranked as Ry-R-R>Mv-R-R>Fa-R-R. As a result, straw returning of winter cover crops has significant effects on increase of CH4 and N2O emission from paddy field in double cropping rice system.

  7. Fall cover cropping can increase arbuscular mycorrhizae in soils supporting intensive agricultural production

    USDA-ARS?s Scientific Manuscript database

    Intensive agricultural practices, such as tillage, monocropping, seasonal fallow periods, and inorganic nutrient application have been shown to reduce arbuscular mycorrrhizal fungi (AMF) populations and thus may reduce benefits frequently provided to crops by AMF, such as nutrient acquisition, disea...

  8. Remote sensing weeds, cover crop residue, and tillage practices in soybean

    NASA Astrophysics Data System (ADS)

    Koger, Clifford Hubert

    Research was conducted to evaluate the potential of remote sensing for detecting weeds in soybean. The first objective was to evaluate the potential of multispectral imagery for detection of late-season weed-infestations. The second objective was to identify bands derived from hyperspectral data capable of discriminating small, early-season pitted morningglory intermixed with soybean from weed-free soybean in different tillage and cover crop residue systems. The final objective was to determine the success of wavelet-based analysis of ground-collected hyperspectral data for discriminating reflectance patterns of pitted morningglory intermixed with soybean from weed-free soybean. Late-season weed infestations were discriminated from weed-free soybean with at least 90% accuracy when using green, red, and near-infrared spectral bands and a normalized difference vegetation index as classification variables in discriminant analysis. Discriminant analysis functions formed for one data set and tested on another set were 81 to 90% accurate in discriminating weed-infestations when soybean growth stage between data sets did not differ substantially. For the second objective, reflectance data were collected between 350 and 2,500 nm in 2151 discrete bands, with spectral bandwidths of 1.4 nm between 350 and 1050 nm and 1.0 nm from 1000 to 2500 nm. Eight 50-nm bands (1 ultraviolet, 2 visible, 4 near-infrared, 1 mid-infrared) were used to classify reflectance properties of pitted morningglory intermixed with soybean from weed-free soybean with 83 to 100% accuracy within the different tillage/residue systems. Pitted morningglory growth stage influenced detection capabilities more than tillage and residue systems. The ability to discriminate pitted morningglory intermixed with soybean from weed-free soybean was attributed to differences in reflectance properties of pitted morningglory and soybean, not from increase in total vegetation biomass in the pitted morningglory intermixed

  9. From Model to Crop: Functional Analysis of a STAY-GREEN Gene in the Model Legume Medicago truncatula and Effective Use of the Gene for Alfalfa Improvement1[W][OA

    PubMed Central

    Zhou, Chuanen; Han, Lu; Pislariu, Catalina; Nakashima, Jin; Fu, Chunxiang; Jiang, Qingzhen; Quan, Li; Blancaflor, Elison B.; Tang, Yuhong; Bouton, Joseph H.; Udvardi, Michael; Xia, Guangmin; Wang, Zeng-Yu

    2011-01-01

    Medicago truncatula has been developed into a model legume. Its close relative alfalfa (Medicago sativa) is the most widely grown forage legume crop in the United States. By screening a large population of M. truncatula mutants tagged with the transposable element of tobacco (Nicotiana tabacum) cell type1 (Tnt1), we identified a mutant line (NF2089) that maintained green leaves and showed green anthers, central carpels, mature pods, and seeds during senescence. Genetic and molecular analyses revealed that the mutation was caused by Tnt1 insertion in a STAY-GREEN (MtSGR) gene. Transcript profiling analysis of the mutant showed that loss of the MtSGR function affected the expression of a large number of genes involved in different biological processes. Further analyses revealed that SGR is implicated in nodule development and senescence. MtSGR expression was detected across all nodule developmental zones and was higher in the senescence zone. The number of young nodules on the mutant roots was higher than in the wild type. Expression levels of several nodule senescence markers were reduced in the sgr mutant. Based on the MtSGR sequence, an alfalfa SGR gene (MsSGR) was cloned, and transgenic alfalfa lines were produced by RNA interference. Silencing of MsSGR led to the production of stay-green transgenic alfalfa. This beneficial trait offers the opportunity to produce premium alfalfa hay with a more greenish appearance. In addition, most of the transgenic alfalfa lines retained more than 50% of chlorophylls during senescence and had increased crude protein content. This study illustrates the effective use of knowledge gained from a model system for the genetic improvement of an important commercial crop. PMID:21957014

  10. Molecular diversity and distribution of indigenous arbuscular mycorrhizal communities colonizing roots of two different winter cover crops in response to their root proliferation.

    PubMed

    Higo, Masao; Isobe, Katsunori; Miyazawa, Yusuke; Matsuda, Yukiya; Drijber, Rhae A; Torigoe, Yoichi

    2016-02-01

    A clear understanding of how crop root proliferation affects the distribution of the spore abundance of arbuscular mycorrhizal fungi (AMF) and the composition of AMF communities in agricultural fields is imperative to identify the potential roles of AMF in winter cover crop rotational systems. Toward this goal, we conducted a field trial using wheat (Triticum aestivum L.) or red clover (Trifolium pratense L.) grown during the winter season. We conducted a molecular analysis to compare the diversity and distribution of AMF communities in roots and spore abundance in soil cropped with wheat and red clover. The AMF spore abundance, AMF root colonization, and abundance of root length were investigated at three different distances from winter crops (0 cm, 7.5 cm, and 15 cm), and differences in these variables were found between the two crops. The distribution of specific AMF communities and variables responded to the two winter cover crops. The majority of Glomerales phylotypes were common to the roots of both winter cover crops, but Gigaspora phylotypes in Gigasporales were found only in red clover roots. These results also demonstrated that the diversity of the AMF colonizing the roots did not significantly change with the three distances from the crop within each rotation but was strongly influenced by the host crop identity. The distribution of specific AMF phylotypes responded to the presence of wheat and red clover roots, indicating that the host crop identity was much more important than the proliferation of crop roots in determining the diversity of the AMF communities.

  11. Effects of Winter Cover Crops Residue Returning on Soil Enzyme Activities and Soil Microbial Community in Double-Cropping Rice Fields

    PubMed Central

    Hai-Ming, Tang; Xiao-Ping, Xiao; Wen-Guang, Tang; Ye-Chun, Lin; Ke, Wang; Guang-Li, Yang

    2014-01-01

    Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L.) system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice–rice–ryegrass (Lolium multiflorum L.) (R-R-Ry), rice–rice–Chinese milk vetch (Astragalus sinicus L.) (R-R-Mv), rice–rice–rape (Brassica napus L.) (R-R-Ra) and rice–rice with winter fallow (R-R-Fa). The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (P<0.05) than in the R-R-Fa system during the early and late rice season. The β-glucosidase activities reached peak values at the tillering stage after residue application, and alkaline phosphatase activities reached peak values at the booting stage after residue application, respectively, the activities of β-glucosidase and alkaline phosphatase gradually decreased after this. Arylsulfatase activities reached peak values at the maturity stage. Arylamidase activities reached peak values at the maturity stage. The numbers of aerobic bacteria, actinomycete and fungus of residue treatments were significantly higher (P<0.05) than that the R-R-Ra system. However, the number of anaerobic bacteria under the R-R-Ry and R-R-Mv systems was significantly lower (P<0.05) than that under the R-R-Fa system during early rice and late rice growth stage. Thus, incorporation of winter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality. PMID:24956152

  12. Effects of a killed-cover crop mulching system on sweetpotato production, soil pests, and insect predators in South Carolina.

    PubMed

    Jackson, D Michael; Harrison, Howard F

    2008-12-01

    Sweetpotatoes, Ipomoea batatas (L.) Lam. (Convolvulaceae), are typically grown on bare soil where weeds and erosion can be serious problems. Conservation tillage systems using cover crop residues as mulch can help reduce these problems, but little is known about how conservation tillage affects yield and quality of sweetpotato or how these systems impact populations of beneficial and pest insects. Therefore, field experiments were conducted at the U.S. Vegetable Laboratory, Charleston, SC, in 2002-2004 to evaluate production of sweetpotatoes in conventional tillage versus a conservation tillage system by using an oat (Avena sativa L. (Poaceae)-crimson clover (Trifolium incarnatum L.) (Fabaceae) killed-cover crop (KCC) mulch. The four main treatments were 1) conventional tillage, hand-weeded; 2) KCC, hand-weeded; 3) conventional tillage, weedy; and 4) KCC, weedy. Each main plot was divided into three subplots, whose treatments were sweetpotato genotypes: 'Ruddy', which is resistant to soil insect pests; and 'SC1149-19' and 'Beauregard', which are susceptible to soil insect pests. For both the KCC and conventional tillage systems, sweetpotato yields were higher in plots that received hand weeding than in weedy plots. Orthogonal contrasts revealed a significant effect of tillage treatment (conventional tillage versus KCC) on yield in two of the 3 yr. Ruddy remained resistant to injury by soil insect pests in both cropping systems; and it consistently had significantly higher percentages of clean roots and less damage by wireworm-Diabrotica-Systena complex, sweetpotato flea beetles, grubs, and sweetpotato weevils than the two susceptible genotypes. In general, injury to sweetpotato roots by soil insect pests was not significantly higher in the KCC plots than in the conventionally tilled plots. Also, more fire ants, rove beetles, and carabid beetle were captured by pitfall traps in the KCC plots than in the conventional tillage plots during at least 1 yr of the study

  13. Genetic control of inflorescence architecture in legumes

    PubMed Central

    Benlloch, Reyes; Berbel, Ana; Ali, Latifeh; Gohari, Gholamreza; Millán, Teresa; Madueño, Francisco

    2015-01-01

    The architecture of the inflorescence, the shoot system that bears the flowers, is a main component of the huge diversity of forms found in flowering plants. Inflorescence architecture has also a strong impact on the production of fruits and seeds, and on crop management, two highly relevant agronomical traits. Elucidating the genetic networks that control inflorescence development, and how they vary between different species, is essential to understanding the evolution of plant form and to being able to breed key architectural traits in crop species. Inflorescence architecture depends on the identity and activity of the meristems in the inflorescence apex, which determines when flowers are formed, how many are produced and their relative position in the inflorescence axis. Arabidopsis thaliana, where the genetic control of inflorescence development is best known, has a simple inflorescence, where the primary inflorescence meristem directly produces the flowers, which are thus borne in the main inflorescence axis. In contrast, legumes represent a more complex inflorescence type, the compound inflorescence, where flowers are not directly borne in the main inflorescence axis but, instead, they are formed by secondary or higher order inflorescence meristems. Studies in model legumes such as pea (Pisum sativum) or Medicago truncatula have led to a rather good knowledge of the genetic control of the development of the legume compound inflorescence. In addition, the increasing availability of genetic and genomic tools for legumes is allowing to rapidly extending this knowledge to other grain legume crops. This review aims to describe the current knowledge of the genetic network controlling inflorescence development in legumes. It also discusses how the combination of this knowledge with the use of emerging genomic tools and resources may allow rapid advances in the breeding of grain legume crops. PMID:26257753

  14. Soil water improvements with the long-term use of a winter rye cover crop

    USDA-ARS?s Scientific Manuscript database

    The Midwestern United States, a region that produces one-third of maize and one-quarter of soybeans globally, is projected to experience increasing rainfall variability with future climate change. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance ...

  15. Reduced-tillage organic corn production in a hairy vetch cover crop

    USDA-ARS?s Scientific Manuscript database

    There is much interest in developing no-tillage systems for organic farming, however, potential limitations include the inability to control weeds and to provide sufficient crop available N. A three-year field experiment was conducted on organically-certified land to explore the use of roller-crimp...

  16. Low-disturbance manure application methods in a corn silage-rye cover crop system

    USDA-ARS?s Scientific Manuscript database

    Incorporation of manure by tillage can conserve manure N by reducing ammonia volatilization losses, but tillage also incorporates crop residue, which increases erosion potential. This study compared several low-disturbance manure application methods, designed to incorporate manure while still mainta...

  17. Multistate evaluation of Brassica cover crop, biocontrol agent, and fungicide for integrated management of sheath blight

    USDA-ARS?s Scientific Manuscript database

    Sheath blight, caused by Rhizoctonia solani, is one of the most important diseases limiting rice production in the southern rice-producing states. The fungus survives between crops as sclerotia and mycelia in infected plant debris and serves as the primary inoculum. Infection starts when sclerotia a...

  18. Evaluation of tillage, cover crop, & herbicide effects on weed control, yield and grade in peanut?

    USDA-ARS?s Scientific Manuscript database

    Peanut production continues to play a large role in agriculture in the Southeastern United States and weed challenges persist. Therefore, it is important to reduce weed competition in peanut to protect yield and grade. With traditional use of herbicides for weed control in peanut and rotational crop...

  19. Cover crop mixtures for promoting arbuscular mycorrhizal fungi in production agriculture

    USDA-ARS?s Scientific Manuscript database

    Arbuscular mycorrhizal fungi (AMF) associate with an estimated 80-90 percent of flowering plants and virtually every crop species that supplies food to the world. AMF play a vital role in nutrient uptake and are particularly adept at increasing phosphorus availability to plants. With the growing e...

  20. Reduction in metolachlor and degradates concentrations in shallow groundwater through cover crop use

    USDA-ARS?s Scientific Manuscript database

    Pesticide use during crop production has the potential to adversely impact groundwater quality. In southern Florida climatic and hydrogeologic conditions and agronomic practices indicate that contamination risks are high. In the current study soil dissipation of the widely used herbicide, metolachlo...

  1. Performance assessment of the cellulose absorption index (CAI) method for estimating crop residue cover

    USDA-ARS?s Scientific Manuscript database

    Accurate and quick field estimation of crop residues are important for carbon sequestration and biofuel production programs. Landscape-scale assessment of this vital information has promoted the use of remote sensing technology. The cellulose absorption index (CAI) technique has outperformed other ...

  2. Kenaf (Hibiscus cannabinus) and cowpea (Vigna unguiculata) as sugarcane cover crops

    USDA-ARS?s Scientific Manuscript database

    A Louisiana sugarcane field is typically replanted every four years due to declining yields, and, although, it is a costly process, it is both necessary and an opportunity to maximize the financial return during the next four year cropping cycle. Fallow planting systems (FPS) during the fallow perio...

  3. Cover Crop, Amendment, and Tillage Effects on Decomposers, Nematodes, and Collembolans in An Organic Vegetable System

    USDA-ARS?s Scientific Manuscript database

    Soil organisms are sensitive indicators of changes in soil properties. This study reports the effects of different organic management practices on microbial biomass, nematodes and collembolans. Cropping systems treatments are traditional post-harvest, fall-seeded cereal rye-hairy vetch mix; relay-...

  4. Weed hosts and relative weed and cover crop susceptibility to Rotylenchulus reniformis in the Mississippi Delta

    USDA-ARS?s Scientific Manuscript database

    The reniform nematode (Rotylenchulus reniformis) causes economic losses in cotton and soybean in the southeastern United States, and has the ability to reproduce on more than 300 plant species. Even when the host crop is protected through the use of nematicides or host plant resistance, the potentia...

  5. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region

    PubMed Central

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, W. Dean; Lang, Megan W.

    2016-01-01

    The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB) is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT) and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE) reduced NO3-N loads by ~49.3% compared to the baseline (no WCC). The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean), with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  6. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    PubMed

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M; McCarty, Gregory W; Hively, W Dean; Lang, Megan W

    2016-01-01

    The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB) is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT) and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE) reduced NO3-N loads by ~49.3% compared to the baseline (no WCC). The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean), with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  7. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne.

    PubMed

    Kokalis-Burelle, Nancy; Butler, David M; Rosskopf, Erin N

    2013-12-01

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (ASD) applications. Nematode juvenile (J2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (Eruca sativa, cv. Nemat), cowpea (Vigna unguiculata, cv. Iron & Clay), jack bean (Canavalia ensiformis, cv. Comum), two commercial mixtures of Indian mustard and white mustard (Brassica juncea & Sinapis alba, mixtures Caliente 61 and Caliente 99), pearl millet (Pennisetum glaucum, cv. Tifleaf III), sorghum-sudangrass hybrid (Sorghum bicolor × S. bicolor var. sudanense, cv. Sugar Grazer II), and three cultivars of sunflower (Helianthus annuus, cvs. 545A, Nusun 660CL, and Nusun 5672). Tomato (Solanum lycopersicum, cv. Rutgers) was included in all trials as a susceptible host to all three nematode species. The majority of cover crops tested were less susceptible than tomato to M. arenaria, with the exception of jack bean. Sunflower cv. Nusun 5672 had fewer M. arenaria J2 isolated from roots than the other sunflower cultivars, less galling than tomato, and fewer eggs than tomato and sunflower cv. 545A. Several cover crops did not support high populations of M. incognita in roots or exhibit significant galling, although high numbers of M. incognita J2 were isolated from the soil. Arugula, cowpea, and mustard mixture Caliente 99 did not support M. incognita in soil or roots. Jack bean and all three cultivars of sunflower were highly susceptible to M. javanica, and all sunflower cultivars had high numbers of eggs isolated from roots. Sunflower, jack bean, and both mustard mixtures exhibited significant galling in response to M. javanica. Arugula, cowpea, and sorghum-sudangrass consistently had low numbers of all three

  8. On the Ground or in the Air? A Methodological Experiment on Crop Residue Cover Measurement in Ethiopia.

    PubMed

    Kosmowski, Frédéric; Stevenson, James; Campbell, Jeff; Ambel, Alemayehu; Haile Tsegay, Asmelash

    2017-06-08

    Maintaining permanent coverage of the soil using crop residues is an important and commonly recommended practice in conservation agriculture. Measuring this practice is an essential step in improving knowledge about the adoption and impact of conservation agriculture. Different data collection methods can be implemented to capture the field level crop residue coverage for a given plot, each with its own implication on survey budget, implementation speed and respondent and interviewer burden. In this paper, six alternative methods of crop residue coverage measurement are tested among the same sample of rural households in Ethiopia. The relative accuracy of these methods are compared against a benchmark, the line-transect method. The alternative methods compared against the benchmark include: (i) interviewee (respondent) estimation; (ii) enumerator estimation visiting the field; (iii) interviewee with visual-aid without visiting the field; (iv) enumerator with visual-aid visiting the field; (v) field picture collected with a drone and analyzed with image-processing methods and (vi) satellite picture of the field analyzed with remote sensing methods. Results of the methodological experiment show that survey-based methods tend to underestimate field residue cover. When quantitative data on cover are needed, the best estimates are provided by visual-aid protocols. For categorical analysis (i.e., >30% cover or not), visual-aid protocols and remote sensing methods perform equally well. Among survey-based methods, the strongest correlates of measurement errors are total farm size, field size, distance, and slope. Results deliver a ranking of measurement options that can inform survey practitioners and researchers.

  9. Changes in Plant-Parasitic Nematode Populations in Pineapple Fields Following Inter-Cycle Cover Crops

    PubMed Central

    Ko, M. P.; Schmitt, D. P.

    1996-01-01

    The use of plant-covers oat (Arena sativa L.), rhodesgrass (Chloris gayana Kunth), soybean (Glycine max [L.] Merr.), and marigold (Tagetes patula L.) during pineapple inter-cycle planting periods was investigated at two sites (Kunia and Whitmore, Oahu, HI) as a potential means to reduce population densities of Rotylenchulus reniformis, Helicotylenchus dihystera, and Paratylenchus spp. Clean fallow and fallow covered with pineapple-plant residues (mulch) were the controls without plant-cover. Regardless of treatments, population densities of R. reniformis declined with time at both sites to low residue levels by the end of the 6-month period. Treatment means of R. reniformis population densities in the plant-cover treatments were lower than the controls' (P = 0.05). The plant-cover treatments also effected higher rates of R. reniformis population decline at both sites during the period, being 2.0 to 2.2 times that of the mulch control and 1.2 to 1.4 times that of the fallow control. Plant-covers' effect on H. dihystera during the same period at both sites was variable, resulting in decreased, unchanged, or increased population densities. The change was especially obvious in the oat-cover treatment, where H. dihystera population densities increased 9 to 15-fold at both sites. Population of Paratylenchus spp. was absent or present at low levels at the sites throughout the period. Biological activities antagonistic to R. reniformis at Kunia were estimated at the end of 6 months by comparing the extent of nematode's reproduction (on cowpea seedlings) in the treatment soils that had been subjected to autoclaving or freezing temperature. Although higher indices of antagonistic activities were observed in soils with prior plant-cover treatments than in soils from the controls, none of the treatments resulted in conferring soils the increased ability to suppress re-introduced R. reniformis populations or enhance subsequent pineapple-plant growth. PMID:19277173

  10. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots.

    PubMed

    Carval, Dominique; Resmond, Rémi; Achard, Raphaël; Tixier, Philippe

    2016-06-01

    The data presented in this article are related to the research article entitled "Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants" (Carval et al., in press) [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes.

  11. Suitability of leguminous cover crop pollens as food source for the green lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae).

    PubMed

    Venzon, Madelaine; Rosado, Maria C; Euzébio, Denise E; Souza, Brígida; Schoereder, José H

    2006-01-01

    Diversification of crops with species that provide suitable pollen for predators may reduce pest population on crops by enhancing predator effectiveness. In this paper we evaluated the suitability of leguminous cover crop pollens to the predatory green lacewing Chrysoperla externa (Hagen). The predator is commonly found in coffee agroecosystems and the plant species tested were pigeon pea and sunn hemp, which are used in organic coffee systems. Newly emerged females and males of C. externa were reared on diets containing pollen of pigeon pea, sunn hemp, or castor bean, used as a control. The reproductive success of C. externa was evaluated when females fed the pollen species and when honey was added to the diets, to verify the predator need for an extra carbohydrate source. Similar intrinsic growth rates were found for females fed on pigeon pea pollen and on sunn hemp pollen but these rates increased significantly when honey was added to the diets. Females fed with pigeon pea pollen plus honey and with sunn hemp pollen plus honey had higher intrinsic growth rates than those fed with castor bean pollen plus honey. Females fed on castor bean pollen only or on honey only, did not oviposit. Leguminous pollen species were equally suitable for C. externa especially when they were complemented with honey. The results suggest that to successfully enhance predator effectiveness, organic coffee plantation should be diversified with plant providing pollen in combination with plant providing nectar.

  12. A comparative analysis of transcriptomic, biochemical and physiological responses to elevated ozone identifies species-specific mechanisms of resilience in legume crops

    USDA-ARS?s Scientific Manuscript database

    Current concentrations of tropospheric ozone (O3) pollution negatively impact plant metabolism, which can result in decreased crop yields. Interspecific variation in the physiological response of plants to elevated [O3] exists; however, the underlying cellular responses explaining species-specific d...

  13. Influence on wine biogenic amine composition of modifications to soil N availability and grapevine N by cover crops.

    PubMed

    Pérez-Álvarez, Eva P; Garde-Cerdán, Teresa; Cabrita, Maria João; García-Escudero, Enrique; Peregrina, Fernando

    2017-04-04

    Vineyard soil management can modify the nitrogen soil availability and, therefore, grape amino acid content. These compounds are precursors of biogenic amines, which have negative effects on wine quality and human health. The objective was to study whether the effect of conventional tillage and two cover crops (barley and clover) on grapevine nitrogen status could be related to wine biogenic amines. Over 4 years, soil NO3(-) -N, nitrogen content in leaf and wine biogenic amine concentration were determined. Barley reduced soil NO3(-) -N availability and clover increased it. In 2011, at bloom, nitrogen content decreased with barley treatment in both blade and petiole. In 2012, nitrogen content in both leaf tissues at bloom was greater with clover than with tillage and barley treatments. Also, total biogenic amines decreased in barley with respect to tillage and clover treatments. There were correlations between some individual and total biogenic amine concentrations with respect to nitrogen content in leaf tissues. Wine biogenic amine concentration can be affected by the grapevine nitrogen status, provoked by changes in the soil NO3(-) -N availability with both cover crop treatments. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Modeling tropical land-use and land-cover change related to sugarcane crops using remote sensing and soft computing techniques

    NASA Astrophysics Data System (ADS)

    Vicente, L. E.; Koga-Vicente, A.; Friedel, M. J.; Zullo, J.; Victoria, D.; Gomes, D.; Bayma, G.

    2013-12-01

    Agriculture is closely related to land-use/cover changes (LUCC). The increase in demand for ethanol necessitates the expansion of areas occupied by corn and sugar cane. In São Paulo state, the conversion of this land raises concern for impacts on food security, such as the decrease in traditional food crop production areas. We used remote sensing data to train and evaluate future land-cover scenarios using a machine-learning algorithm. The land cover classification procedure was based on Landsat 5 TM images, obtained from the Global Land Survey, covering three time periods over twenty years (1990 - 2010). Landsat images were segmented into homogeneous objects, which represent areas on the ground with similar spatial and spectral characteristics. These objects are related to the distinct land cover types that occur in each municipality. Based on the object shape, texture and spectral characteristics, land use/cover was visually identified, considering the following classes: sugarcane plantations, pasture lands, natural cover, forest plantation, permanent crop, short cycle crop, water bodies and urban areas. Results for the western regions of São Paulo state indicate that sugarcane crop area advanced mostly upon pasture areas with few areas of food crops being replaced by sugarcane.

  15. Do cover crops enhance N₂O, CO₂ or CH₄ emissions from soil in Mediterranean arable systems?

    PubMed

    Sanz-Cobena, A; García-Marco, S; Quemada, M; Gabriel, J L; Almendros, P; Vallejo, A

    2014-01-01

    This study evaluates the effect of planting three cover crops (CCs) (barley, Hordeum vulgare L.; vetch, Vicia villosa L.; rape, Brassica napus L.) on the direct emission of N₂O, CO₂ and CH₄ in the intercrop period and the impact of incorporating these CCs on the emission of greenhouse gas (GHG) from the forthcoming irrigated maize (Zea mays L.) crop. Vetch and barley were the CCs with the highest N₂O and CO₂ losses (75 and 47% increase compared with the control, respectively) in the fallow period. In all cases, fluxes of N₂O were increased through N fertilization and the incorporation of barley and rape residues (40 and 17% increase, respectively). The combination of a high C:N ratio with the addition of an external source of mineral N increased the fluxes of N₂O compared with -Ba and -Rp. The direct emissions of N₂O were lower than expected for a fertilized crop (0.10% emission factor, EF) compared with other studies and the IPCC EF. These results are believed to be associated with a decreased NO₃(-) pool due to highly denitrifying conditions and increased drainage. The fluxes of CO₂ were in the range of other fertilized crops (i.e., 1118.71-1736.52 kg CO₂-Cha(-1)). The incorporation of CC residues enhanced soil respiration in the range of 21-28% for barley and rape although no significant differences between treatments were detected. Negative CH₄ fluxes were measured and displayed an overall sink effect for all incorporated CC (mean values of -0.12 and -0.10 kg CH₄-Cha(-1) for plots with and without incorporated CCs, respectively). © 2013 Elsevier B.V. All rights reserved.

  16. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    PubMed

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings.

  17. Effects of Cover Crops to Offset Soil Carbon Changes Under No-till on an Ohio farm when Biomass is Harvested

    NASA Astrophysics Data System (ADS)

    Kimble, J. M.; Everett, L. R.; Richards, W.

    2003-12-01

    The results of a long term experiment to look at the use of cover crops and there effect on soil organic carbon. No-till has been shown to increase SOC and improve the overall soil quality under conditions where the biomass has been returned to the field. However, biomass may be removed as silage or for use in biofuels. The removal will reduce the inputs to the field so to overcome the amount of biomass not returned to the soil different cover crops were used. This experiment was done on a working farm where the corn biomass was being removed as silage. Four cover crops were planted in early September of 2002: rye, oats, clover, and canola with two controls, one with no cover crop and one where corn stubble was left on the field. The soils were sampled soon after the crops were planted and again in the spring of 2003 before the cover crops were killed just prior to planting. The first results indicate that the most root biomass was produced by the rye followed by oats then canola and then clover.

  18. Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups

    PubMed Central

    Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

    2016-01-01

    A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5–43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3–37.2°C, maximum temperatures at which the species could germinate varied from 27.7–43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

  19. Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups.

    PubMed

    Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

    2016-01-01

    A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

  20. The effects of a winter cover crop on Diabrotica virgifera (Coleoptera: Chrysomelidae) populations and beneficial arthropod communities in no-till maize.

    PubMed

    Lundgren, Jonathan G; Fergen, Janet K

    2010-12-01

    The effects of an autumn-planted, spring-killed, grass cover crop (Elymus trachycaulus [Link] Gould ex Shinners) on populations of Diabrotica virgifera virgifera LeConte and its predator community were evaluated in South Dakota maize fields over two seasons. Abundance and size of D. virgifera larvae and adults and sex ratio of adults were measured in maize produced under two treatments (i.e., a winter cover crop or bare soil), as were maize root damage and the abundance and diversity of the predator communities collected on the soil surface and in the soil column. First and second instars and adults of D. virgifera were similarly abundant in the two treatments, but third instars were significantly fewer in maize planted after a winter cover crop. Larvae developed at different rates in the two treatments, and second instars were significantly smaller (head capsule width and body length) in the maize planted after a cover crop. First and third instars and adults were of similar size in the two treatments, and adult sex ratios were also similar. Although initially similar, predator populations increased steadily in the cover-cropped maize, which led to a significantly greater predator population by the time D. virgifera pupated. There was significantly less root damage in the cover-cropped maize. Predator communities were similarly diverse in both treatments. Predator abundance per plot was significantly and negatively correlated with the abundance of third instars per plot. Clearly, winter cover crops reduce D. virgifera performance and their damage to the crop, and we suspect that this reduction is caused by both environmental effects of the treatment on D. virgifera size and development, and of increased predation on the third instars of the pest. Additional data on the impact of cover crops on actual predation levels, grain yield and quality, and farmer profitability, and correlations among pest performance, crop characteristics, and predator populations and

  1. A comparative analysis to quantify the biogeochemical and biogeophysical cooling effects on climate of a white mustard cover crop

    NASA Astrophysics Data System (ADS)

    Ferlicoq, Morgan; Ceschia, Eric; Brut, Aurore; Tallec, Tiphaine; Carrer, Dominique; Pique, Gaetan; Ferroni, Nicole

    2017-04-01

    During the COP21, agriculture was recognised as a strategic sector and an opportunity to strengthen climate mitigation. In particular, the "4 per 1000" initiative relies upon solutions that refer to agro-ecology, conservation agriculture, … that could lead to increase carbon storage. Among those agro-ecology practices, including cover crops during fallow periods is considered as a fundamental agronomic lever for storing carbon. However, if biogeochemical benefits of cover-crops (CC) have already been addressed, their biogeophysical effects on climate have never been quantified and compared to biogeochemical effects. This comparative study (CC vs. bare soil), quantified and compared biogeochemical (including carbon storage) and biophysical effects (albedo and energy partitioning effect) of CC on climate. An experimental campaign was performed in 2013 in Southwest France, during the fallow period following a winter-wheat crop (and before a maize). The experimental plot was divided in two: the northern part was maintained in bare soil (BS) while white-mustard (WM) was grown during 3-months on the southern part. On each subplot, continuous measurements of CO2, latent and sensible fluxes (by eddy covariance) and solar radiation were acquired. Also, N2O emissions were measured by means of automatic chambers on each subplots. Moreover, by using a Life-Cycle-Analysis approach, each component of the greenhouse gas budget (GHGB) was quantified for each subplot, including emissions associated to field operations (FO). To quantify the albedo induced radiative forcing (RFα) caused by the white-mustard, the bare soil subplot was used as a reference state (IPCC, 2007). Finally, the net radiative forcing for each subplot was calculated as the sum of biogeochemical and biogeophysical (albedo effect) radiative forcing. The white-mustard allowed a net CO2 fixation of 63 g C-eq.m-2, corresponding to 20% of the net annual CO2 flux that year (-332 g C-eq.m-2). Through the WM seeds

  2. Effect of timing of glyphosate application to a winter wheat cover crop on stunting of spring-sown onions caused by Rhizoctonia spp. in the Columbia Basin of Washington, 2012.

    USDA-ARS?s Scientific Manuscript database

    The development of patches of stunted onion plants caused by Rhizoctonia spp. is an emerging problem in onion bulb crops planted in the semi-arid Columbia Basin of Oregon and Washington following winter cereal cover crops. Cereals such as winter wheat are used as cover crops to protect onion seedlin...

  3. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management.

    PubMed

    Lawson, Andrew; Cogger, Craig; Bary, Andy; Fortuna, Ann-Marie

    2015-01-01

    Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight), two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3(-)-N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha(-1) biomass, whereas mixtures averaged 4.1 Mg ha(-1) and hairy vetch 2.3 Mg ha(-1). Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha(-1) N and had mean C:N ratio <17:1 when planted in mid-September and terminated in late April. June soil NO3(-)-N (0 to 30 cm depth) averaged 62 kg ha(-1) for rye, 97 kg ha(-1) for the mixtures, and 119 kg ha(-1) for hairy vetch. Weeds comprised less of the mixtures biomass (20% weeds by weight at termination) compared with the monocultures (29%). Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures.

  4. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management

    PubMed Central

    Lawson, Andrew; Cogger, Craig; Bary, Andy; Fortuna, Ann-Marie

    2015-01-01

    Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight), two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3--N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha-1 biomass, whereas mixtures averaged 4.1 Mg ha-1 and hairy vetch 2.3 Mg ha-1. Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha-1 N and had mean C:N ratio <17:1 when planted in mid-September and terminated in late April. June soil NO3--N (0 to 30 cm depth) averaged 62 kg ha-1 for rye, 97 kg ha-1 for the mixtures, and 119 kg ha-1 for hairy vetch. Weeds comprised less of the mixtures biomass (20% weeds by weight at termination) compared with the monocultures (29%). Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures. PMID:26080008

  5. Planting date and seeding rate effects on sunn hemp biomass and nitrogen production for a winter cover crop

    USDA-ARS?s Scientific Manuscript database

    Sunn hemp (Crotalaria juncea L.) is a tropical legume that produces plant biomass and nitrogen (N) quickly. Our objectives were to assess the growth of a new sunn hemp cultivar breed to produce seed in a temperate climate and determine the residual N effect on a subsequent rye (Secale cereale L.) wi...

  6. Preliminary evaluation of the SIR-B response to soil moisture, surface roughness, and crop canopy cover

    NASA Technical Reports Server (NTRS)

    Dobson, M. C.; Ulaby, F. T.

    1986-01-01

    Two predawn ascending data-takes by the Shuttle Imaging Radar-B (SIR-B) were used to evaluate the effects of surface roughness, crop canopy, and soil moisture on radar backscatter. The two images, separated by three days, were both obtained at 30-deg local angle of incidence, but with opposite azimuth viewing directions. The imagery was externally calibrated with respect to the radar backscattering coefficient sigma(0) via response to arrays of point and area-extended targets of known radar cross section. Three land-cover classes: (1) corn, (2) corn stubble and plowed bare soil, and (3) disked bare soil, soybeans, soybean stubble, alfalfa, and clover could be readily separated for either observation date on the basis of image tone alone. The dependence of sigma(0) on the surface roughness and canopy brightness inhibits the capability of SIR to globally estimate the near-surface soil moisture from the value of sigma(0) for single date observations, unless the surface roughness or canopy cover conditions are accounted for. However, within given ranges of these conditions, the sigma(0) was found to be highly correlated with the soil moisture.

  7. Rhizobia from wild legumes: diversity, taxonomy, ecology, nitrogen fixation and biotechnology.

    PubMed

    Zahran, H H

    2001-10-04

    Wild legumes (herb or tree) are widely distributed in arid regions and actively contribute to soil fertility in these environments. The N2-fixing activity and tolerance to drastic conditions may be higher in wild legumes than in crop legumes. The wild legumes in arid zones harbor diverse and promiscuous rhizobia in their root-nodules. Specificity existed only in few rhizobia from wild legumes, however, the majority of them are with wide host range. Based on phenotypic characteristics and molecular techniques (protein profiles, polysaccharides, plasmids, DNA-DNA hybridization, 16SrRNA, etc.), the root-nodule bacteria that was isolated from wild legumes had been classified into four genera (Rhizobium, Bradyrhizobium, Mesorhizobium and Sinorhizobium). The rhizobia of wild legumes in arid zones, exhibit higher tolerance to the prevailing adverse conditions, e.g. salt stress, elevated temperatures and desiccation. These rhizobia may be used to inoculate wild, as well as, crop legumes, cultivated in reclaimed desert lands. Recent reports indicated that the wild-legume rhizobia formed successful symbioses with some grain legumes. Moreover, intercropping of some N2-fixing tree legumes (e.g. Lablab, Leucaena, Sesbania, etc.) to pasture grasses improved biomass yield and herb quality. In recent years, the rhizobia of wild legumes turn the attention of biotechnologists. These bacteria may have specific traits that can be transferred to other rhizobia through genetic engineering tools or used to produce industrially important compounds. Therefore, these bacteria are very important from both economic and environmental points of view.

  8. Evaluating the relationship between biomass, percent groundcover and remote sensing indices across six winter cover crop fields in Maryland, United States

    NASA Astrophysics Data System (ADS)

    Prabhakara, Kusuma; Hively, W. Dean; McCarty, Gregory W.

    2015-07-01

    Winter cover crops are an essential part of managing nutrient and sediment losses from agricultural lands. Cover crops lessen sedimentation by reducing erosion, and the accumulation of nitrogen in aboveground biomass results in reduced nutrient runoff. Winter cover crops are planted in the fall and are usually terminated in early spring, making them susceptible to senescence, frost burn, and leaf yellowing due to wintertime conditions. This study sought to determine to what extent remote sensing indices are capable of accurately estimating the percent groundcover and biomass of winter cover crops, and to analyze under what critical ranges these relationships are strong and under which conditions they break down. Cover crop growth on six fields planted to barley, rye, ryegrass, triticale or wheat was measured over the 2012-2013 winter growing season. Data collection included spectral reflectance measurements, aboveground biomass, and percent groundcover. Ten vegetation indices were evaluated using surface reflectance data from a 16-band CROPSCAN sensor. Restricting analysis to sampling dates before the onset of prolonged freezing temperatures and leaf yellowing resulted in increased estimation accuracy. There was a strong relationship between the normalized difference vegetation index (NDVI) and percent groundcover (r2 = 0.93) suggesting that date restrictions effectively eliminate yellowing vegetation from analysis. The triangular vegetation index (TVI) was most accurate in estimating high ranges of biomass (r2 = 0.86), while NDVI did not experience a clustering of values in the low and medium biomass ranges but saturated in the higher range (>1500 kg/ha). The results of this study show that accounting for index saturation, senescence, and frost burn on leaves can greatly increase the accuracy of estimates of percent groundcover and biomass for winter cover crops.

  9. Evaluating the relationship between biomass, percent groundcover and remote sensing indices across six winter cover crop fields in Maryland, United States

    USGS Publications Warehouse

    Prabhakara, Kusuma; Hively, W. Dean; McCarty, Greg W.

    2015-01-01

    Winter cover crops are an essential part of managing nutrient and sediment losses from agricultural lands. Cover crops lessen sedimentation by reducing erosion, and the accumulation of nitrogen in aboveground biomass results in reduced nutrient runoff. Winter cover crops are planted in the fall and are usually terminated in early spring, making them susceptible to senescence, frost burn, and leaf yellowing due to wintertime conditions. This study sought to determine to what extent remote sensing indices are capable of accurately estimating the percent groundcover and biomass of winter cover crops, and to analyze under what critical ranges these relationships are strong and under which conditions they break down. Cover crop growth on six fields planted to barley, rye, ryegrass, triticale or wheat was measured over the 2012–2013 winter growing season. Data collection included spectral reflectance measurements, aboveground biomass, and percent groundcover. Ten vegetation indices were evaluated using surface reflectance data from a 16-band CROPSCAN sensor. Restricting analysis to sampling dates before the onset of prolonged freezing temperatures and leaf yellowing resulted in increased estimation accuracy. There was a strong relationship between the normalized difference vegetation index (NDVI) and percent groundcover (r2 = 0.93) suggesting that date restrictions effectively eliminate yellowing vegetation from analysis. The triangular vegetation index (TVI) was most accurate in estimating high ranges of biomass (r2 = 0.86), while NDVI did not experience a clustering of values in the low and medium biomass ranges but saturated in the higher range (>1500 kg/ha). The results of this study show that accounting for index saturation, senescence, and frost burn on leaves can greatly increase the accuracy of estimates of percent groundcover and biomass for winter cover crops.

  10. [Establishment of The Crop Growth and Nitrogen Nutrition State Model Using Spectral Parameters Canopy Cover].

    PubMed

    Tao, Zhi-Qiang; Bagum, Shamim Ara; Ma, Wei; Zhou, Bao-yuan; Fu, Jin-dong; Cui, Ri-xian; Sun, Xue-fang; Zhao, Ming

    2016-01-01

    In order to explore a non-destructive monitoring technique, the use of digital photo pixels canopy cover (CC) diagnosis and prediction on maize growth and its nitrogen nutrition status. This study through maize canopy digital photo images on relationship between color index in the photo and the leaf area index (LAI), shoot dry matter weight (DM), leaf nitrogen content percentage (N%). The test conducted in the Chinese Academy of Agricultural Science from 2012 to 2013, based on Maize canopy Visual Image Analysis System developed by Visual Basic Version 6.0, analyzed the correlation of CC, color indices, LAI, DM, N% on maize varieties (Zhongdan909, ZD 909) under three nitrogen levels treatments, furthermore the indicators significantly correlated were fitted with modeling, The results showed that CC had a highly significant correlation with LAI (r = 0.93, p < 0.01), DM (r = 0. 94, p < 0.01), N% (r = 0.82, p < 0.01). Estimating the model of LAI, DM and N% by CC were all power function, and the equation respectively were y = 3.281 2x(0.763 9), y = 283.658 1x(0.553 6) and y = 3.064 5x(0.932 9); using independent data from modeling for model validation indicated that R2, RMSE and RE based on 1 : 1 line relationship between measured values and simulated values in the model of CC estimating LAI were 0.996, 0.035 and 1.46%; R2, RMSE and RE in the model of CC estimating DM were 0.978, 5.408 g and 2.43%; R2, RMSE and RE in the model of CC estimating N% were 0.990, 0.054 and 2.62%. In summary, the model can comparatively accurately estimate the LAI, DM and N% by CC under different nitrogen levels at maize grain filling stage, indicating that it is feasible to apply digital camera on real-time undamaged rapid monitoring and prediction for maize growth conditions and its nitrogen nutrition status. This research finding is to be verified in the field experiment, and further analyze the applicability throughout the growing period in other maize varieties and different planting

  11. Spatial arrangement, population density and legume species effect of yield of forage sorghum-legume intercropping

    USDA-ARS?s Scientific Manuscript database

    Sorghum (Sorghum bicolor) is a stress tolerant forage crop grown extensively in the Southern High Plains. However, sorghum forage quality is lower than that of corn. Intercropping sorghum with legumes can improve quality and productivity of forage. However, tall statured sorghum limits the resources...

  12. No-till with high biomass cover crops and invasive legume mulches increased total soil carbon after three years of collard production

    USDA-ARS?s Scientific Manuscript database

    A great deal of literature has found that conversion to conservation tillage from conventional tillage does not increase total soil organic carbon (SOC) significantly in the short term (<5 yrs), particularly for limited-input producers. While no-till increases total SOC in the medium to long term, w...

  13. Forage legumes - untrapped resource

    SciTech Connect

    Barnes, R.F.

    1985-02-01

    Legumes are important in nutrition, nitrogen fixation and in reducing dependence on nitrogen fertilizers. At a meeting between scientists from Australia, New Zealand and the United States the role of legumes was assessed and coordinated research programs set up to deal with problems such as disease, soil, climate and selective breeding.

  14. A global experimental dataset for assessing grain legume production

    PubMed Central

    Cernay, Charles; Pelzer, Elise; Makowski, David

    2016-01-01

    Grain legume crops are a significant component of the human diet and animal feed and have an important role in the environment, but the global diversity of agricultural legume species is currently underexploited. Experimental assessments of grain legume performances are required, to identify potential species with high yields. Here, we introduce a dataset including results of field experiments published in 173 articles. The selected experiments were carried out over five continents on 39 grain legume species. The dataset includes measurements of grain yield, aerial biomass, crop nitrogen content, residual soil nitrogen content and water use. When available, yields for cereals and oilseeds grown after grain legumes in the crop sequence are also included. The dataset is arranged into a relational database with nine structured tables and 198 standardized attributes. Tillage, fertilization, pest and irrigation management are systematically recorded for each of the 8,581 crop*field site*growing season*treatment combinations. The dataset is freely reusable and easy to update. We anticipate that it will provide valuable information for assessing grain legume production worldwide. PMID:27676125

  15. A global experimental dataset for assessing grain legume production

    NASA Astrophysics Data System (ADS)

    Cernay, Charles; Pelzer, Elise; Makowski, David

    2016-09-01

    Grain legume crops are a significant component of the human diet and animal feed and have an important role in the environment, but the global diversity of agricultural legume species is currently underexploited. Experimental assessments of grain legume performances are required, to identify potential species with high yields. Here, we introduce a dataset including results of field experiments published in 173 articles. The selected experiments were carried out over five continents on 39 grain legume species. The dataset includes measurements of grain yield, aerial biomass, crop nitrogen content, residual soil nitrogen content and water use. When available, yields for cereals and oilseeds grown after grain legumes in the crop sequence are also included. The dataset is arranged into a relational database with nine structured tables and 198 standardized attributes. Tillage, fertilization, pest and irrigation management are systematically recorded for each of the 8,581 crop*field site*growing season*treatment combinations. The dataset is freely reusable and easy to update. We anticipate that it will provide valuable information for assessing grain legume production worldwide.

  16. A global experimental dataset for assessing grain legume production.

    PubMed

    Cernay, Charles; Pelzer, Elise; Makowski, David

    2016-09-27

    Grain legume crops are a significant component of the human diet and animal feed and have an important role in the environment, but the global diversity of agricultural legume species is currently underexploited. Experimental assessments of grain legume performances are required, to identify potential species with high yields. Here, we introduce a dataset including results of field experiments published in 173 articles. The selected experiments were carried out over five continents on 39 grain legume species. The dataset includes measurements of grain yield, aerial biomass, crop nitrogen content, residual soil nitrogen content and water use. When available, yields for cereals and oilseeds grown after grain legumes in the crop sequence are also included. The dataset is arranged into a relational database with nine structured tables and 198 standardized attributes. Tillage, fertilization, pest and irrigation management are systematically recorded for each of the 8,581 crop*field site*growing season*treatment combinations. The dataset is freely reusable and easy to update. We anticipate that it will provide valuable information for assessing grain legume production worldwide.

  17. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots

    PubMed Central

    Carval, Dominique; Resmond, Rémi; Achard, Raphaël; Tixier, Philippe

    2016-01-01

    The data presented in this article are related to the research article entitled “Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants” (Carval et al., in press) [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes. PMID:27222854

  18. Converting perennial legumes to organic cropland without tillage

    USDA-ARS?s Scientific Manuscript database

    Organic producers are interested in developing a no-till system for crop production. In this study, we examined management tactics to convert perennial legumes to annual crops without tillage. Our hypothesis was that reducing carbohydrate production in the fall by mowing would favor winterkill. M...

  19. Legumes, N2 fixation and the H2 cycle

    NASA Astrophysics Data System (ADS)

    Layzell, D. B.

    2004-12-01

    Legume plants such as soybean or pea can form symbiotic, N2 fixing associations with bacteria that exist in root nodules. For every N2 fixed, 1 to 3 H2 are produced as a by-product of the nitrogenase reaction. Therefore, a typical N2 fixing legume crop produces about 200,000 L H2 gas (at STP) per hectare per crop season. This paper will summarize our current understanding of the processes leading to H2 production in legumes, the magnitude of H2 production associated with global cropping systems, and the implications for its production and oxidation on both the legumes and the soils in which they grow. Specific points may include: ˜ In symbioses lacking uptake hydrogenase (HUP) activity (thought to be the majority of crop legumes), the H2 diffuses into the soil where it is oxidized by soil microbes that grow up around the legume nodules. The kinetic properties of these microbes are very different (higher Km and Vmax) from that of microbes in soils exposed to normal air (ca. 0.5 ppm H2); ˜ Laboratory studies indicate that 60% of the reducing power from H2 is coupled to O2 uptake, whereas 40% is coupled to autotrophic CO2 fixation. The latter process should increase soil carbon stocks by about 25 kg C/ha/yr; ˜ At the site of the nitrogenase enzyme, H2 production is autocatalytic such that the higher the H2 concentration, the more H2 is produced and the less N2 fixed. The variable O2 diffusion barrier in legumes can act to restrict H2 diffusion from the nodule, thereby increasing the relative magnitude of H2 production versus N2 fixation; ˜ Studies to understand why legume symbioses make such an energy investment in H2 production have led to the discovery that H2 treated soils have improved fertility, supporting the growth and yield of legume and non-legume crops. This observation may account for the benefits of legumes when used in rotation with cereal crops, a phenomenon that has been used by farmers for over 2000 years, but which has remained unexplained. An

  20. Global Synthesis of Drought Effects on Food Legume Production

    PubMed Central

    Daryanto, Stefani; Wang, Lixin; Jacinthe, Pierre-André

    2015-01-01

    Food legume crops play important roles in conservation farming systems and contribute to food security in the developing world. However, in many regions of the world, their production has been adversely affected by drought. Although water scarcity is a severe abiotic constraint of legume crops productivity, it remains unclear how the effects of drought co-vary with legume species, soil texture, agroclimatic region, and drought timing. To address these uncertainties, we collected literature data between 1980 and 2014 that reported monoculture legume yield responses to drought under field conditions, and analyzed this data set using meta-analysis techniques. Our results showed that the amount of water reduction was positively related with yield reduction, but the extent of the impact varied with legume species and the phenological state during which drought occurred. Overall, lentil (Lens culinaris), groundnut (Arachis hypogaea), and pigeon pea (Cajanus cajan) were found to experience lower drought-induced yield reduction compared to legumes such as cowpea (Vigna unguiculata) and green gram (Vigna radiate). Yield reduction was generally greater when legumes experienced drought during their reproductive stage compared to during their vegetative stage. Legumes grown in soil with medium texture also exhibited greater yield reduction compared to those planted on soil of either coarse or fine texture. In contrast, regions and their associated climatic factors did not significantly affect legume yield reduction. In the face of changing climate, our study provides useful information for agricultural planning and research directions for development of drought-resistant legume species to improve adaptation and resilience of agricultural systems in the drought-prone regions of the world. PMID:26061704

  1. Global Synthesis of Drought Effects on Food Legume Production.

    PubMed

    Daryanto, Stefani; Wang, Lixin; Jacinthe, Pierre-André

    2015-01-01

    Food legume crops play important roles in conservation farming systems and contribute to food security in the developing world. However, in many regions of the world, their production has been adversely affected by drought. Although water scarcity is a severe abiotic constraint of legume crops productivity, it remains unclear how the effects of drought co-vary with legume species, soil texture, agroclimatic region, and drought timing. To address these uncertainties, we collected literature data between 1980 and 2014 that reported monoculture legume yield responses to drought under field conditions, and analyzed this data set using meta-analysis techniques. Our results showed that the amount of water reduction was positively related with yield reduction, but the extent of the impact varied with legume species and the phenological state during which drought occurred. Overall, lentil (Lens culinaris), groundnut (Arachis hypogaea), and pigeon pea (Cajanus cajan) were found to experience lower drought-induced yield reduction compared to legumes such as cowpea (Vigna unguiculata) and green gram (Vigna radiate). Yield reduction was generally greater when legumes experienced drought during their reproductive stage compared to during their vegetative stage. Legumes grown in soil with medium texture also exhibited greater yield reduction compared to those planted on soil of either coarse or fine texture. In contrast, regions and their associated climatic factors did not significantly affect legume yield reduction. In the face of changing climate, our study provides useful information for agricultural planning and research directions for development of drought-resistant legume species to improve adaptation and resilience of agricultural systems in the drought-prone regions of the world.

  2. Priority regions for research on dryland cereals and legumes

    PubMed Central

    Hyman, Glenn; Barona, Elizabeth; Biradar, Chandrashekhar; Guevara, Edward; Dixon, John; Beebe, Steve; Castano, Silvia Elena; Alabi, Tunrayo; Gumma, Murali Krishna; Sivasankar, Shoba; Rivera, Ovidio; Espinosa, Herlin; Cardona, Jorge

    2016-01-01

    Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes. PMID:27303632

  3. Priority regions for research on dryland cereals and legumes.

    PubMed

    Hyman, Glenn; Barona, Elizabeth; Biradar, Chandrashekhar; Guevara, Edward; Dixon, John; Beebe, Steve; Castano, Silvia Elena; Alabi, Tunrayo; Gumma, Murali Krishna; Sivasankar, Shoba; Rivera, Ovidio; Espinosa, Herlin; Cardona, Jorge

    2016-01-01

    Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes.

  4. Effects of break crops, and of wheat volunteers growing in break crops or in set-aside or conservation covers, all following crops of winter wheat, on the development of take-all (Gaeumannomyces graminis var. tritici) in succeeding crops of winter wheat.

    PubMed

    Jenkyn, Jf; Gutteridge, Rj; White, Rp

    2014-11-01

    Experiments on the Rothamsted and Woburn Experimental Farms studied the effects on take-all of different break crops and of set-aside/conservation covers that interrupted sequences of winter wheat. There was no evidence for different effects on take-all of the break crops per se but the presence of volunteers, in crops of oilseed rape, increased the amounts of take-all in the following wheat. Severity of take-all was closely related to the numbers of volunteers in the preceding break crops and covers, and was affected by the date of their destruction. Early destruction of set-aside/conservation covers was usually effective in preventing damaging take-all in the following wheat except, sometimes, when populations of volunteers were very large. The experiments were not designed to test the effects of sowing dates but different amounts of take-all in the first wheats after breaks or covers apparently affected the severity of take-all in the following (second) wheats only where the latter were relatively late sown. In earlier-sown second wheats, take-all was consistently severe and unrelated to the severity of the disease in the preceding (first) wheats. Results from two very simple experiments suggested that substituting set-aside/conservation covers for winter wheat, for 1 year only, did not seriously interfere with the development of take-all disease or with the development or maintenance of take-all decline (TAD). With further research, it might be possible for growers wishing to exploit TAD to incorporate set-aside/conservation covers into their cropping strategies, and especially to avoid the worst effects of the disease on grain yield during the early stages of epidemics.

  5. Effects of break crops, and of wheat volunteers growing in break crops or in set-aside or conservation covers, all following crops of winter wheat, on the development of take-all (Gaeumannomyces graminis var. tritici) in succeeding crops of winter wheat

    PubMed Central

    Jenkyn, JF; Gutteridge, RJ; White, RP

    2014-01-01

    Experiments on the Rothamsted and Woburn Experimental Farms studied the effects on take-all of different break crops and of set-aside/conservation covers that interrupted sequences of winter wheat. There was no evidence for different effects on take-all of the break crops per se but the presence of volunteers, in crops of oilseed rape, increased the amounts of take-all in the following wheat. Severity of take-all was closely related to the numbers of volunteers in the preceding break crops and covers, and was affected by the date of their destruction. Early destruction of set-aside/conservation covers was usually effective in preventing damaging take-all in the following wheat except, sometimes, when populations of volunteers were very large. The experiments were not designed to test the effects of sowing dates but different amounts of take-all in the first wheats after breaks or covers apparently affected the severity of take-all in the following (second) wheats only where the latter were relatively late sown. In earlier-sown second wheats, take-all was consistently severe and unrelated to the severity of the disease in the preceding (first) wheats. Results from two very simple experiments suggested that substituting set-aside/conservation covers for winter wheat, for 1 year only, did not seriously interfere with the development of take-all disease or with the development or maintenance of take-all decline (TAD). With further research, it might be possible for growers wishing to exploit TAD to incorporate set-aside/conservation covers into their cropping strategies, and especially to avoid the worst effects of the disease on grain yield during the early stages of epidemics. PMID:25653455

  6. Rhizoctonia spp. dynamics and optimal timing of glyphosate application to cereal cover crops to manage onion stunting in Washington and Oregon

    USDA-ARS?s Scientific Manuscript database

    Onion stunting or bare patch caused by Rhizoctonia spp. is an economically important disease in sandy soils of the Columbia Basin of Oregon and Washington. Patches of stunted onions develop where cover crops of wheat or barley are killed with a herbicide spray prior to spring planting of onion seed....

  7. Effects of different roller/crimper designs and rolling speed on rye cover crop termination and seedcotton yield in A no-till system

    USDA-ARS?s Scientific Manuscript database

    Rollers/crimpers have been utilized in no-till systems to mechanically terminate cover crops as a substitute for chemical termination; however, excessive vibration generated by the original straight bar roller adopted from Brazil has delayed its adoption in the U.S. To reduce excessive vibration, pr...

  8. Effect of length of interval between cereal rye cover crop termination and corn planting on seedling root disease and corn growth

    USDA-ARS?s Scientific Manuscript database

    Cereal rye cover crops terminated immediately before corn planting can sometimes reduce corn population, early growth, and yield. We hypothesized that cereal rye may act as a green bridge for corn pathogens and may increase corn seedling root disease. A field experiment was conducted over two years ...

  9. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    USDA-ARS?s Scientific Manuscript database

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  10. Assessing climate change impacts on winter cover crop nitrate uptake efficiency on the coastal plain of the Chesapeake Bay watershed using the SWAT model

    USDA-ARS?s Scientific Manuscript database

    Climate change is expected to exacerbate water quality degradation in the Chesapeake Bay watershed (CBW). Winter cover crops (WCCs) have been widely implemented in this region owing to their high effectiveness at reducing nitrate loads. However, little is known about climate change impacts on the ef...

  11. Effects of high biomass cover crops and organic mulches on soil properties and collard yield three years after conversion to no-till

    USDA-ARS?s Scientific Manuscript database

    Organic producers interested in the adoption of conservation tillage continue to face considerable challenges, particularly with regard to weed control. Previous work demonstrated that high biomass cover crops in conjunction with organic mulches can provide adequate weed control in a no-till system...

  12. Annual cover crops do not inhibit early growth of perennial grasses on a disturbed restoration soil in the Northern Great Plains, USA

    USDA-ARS?s Scientific Manuscript database

    In agricultural, rangeland, and forest system revegetation projects, cover crops are used for competitive exclusion of weeds and to stabilize soil. Within revegetation projects, annual or short-lived perennial grasses are often sown at the same time as the perennial grasses that are the desired spec...

  13. Lentils: the Forgotten Legumes

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_166192.html Lentils: The Forgotten Legumes Beans' little cousins pack in ... 2, 2017 FRIDAY, June 2, 2017 (HealthDay News) -- Lentils may be the least well known members of ...

  14. Changes in Soil Moisture, Microbial Biomass, Mineralization and Nitrification Explain Increases in N2O Emissions from a Spring Barley Crop Under Combined Reduced Tillage and Cover Crop Management

    NASA Astrophysics Data System (ADS)

    Rueangritsarakul, K.; Jones, M.; Roth, B.; Abdalla, M.; Williams, M.

    2012-04-01

    This study investigated the effect of conventional tillage (CT), combined reduced tillage-cover crop (RT-CC), and reduced N application on crop yield and N2O emissions from spring barley. Reduced tillage plots were established for seven years, the final four incorporating a mustard cover crop. Higher N2O fluxes were from fertilized, RT-CC plots due to higher WFPS, soil nitrate, and soil carbon. Fluxes during the non-growing season were variable and the main source of cumulative emissions. Emission factors were in the range of IPCC default values. Low N fertilization reduced cumulative emissions, however during the wetter growing season this reduction was smaller than the reduction in barley production particular in the conventional tillage plots. Adopting RT-CC management for cereal crops may be problematic in reducing GHG emissions due to high N2O fluxes. Reducing N fertilizer in order to reduce N2O emissions is not feasible due to high inter-annual variation in crop yield. N2O flux in all plots was positively correlated with microbial biomass carbon, net nitrification and mineralization determined in the field. Increased emissions of N2O in the RT-CC plots are accounted for by increases in organic carbon in the soil and increases in mineralization.

  15. Linking Biomarker and Comparative Omics to Pathogens in Legumes.

    PubMed

    Diapari, Marwan

    2016-01-01

    It is envisioned that a more precise study of the association between the traits and biomarkers will dramatically decrease the time and costs required to bring new improved disease resistance lines to market. The field of omics has an enormous potential to assess diseases more precise, including the identification and understanding of pathogenic mechanisms in legume crops, and have been exemplified by a relatively large number of studies. Recently, molecular genetic studies have accumulated a huge amount of genotypic data, through a more affordable next generation sequencing (NGS) technology, causing the omics approaches to fall behind. In this paper I provide an overview of genomics and proteomics and their use in legume crops, including the use of comparative genomics to identify homologous markers within legume crops.

  16. Transcriptome sequencing and marker development for four underutilized legumes.

    PubMed

    Chapman, Mark A

    2015-02-01

    • Combating threats to food and nutrition security in the context of climate change and global population increase is one of the highest priorities of major international organizations. Hundreds of species are grown on a small scale in some of the most drought/flood-prone regions of the world and as such may harbor some of the most environmentally tolerant crops (and alleles). • In this study, transcriptomes were sequenced, assembled, and annotated for four underutilized legume crops. Microsatellite markers were identified in each species, as well as a conserved orthologous set of markers for cross-family phylogenetics and comparative mapping, which were ground-truthed on a panel of diverse legume germplasm. • An understanding of these underutilized legumes will inform crop selection and breeding by allowing the investigation of genetic variation and the genetic basis of adaptive traits to be established.

  17. Transcriptome sequencing and marker development for four underutilized legumes1

    PubMed Central

    Chapman, Mark A.

    2015-01-01

    • Premise of the study: Combating threats to food and nutrition security in the context of climate change and global population increase is one of the highest priorities of major international organizations. Hundreds of species are grown on a small scale in some of the most drought/flood-prone regions of the world and as such may harbor some of the most environmentally tolerant crops (and alleles). • Methods and Results: In this study, transcriptomes were sequenced, assembled, and annotated for four underutilized legume crops. Microsatellite markers were identified in each species, as well as a conserved orthologous set of markers for cross-family phylogenetics and comparative mapping, which were ground-truthed on a panel of diverse legume germplasm. • Conclusions: An understanding of these underutilized legumes will inform crop selection and breeding by allowing the investigation of genetic variation and the genetic basis of adaptive traits to be established. PMID:25699221

  18. Modelling the impact of climatic conditions and plant species on the nitrogen release from mulch of legumes at the soil surface

    NASA Astrophysics Data System (ADS)

    Gaudinat, Germain; Lorin, Mathieu; Valantin-morison, Muriel; Garnier, Patricia

    2015-04-01

    Cover crops provide multiple services to the agro ecosystem. Among them, the use of legumes as cover crop is one of the solutions for limiting the use of herbicides, mineral fertilizers, and insecticides. However, the dynamic of mineralization is difficult to understand because of the difficulty of measuring nitrogen release from mulch in field. Indeed, residues are degraded at the soil surface as mulch, while the nitrogen uptake by the main crop occurred simultaneously in the soil. This work aims to study the dynamics of nitrogen mineralization from legume residues through i) the use of a model able to describe the physical and biological dynamic of mulch and ii) a data set from a field experiment of intercropping systems "oilseed rape-legumes" from different species (grass pea, lentil, Berseem clover, field pea, vetch). The objective of the simulations is to identify the variations of expected quantities of nitrogen from different legumes. The soil-plant model of mulch decomposition PASTIS-Mulch was used to determine the nitrogen supply from mulch available for rapeseed. These simulation results were compared to the data collected in the experimental field of Grignon (France). We performed analyzes of biochemical and physical characteristics of legume residues and monitored the evolution of mulches (moisture, density, cover surface, biomass) in fields. PASTIS simulations of soil temperature, soil moisture, mulch humidity and mulch decomposition were close to the experimental results. The PASTIS model was suitable to simulate the dynamic of legume mulches in the case of "rape - legume" associations. The model simulated nitrogen restitution of aerial and root parts. We found a more rapid nitrogen release by grass pea than other species. Vetch released less nitrogen than the other species. The scenarios for climate conditions were : i) a freezing in December that causes the destruction of plants, or a destruction by herbicide in March, ii) a strong or a weak rainy

  19. Migration and enrichment of arsenic in the rock-soil-crop plant system in areas covered with black shale, Korea.

    PubMed

    Yi, Ji-Min; Chon, Hyo-Taek; Park, Min

    2003-04-07

    The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4) were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg(-1) is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg(-1)) and the Chubu areas (32.6 mg kg(-1)). As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg(-1)) and the Chubu areas (1.35 mg kg(-1)). The biological absorption coefficient (BAC) of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.

  20. Integrating high residue cover crops and weed control options for resistant weeds threatening conservation agriculture and water resources

    USDA-ARS?s Scientific Manuscript database

    Conservation tillage reduces the physical movement of soil to the minimum required for crop establishment and production. When consistently practiced as a soil and crop management system, it greatly reduces soil erosion and is recognized for the potential to improve soil quality and plant water avai...