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Sample records for legume cover crops

  1. Differential Soil Acidity Tolerance of Tropical Legume Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Symbiotic performance of herbaceous legumes in tropical cover cropping systems.

    PubMed

    Ibewiro, B; Onuh, M; Sanginga, N; Bernard, V; Merckx, R

    2001-11-10

    Increasing use of herbaceous legumes such as mucuna ( Mucuna pruriens var. utilis [Wright] Bruck) and lablab ( Lablab purpureus [L.] Sweet) in the derived savannas of West Africa can be attributed to their potential to fix atmospheric nitrogen (N2). The effects of management practices on N2 fixation in mucuna and lablab were examined using 15N isotope dilution technique. Dry matter yield of both legumes at 12 weeks was two to five times more in in situ mulch (IM) than live mulch (LM) systems. Land Equivalent Ratios, however, showed 8 to 30% more efficient utilization of resources required for biomass production under LM than IM systems. Live mulching reduced nodule numbers in the legumes by one third compared to values in the IM systems. Similarly, nodule mass was reduced by 34 to 58% under LM compared to the IM systems. The proportion of fixed N2 in the legumes was 18% higher in LM than IM systems. Except for inoculated mucuna, the amounts of N fixed by both legumes were greater in IM than LM systems. Rhizobia inoculation of the legumes did not significantly increase N2 fixation compared to uninoculated plots. Application of N fertilizer reduced N2 fixed in the legumes by 36 to 51% compared to inoculated or uninoculated systems. The implications of cover cropping, N fertilization, and rhizobia inoculation on N contributions of legumes into tropical low-input systems were discussed. PMID:12805778

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  4. Legume Cover Crops are More Beneficial than Natual Fallows in MInimally Tilled Ugandan Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is important to establish the various eff ects of legume cover crops on soil physicochemical properties because they have been considered for use as improved fallows (with shorter rest periods) to enhance development and maintenance of soil productivity. Our objectives were to assess: (i) abovegr...

  5. Nutrient Uptake and Use Efficiency by Tropical Legume Cover Crops at varying pH of an Oxisol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxisols comprise large soil group in tropical America. These soils are acidic and having low fertility. Use of tropical legume cover crops in cropping systems is an important strategy to improve fertility of these soils for sustainable crop production. Data are limited on nutrient uptake and use ef...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Soil phosphorous influence on growth and nutrition of tropical legume cover crops in acidic soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In tropical regions, the use of cover crops in crop production is an important strategy in maintaining sustainability of cropping systems. Phosphorus deficiency in tropical soils is one of the most yield limiting factors for successful production of cover crops. A greenhouse experiment was conduct...

  8. Cover crops and N credits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, ...

  13. Winter cover crops influence Amaranthus palmeri establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Tomato response to legume cover crop and nitrogen: differing enhancement patterns of fruit yield, photosynthesis and gene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Cover crops for Alabama

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  17. Legumes Can Increase Cadmium Contamination in Neighboring Crops

    PubMed Central

    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. PMID:22905189

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. 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.

  20. Midwest Cover Crops Field Guide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, ...

  1. Cover crops for erosion control in bioenergy hardwood plantations

    SciTech Connect

    Malik, R.K.; Green, T.H.; Mays, D.

    1996-12-31

    The use of cover crops between tree rows has been suggested as a means of reducing soil erosion in short-rotation woody crops (SRWC) plantations for bioenergy production. This study is designed to test whether cover crops could reduce erosion without significantly reducing the growth and biomass yield of sweetgum (Liquidambar styraciflua L.) planted as the SRWC at a 1.5 X 3 in spacing. Four cover crops, winter rye grass (Lolium multigeonum L., a winter annual grass); tall fescue (Fescuta eliator L., a winter perennial grass); crimson clover (Trifolium incarnatum L., a winter annual legume); and interstate sericea (Lespedeza ameata L., a growing season perennial legume), are tested at two different strip widths (1.22 and 2.44 m) as well as a control with complete competition control. Small berms were built to direct runoff to a sediment fence installed at the down slope ends of each plot. Soil erosion is measured by sediment accumulation near the fence. Height, ground-line diameter and crown width of trees were measured on a monthly basis. During the first growing season all cover crops reduced growth of trees. There were some significant differences among cover crop regimes. Slight differences in soil erosion were detected during the first growing season. The control plots lost more soil per hectare than cover crops, however, strip widths and cover crops did not show any significant difference.

  2. 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.

  3. High retention of N P nutrients, soil organic carbon, and fine particles by cover crops under tropical climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover cropping system has shown a potential to improve soil quality and carbon sequestration but the residue decomposition rates determined by biotic and abiotic factors play a crucial role to reach such objectives. Legume and non-legume cover crop residues were applied to the surface of two soils i...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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)...

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

    PubMed

    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

  7. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  9. 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.

  10. Managing cover crops: an economic perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Selection of fungi by candidate cover crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  12. Roadmap to increased cover crop adoption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Timely precipitation drives cover crop outcomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Winter cover crop seeding rate and variety effects during eight years of organic vegetables: III. Cover crop residue quality and nitrogen mineralization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops (CC) can improve nutrient-use efficiency in tillage-intensive systems. Shoot residue quality and soil mineral N following incorporation of rye (Secale cereale L.), legume-rye, and mustard CC was determined in December to February or March during the first 8 yr of the Salinas Orga...

  15. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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,...

  19. Responses of legume and non-legume crop species to heavy metals in soils with multiple metal contamination.

    PubMed

    Wang, Qing-Ren; Liu, Xiu-Mei; Cui, Yan-Shan; Dong, Yi-Ting; Christie, Peter

    2002-01-01

    Field and glasshouse investigations were conducted on the responses of two legumes (field pea and fodder vetch) and three non-leguminous crops (maize, wheat and rapeseed) to the heavy metals Cd, Cr, Zn, Pb, Cu and Mn in soil with multiple metal contamination. In general, the results indicate that the two legumes and wheat were more susceptible to soil metals than were rapeseed and maize. The dry matter yields of field pea, wheat, fodder vetch, rapeseed and maize decreased by up to 169, 123, 113, 93 and 68%, respectively, in metal-contaminated soil. Among the crops, maize had the highest concentrations of Mn, Zn and Cd, rapeseed had the highest concentrations of Cr, the concentration of Cu was highest in fodder vetch, and wheat was the highest accumulator of Pb. The bioconcentration factors (BCF) of the metals decreased as the soil metal loading rates increased except for Cr in fodder vetch and Cd in wheat, whose BCF increased as the metal loading rate increased. Significant linear correlations were found between plant and soil metal concentrations. Patterns of metal distribution in plant parts varied with different crops and metals, with more Cd and Cu accumulating in the grain of wheat than of maize, suggesting that growing wheat would represent a higher risk of food contamination than growing maize in Cd- or Cu-contaminated soil. The results suggest that on sites with multiple metal contamination, growing maize and rapeseed would be safer than growing wheat or legumes. However, maize could perhaps be used for phytoremediation of lightly contaminated soils, providing that the crop residues were safely disposed of.

  20. Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.

    PubMed

    Timper, Patricia; Davis, Richard F; Tillman, P Glynn

    2006-03-01

    Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations

  1. 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

  2. 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.

  3. Managing cover crops on strawberry furrow bottoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. 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

  5. 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.

  6. 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).

  7. Using cash cover crops to provide pollinator provisions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. 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. PMID:25410103

  9. Unique cover crops for Louisiana sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Hypoallergenic legume crops and food allergy: factors affecting feasibility and risk.

    PubMed

    Riascos, John J; Weissinger, Arthur K; Weissinger, Sandra M; Burks, A Wesley

    2010-01-13

    Currently, the sole strategy for managing food hypersensitivity involves strict avoidance of the trigger. Several alternate strategies for the treatment of food allergies are currently under study. Also being explored is the process of eliminating allergenic proteins from crop plants. Legumes are a rich source of protein and are an essential component of the human diet. Unfortunately, legumes, including soybean and peanut, are also common sources of food allergens. Four protein families and superfamilies account for the majority of legume allergens, which include storage proteins of seeds (cupins and prolamins), profilins, and the larger group of pathogenesis-related proteins. Two strategies have been used to produce hypoallergenic legume crops: (1) germplasm lines are screened for the absence or reduced content of specific allergenic proteins and (2) genetic transformation is used to silence native genes encoding allergenic proteins. Both approaches have been successful in producing cultivars of soybeans and peanuts with reduced allergenic proteins. However, it is unknown whether the cultivars are actually hypoallergenic to those with sensitivity. This review describes efforts to produce hypoallergenic cultivars of soybean and peanut and discusses the challenges that need to be overcome before such products could be available in the marketplace.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. 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.

  13. 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. PMID:25592547

  14. Are Cover Crops Being Used in the Corn Belt?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A wealth of scientific information exists quantifying the benefits of cover crops, yet adoption of cover crops in agronomic farming systems is low. Research has documented the effectiveness of using cover crops to decrease soil erosion and decrease nitrogen losses to sub-surface drainage water. Othe...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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

  17. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. 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

  20. 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…

  1. Cover crops can improve potato tuber yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is the need to develop sustainable systems with higher yields and crop quality. We conducted studies with cover crops grown under limited irrigation (< 200 mm) to assess the effects of certain types of cover crops on tuber yield and quality. On a commercial farm operation prior to the 2006 and...

  2. Summary of cover crop effects on cotton production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Cover cropping and no-tillage improve soil health in arid irrigated cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact on soil health of long-term no-tillage (NT) and cover cropping (CC) practices, alone and in combination, was measured and compared with standard tillage (ST) with and without cover crops (NO) in irrigated row crops after 15 years of management in the San Joaquin Valley, CA. Soil aggregat...

  8. Termination of cover crops using rollers/crimpers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Black oat cover crop management in watermelon production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. 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

  12. 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. PMID:25944929

  13. Cover Crop Biomass and Corn Yield Following 13 Rye, Wheat, and Triticale Cultivars Used as Winter Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops have the potential to reduce nitrate leaching and erosion in corn-soybean rotations in the upper Midwest. The cover crop growing season between harvest and planting of corn and soybean, however, is short and cold. Additionally, previous studies in Iowa have indicated that winter r...

  14. Landmark Research in Legumes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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. PMID:23313999

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  1. 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

    2012-01-01

    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. PMID:22057054

  2. 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

  3. 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

  4. 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

  5. Effect of winter cover crops on soil nitrogen availability, corn yield, and nitrate leaching.

    PubMed

    Kuo, S; Huang, B; Bembenek, R

    2001-10-25

    Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3 leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha(-1), referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N 0, N 2, and N 3 treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency's drinking water standard of 10 mg N l(-1) even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during

  6. Effect of different cover crops on C and N cycling in sorghum NT systems.

    PubMed

    Frasier, Ileana; Quiroga, Alberto; Noellemeyer, Elke

    2016-08-15

    In many no-till (NT) systems, residue input is low and fallow periods excessive, for which reasons soil degradation occurs. Cover crops could improve organic matter, biological activity, and soil structure. In order to study changes in soil carbon, nitrogen and microbial biomass a field experiment (2010-2012) was set up with sorghum (Sorghum bicolor Moench.) monoculture and with cover crops. Treatments were control (NT with bare fallow), rye (Secale cereale L.) (R), rye with nitrogen fertilization (R+N), vetch (Vicia villosa Roth.) (V), and rye-vetch mixture (VR) cover crops. A completely randomized block design with 4 replicates was used. Soil was sampled once a year at 0.06 and 0.12m depth for total C, microbial biomass carbon (MBC) and-nitrogen (MBN) determinations. Shoot and root biomass of sorghum and cover crops, litter biomass, and their respective carbon and nitrogen contents were determined. Soil temperatures at 0.06 and 0.12m depth, volumetric water contents and nitrate concentrations were determined at sowing, and harvest of each crop, and during sorghum's vegetative phase. NT led to a small increase in MBC and MBN, despite low litter and root biomass residue. Cover crops increased litter, root biomass, total C, MBC, and MBN. Relationships between MBC, MBN, and root-C and -N adjusted to logistic models (R(2)=0.61 and 0.43 for C and N respectively). Litter cover improved soil moisture to 45-50% water filled pore space and soil temperatures not exceeding 25°C during the warmest month. Microbial biomass stabilized at 20.1gCm(-2) and 1.9gNm(-2) in the upper 0.06m. Soil litter disappearance was a good indicator of mineral N availability. These findings support the view that cover crops, specifically legumes in NT systems can increase soil ecosystem services related to water and carbon storage, habitat for biodiversity, and nutrient availability. PMID:27107651

  7. Carbon supply and storage in tilled and nontilled soils as influenced by cover crops and nitrogen fertilization.

    PubMed

    Sainju, Upendra M; Singh, Bharat P; Whitehead, Wayne F; Wang, Shirley

    2006-01-01

    Soil carbon (C) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant C inputs and their rate of mineralization. We examined the influence of four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)} and three nitrogen (N) fertilization rates (0, 60 to 65, and 120 to 130 kg N ha(-1)) on C inputs from cover crops, cotton (Gossypium hirsutum L.), and sorghum [Sorghum bicolor (L.) Moench)], and soil organic carbon (SOC) at the 0- to 120-cm depth in tilled and nontilled areas. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic Plinthic Paleudults) from 1999 to 2002 in central Georgia. Total C inputs to the soil from cover crops, cotton, and sorghum from 2000 to 2002 ranged from 6.8 to 22.8 Mg ha(-1). The SOC at 0 to 10 cm fluctuated with C input from October 1999 to November 2002 and was greater from cover crops than from weeds in no-tilled plots. In contrast, SOC values at 10 to 30 cm in no-tilled and at 0 to 60 cm in chisel-tilled plots were greater for biculture than for weeds. As a result, C at 0 to 30 cm was sequestered at rates of 267, 33, -133, and -967 kg C ha(-1) yr(-1) for biculture, rye, vetch, and weeds, respectively, in the no-tilled plot. In strip-tilled and chisel-tilled plots, SOC at 0 to 30 cm decreased at rates of 233 to 1233 kg C ha(-1) yr(-1). The SOC at 0 to 30 cm increased more in cover crops with 120 to 130 kg N ha(-1) yr(-1) than in weeds with 0 kg N ha(-1) yr(-1), regardless of tillage. In the subtropical humid region of the southeastern United States, cover crops and N fertilization can increase the amount of C input and storage in tilled and nontilled soils, and hairy vetch and rye biculture was more effective in sequestering C than monocultures or no cover crop.

  8. 7 CFR 1437.503 - Covered losses and recordkeeping requirements for covered tropical crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Covered losses and recordkeeping requirements for covered tropical crops. 1437.503 Section 1437.503 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER...

  9. 7 CFR 1437.503 - Covered losses and recordkeeping requirements for covered tropical crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Covered losses and recordkeeping requirements for covered tropical crops. 1437.503 Section 1437.503 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Minimizing interspecific competition in soybean by optimizing cover crop self-seeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Developing self-seeding cover crop systems that minimize interspecific competition with soybean [Glycine max (L.) Merr.] are possible if cover crop growth is restricted to optimize cover crop seed production and dispersal. The objectives of this research were to quantify cover crop seed production, ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Using Mustard Seed Meal and Cover Crops for Weed Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There continues to be a steady growth in the use of fall planted brassica cover crops in the Columbia Basin especially prior to potatoes. Several benefits include better water infiltration, reclaiming nitrogen, reduced erosion, and suppression of nematodes, diseases, and weeds. Weed suppression is...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Corn Belt Assessment of Cover Crop Management and Preferences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. 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

  1. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Decomposition, nitrogen and carbon mineralization from food and cover crop residues in the central plateau of Haiti.

    PubMed

    Lynch, M J; Mulvaney, M J; Hodges, S C; Thompson, T L; Thomason, W E

    2016-01-01

    Cover crops are a major focus of conservation agriculture efforts because they can provide soil cover and increase nutrient availability after their mineralization in cropping systems. To evaluate the effect of residue type and placement on rate of decomposition and carbon (C) and nitrogen (N) mineralization, residues from two food crops, maize (Zea mays L.) and common bean (Phaseolus vulgaris L.), and two promising cover crops, sunn hemp (Crotalaria juncea L.) and sorghum sudangrass (Sorghum bicolor [L.] Moench x S. bicolor var. Sudanese [Piper] Stapf) were used in a litterbag study in the Central Plateau region of Haiti from May to September, 2013. Residues were placed in litterbags at a rate equivalent to 3.25 Mg residue ha(-1) either on the soil surface or buried at 15 cm to represent a tilled and no-tillage system, respectively. Initial C:N ratios were: maize > common bean > sorghum sudangrass > sunn hemp. Highest residue mass loss rates and C and N mineralization generally occurred in the reverse order. Overall, surface-placed residues decomposed more slowly with 40 and 17 % of initial residue mass of surface and buried residues, respectively, remaining at 112 days. Carbon and N mineralization was higher when residues were buried. Net N mineralization of buried residues was 0.12, 0.07, 0.06, and 0.03 g N g residue(-1) for sunn hemp, sorghum sudangrass, maize, and common bean, respectively over 112 days. To achieve the goal of increasing nutrient supply while maintaining year-round cover, a combination of grass and legume cover crops may be required with benefits increasing over multiple seasons. PMID:27429883

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Effect of nitrogen fertilization and cover cropping systems on sorghum grain characteristics.

    PubMed

    Kaufman, R C; Wilson, J D; Bean, S R; Presley, D R; Blanco-Canqui, H; Mikha, M

    2013-06-19

    Cover crop treatments and nitrogen (N) fertilization rates were investigated for their impact on sorghum grain quality attributes. Sorghum was planted in field plots treated with differing cover cropping systems and fertilization rates. The size (weight and diameter) and hardness of the kernels were influenced by both the cover crop and N rates. The protein content increased as the N rate increased and also with the addition of cover crops to the system. The protein digestibility values and starch granule size distributions were not affected by N rate or the cover cropping treatments. Soil properties were tested to determine relationships with grain quality attributes. The utilization of cover crops appears to increase the protein content without causing a deleterious effect on protein digestibility. The end-product quality is not hampered by the use of beneficial cropping systems necessary for sustainable agriculture.

  16. 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.

  17. 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. PMID:26314045

  18. 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.

  19. 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. PMID:26882164

  20. Assessing crop residue cover as scene moisture conditions change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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. PMID:27446635

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Edible grain legumes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Impact of Winter Cover Crop Biomass Removal on Soil Properties and Cotton Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, there has been a renewed interest on alternatives sources of energy, especially renewable sources. Numerous materials can be used for this purpose, including crop residues. The use of crop residues would give farmers a new source of income. The use of winter cover crops (WCC) is recommende...

  13. 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…

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. Winter Cover Crop Effects on Nitrate Leaching in Subsurface Drainage as Simulated by RZWQM-DSSAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting winter cover crops such as winter rye after corn and soybean harvest is one of the more promising practices to reduce nitrate loss to streams from tile drainage systems. Because use of cover crops to reduce nitrate loss has only been tested over a few years with limited environmental and ma...

  20. Effect of winter cover crops on nematode population levels in north Florida.

    PubMed

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

    2004-12-01

    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 cover crops: soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sorghum bicolor x S. sudanense), sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  2. 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.

  3. 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. PMID:21539250

  4. 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

  5. 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. PMID:27060167

  6. 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.

  7. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    PubMed

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

  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. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    PubMed

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping. PMID:26926485

  10. Advances in genetics and molecular breeding of three legume crops of semi-arid tropics using next-generation sequencing and high-throughput genotyping technologies.

    PubMed

    Varshney, Rajeev K; Kudapa, Himabindu; Roorkiwal, Manish; Thudi, Mahendar; Pandey, Manish K; Saxena, Rachit K; Chamarthi, Siva K; Mohan, S Murali; Mallikarjuna, Nalini; Upadhyaya, Hari; Gaur, Pooran M; Krishnamurthy, L; Saxena, K B; Nigam, Shyam N; Pande, Suresh

    2012-11-01

    Molecular markers are the most powerful genomic tools to increase the efficiency and precision of breeding practices for crop improvement. Progress in the development of genomic resources in the leading legume crops of the semi-arid tropics (SAT), namely, chickpea (Cicer arietinum), pigeonpea (Cajanus cajan) and groundnut (Arachis hypogaea), as compared to other crop species like cereals, has been very slow. With the advances in next-generation sequencing (NGS) and high-throughput (HTP) genotyping methods, there is a shift in development of genomic resources including molecular markers in these crops. For instance, 2,000 to 3,000 novel simple sequence repeats (SSR) markers have been developed each for chickpea, pigeonpea and groundnut. Based on Sanger, 454/FLX and Illumina transcript reads, transcriptome assemblies have been developed for chickpea (44,845 transcript assembly contigs, or TACs) and pigeonpea (21,434 TACs). Illumina sequencing of some parental genotypes of mapping populations has resulted in the development of 120 million reads for chickpea and 128.9 million reads for pigeonpea. Alignment of these Illumina reads with respective transcriptome assemblies have provided more than 10,000 SNPs each in chickpea and pigeonpea. A variety of SNP genotyping platforms including GoldenGate, VeraCode and Competitive Allele Specific PCR (KASPar) assays have been developed in chickpea and pigeonpea. By using above resources, the first-generation or comprehensive genetic maps have been developed in the three legume speciesmentioned above. Analysis of phenotyping data together with genotyping data has provided candidate markers for drought-tolerance-related root traits in chickpea, resistance to foliar diseases in groundnut and sterility mosaic disease (SMD) and fertility restoration in pigeonpea. Together with these traitassociated markers along with those already available, molecular breeding programmes have been initiated for enhancing drought tolerance, resistance

  11. 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

  12. 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.

  13. Legumes as a Model Plant Family

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The human population derives the majority of its nutrition either directly or indirectly (via animal protein) from two plant families: the grasses and the legumes. Grain legumes alone supply approximately 33% of human protein nutrition. Thus, it is critical for genetic improvement of legume crop spe...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Soil response to corn residue removal and cover crops in Eastern South Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Removal of crop residue has been shown to degrade soil organic carbon (SOC), and hence soil quality. The present study was conducted to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality parameters. The experimental site was located in Brookings County, ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Cover crop and poultry litter management influence spatiotemporal availability of topsoil nitrogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Green and animal manures provide plant-available nitrogen (N) in annual cropping systems and contribute to improved soil quality. Our objectives were to determine the effects of cover crop residue type and pelletized poultry litter (PPL) application method on: 1) the spatiotemporal distribution of s...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 in Missouri: putting them to work on your farm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Increased Risk of Insect Injury to Corn Following Rye Cover Crop.

    PubMed

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

    2016-08-01

    Decreased pest pressure is sometimes associated with more diverse agroecosystems, including the addition of a rye cover crop (Secale cereale L.). However, not all pests respond similarly to greater vegetational diversity. Polyphagous pests, such as true armyworm (Mythimna unipuncta Haworth), black cutworm (Agrotis ipsilon Hufnagel), and common stalk borer (Papaipema nebris Guenee), whose host range includes rye have the potential to cause injury to crops following a rye cover crop. The objectives of this study were to compare the abundance of early-season insect pests and injury to corn (Zea mays L.) from fields with and without a rye cover crop on commercial farms. Fields were sampled weekly to quantify adult and larval pests and feeding injury to corn plants from mid-April until corn reached V8 stage, during 2014 and 2015. Measurements within fields were collected along transects that extended perpendicularly from field edges into the interior of cornfields. Adult true armyworm and adult black cutworm were captured around all cornfields, but most lepidopteran larvae captured within cornfields were true armyworm and common stalk borer. Cornfields with a rye cover crop had significantly greater abundance of true armyworm and greater proportion of injured corn. Both true armyworm abundance and feeding injury were significantly greater in the interior of cornfields with rye. Common stalk borer abundance did not differ between cornfields with or without rye cover. Farmers planting corn following a rye cover crop should be aware of the potential for increased presence of true armyworm and for greater injury to corn.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 (...

  4. 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.

  5. Oat cover cropping and soil insecticides in an integrated sugarbeet root maggot (Diptera: Otitidae) management program.

    PubMed

    Dregseth, Robert J; Boetel, Mark A; Schroeder, Allen J; Carlson, Robert B; Armstrong, J S

    2003-10-01

    Sugarbeet, Beta vulgaris L., producers occasionally establish cereal cover crops to minimize early-season soil erosion, wind abrasion, and mechanical injury of seedlings. We evaluated the use of living oat, Avena sativa L., cover cropping as a cultural tactic to minimize feeding injury from sugarbeet root maggot, Tetanops myopaeformis (Röder), larvae at five field sites during 1996, 1998, and 1999. Sweep-net sampling yielded 4.8-, 11.2-, and 7.2-fold more flies from oat cover-cropped chlorpyrifos, terbufos, and untreated control plots, respectively, than in noncover counterparts. However, larval feeding injury in terbufos-treated plots was reduced when cover-cropped (383 seeds/m2) at St. Thomas in all years. A reduced oat seeding rate (224 seeds/m2) also enhanced root protection in terbufos-treated plots at St. Thomas in 1999. Less root injury was sustained in cover-cropped chlorpyrifos plots than in noncover counterparts at St. Thomas in 2 study yr. Oat cover cropping also frequently resulted in reduced T. myopaeformis feeding injury in the absence of a soil insecticide. Although trends toward increased yields were often evident, significant yield benefits were limited to a 6.8% root yield increase in oat cover plots when compared with noncover treatments overall at St. Thomas in 1996 and an 18.4% sucrose yield increase in terbufos-treated plots at St. Thomas in 1999. These findings suggest that beneficial interactions between planting-time soil insecticides and cereal cover crops are achievable in areas infested by T. myopaeformis. Demonstrated reductions in root feeding injury, combined with additional agronomic benefits, may warrant use of this production practice as part of an integrated management program for this key insect pest of sugarbeet.

  6. 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.

  7. Swine manure injection with low-disturbance applicator and cover crops reduce phosphorus losses.

    PubMed

    Kovar, J L; Moorman, T B; Singer, J W; Cambardella, C A; Tomer, M D

    2011-01-01

    Injection of liquid swine manure disturbs surface soil so that runoff from treated lands can transport sediment and nutrients to surface waters. We determined the effect of two manure application methods on P fate in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] production system, with and without a winter rye (Secale cereale L.)-oat (Avena sativa L.) cover crop. Treatments included: (i) no manure; (ii) knife injection; and (iii) low-disturbance injection, each with and without the cover crop. Simulated rainfall runoff was analyzed for dissolved reactive P (DRP) and total P (TP). Rainfall was applied 8 d after manure application (early November) and again in May after emergence of the corn crop. Manure application increased soil bioavailable P in the 20- to 30-cm layer following knife injection and in the 5- to 20-cm layer following low-disturbance injection. The low-disturbance system caused less damage to the cover crop, so that P uptake was more than threefold greater. Losses of DRP were greater in both fall and spring following low-disturbance injection; however, application method had no effect on TP loads in runoff in either season. The cover crop reduced fall TP losses from plots with manure applied by either method. In spring, DRP losses were significantly higher from plots with the recently killed cover crop, but TP losses were not affected. Low-disturbance injection of swine manure into a standing cover crop can minimize plant damage and P losses in surface runoff while providing optimum P availability to a subsequent agronomic crop.

  8. 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

  9. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Evaluation of cover crop and reduced cultivation for reducing nitrate leaching in Ireland.

    PubMed

    Hooker, K V; Coxon, C E; Hackett, R; Kirwan, L E; O'Keeffe, E; Richards, K G

    2008-01-01

    Nitrate (NO(3)) loss from arable systems to surface and groundwater has attracted considerable attention in recent years in Ireland. Little information exists under Irish conditions, which are wet and temperate, on the effects of winter cover crops and different tillage techniques on NO(3) leaching. This study investigated the efficacy of such practices in reducing NO(3) leaching from a spring barley (Hordeum vulgare L.) system in the Barrow River valley, southeast Ireland. The study compared the effect of two tillage systems (plow-based tillage and noninversion tillage) and two over-winter alternatives (no vegetative cover and a mustard cover crop) on soil solution NO(3) concentrations at 90 cm depth over two winter drainage seasons (2003/04 and 2004/05). Soil samples were taken and analyzed for inorganic N. During both years of the study, the use of a mustard cover crop significantly reduced NO(3) losses for the plowed and reduced cultivation treatments. Mean soil solution NO(3) concentrations were between 38 and 70% lower when a cover crop was used, and total N load lost over the winter was between 18 and 83% lower. Results from this study highlight the importance of drainage volume and winter temperatures on NO(3) concentrations in soil solution and overall N load lost. It is suggested that cover crops will be of particular value in reducing NO(3) loss in temperate regions with mild winters, where winter N mineralization is important and high winter temperatures favor a long growing season.

  12. 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

  13. 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

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

    PubMed

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

    2003-03-01

    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 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

  15. 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

  16. 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. PMID:24695585

  17. Bacterial endophytes mediate positive feedback effects of early legume termination times on the yield of subsequent durum wheat crops.

    PubMed

    Yang, Chao; Hamel, Chantal; Gan, Yantai; Vujanovic, Vladimir

    2012-12-01

    Field crops influence the biotic properties of the soil, impacting the health and productivity of subsequent crops. Polymerase chain reaction and 454 GS FLX pyrosequencing of amplicons were used to clarify the legacy of chickpea and pea crops on the quality of the bacterial community colonizing the root endosphere of subsequent crops of wheat, in a replicated field study. Similar communities of root endosphere bacteria were formed in durum wheat grown after pea and chickpea crops when chickpea crops were terminated as early as pea (July). Termination of the chickpea crops in September led to the domination of Firmicutes in wheat root endosphere; Actinobacteria dominated the wheat root endosphere following early pulse crop termination. The architecture of wheat plants was correlated with the composition of its root endosphere community. High grain yield was associated with the production of fewer but larger wheat heads, the abundance of endospheric Actinobacteria and Acidobacteria, and the scarcity of endospheric Firmicutes. Pulse termination time affected wheat root endosphere colonization strongly in 2009 but weakly in 2010, an abnormally wet year. This study improved our understanding of the so-called "crop rotation effect" in pulse-wheat systems and showed how this system can be manipulated through agronomic decisions. PMID:23210994

  18. Bacterial endophytes mediate positive feedback effects of early legume termination times on the yield of subsequent durum wheat crops.

    PubMed

    Yang, Chao; Hamel, Chantal; Gan, Yantai; Vujanovic, Vladimir

    2012-12-01

    Field crops influence the biotic properties of the soil, impacting the health and productivity of subsequent crops. Polymerase chain reaction and 454 GS FLX pyrosequencing of amplicons were used to clarify the legacy of chickpea and pea crops on the quality of the bacterial community colonizing the root endosphere of subsequent crops of wheat, in a replicated field study. Similar communities of root endosphere bacteria were formed in durum wheat grown after pea and chickpea crops when chickpea crops were terminated as early as pea (July). Termination of the chickpea crops in September led to the domination of Firmicutes in wheat root endosphere; Actinobacteria dominated the wheat root endosphere following early pulse crop termination. The architecture of wheat plants was correlated with the composition of its root endosphere community. High grain yield was associated with the production of fewer but larger wheat heads, the abundance of endospheric Actinobacteria and Acidobacteria, and the scarcity of endospheric Firmicutes. Pulse termination time affected wheat root endosphere colonization strongly in 2009 but weakly in 2010, an abnormally wet year. This study improved our understanding of the so-called "crop rotation effect" in pulse-wheat systems and showed how this system can be manipulated through agronomic decisions.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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,...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. 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.

  3. Increased Risk of Insect Injury to Corn Following Rye Cover Crop.

    PubMed

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

    2016-08-01

    Decreased pest pressure is sometimes associated with more diverse agroecosystems, including the addition of a rye cover crop (Secale cereale L.). However, not all pests respond similarly to greater vegetational diversity. Polyphagous pests, such as true armyworm (Mythimna unipuncta Haworth), black cutworm (Agrotis ipsilon Hufnagel), and common stalk borer (Papaipema nebris Guenee), whose host range includes rye have the potential to cause injury to crops following a rye cover crop. The objectives of this study were to compare the abundance of early-season insect pests and injury to corn (Zea mays L.) from fields with and without a rye cover crop on commercial farms. Fields were sampled weekly to quantify adult and larval pests and feeding injury to corn plants from mid-April until corn reached V8 stage, during 2014 and 2015. Measurements within fields were collected along transects that extended perpendicularly from field edges into the interior of cornfields. Adult true armyworm and adult black cutworm were captured around all cornfields, but most lepidopteran larvae captured within cornfields were true armyworm and common stalk borer. Cornfields with a rye cover crop had significantly greater abundance of true armyworm and greater proportion of injured corn. Both true armyworm abundance and feeding injury were significantly greater in the interior of cornfields with rye. Common stalk borer abundance did not differ between cornfields with or without rye cover. Farmers planting corn following a rye cover crop should be aware of the potential for increased presence of true armyworm and for greater injury to corn. PMID:27325884

  4. 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

  5. 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.

  6. 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. PMID:25199100

  7. 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.

  8. 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

  9. Rye cover crop and gamagrass strip effects on NO3 concentration and load in tile drainage.

    PubMed

    Kaspar, T C; Jaynes, D B; Parkin, T B; Moorman, T B

    2007-01-01

    A significant portion of the NO3 from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or "tiles." Previous research has shown that N fertilizer management alone is not sufficient for reducing NO3 concentrations in subsurface drainage to acceptable levels; therefore, additional approaches need to be devised. We compared two cropping system modifications for NO3 concentration and load in subsurface drainage water for a no-till corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) management system. In one treatment, eastern gamagrass (Tripsacum dactyloides L.) was grown in permanent 3.05-m-wide strips above the tiles. For the second treatment, a rye (Secale cereale L.) winter cover crop was seeded over the entire plot area each year near harvest and chemically killed before planting the following spring. Twelve 30.5x42.7-m subsurface-drained field plots were established in 1999 with an automated system for measuring tile flow and collecting flow-weighted samples. Both treatments and a control were initiated in 2000 and replicated four times. Full establishment of both treatments did not occur until fall 2001 because of dry conditions. Treatment comparisons were conducted from 2002 through 2005. The rye cover crop treatment significantly reduced subsurface drainage water flow-weighted NO3 concentrations and NO3 loads in all 4 yr. The rye cover crop treatment did not significantly reduce cumulative annual drainage. Averaged over 4 yr, the rye cover crop reduced flow-weighted NO3 concentrations by 59% and loads by 61%. The gamagrass strips did not significantly reduce cumulative drainage, the average annual flow-weighted NO3 concentrations, or cumulative NO3 loads averaged over the 4 yr. Rye winter cover crops grown after corn and soybean have the potential to reduce the NO3 concentrations and loads delivered to surface waters by subsurface drainage systems.

  10. 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.

  11. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. 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. 1437.502 Section 1437.502 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS...

  7. 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. 1437.502 Section 1437.502 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. 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.

  15. The legume NOOT-BOP-COCH-LIKE genes are conserved regulators of abscission, a major agronomical trait in cultivated crops.

    PubMed

    Couzigou, Jean-Malo; Magne, Kevin; Mondy, Samuel; Cosson, Viviane; Clements, Jonathan; Ratet, Pascal

    2016-01-01

    Plants are able to lose organs selectively through a process called abscission. This process relies on the differentiation of specialized territories at the junction between organs and the plant body that are called abscission zones (AZ). Several genes control the formation or functioning of these AZ. We have characterized BLADE-ON-PETIOLE (BOP) orthologues from several legume plants and studied their roles in the abscission process using a mutant approach. Here, we show that the Medicago truncatula NODULE ROOT (NOOT), the Pisum sativum COCHLEATA (COCH) and their orthologue in Lotus japonicus are strictly necessary for the abscission of not only petals, but also leaflets, leaves and fruits. We also showed that the expression pattern of the M. truncatula pNOOT::GUS fusion is associated with functional and vestigial AZs when expressed in Arabidopsis. In addition, we show that the stip mutant from Lupinus angustifolius, defective in stipule formation and leaf abscission, is mutated in a BOP orthologue. In conclusion, this study shows that this clade of proteins plays an important conserved role in promoting abscission of all aerial organs studied so far.

  16. A comprehensive review of legume allergy.

    PubMed

    Verma, Alok Kumar; Kumar, Sandeep; Das, Mukul; Dwivedi, Premendra D

    2013-08-01

    Legumes belonging to Fabaceae family of the order Fabales are a rich and important source of proteins and many essential elements. Due to its nutritious elements, these are preferably included in human diet in most part of the world. But, unfortunately, IgE binding proteins have been identified in majority of legumes, and allergenic response to these legumes may range from mild skin reactions to life-threatening anaphylactic reaction. Overall, allergenicity due to consumption of legumes in decreasing order may be peanut, soybean, lentil, chickpea, pea, mung bean, and red gram. So far, several allergens from different legumes have been identified and characterized. Most of identified allergens belong to storage proteins family, profilins, or the pathogenesis-related proteins. Legumes also have property of immunological cross-reactivity among themselves and from other sources that also increases the severity of allergenic response to a particular legume. This review summarizes the currently available knowledge on legume allergy and describes the allergenic problems associated with different legumes. It also tries to explore about the legume allergens identified so far by different scientific groups. The culmination of knowledge about identification and characterization of allergens from different legumes will be helpful in diagnosis and treatment of allergy, for development of novel therapeutic strategies, for strict avoidance of particular legume in diet by susceptible individual and also to produce hypoallergenic cultivars of leguminous crop through conventional breeding or genetic modification.

  17. Efficacy of Cotton Root Destruction and Winter Cover Crops for Suppression of Hoplolaimus columbus.

    PubMed

    Davis, R F; Baird, R E; McNeil, R D

    2000-12-01

    The efficacy of rye (Secale cereale) and wheat (Triticum aestivum) winter cover crops and cotton stalk and root destruction (i.e., pulling them up) were evaluated in field tests during two growing seasons for Hoplolaimus columbus management in cotton. The effect of removing debris from the field following root destruction also was evaluated. Wheat and rye produced similar amounts of biomass, and both crops produced more biomass (P Cover crops did not suppress H. columbus population levels or increase subsequent cotton yields. Cotton root destruction did not affect cotton stand or plant height the following year. Cotton root destruction lowered (P cover crop or cotton root destruction following harvest is ineffective for H. columbus management in cotton.

  18. Winter annual cover crop has only minor effects on major corn arthropod pests.

    PubMed

    Davis, Holly N; Currie, Randall S; Klocke, Norman L; Buschman, Lawrent L

    2010-04-01

    We studied the effects of downy brome, Bromus tectorum L., winter cover crop on several corn, Zea mays L., pests in the summer crop after the cover crop. An experiment was conducted that consisted of two trials with two levels of irrigation, two levels of weed control, and two levels of downy brome. Corn was grown three consecutive years after the downy brome grown during the winter. Banks grass mites, Oligonychus pratensis (Banks), twospotted spider mites, Tetranychus urticae Koch, and predatory mites from the genus Neoseiulus were present in downy brome at the beginning of the growing season. They moved into corn, but their numbers did not differ significantly across the treatments. Larval western corn rootworm, Diabrotica virgifera virgifera LeConte, feeding on corn roots was evaluated the second and third years of corn, production. Irrigation and herbicide treatments had no significant effects on rootworm injury levels. In one trial, rootworm injury ratings were significantly greater in treatments with a history of high versus low brome, but this effect was not significant in the other trial. Rootworm injury seemed to be similar across plots with different surface soil moistures. This suggests that the use of a winter cover crop such as downy brome will not have a major negative impact the arthropods studied.

  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. 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.

  1. 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. PMID:23575020

  2. 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. PMID:12805756

  3. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Effects of winter cover crop, soil amendment, and variety on organic rice production and greenhouse gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen supply and disease are two main challenges in organic rice production. Cover crop and soil amendment can be options to increase soil N while keeps rice health. The objective of this study was to test the effects of cover crop and soil amendment on the production of organic rice. Three popul...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. The water conundrum of planting cover crops in the great plains: when is an inch not an inch?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crop use is being widely promoted throughout the entire United States because of the potential benefits related to protecting and improving the soil. However, the semi-arid environment of the western and central Great Plains has a much different environment from areas where cover cropping has ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Cover crop effects on nitrogen load in tile drainage from Walnut Creek Iowa using root zone water quality model (RZWQM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies quantifying winter annual cover crop effects on water quality are mostly limited to short-term studies at the plot scale. Long-term studies scaling-up water quality effects of cover crops to the watershed scale provide more integrated spatial responses from the landscape. The objective of th...

  13. 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

  14. 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

  15. Cover cropping to reduce nitrate loss through subsurface drainage in the northern U.S. corn belt.

    PubMed

    Strock, J S; Porter, P M; Russelle, M P

    2004-01-01

    Despite the use of best management practices for nitrogen (N) application rate and timing, significant losses of nitrate nitrogen (NO3(-)-N) in drainage discharge continue to occur from row crop cropping systems. Our objective was to determine whether a autumn-seeded winter rye (Secale cereale L.) cover crop following corn (Zea mays L.) would reduce NO3(-)-N losses through subsurface tile drainage in a corn-soybean [Glycine mar (L.) Merr.] cropping system in the northern Corn Belt (USA) in a moderately well-drained soil. Both phases of the corn-soybean rotation, with and without the winter rye cover crop following corn, were established in 1998 in a Normania clay loam (fine-loamy, mixed, mesic Aquic Haplustoll) soil at Lamberton, MN. Cover cropping did not affect subsequent soybean yield, but reduced drainage discharge, flow-weighted mean nitrate concentration (FWMNC), and NO3(-)-N loss relative to winter fallow, although the magnitude of the effect varied considerably with annual precipitation. Three-year average drainage discharge was lower with a winter rye cover crop than without (p = 0.06). Over three years, subsurface tile-drainage discharge was reduced 11% and NO3(-)-N loss was reduced 13% for a corn-soybean cropping system with a rye cover crop following corn than with no rye cover crop. We estimate that establishment of a winter rye cover crop after corn will be successful in one of four years in southwestern Minnesota. Cover cropping with rye has the potential to be an effective management tool for reducing NO3(-)-N loss from subsurface drainage discharge despite challenges to establishment and spring growth in the north-central USA.

  16. 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.

  17. 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. PMID:17390812

  18. 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.

  19. 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.

  20. Utilization of summer legumes as bioenergy feedstocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Molecular characterization of fungal communities in non-tilled, cover-cropped upland rice field soils.

    PubMed

    Nishizawa, Tomoyasu; Zhaorigetu; Komatsuzaki, Masakazu; Sato, Yoshinori; Kaneko, Nobuhiro; Ohta, Hiroyuki

    2010-01-01

    This study aimed to characterize soil fungal communities in upland rice fields managed with tillage/non-tillage and winter cover-cropping (hairy vetch and cereal rye) practices, using PCR-based molecular methods. The study plots were maintained as upland fields for 5 years and the soils sampled in the second and fifth years were analyzed using T-RFLP (terminal restriction fragment length polymorphism) profiling and clone libraries with the internal transcribed spacer (ITS) region and domain 1 (D1) of the fungal large-subunit (fLSU) rRNA (D1(fLSU)) as the target DNA sequence. From the 2nd-year-sample, 372 cloned sequences of fungal ITS-D1(fLSU) were obtained and clustered into 80 nonredundant fungal OTUs (operational taxonomic units) in 4 fungal phyla. The T-RFLP profiling was performed with the 2nd- and 5th-year-samples and the major T-RFs (terminal restriction fragments) were identified using a theoretical fragment analysis of the ITS-D1(fLSU) clones. These molecular analyses showed that the fungal community was influenced more strongly by the cover-cropping than tillage practices. Moreover, the non-tilled, cover-cropped soil was characterized by a predominance of Cryptococcus sp. in the phylum Basidiomycota. We provided a genetic database of the fungal ITS-D1(fLSU)s in the differently managed soils of upland rice fields.

  2. 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

  3. 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

  4. Legume information system (LegumeInfo.org): a key component of a set of federated data resources for the legume family.

    PubMed

    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.

  5. [Effects of winter cover crop on methane and nitrous oxide emission from paddy field].

    PubMed

    Tang, Hai-ming; Tang, Wen-guang; Shuai, Xi-qiang; Yang, Guang-li; Tang, Hai-tao; Xiao, Xiao-Ping

    2010-12-01

    Static chamber-GC technique was employed to study the effects of different treatment winter cover crops, including no-tillage and directly sowing ryegrass (T1), no-tillage and directly sowing Chinese milk vetch (T2), tillage and transplanting rape (T3), no-tillage and directly sowing rape (T4), and fallowing (CK), on the CH4 and N2O emission from double cropping rice paddy field. During the growth period of test winter cover crops, the CH4 and N2O emission in treatments T1-T4 was significantly higher than that in CK (P < 0.01). Treatments T1 and T3 not only had the largest CH4 emission (0.60 and 0.88 g x m(-2)), but also had the largest N2O emission (0.20 and 0.23 g x m(-2), respectively). After the winter cover crops returned to field, the CH4 emission from early and late rice fields in treatments T1, T2, T3, and T4 was larger than that in CK. In early rice field, treatments T1 and T2 had the largest CH4 emission (21.70 and 20.75 g x m(-2)); while in late rice field, treatments T3 and T4 had the largest one (58.90 and 54.51 g x m(-2) respectively). Treatments T1-T4 also had larger N2O emission from early and late rice fields than the CK did. The N2O emission from early rice field in treatments T1, T2, T3, and T4 was increased by 53.7%, 12.2%, 46.3%, and 29.3%, and that from late rice field in corresponding treatments was increased by 28.6%, 3.8%, 34.3%, and 27.6%, respectively, compared with CK.

  6. 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

  7. 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

  8. Population Growth of Pratylenchus penetrans on Winter Cover Crops Grown in the Pacific Northwest

    PubMed Central

    Forge, T. A.; Ingham, R. E.; Kaufman, D.; Pinkerton, J. N.

    2000-01-01

    Population growth of Pratylenchus penetrans on 13 fall and winter cover crops was studied in the greenhouse and field. All crops except oat cv. Saia supported population growth of P. penetrans in greenhouse experiments, although the response of P. penetrans to oat cv. Saia varied considerably between experiments. The mean ratio of the final population density/initial population density (Pf/Pi) after 16 weeks for P. penetrans added to a greenhouse soil mix was 0.09, whereas Pf/Pi values after 10 weeks for two experiments with naturally infested soil were 0.95 and 2.3. Although P. penetrans increased on sudangrass cv. Trudan 8 and sudangrass × sorghum hybrid cv. SS 222, subsequent incorporation of sudangrass vegetation into soil reduced P. penetrans populations to preplant levels. Field experiments were inconclusive but suggested that oat cv. Saia or rye cv. Wheeler may be better choices for winter cover than weed-contaminated fallow or other crops on P. penetrans-infested sites in the Pacific Northwest. PMID:19270948

  9. 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. PMID:25740925

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:25026645

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Assessing Natural Isothiocyanate Air Emissions after Field Incorporation of Mustard Cover Crop

    SciTech Connect

    Trott, Donna M.; LePage, Jane; Hebert, Vincent

    2012-01-01

    A regional air assessment was performed to characterize volatile natural isothiocyanate (NITC) compounds in air during soil incorporation of mustard cover crops in Washington State. Field air sampling and analytical methods were developed specific to three NITCs known to be present in air at appreciable concentrations during/after field incorporation. The maximum observed concentrations in air for the allyl, benzyl, and phenethyl isothiocyanates were respectively 188, 6.1, and 0.7 lg m-3 during mustard incorporation. Based on limited inhalation toxicity information, airborne NITC concentrations did not appear to pose an acute human inhalation exposure concern to field operators and bystanders.

  1. 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

  2. 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.

  3. Crop cover the principal influence on non-crop ground beetle (Coleoptera, Carabidae) activity and assemblages at the farm scale in a long-term assessment.

    PubMed

    Eyre, M D; Sanderson, R A; McMillan, S D; Critchley, C N R

    2016-04-01

    Ground beetle data were generated using pitfall traps in the 17-year period from 1993 to 2009 and used to investigate the effects of changes in surrounding crop cover on beetle activity and assemblages, together with the effects of weather variability. Beetles were recorded from non-crop field margins (overgrown hedges). Crop cover changes explained far more variation in the beetle assemblages recorded than did temperature and rainfall variation. A reduction in management intensity and disturbance in the crops surrounding the traps, especially the introduction and development of willow coppice, was concomitant with changes in individual species activity and assemblage composition of beetles trapped in non-crop habitat. There were no consistent patterns in either overall beetle activity or in the number of species recorded over the 17-year period, but there was a clear change from assemblages dominated by smaller species with higher dispersal capability to ones with larger beetles with less dispersal potential and a preference for less disturbed agroecosystems. The influence of surrounding crops on ground beetle activity in non-crop habitat has implications for ecosystem service provision by ground beetles as pest predators. These results are contrary to conventional assumptions and interpretations, which suggest activity of pest predators in crops is influenced primarily by adjacent non-crop habitat. The long-term nature of the assessment was important in elucidation of patterns and trends, and indicated that policies such as agri-environment schemes should take cropping patterns into account when promoting management options that are intended to enhance natural pest control.

  4. Crop cover the principal influence on non-crop ground beetle (Coleoptera, Carabidae) activity and assemblages at the farm scale in a long-term assessment.

    PubMed

    Eyre, M D; Sanderson, R A; McMillan, S D; Critchley, C N R

    2016-04-01

    Ground beetle data were generated using pitfall traps in the 17-year period from 1993 to 2009 and used to investigate the effects of changes in surrounding crop cover on beetle activity and assemblages, together with the effects of weather variability. Beetles were recorded from non-crop field margins (overgrown hedges). Crop cover changes explained far more variation in the beetle assemblages recorded than did temperature and rainfall variation. A reduction in management intensity and disturbance in the crops surrounding the traps, especially the introduction and development of willow coppice, was concomitant with changes in individual species activity and assemblage composition of beetles trapped in non-crop habitat. There were no consistent patterns in either overall beetle activity or in the number of species recorded over the 17-year period, but there was a clear change from assemblages dominated by smaller species with higher dispersal capability to ones with larger beetles with less dispersal potential and a preference for less disturbed agroecosystems. The influence of surrounding crops on ground beetle activity in non-crop habitat has implications for ecosystem service provision by ground beetles as pest predators. These results are contrary to conventional assumptions and interpretations, which suggest activity of pest predators in crops is influenced primarily by adjacent non-crop habitat. The long-term nature of the assessment was important in elucidation of patterns and trends, and indicated that policies such as agri-environment schemes should take cropping patterns into account when promoting management options that are intended to enhance natural pest control. PMID:26786247

  5. Crop and cattle production responses to tillage and cover crop management in an integrated crop-livestock system in the southeastern USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. The kill date as a management tool for cover cropping success.

    PubMed

    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

  7. The kill date as a management tool for cover cropping success.

    PubMed

    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.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. Estimating variability in grain legume yields across Europe and the Americas.

    PubMed

    Cernay, Charles; Ben-Ari, Tamara; Pelzer, Elise; Meynard, Jean-Marc; Makowski, David

    2015-01-01

    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. 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

  14. 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.

  15. 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

  16. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study.

    PubMed

    Cassigneul, A; Benoit, P; Bergheaud, V; Dumeny, V; Etiévant, V; Goubard, Y; Maylin, A; Justes, E; Alletto, L

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of (14)C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. (14)C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH4OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends (14)C-glyphosate degradation half-life from 7 to 28 days depending on the CC. (14)C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity.

  17. Suppression of phytophthora blight in bell pepper by a no-till wheat cover crop.

    PubMed

    Ristaino, J B; Parra, G; Campbell, C L

    1997-03-01

    ABSTRACT Four mechanisms of dispersal of propagules of Phytophthora capsici were investigated through modifications in cultural practices and fungicide applications in field plots of bell pepper (Capsicum annuum). Dispersal of soil inoculum was suppressed, and final incidence of disease was 2.5 to 43% when stubble from a fall-sown, no-till, wheat cover crop was present. Final disease incidence was 71 to 72% and pathogen spread occurred within and across rows when all dispersal mechanisms were operative in plots of pepper planted into bare soil. Final disease incidence was 42 to 78% with black plastic mulch when a sporulating pepper fruit placed on the surface served as the source of initial inoculum. The fungicide metalaxyl applied in the irrigation system did not suppress within-row spread of surface inoculum from a sporulating fruit on plastic, but did limit across-row spread; final disease incidence in metalaxyl-treated plots was 11.5 to 14%. Pathogen dispersal mechanisms were modified most dramatically by the no-till cropping system. Thus, simple changes in cultural practices can have dramatic effects on the development of Phytophthora epidemics. Ecologically based disease management strategies have the potential to reduce our reliance on agrichemicals in this and similar pathosystems.

  18. Simulating long-term impacts of cover crops and climate change on crop production and environmental outcomes in the midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. Simulating long-term impacts of winter rye cover crop on hydrologic cycling and nitrogen dynamics for a corn-soybean crop system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting winter cover crops into corn-soybean rotation is a promising approach for reducing subsurface drainage and nitrate loss. However, the long-term impact of this practice needs investigation. We evaluated the performance of the RZWQM-DSSAT model against five years of comprehensive field data n...

  20. Seeding date affects fall growth of winter canola (Brassica napus L. ‘Baldur’) and its performance as a winter cover crop in central Iowa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. 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

  2. The efficacy of winter cover crops to stabilize soil inorganic nitrogen after fall-applied anhydrous ammonia.

    PubMed

    Lacey, Corey; Armstrong, Shalamar

    2015-03-01

    There is a dearth of knowledge on the ability of cover crops to increase the effectiveness of fall-applied nitrogen (N). The objective of this study was to investigate the efficacy of two cover crop species to stabilize inorganic soil N after a fall application of N. Fall N was applied at a rate of 200 kg N ha into living stands of cereal rye, tillage radish, and a control (no cover crop) at the Illinois State University Research and Teaching Farm in Lexington, Illinois. Cover crops were sampled to determine N uptake, and soil samples were collected in the spring at four depths to 80 cm to determine the distribution of inorganic N within the soil profile. Tillage radish (131.9-226.8 kg ha) and cereal rye (188.1-249.9 kg ha N) demonstrated the capacity to absorb a minimum of 60 to 80% of the equivalent rate of fall-applied N, respectively. Fall applying N without cover crops resulted in a greater percentage of soil NO-N (40%) in the 50- to 80-cm depth, compared with only 31 and 27% when tillage radish and cereal rye were present at N application. At planting, tillage radish stabilized an average of 91% of the equivalent rate of fall-applied N within the 0- to 20-cm, depth compared with 66 and 57% for the cereal rye and control treatments, respectively. This study has demonstrated that fall applying N into a living cover crop stand has the potential to reduce the vulnerability of soil nitrate and to stabilize a greater concentration of inorganic N within the agronomic depths of soil.

  3. 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

  4. 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

    2016-03-01

    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

  5. 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

    2016-03-01

    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.

  6. Legume proteomics: Progress, prospects, and challenges.

    PubMed

    Rathi, Divya; Gayen, Dipak; Gayali, Saurabh; Chakraborty, Subhra; Chakraborty, Niranjan

    2016-01-01

    Legumes are the major sources of food and fodder with strong commercial relevance, and are essential components of agricultural ecosystems owing to their ability to carry out endosymbiotic nitrogen fixation. In recent years, legumes have become one of the major choices of plant research. The legume proteomics is currently represented by more than 100 reference maps and an equal number of stress-responsive proteomes. Among the 48 legumes in the protein databases, most proteomic studies have been accomplished in two model legumes, soybean, and barrel medic. This review highlights recent contributions in the field of legume proteomics to comprehend the defence and regulatory mechanisms during development and adaptation to climatic changes. Here, we attempted to provide a concise overview of the progress in legume proteomics and discuss future developments in three broad perspectives: (i) proteome of organs/tissues; (ii) subcellular compartments; and (iii) spatiotemporal changes in response to stress. Such data mining may aid in discovering potential biomarkers for plant growth, in general, apart from essential components involved in stress tolerance. The prospect of integrating proteome data with genome information from legumes will provide exciting opportunities for plant biologists to achieve long-term goals of crop improvement and sustainable agriculture.

  7. 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.

  8. Enhancing management of fall-applied poultry litter with cover crop and subsurface band placement in no-till cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whether yield reduction risk of cotton fertilized with fall-applied poultry litter in regions with warm fall or winter months can be minimized by applying the litter in subsurface bands in conjunction with winter cover crop is unknown. A field study was conducted in Mississippi to test whether litte...

  9. Cultural strategies for managing weeds and soil moisture in cover crop-based no-till soybean production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 pressure, soybean lodging and yield in a cover crop-based soybean production system. Soybean planting timing included roll-kill and soybean planting occu...

  10. Cultural strategies for managing weeds and soil moisture in cover crop based no-till soybean production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Effects of terminating cover crops with rolling/crimping and herbicides in a cotton no-till system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Linking a Germplasm Collection of the Cover Crop Hairy Vetch (Vicia villosa Roth) to Traits Related to Improved Nitrogen Fixation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Cover crops and tillage in a mature Merlot vineyard affect yields and cluster weight but not nutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Allelopathic influence of a wheat or rye cover crop on growth and yield of no-till cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Cover crops in the upper midwestern United States: Potential adoption and reduction of nitrate leaching in the Mississippi River Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. High Residue Winter Cover Crops Deplete Winter Annual Weed Seed Across a Landscape in a Long-Term Tillage Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High residue conservation agriculture systems have the potential to maximize environmental benefits achieved when practicing reduced tillage. A greenhouse study was conducted in 2006 through 2008 to determine the effects of cover crop residue on weed seed density within the soil seedbank under varyi...

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. Genetic control of inflorescence architecture in legumes.

    PubMed

    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.

  2. Genetic control of flowering time in legumes

    PubMed Central

    Weller, James L.; Ortega, Raúl

    2015-01-01

    The timing of flowering, and in particular the degree to which it is responsive to the environment, is a key factor in the adaptation of a given species to various eco-geographic locations and agricultural practices. Flowering time variation has been documented in many crop legumes, and selection for specific variants has permitted significant expansion and improvement in cultivation, from prehistoric times to the present day. Recent advances in legume genomics have accelerated the process of gene identification and functional analysis, and opened up new prospects for a molecular understanding of flowering time adaptation in this important crop group. Within the legumes, two species have been prominent in flowering time studies; the vernalization-responsive long-day species pea (Pisum sativum) and the warm-season short-day plant soybean (Glycine max). Analysis of flowering in these species is now being complemented by reverse genetics capabilities in the model legumes Medicago truncatula and Lotus japonicus, and the emergence of genome-scale resources in a range of other legumes. This review will outline the insights gained from detailed forward genetic analysis of flowering time in pea and soybean, highlighting the importance of light perception, the circadian clock and the FT family of flowering integrators. It discusses the current state of knowledge on genetic mechanisms for photoperiod and vernalization response, and concludes with a broader discussion of flowering time adaptation across legumes generally. PMID:25914700

  3. 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.

  4. Removal impact of rye (Secale cereale L.) as a winter cover crop for biomass production on soil properties and cotton yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, there has been a renewed interest on alternatives sources of energy, especially renewable sources. Numerous materials can be used for this purpose, including crop residues. The use of crop residues would give farmers a new source of income. Utilization of winter cover crops (WCC) is a re...

  5. Soil water improvements with the long-term use of a winter rye cover crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  6. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... production, before or after the loss event, will be taken into account in computing eligibilities. (ii... taken into account in the loss determinations made under this part. The producer is obligated to... having a zero yield capability for the crop year involved for purposes of constructing a crop...

  7. Effects of winter covering crop residue incorporation on CH₄ and N₂O emission from double-cropped paddy fields in southern China.

    PubMed

    Tang, Haiming; Xiao, Xiaoping; Tang, Wenguang; Wang, Ke; Sun, Jimin; Li, Weiyan; Yang, Guangli

    2015-08-01

    Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on methane (CH4) and nitrous oxide (N2O) emission from paddy field in southern China are few. Therefore, the emissions of CH4 and N2O were investigated in double cropping rice (Oryza sativa L.) systems with different winter covering crops using the static chamber-gas chromatography technique to assess the effects of different covering crops on the emissions of greenhouse gases. The experiment was established in 2004 in Hunan Province, China. Three winter cropping systems were used: rice-rice-rape (Brassica napus L.) (T1), rice-rice-potato with straw mulching (Solanum tuberosum L.) (T2), and rice-rice with winter fallow (CK). A randomized block design was adopted in plots, with three replications. The results showed that T2 plots had the largest CH4 emissions during the early and late rice growing season with 12.506 and 32.991 g m(-2), respectively. When compared to CK, total N2O emissions in the early rice growth period and the emissions of the gas increased by 0.013 g m(-2) in T1 and 0.045 g m(-2) in T2, respectively. Similar results were obtained in the late rice growth period; the total N2O emissions increased by 0.027 g m(-2) in T1 and 0.084 g m(-2) in T2, respectively. The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of T2 > T1 > CK, which indicated CK and T1 was significantly lower than T2 (P < 0.05). This suggests that adoption of T1 would be beneficial for greenhouse gas emission mitigation and could be a good option cropping pattern in double rice cropped regions. PMID:25913315

  8. Organic weed conrol and cover crop residue integration impacts on weed control, quality, and yield and economics in conservation tillage tomato - A case study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  9. Planting date impacts on soil water management, plant growth, and weeds in cover-crop-based no-till corn production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. 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. PMID:25789485

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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. PMID:26832664

  18. 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.

  19. 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. PMID:26479907

  20. 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

  1. 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

  2. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    PubMed

    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.

  3. 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

  4. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    PubMed

    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

  5. Weed control and cover crop management affect mycorrhizal colonization of grapevine roots and arbuscular mycorrhizal fungal spore populations in a California vineyard.

    PubMed

    Baumgartner, Kendra; Smith, Richard F; Bettiga, Larry

    2005-03-01

    Arbuscular mycorrhizal (AM) fungi naturally colonize grapevines in California vineyards. Weed control and cover cropping may affect AM fungi directly, through destruction of extraradical hyphae by soil disruption, or indirectly, through effects on populations of mycorrhizal weeds and cover crops. We examined the effects of weed control (cultivation, post-emergence herbicides, pre-emergence herbicides) and cover crops (Secale cereale cv. Merced rye, x Triticosecale cv.Trios 102) on AM fungi in a Central Coast vineyard. Seasonal changes in grapevine mycorrhizal colonization differed among weed control treatments, but did not correspond with seasonal changes in total weed frequency. Differences in grapevine colonization among weed control treatments may be due to differences in mycorrhizal status and/or AM fungal species composition among dominant weed species. Cover crops had no effect on grapevine mycorrhizal colonization, despite higher spring spore populations in cover cropped middles compared to bare middles. Cover crops were mycorrhizal and shared four AM fungal species (Glomus aggregatum, G. etunicatum, G. mosseae, G. scintillans) in common with grapevines. Lack of contact between grapevine roots and cover crop roots may have prevented grapevines from accessing higher spore populations in the middles. PMID:15133724

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Cover Crop, Amendment, and Tillage Effects on Decomposers, Nematodes, and Collembolans in An Organic Vegetable System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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-...

  8. Multistate evaluation of Brassica cover crop, biocontrol agent, and fungicide for integrated management of sheath blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Reduced-tillage organic corn production in a hairy vetch cover crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Kenaf (Hibiscus cannabinus) and cowpea (Vigna unguiculata) as sugarcane cover crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Nitrogen storage with cover crops and nitrogen fertilization in tilled and non-tilled soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Higher cost of nitrogen (N) fertilization due to increase in the price of gasoline and increased N leaching from croplands necessitate that soil N be conserved and N fertilization rate be reduced. Proper crop and N management practices may increase soil N conservation and reduce N fertilization rate...

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... day the eligible natural disaster occurred or, for prolonged natural disasters, such as a drought and... loss event that can be harvested after the eligible natural disaster must be harvested, or continue to... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP...

  13. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... day the eligible natural disaster occurred or, for prolonged natural disasters, such as a drought and... loss event that can be harvested after the eligible natural disaster must be harvested, or continue to... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP...

  14. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... day the eligible natural disaster occurred or, for prolonged natural disasters, such as a drought and... loss event that can be harvested after the eligible natural disaster must be harvested, or continue to... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP...

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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). PMID:23906854

  3. 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).

  4. 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

  5. Converting perennial legumes to organic cropland without tillage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. 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.

  7. 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. PMID:26061704

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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. PMID:27303632

  13. 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

  14. Dynamics of nonpersistent aphid-borne viruses in lettuce crops covered with UV-absorbing nets.

    PubMed

    Legarrea, S; Betancourt, M; Plaza, M; Fraile, A; García-Arenal, F; Fereres, A

    2012-04-01

    Aphid-transmitted viruses frequently cause severe epidemics in lettuce grown under Mediterranean climates. Spatio-temporal dynamics of aphid-transmitted viruses and its vector were studied on lettuce (Lactuca sativa L.) grown under tunnels covered by two types of nets: a commercial UV-absorbing net (Bionet) and a Standard net. A group of plants infected by Cucumber mosaic virus (CMV, family Bromoviridae, genus Cucumovirus) and Lettuce mosaic virus (LMV, family Potyviridae, genus Potyvirus) was transplanted in each plot. The same virus-infected source plants were artificially infested by the aphid Macrosiphum euphorbiae (Thomas). Secondary spread of insects was weekly monitored and plants were sampled for the detection of viruses every two weeks. In 2008, the infection rate of both CMV and LMV were lower under the Bionet than under the Standard cover, probably due to the lower population density and lower dispersal rate achieved by M. euphorbiae. However, during spring of 2009, significant differences in the rate of infection between the two covers were only found for LMV six weeks after transplant. The spatial distribution of the viruses analysed by SADIE methodology was "at random", and it was not associated to the spatial pattern of the vector. The results obtained are discussed analyzing the wide range of interactions that occurred among UV-radiation, host plant, viruses, insect vector and environmental conditions. Our results show that UV-absorbing nets can be recommended as a component of an integrated disease management program to reduce secondary spread of lettuce viruses, although not as a control measure on its own. PMID:22226944

  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. PMID:26364313

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. [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

  4. [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

  5. 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

  6. 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. PMID:27222854

  7. Economics of Rainfed Cropping Systems: Northeast Thailand

    NASA Astrophysics Data System (ADS)

    Johnson, Sam H., III; Charoenwatana, Terd

    1981-06-01

    Using a computer model to simulate effective rainfall, it is shown that a flexible rainfed cropping system based on a legume crop planted before rice has a greater expected return than present subsistent rainfed cropping systems. Combining a legume crop intercropped with cassava or kenaf further increases the expected returns yet maintains the stability of the new system. Further research is required to bring the farmer's yields up to match experiment station results and to facilitate effective transfer policies.

  8. Potential of Leguminous Cover Crops in Management of a Mixed Population of Root-knot Nematodes (Meloidogyne spp.)

    PubMed Central

    Osei, Kingsley; Gowen, Simon R.; Pembroke, Barbara; Brandenburg, Rick L.; Jordan, David L.

    2010-01-01

    Root-knot nematode is an important pest in agricultural production worldwide. Crop rotation is the only management strategy in some production systems, especially for resource poor farmers in developing countries. A series of experiments was conducted in the laboratory with several leguminous cover crops to investigate their potential for managing a mixture of root-knot nematodes (Meloidogyne arenaria, M. incognita, M. javanica). The root-knot nematode mixture failed to multiply on Mucuna pruriens and Crotalaria spectabilis but on Dolichos lablab the population increased more than 2- fold when inoculated with 500 and 1,000 nematodes per plant. There was no root-galling on M. pruriens and C. spectabilis but the gall rating was noted on D. lablab. Greater mortality of juvenile root-knot nematodes occurred when exposed to eluants of roots and leaves of leguminous crops than those of tomato; 48.7% of juveniles died after 72 h exposure to root eluant of C. spectabilis. The leaf eluant of D. lablab was toxic to nematodes but the root eluant was not. Thus, different parts of a botanical contain different active ingredients or different concentrations of the same active ingredient. The numbers of root-knot nematode eggs that hatched in root exudates of M. pruriens and C. spectabilis were significantly lower (20% and 26%) than in distilled water, tomato and P. vulgaris root exudates (83%, 72% and 89%) respectively. Tomato lacks nematotoxic compounds found in M. pruriens and C. spectabilis. Three months after inoculating plants with 1,000 root-knot nematode juveniles the populations in pots with M. pruriens, C. spectabilis and C. retusa had been reduced by approximately 79%, 85% and 86% respectively; compared with an increase of 262% nematodes in pots with Phaseolus vulgaris. There was significant reduction of 90% nematodes in fallow pots with no growing plant. The results from this study demonstrate that some leguminous species contain compounds that either kill root

  9. Effects of Cover Crop Systems on Soil Physical Properties and Carbon/Nitrogen Sequestration in Coastal Plain Soils Under Conservation Tillage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation practices are needed to prevent erosion and preserve soil and water quality. Conservation tillage has been found to be an effective environmental practice. Uncertainty exists concerning the impact of cover crops with conservation tillage on the total agricultural environment. A study...

  10. Effect of length of interval between cereal rye cover crop termination and corn planting on seedling root disease and corn growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  11. 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

  12. Extrusion cooking: Legume pulses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion is used commercially to produce high value breakfast and snack foods based on cereals such as wheat or corn. However, this processing method is not being commercially used for legume pulses seeds due to the perception that they do not expand well in extrusion. Extrusion cooking of pulses (...

  13. Regulation of legume nodulation by acidic growth conditions.

    PubMed

    Ferguson, Brett J; Lin, Meng-Han; Gresshoff, Peter M

    2013-03-01

    Legumes represent some of the most important crop species worldwide. They are able to form novel root organs known as nodules, within which biological nitrogen fixation is facilitated through a symbiotic interaction with soil-dwelling bacteria called rhizobia. This provides legumes with a distinct advantage over other plant species, as nitrogen is a key factor for growth and development. Nodule formation is tightly regulated by the plant and can be inhibited by a number of external factors, such as soil pH. This is of significant agricultural and economic importance as much of global legume crops are grown on low pH soils. Despite this, the precise mechanism by which low pH conditions inhibits nodule development remains poorly characterized.

  14. Contribution of legumes to the soil N pool.

    NASA Astrophysics Data System (ADS)

    Fustec, Joëlle; Malagoli, Philippe; Mahieu, Stéphanie

    2010-05-01

    Grain legumes can be used for nitrogen acquisition in different ways in sustainable agriculture (Fustec et al., 2009). They are seen as a tool to reduce mineral N fertilizers in cropping systems. However, estimates of biological N fixation, N balance and N benefit either for the following crop or in mixed crops, remain unclear. The contribution of legumes to the soil N pool is difficult to measure, especially N rhizodeposition, since it is a critical point for assessing N benefits for other crops and for soil biological activity, and for reducing water pollution (Mayer et al., 2003). We adapted and refined the cotton-wick 15N stem labeling method for measuring the amount of soil N derived from rhizodeposition by field peas (Mahieu et al., 2007, 2009). The method was tested in different conditions in the field and in the greenhouse with various pea varieties and isolines. In addition, we used the cotton-wick method for assessing N transfers from pea to neighbouring durum wheat. In the greenhouse, a positive relationship was found between the amount of N rhizodeposits and the legume N content. N rhizodeposition was about 15% of the plant N and 30% in the field. In field pea / durum wheat intercrops, plant-plant N transfers were quantified and found to be bidirectional. Such results should be taken into account when estimating N benefits from biological N fixation by a grain legume crop and for the prediction of N economies in legume-based cropping systems. More studies dealing with rhizodeposit compounds and soil biological activity would now be necessary. Fustec et al. 2009. Agron. Sustain. Dev., DOI 10.1051/agro/2009003, in press. Mahieu et al. 2007. Plant Soil 295, 193-205. Mahieu et al. 2009. Soil Biol. Biochem. 41, 2236-2243. Mayer et al. 2003. Soil Biol. Biochem. 35, 21-28.

  15. Proteomics and Metabolomics: Two Emerging Areas for Legume Improvement.

    PubMed

    Ramalingam, Abirami; Kudapa, Himabindu; Pazhamala, Lekha T; Weckwerth, Wolfram; Varshney, Rajeev K

    2015-01-01

    The crop legumes such as chickpea, common bean, cowpea, peanut, pigeonpea, soybean, etc. are important sources of nutrition and contribute to a significant amount of biological nitrogen fixation (>20 million tons of fixed nitrogen) in agriculture. However, the production of legumes is constrained due to abiotic and biotic stresses. It is therefore imperative to understand the molecular mechanisms of plant response to different stresses and identify key candidate genes regulating tolerance which can be deployed in breeding programs. The information obtained from transcriptomics has facilitated the identification of candidate genes for the given trait of interest and utilizing them in crop breeding programs to improve stress tolerance. However, the mechanisms of stress tolerance are complex due to the influence of multi-genes and post-transcriptional regulations. Furthermore, stress conditions greatly affect gene expression which in turn causes modifications in the composition of plant proteomes and metabolomes. Therefore, functional genomics involving various proteomics and metabolomics approaches have been obligatory for understanding plant stress tolerance. These approaches have also been found useful to unravel different pathways related to plant and seed development as well as symbiosis. Proteome and metabolome profiling using high-throughput based systems have been extensively applied in the model legume species, Medicago truncatula and Lotus japonicus, as well as in the model crop legume, soybean, to examine stress signaling pathways, cellular and developmental processes and nodule symbiosis. Moreover, the availability of protein reference maps as well as proteomics and metabolomics databases greatly support research and understanding of various biological processes in legumes. Protein-protein interaction techniques, particularly the yeast two-hybrid system have been advantageous for studying symbiosis and stress signaling in legumes. In this review, several

  16. Proteomics and Metabolomics: Two Emerging Areas for Legume Improvement

    PubMed Central

    Ramalingam, Abirami; Kudapa, Himabindu; Pazhamala, Lekha T.; Weckwerth, Wolfram; Varshney, Rajeev K.

    2015-01-01

    The crop legumes such as chickpea, common bean, cowpea, peanut, pigeonpea, soybean, etc. are important sources of nutrition and contribute to a significant amount of biological nitrogen fixation (>20 million tons of fixed nitrogen) in agriculture. However, the production of legumes is constrained due to abiotic and biotic stresses. It is therefore imperative to understand the molecular mechanisms of plant response to different stresses and identify key candidate genes regulating tolerance which can be deployed in breeding programs. The information obtained from transcriptomics has facilitated the identification of candidate genes for the given trait of interest and utilizing them in crop breeding programs to improve stress tolerance. However, the mechanisms of stress tolerance are complex due to the influence of multi-genes and post-transcriptional regulations. Furthermore, stress conditions greatly affect gene expression which in turn causes modifications in the composition of plant proteomes and metabolomes. Therefore, functional genomics involving various proteomics and metabolomics approaches have been obligatory for understanding plant stress tolerance. These approaches have also been found useful to unravel different pathways related to plant and seed development as well as symbiosis. Proteome and metabolome profiling using high-throughput based systems have been extensively applied in the model legume species, Medicago truncatula and Lotus japonicus, as well as in the model crop legume, soybean, to examine stress signaling pathways, cellular and developmental processes and nodule symbiosis. Moreover, the availability of protein reference maps as well as proteomics and metabolomics databases greatly support research and understanding of various biological processes in legumes. Protein-protein interaction techniques, particularly the yeast two-hybrid system have been advantageous for studying symbiosis and stress signaling in legumes. In this review, several

  17. Uses of tree legumes in semi-arid regions

    SciTech Connect

    Felker, P.

    1980-01-01

    Uses of tree legumes in semi-arid and arid regions are reviewed. This review is divided into sections according to the following general use categories: fuels; human food; livestock food; to increase yields of crops grown beneath their canopies;and control of desertification. (MHR)

  18. The influence of cover crops and tillage on actual and potential soil erosion in an olive grove

    NASA Astrophysics Data System (ADS)

    Sastre, Blanca; Bienes, Ramón; García-Díaz, Andrés; Panagopoulos, Thomas; José Marqués, Maria

    2014-05-01

    The study was carried out in an olive grove in central Spain (South of Madrid; Tagus River Basin). In this semi-arid zone, the annual mean temperature is 13.8 ºC and the annual precipitation is 395 mm. Olive groves are planted in an erosion prone area due to steep slopes up to 15%. Soil is classified as Typic Haploxerept with clay loam texture. The land studied was formerly a vineyard, but it was replaced by the studied olive grove in 2004. It covers approximately 3 ha and olive trees are planted every 6 x 7 metres. They were usually managed by tillage to decrease weed competition. This conventional practice results in a wide surface of bare soil prone to erosion processes. In the long term soil degradation may lead to increase the desertification risk in the area. Storms have important consequences in this shallow and vulnerable soil, as more than 90 Mg ha-1 have been measured after one day with 40 mm of rainfall. In order to avoid this situation, cover crops between the olive trees were planted three years ago: sainfoin (Onobrychis viciifolia), barley (Hordeum vulgare), and purple false brome (Brachypodium distachyon), and they were compared with annual spontaneous vegetation after a minimum tillage treatment (ASV). The results regarding erosion control were positive. We observed (Oct. 2012/Sept. 2013) annual soil loss up to 11 Mg ha-1 in ASV, but this figure was reduced in the sown covers, being 8 Mg ha-1 in sainfoin treatment, 3,7 Mg ha-1 in barley treatment, and only 1,5 Mg ha-1 in false brome treatment. Those results are used to predict the risk of erosion in long term. Moreover, soil organic carbon (SOC) increased with treatments, this is significant as it reduces soil erodibility. The increases were found both in topsoil (up to 5 cm) and more in depth, in the root zone (from 5 to 10 cm depth). From higher to lower SOC values we found the false brome (1.05%), barley (0.92%), ASV (0.79%) and sainfoin (0.71%) regarding topsoil. In the root zone (5-10 cm depth

  19. Genetic diversity and phylogeography of begomoviruses infecting legumes in Pakistan.

    PubMed

    Ilyas, Muhammad; Qazi, Javaria; Mansoor, Shahid; Briddon, Rob W

    2010-08-01

    Grain legumes are an important source of dietary protein across southern Asia, but they suffer extensive losses due to several viruses that are members of the genus Begomovirus (family Geminiviridae), which are collectively known as legume yellow mosaic viruses (LYMVs). Despite their economic importance, little attention has been paid to LYMVs in Pakistan and only partial sequences of virus isolates originating from this country are available in the databases. Here, a survey of LYMVs occurring across Pakistan is described. Complete sequences of 44 components (23 DNA-A, 19 DNA-B and 2 betasatellites) were determined. The results show that only the mungbean yellow mosaic India virus (MYMIV) is of agricultural significance in Pakistan having been isolated from all cultivated grain legumes examined. Mungbean yellow mosaic virus, a significant crop pathogen in India, was only identified in a weed, which together with a novel species of LYMV we reported earlier, represents the first LYMV identified in non-cultivated plants. MYMIV was shown to occur as two types in Pakistan that show phylogeographical segregation. Additionally, two begomovirus species not considered pathogens of legumes and a betasatellite were isolated. This is of grave concern since it suggests that the presumed genetic isolation of the LYMVs in legumes may be being breached. LYMVs show little, if any, evidence of interspecific recombination with non-legume infecting begomoviruses. Thus, either recombination with non-legume viruses or interaction with betasatellites, which are host range and pathogenicity determining satellites of begomoviruses, could lead to the appearance of more aggressive virus variants/strains affecting legumes.

  20. Assessing the effectiveness of winter cover crop on nitrate reduction in two-paired sub-basins on the Coastal Plain of the Chesapeake Bay Watershed

    NASA Astrophysics Data System (ADS)

    Lee, S.; Yeo, I. Y.; Sadeghi, A. M.; Mccarty, G.; Hively, W. D.; Lang, M. W.

    2014-12-01

    Best management practices (BMPs) have been widely adopted to improve water quality throughout the Chesapeake Bay Watershed (CBW). Winter cover crops (WCC) use has been highlighted for the reduction of nitrate leaching over the fallow season. Although various WCC practices are currently conducted in local croplands, the water quality improvement benefits of WCC have not been studied thoroughly at the watershed scale. The objective of this study is to assess the long-term impacts of WCC on reducing nitrate loadings using a processed-based watershed model, Soil and Water Assessment Tool (SWAT). Remote sensing based estimates of WCC biomass will be used to calibrate plant growth processes of SWAT and its nutrient cycling. The study will be undertaken in two-paired agricultural watersheds in the Coastal Plain of CBW. Multiple WCC practice scenarios will be prepared to investigate how nitrate loading varies with crop species, planting dates, and implementation areas. The performance of WCC on two-paired watersheds will be compared in order to understand the effects of different watershed characteristics on nitrate uptake by crops. The results will demonstrate the nitrate reduction efficiency of different WCC practices and identify the targeting area for WCC implementation at the watershed scale. This study will not only integrate remote sensing data into the physically based model but also extend our understandings of WCC functions. This will provide key information for effective conservation decision making. Key words: Water quality, Chesapeake Bay Watershed, Winter Cover Crop, Soil and Water Assessment Tool (SWAT)

  1. Herbicide and cover crop residue integration for amaranth control in conservation agriculture cotton and implications for resistance management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation agriculture practices are threatened by glyphosate-resistant Palmer amaranth. Integrated practices including PRE herbicides and high-residue conservation agriculture systems may decrease Amaranth emergence. Field experiments were conducted from autumn 2006 through cash crop harvest in...

  2. Assessment of the AquaCrop model for use in simulation of irrigated winter wheat canopy cover, biomass, and grain yield in the North China Plain.

    PubMed

    Jin, Xiu-liang; Feng, Hai-kuan; Zhu, Xin-kai; Li, Zhen-hai; Song, Sen-nan; Song, Xiao-yu; Yang, Gui-Jun; Xu, Xin-gang; Guo, Wen-shan

    2014-01-01

    Improving winter wheat water use efficiency in the North China Plain (NCP), China is essential in light of current irrigation water shortages. In this study, the AquaCrop model was used to calibrate, and validate winter wheat crop performance under various planting dates and irrigation application rates. All experiments were conducted at the Xiaotangshan experimental site in Beijing, China, during seasons of 2008/2009, 2009/2010, 2010/2011 and 2011/2012. This model was first calibrated using data from 2008/2009 and 2009/2010, and subsequently validated using data from 2010/2011 and 2011/2012. The results showed that the simulated canopy cover (CC), biomass yield (BY) and grain yield (GY) were consistent with the measured CC, BY and GY, with corresponding coefficients of determination (R(2)) of 0.93, 0.91 and 0.93, respectively. In addition, relationships between BY, GY and transpiration (T), (R(2) = 0.57 and 0.71, respectively) was observed. These results suggest that frequent irrigation with a small amount of water significantly improved BY and GY. Collectively, these results indicate that the AquaCrop model can be used in the evaluation of various winter wheat irrigation strategies. The AquaCrop model predicted winter wheat CC, BY and GY with acceptable accuracy. Therefore, we concluded that AquaCrop is a useful decision-making tool for use in efforts to optimize wheat winter planting dates, and irrigation strategies.

  3. Assessment of the AquaCrop Model for Use in Simulation of Irrigated Winter Wheat Canopy Cover, Biomass, and Grain Yield in the North China Plain

    PubMed Central

    Jin, Xiu-liang; Feng, Hai-kuan; Zhu, Xin-kai; Li, Zhen-hai; Song, Sen-nan; Song, Xiao-yu; Yang, Gui-jun; Xu, Xin-gang; Guo, Wen-shan

    2014-01-01

    Improving winter wheat water use efficiency in the North China Plain (NCP), China is essential in light of current irrigation water shortages. In this study, the AquaCrop model was used to calibrate, and validate winter wheat crop performance under various planting dates and irrigation application rates. All experiments were conducted at the Xiaotangshan experimental site in Beijing, China, during seasons of 2008/2009, 2009/2010, 2010/2011 and 2011/2012. This model was first calibrated using data from 2008/2009 and 2009/2010, and subsequently validated using data from 2010/2011 and 2011/2012. The results showed that the simulated canopy cover (CC), biomass yield (BY) and grain yield (GY) were consistent with the measured CC, BY and GY, with corresponding coefficients of determination (R2) of 0.93, 0.91 and 0.93, respectively. In addition, relationships between BY, GY and transpiration (T), (R2 = 0.57 and 0.71, respectively) was observed. These results suggest that frequent irrigation with a small amount of water significantly improved BY and GY. Collectively, these results indicate that the AquaCrop model can be used in the evaluation of various winter wheat irrigation strategies. The AquaCrop model predicted winter wheat CC, BY and GY with acceptable accuracy. Therefore, we concluded that AquaCrop is a useful decision-making tool for use in efforts to optimize wheat winter planting dates, and irrigation strategies. PMID:24489808

  4. Impact of No-till Cover Cropping of Italian Ryegrass on Above and Below Ground Faunal Communities Inhabiting a Soybean Field with Emphasis on Soybean Cyst Nematodes.

    PubMed

    Hooks, Cerruti R R; Wang, Koon-Hui; Meyer, Susan L F; Lekveishvili, Mariam; Hinds, Jermaine; Zobel, Emily; Rosario-Lebron, Armando; Lee-Bullock, Mason

    2011-09-01

    Two field trials were conducted between 2008 and 2010 in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop to reduce populations of plant-parasitic nematodes while enhancing beneficial nematodes, soil mites and arthropods in the foliage of a no-till soybean (Glycine max) planting. Preplant treatments were: 1) previous year soybean stubble (SBS); and 2) herbicide-killed IR cover crop + previous year soybean stubble (referred to as IR). Heterodera glycines population densities were very low and no significant difference in population densities of H. glycines or Pratylenchus spp. were observed between IR and SBS. Planting of IR increased abundance of bacterivorous nematodes in 2009. A reverse trend was observed in 2010 where SBS had higher abundance of bacterivorous nematodes and nematode richness at the end of the cover cropping period. Italian ryegrass also did not affect insect pests on soybean foliage. However, greater populations of spiders were found on soybean foliage in IR treatments during both field trials. Potential causes of these findings are discussed.

  5. Overland flow connectivity in olive orchard plots with cover crops and conventional tillage, and under different rainfall scenarios

    NASA Astrophysics Data System (ADS)

    López-Vicente, Manuel; García-Ruiz, Roberto; Guzmán, Gema; Vicente-Vicente, José Luis; Gómez, José Alfonso

    2016-04-01

    The study of overland flow connectivity (QC) allows understanding the redistribution dynamics of runoff and soil components as an emergent property of the spatio-temporal interactions of hydrological and geomorphic processes. However, very few studies have dealt with runoff connectivity in olive orchards. In this study we simulated QC in four olive orchard plots, located on the Santa Marta farm (37° 20' 33.6" N, 6° 13' 44" W), in Seville province (Andalusia) in SW Spain. The olive plantation was established in 1985 with trees planted at 8 m x 6 m. Each bounded plot is 8 m wide (between 2 tree lines) and 60 m long (total area of 480 m2), laid out with the longest dimension parallel to the maximum slope and to the tree lines. The slope is uniform, with an average steepness of 11%. Two plots (P2 and P4) were devoted to conventional tillage (CT) consisting of regular chisel plow passes depending on weed growth. Another set of two plots had two types of cover crops (CC) in the inter tree rows (the area outside the vertical olive canopy projection): uniform CC of Lolium multiflorum (P3) and a mixture of L. rigidum and L. multiflorum together with other species (P5). The tree rows were treated with herbicide to keep bare soil. We selected the Index of runoff and sediment Connectivity (IC) of Borselli et al. (2008) to simulate three rainfall scenarios: i) low rainfall intensity (Sc-LowInt) and using the MD flow accumulation algorithm; ii) moderate rainfall intensity (Sc-ModInt) and using MD8; and iii) high rainfall intensity (Sc-HighInt) and using D8. After analysing the values of rainfall intensity during two hydrological years (Oct'09-Sep'10 and Oct'10-Sep'11) we associated the three scenarios with the followings months: Sc-LowInt during the period Jan-Mar, that summarizes 42% of all annual rainfall events; Sc-ModInt during Oct-Nov and Apr-May (32% of all events); and Sc-HighInt during the period Jun-Sep and in December (26% of all events). Instead of using the C

  6. Nitrogen yield advantage from grass-legume mixtures is robust over a wide range of legume proportions and environmental conditions.

    PubMed

    Suter, Matthias; Connolly, John; Finn, John A; Loges, Ralf; Kirwan, Laura; Sebastià, Maria-Teresa; Lüscher, Andreas

    2015-06-01

    Current challenges to global food security require sustainable intensification of agriculture through initiatives that include more efficient use of nitrogen (N), increased protein self-sufficiency through homegrown crops, and reduced N losses to the environment. Such challenges were addressed in a continental-scale field experiment conducted over 3 years, in which the amount of total nitrogen yield (Ntot ) and the gain of N yield in mixtures as compared to grass monocultures (Ngainmix ) was quantified from four-species grass-legume stands with greatly varying legume proportions. Stands consisted of monocultures and mixtures of two N2 -fixing legumes and two nonfixing grasses. The amount of Ntot of mixtures was significantly greater (P ≤ 0.05) than that of grass monocultures at the majority of evaluated sites in all 3 years. Ntot and thus Ngainmix increased with increasing legume proportion up to one-third of legumes. With higher legume percentages, Ntot and Ngainmix did not continue to increase. Thus, across sites and years, mixtures with one-third proportion of legumes attained ~95% of the maximum Ntot acquired by any stand and had 57% higher Ntot than grass monocultures. Realized legume proportion in stands and the relative N gain in mixture (Ngainmix /Ntot in mixture) were most severely impaired by minimum site temperature (R = 0.70, P = 0.003 for legume proportion; R = 0.64, P = 0.010 for Ngainmix /Ntot in mixture). Nevertheless, the relative N gain in mixture was not correlated to site productivity (P = 0.500), suggesting that, within climatic restrictions, balanced grass-legume mixtures can benefit from comparable relative gains in N yield across largely differing productivity levels. We conclude that the use of grass-legume mixtures can substantially contribute to resource-efficient agricultural grassland systems over a wide range of productivity levels, implying important savings in N fertilizers and thus greenhouse gas emissions and a

  7. How legumes recognize rhizobia.

    PubMed

    Via, Virginia Dalla; Zanetti, María Eugenia; Blanco, Flavio

    2016-01-01

    Legume plants have developed the capacity to establish symbiotic interactions with soil bacteria (known as rhizobia) that can convert N2 to molecular forms that are incorporated into the plant metabolism. The first step of this relationship is the recognition of bacteria by the plant, which allows to distinguish potentially harmful species from symbiotic partners. The main molecular determinant of this symbiotic interaction is the Nod Factor, a diffusible lipochitooligosaccharide molecule produced by rhizobia and perceived by LysM receptor kinases; however, other important molecules involved in the specific recognition have emerged over the years. Secreted exopolysaccharides and the lipopolysaccharides present in the bacterial cell wall have been proposed to act as signaling molecules, triggering the expression of specific genes related to the symbiotic process. In this review we will briefly discuss how transcriptomic analysis are helping to understand how multiple signaling pathways, triggered by the perception of different molecules produced by rhizobia, control the genetic programs of root nodule organogenesis and bacterial infection. This knowledge can help to understand how legumes have evolved to recognize and establish complex ecological relationships with particular species and strains of rhizobia, adjusting gene expression in response to identity determinants of bacteria. PMID:26636731

  8. Stover removal and cover crops effects on corn production and water use under full and limited irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn (Zea mays L.) residue removal in irrigated cropping systems for livestock forage or cellulosic ethanol is of great interest in south-central Nebraska. Irrigation water restrictions in the region have also resulted in adoption of limited-irrigation strategies. Little is known regarding the inter...

  9. Genome Structure of the Legume, Lotus japonicus

    PubMed Central

    Sato, Shusei; Nakamura, Yasukazu; Kaneko, Takakazu; Asamizu, Erika; Kato, Tomohiko; Nakao, Mitsuteru; Sasamoto, Shigemi; Watanabe, Akiko; Ono, Akiko; Kawashima, Kumiko; Fujishiro, Tsunakazu; Katoh, Midori; Kohara, Mitsuyo; Kishida, Yoshie; Minami, Chiharu; Nakayama, Shinobu; Nakazaki, Naomi; Shimizu, Yoshimi; Shinpo, Sayaka; Takahashi, Chika; Wada, Tsuyuko; Yamada, Manabu; Ohmido, Nobuko; Hayashi, Makoto; Fukui, Kiichi; Baba, Tomoya; Nakamichi, Tomoko; Mori, Hirotada; Tabata, Satoshi

    2008-01-01

    The legume Lotus japonicus has been widely used as a model system to investigate the genetic background of legume-specific phenomena such as symbiotic nitrogen fixation. Here, we report structural features of the L. japonicus genome. The 315.1-Mb sequences determined in this and previous studies correspond to 67% of the genome (472 Mb), and are likely to cover 91.3% of the gene space. Linkage mapping anchored 130-Mb sequences onto the six linkage groups. A total of 10 951 complete and 19 848 partial structures of protein-encoding genes were assigned to the genome. Comparative analysis of these genes revealed the expansion of several functional domains and gene families that are characteristic of L. japonicus. Synteny analysis detected traces of whole-genome duplication and the presence of synteny blocks with other plant genomes to various degrees. This study provides the first opportunity to look into the complex and unique genetic system of legumes. PMID:18511435

  10. Regional variability of environmental effects of energy crop rotations

    NASA Astrophysics Data System (ADS)

    Prescher, Anne-Katrin; Peter, Christiane; Specka, Xenia; Willms, Matthias; Glemnitz, Michael

    2014-05-01

    The use of energy crops for bioenergy production is increasingly promoted by different frameworks and policies (ECCP, UNFCCC). Energy cropping decreases greenhouse gas emissions by replacing the use of fossil fuel. However, despite this, growing in monocultures energy crop rotations has low environmental benefit. It is broadly accepted consensus that sustainable energy cropping is only realizable by crop rotations which include several energy crop species. Four crop rotations consisting of species mixtures of C3, C4 and leguminous plants and their crop positions were tested to identify the environmental effect of energy cropping systems. The experimental design included four replicates per crop rotation each covering four cultivation years. The study took place at five sites across Germany covering a considerable range of soil types (loamy sand to silt loam), temperatures (7.5 ° C - 10.0 ° C) and precipitation (559 mm - 807 mm) which allow a regional comparison of crop rotation performance. Four indicators were used to characterize the environmental conditions: (1) greenhouse gas (GHG) emissions from the management actions; (2) change in humus carbon (Chum); (3) groundwater recharge (RGW) and (4) nitrogen dynamics. The indicators were derived by balance, by an empirical model and by a dynamic model, respectively, all based and calibrated on measured values. The results show that the crop rotation impact on environmental indicators varied between plant species mixtures and the crop positions, between sites and climate. Crop rotations with 100 % energy crops (including C4 plants) had negative influence on Chum, GHG emissions per area and RGW in comparison to the rotation of 50 % energy crops and 50 % cash crops, which were mainly due to the remaining straw on the field. However, the biogas yield of the latter rotation was smaller, thus GHG emissions per product were higher, pointing out the importance to distinguish between GHG emissions per product and per area

  11. Nitrogen modulation of legume root architecture signaling pathways involves phytohormones and small regulatory molecules.

    PubMed

    Mohd-Radzman, Nadiatul A; Djordjevic, Michael A; Imin, Nijat

    2013-01-01

    Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

  12. Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment.

    PubMed

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

    2016-10-01

    Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were

  13. Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment.

    PubMed

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

    2016-10-01

    Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were

  14. Agricultural management practices to sustain crop yields and improve soil and environmental qualities.

    PubMed

    Sainju, Upendra M; Whitehead, Wayne F; Singh, Bharat P

    2003-08-20

    In the past several decades, agricultural management practices consisting of intensive tillage and high rate of fertilization to improve crop yields have resulted in the degradation of soil and environmental qualities by increasing erosion and nutrient leaching in the groundwater and releasing greenhouses gases, such as carbon dioxide (CO2) and nitrous oxide (N2O), that cause global warming in the atmosphere by oxidation of soil organic matter. Consequently, management practices that sustain crop yields and improve soil and environmental qualities are needed. This paper reviews the findings of the effects of tillage practices, cover crops, and nitrogen (N) fertilization rates on crop yields, soil organic carbon (C) and N concentrations, and nitrate (NO3)-N leaching from the soil. Studies indicate that conservation tillage, such as no-till or reduced till, can increase soil organic C and N concentrations at 0- to 20-cm depth by as much as 7-17% in 8 years compared with conventional tillage without significantly altering crop yields. Similarly, cover cropping and 80-180 kg N ha(-1) year(-1) fertilization can increase soil organic C and N concentrations by as much as 4-12% compared with no cover cropping or N fertilization by increasing plant biomass and amount of C and N inputs to the soil. Reduced till, cover cropping, and decreased rate of N fertilization can reduce soil N leaching compared with conventional till, no cover cropping, and full rate of N fertilization. Management practices consisting of combinations of conservation tillage, mixture of legume and nonlegume cover crops, and reduced rate of N fertilization have the potentials for sustaining crop yields, increasing soil C and N storage, and reducing soil N leaching, thereby helping to improve soil and water qualities. Economical and social analyses of such practices are needed to find whether they are cost effective and acceptable to the farmers.

  15. Comparative sequence analysis of nitrogen fixation-related genes in six legumes.

    PubMed

    Kim, Dong Hyun; Parupalli, Swathi; Azam, Sarwar; Lee, Suk-Ha; Varshney, Rajeev K

    2013-01-01

    Legumes play an important role as food and forage crops in international agriculture especially in developing countries. Legumes have a unique biological process called nitrogen fixation (NF) by which they convert atmospheric nitrogen to ammonia. Although legume genomes have undergone polyploidization, duplication and divergence, NF-related genes, because of their essential functional role for legumes, might have remained conserved. To understand the relationship of divergence and evolutionary processes in legumes, this study analyzes orthologs and paralogs for selected 20 NF-related genes by using comparative genomic approaches in six legumes i.e., Medicago truncatula (Mt), Cicer arietinum, Lotus japonicus, Cajanus cajan (Cc), Phaseolus vulgaris (Pv), and Glycine max (Gm). Subsequently, sequence distances, numbers of synonymous substitutions per synonymous site (Ks) and non-synonymous substitutions per non-synonymous site (Ka) between orthologs and paralogs were calculated and compared across legumes. These analyses suggest the closest relationship between Gm and Cc and the highest distance between Mt and Pv in six legumes. Ks proportional plots clearly showed ancient genome duplication in all legumes, whole genome duplication event in Gm and also speciation pattern in different legumes. This study also reports some interesting observations e.g., no peak at Ks 0.4 in Gm-Gm, location of two independent genes next to each other in Mt and low Ks values for outparalogs for three genes as compared to other 12 genes. In summary, this study underlines the importance of NF-related genes and provides important insights in genome organization and evolutionary aspects of six legume species analyzed. PMID:23986765

  16. Legume genomics: promise versus reality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Legume root nodules, the specialized organs in which symbiotic nitrogen fixation (SNF) occurs, are structurally and metabolically complex organs. Their development and function depends upon coordinated gene expression between the host plant and rhizobial partner. Depending upon the symbiosis, nodule...

  17. The value of biodiversity in legume symbiotic nitrogen fixation and nodulation for biofuel and food production.

    PubMed

    Gresshoff, Peter M; Hayashi, Satomi; Biswas, Bandana; Mirzaei, Saeid; Indrasumunar, Arief; Reid, Dugald; Samuel, Sharon; Tollenaere, Alina; van Hameren, Bethany; Hastwell, April; Scott, Paul; Ferguson, Brett J

    2015-01-01

    Much of modern agriculture is based on immense populations of genetically identical or near-identical varieties, called cultivars. However, advancement of knowledge, and thus experimental utility, is found through biodiversity, whether naturally-found or induced by the experimenter. Globally we are confronted by ever-growing food and energy challenges. Here we demonstrate how such biodiversity from the food legume crop soybean (Glycine max L. Merr) and the bioenergy legume tree Pongamia (Millettia) pinnata is a great value. Legume plants are diverse and are represented by over 18,000 species on this planet. Some, such as soybean, pea and medics are used as food and animal feed crops. Others serve as ornamental (e.g., wisteria), timber (e.g., acacia/wattle) or biofuel (e.g., Pongamia pinnata) resources. Most legumes develop root organs (nodules) after microsymbiont induction that serve as their habitat for biological nitrogen fixation. Through this, nitrogen fertiliser demand is reduced by the efficient symbiosis between soil Rhizobium-type bacteria and the appropriate legume partner. Mechanistic research into the genetics, biochemistry and physiology of legumes is thus strategically essential for future global agriculture. Here we demonstrate how molecular plant science analysis of the genetics of an established food crop (soybean) and an emerging biofuel P. pinnata feedstock contributes to their utility by sustainable production aided by symbiotic nitrogen fixation. PMID:25240795

  18. Tropical food legumes: virus diseases of economic importance and their control.

    PubMed

    Hema, Masarapu; Sreenivasulu, Pothur; Patil, Basavaprabhu L; Kumar, P Lava; Reddy, Dodla V R

    2014-01-01

    Diverse array of food legume crops (Fabaceae: Papilionoideae) have been adopted worldwide for their protein-rich seed. Choice of legumes and their importance vary in different parts of the world. The economically important legumes are severely affected by a range of virus diseases causing significant economic losses due to reduction in grain production, poor quality seed, and costs incurred in phytosanitation and disease control. The majority of the viruses infecting legumes are vectored by insects, and several of them are also seed transmitted, thus assuming importance in the quarantine and in the epidemiology. This review is focused on the economically important viruses of soybean, groundnut, common bean, cowpea, pigeonpea, mungbean, urdbean, chickpea, pea, faba bean, and lentil and begomovirus diseases of three minor tropical food legumes (hyacinth bean, horse gram, and lima bean). Aspects included are geographic distribution, impact on crop growth and yields, virus characteristics, diagnosis of causal viruses, disease epidemiology, and options for control. Effectiveness of selection and planting with virus-free seed, phytosanitation, manipulation of crop cultural and agronomic practices, control of virus vectors and host plant resistance, and potential of transgenic resistance for legume virus disease control are discussed. PMID:25410108

  19. Legume genomics: understanding biology through DNA and RNA sequencing

    PubMed Central

    O'Rourke, Jamie A.; Bolon, Yung-Tsi; Bucciarelli, Bruna; Vance, Carroll P.

    2014-01-01

    Background The legume family (Leguminosae) consists of approx. 17 000 species. A few of these species, including, but not limited to, Phaseolus vulgaris, Cicer arietinum and Cajanus cajan, are important dietary components, providing protein for approx. 300 million people worldwide. Additional species, including soybean (Glycine max) and alfalfa (Medicago sativa), are important crops utilized mainly in animal feed. In addition, legumes are important contributors to biological nitrogen, forming symbiotic relationships with rhizobia to fix atmospheric N2 and providing up to 30 % of available nitrogen for the next season of crops. The application of high-throughput genomic technologies including genome sequencing projects, genome re-sequencing (DNA-seq) and transcriptome sequencing (RNA-seq) by the legume research community has provided major insights into genome evolution, genomic architecture and domestication. Scope and Conclusions This review presents an overview of the current state of legume genomics and explores the role that next-generation sequencing technologies play in advancing legume genomics. The adoption of next-generation sequencing and implementation of associated bioinformatic tools has allowed researchers to turn each species of interest into their own model organism. To illustrate the power of next-generation sequencing, an in-depth overview of the transcriptomes of both soybean and white lupin (Lupinus albus) is provided. The soybean transcriptome focuses on analysing seed development in two near-isogenic lines, examining the role of transporters, oil biosynthesis and nitrogen utilization. The white lupin transcriptome analysis examines how phosphate deficiency alters gene expression patterns, inducing the formation of cluster roots. Such studies illustrate the power of next-generation sequencing and bioinformatic analyses in elucidating the gene networks underlying biological processes. PMID:24769535

  20. Grain and legume allergy.

    PubMed

    Ito, Komei

    2015-01-01

    Among grains and legumes, wheat and soybean are the most frequent and well-characterized allergenic foods. Wheat proteins are divided into water/salt-soluble and water/salt-insoluble (gluten) fractions. The most dominant allergen in the former is α-amylase/trypsin inhibitor, which acts as an inhaled allergen causing baker's asthma. Gluten allergens, including ω-5 gliadin and high- and low-molecular-weight glutenins, contribute to wheat-dependent exercise-induced anaphylaxis in adults and immediate-type wheat allergies, including anaphylaxis, in children. Recently, wheat allergies exclusively caused by hydrolyzed wheat proteins or deamidated glutens have been reported, and the presence of unique IgE-binding epitopes has been suggested. Soybean allergens contributing to immediate-type allergic reactions in children are present in seed storage proteins, namely Gly m 5, Gly m 6 and Gly m 8. However, pollen-related soybean allergy in adults is caused by the Bet v 1 homolog of soybeans, Gly m 4. Taken together, the varying clinical manifestations of wheat and soybean allergies are predominantly caused by their different allergen components.

  1. AgRISTARS: Early warning and crop condition assessment. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L. (Principal Investigator); Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J.

    1981-01-01

    Emissive (10.5 to 12.5 microns) and reflective (0.55 to 1.1 microns) data for ten day scenes and infrared data for six night scenes of southern Texas were analyzed for plant cover, soil temperature, freeze, water stress, and evapotranspiration. Heat capacity mapping mission radiometric temperatures were: within 2 C of dewpoint temperatures, significantly correlated with variables important in evapotranspiration, and related to freeze severity and planting depth soil temperatures.

  2. Increasing crop diversity mitigates weather variations and improves yield stability.

    PubMed

    Gaudin, Amélie C M; Tolhurst, Tor N; Ker, Alan P; Janovicek, Ken; Tortora, Cristina; Martin, Ralph C; Deen, William

    2015-01-01

    Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental

  3. Increasing Crop Diversity Mitigates Weather Variations and Improves Yield Stability

    PubMed Central

    Gaudin, Amélie C. M.; Tolhurst, Tor N.; Ker, Alan P.; Janovicek, Ken; Tortora, Cristina; Martin, Ralph C.; Deen, William

    2015-01-01

    Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental

  4. Increasing crop diversity mitigates weather variations and improves yield stability.

    PubMed

    Gaudin, Amélie C M; Tolhurst, Tor N; Ker, Alan P; Janovicek, Ken; Tortora, Cristina; Martin, Ralph C; Deen, William

    2015-01-01

    Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental

  5. Emerging Genomic Tools for Legume Breeding: Current Status and Future Prospects.

    PubMed

    Pandey, Manish K; Roorkiwal, Manish; Singh, Vikas K; Ramalingam, Abirami; Kudapa, Himabindu; Thudi, Mahendar; Chitikineni, Anu; Rathore, Abhishek; Varshney, Rajeev K

    2016-01-01

    Legumes play a vital role in ensuring global nutritional food security and improving soil quality through nitrogen fixation. Accelerated higher genetic gains is required to meet the demand of ever increasing global population. In recent years, speedy developments have been witnessed in legume genomics due to advancements in next-generation sequencing (NGS) and high-throughput genotyping technologies. Reference genome sequences for many legume crops have been reported in the last 5 years. The availability of the draft genome sequences and re-sequencing of elite genotypes for several important legume crops have made it possible to identify structural variations at large scale. Availability of large-scale genomic resources and low-cost and high-throughput genotyping technologies are enhancing the efficiency and resolution of genetic mapping and marker-trait association studies. Most importantly, deployment of molecular breeding approaches has resulted in development of improved lines in some legume crops such as chickpea and groundnut. In order to support genomics-driven crop improvement at a fast pace, the deployment of breeder-friendly genomics and decision support tools seems appear to be critical in breeding programs in developing countries. This review provides an overview of emerging genomics and informatics tools/approaches that will be the key driving force for accelerating genomics-assisted breeding and ultimately ensuring nutritional and food security in developing countries. PMID:27199998

  6. Emerging Genomic Tools for Legume Breeding: Current Status and Future Prospects

    PubMed Central

    Pandey, Manish K.; Roorkiwal, Manish; Singh, Vikas K.; Ramalingam, Abirami; Kudapa, Himabindu; Thudi, Mahendar; Chitikineni, Anu; Rathore, Abhishek; Varshney, Rajeev K.

    2016-01-01

    Legumes play a vital role in ensuring global nutritional food security and improving soil quality through nitrogen fixation. Accelerated higher genetic gains is required to meet the demand of ever increasing global population. In recent years, speedy developments have been witnessed in legume genomics due to advancements in next-generation sequencing (NGS) and high-throughput genotyping technologies. Reference genome sequences for many legume crops have been reported in the last 5 years. The availability of the draft genome sequences and re-sequencing of elite genotypes for several important legume crops have made it possible to identify structural variations at large scale. Availability of large-scale genomic resources and low-cost and high-throughput genotyping technologies are enhancing the efficiency and resolution of genetic mapping and marker-trait association studies. Most importantly, deployment of molecular breeding approaches has resulted in development of improved lines in some legume crops such as chickpea and groundnut. In order to support genomics-driven crop improvement at a fast pace, the deployment of breeder-friendly genomics and decision support tools seems appear to be critical in breeding programs in developing countries. This review provides an overview of emerging genomics and informatics tools/approaches that will be the key driving force for accelerating genomics-assisted breeding and ultimately ensuring nutritional and food security in developing countries. PMID:27199998

  7. Short term effect of conventional tillage and cover crops in physical and chemical properties in two olive orchards of southern Spain

    NASA Astrophysics Data System (ADS)

    Guzmán, Gema; Giráldez, Juan Vicente; Gómez, José Alfonso

    2014-05-01

    Numerous studies have attempted to assess the differences in soil properties caused by different management systems in olive cropped farms. Nevertheless the influence of the most frequent management systems on the hydraulic properties of these soils has not been evaluated. Contrarily, there are very few studies that have tried to correlate these results with soil losses due to water erosion. There are complementary approaches to traditional degradation indices, as the S index based on the form of the soil retention curve (Dexter 2004a,b,c). The objectives of this study were (i) to evaluate the methods based on the S index to assess the physical quality of soil in olive orchards, (ii) to assess the short-term changes (2 years) in soil physical and chemical properties in two olive orchards under different managements systems, namely conventional tillage and cover crop, and (iii) to formulate strategies for assessing the quality of soil in olive orchards. For the studied soils, degradation processes (associated to conventional tillage) and the improvement of their properties (linked to cover crops) showed a fast response. Chemical changes were quickly observed. However physical changes are slower than chemical changes for both soils. Water retention curves allowed the evaluation of soil porosity based on depth in the profile and the management practices. The S index was computed for every soil using the conventional soil water retention equations fitted to the experimental data. For the olive cropped soils, higher S index values were obtained in the less degradated areas, in most of the cases. Therefore, the S index could be used as a soil quality indicator although further research should be required to study its evolution at a larger temporal scale. References: Dexter, A. R. 2004. a.- Soil physical quality. PartI. Theory, effects of soil texture, density, and organic matter, and effects on root growth. Geoderma 120 (2004) 201-214. Dexter, A. R. 2004. b.- Soil

  8. Short-Term Response of Soil Spiders to Cover-Crop Removal in an Organic Olive Orchard in a Mediterranean Setting

    PubMed Central

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity. PMID:22938154

  9. Short-term response of soil spiders to cover-crop removal in an organic olive orchard in a Mediterranean setting.

    PubMed

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity.

  10. The First Attested Extraction of Ancient DNA in Legumes (Fabaceae).

    PubMed

    Mikić, Aleksandar M

    2015-01-01

    Ancient DNA (aDNA) is any DNA extracted from ancient specimens, important for diverse evolutionary researches. The major obstacles in aDNA studies are mutations, contamination and fragmentation. Its studies may be crucial for crop history if integrated with human aDNA research and historical linguistics, both general and relating to agriculture. Legumes (Fabaceae) are one of the richest end economically most important plant families, not only from Neolithic onwards, since they were used as food by Neanderthals and Paleolithic modern man. The idea of extracting and analyzing legume aDNA was considered beneficial for both basic science and applied research, with an emphasis on genetic resources and plant breeding. The first reported successful and attested extraction of the legume aDNA was done from the sample of charred seeds of pea (Pisum sativum) and bitter vetch (Vicia ervilia) from Hissar, southeast Serbia, dated to 1,350-1,000 Before Christ. A modified version of cetyltrimethylammonium bromide (CTAB) method and the commercial kit for DNA extraction QIAGEN DNAesy yielded several ng μl(-1) of aDNA of both species and, after the whole genome amplification and with a fragment of nuclear ribosomal DNA gene 26S rDNA, resulted in the detection of the aDNA among the PCR products. A comparative analysis of four informative chloroplast DNA regions (trnSG, trnK, matK, and rbcL) among the modern wild and cultivated pea taxa demonstrated not only that the extracted aDNA was genuine, on the basis of mutation rate, but also that the ancient Hissar pea was most likely an early domesticated crop, related to the modern wild pea of a neighboring region. It is anticipated that this premier extraction of legume aDNA may provide taxonomists with the answers to diverse questions, such as leaf development in legumes, as well as with novel data on the single steps in domesticating legume crops worldwide. PMID:26635833

  11. The First Attested Extraction of Ancient DNA in Legumes (Fabaceae)

    PubMed Central

    Mikić, Aleksandar M.

    2015-01-01

    Ancient DNA (aDNA) is any DNA extracted from ancient specimens, important for diverse evolutionary researches. The major obstacles in aDNA studies are mutations, contamination and fragmentation. Its studies may be crucial for crop history if integrated with human aDNA research and historical linguistics, both general and relating to agriculture. Legumes (Fabaceae) are one of the richest end economically most important plant families, not only from Neolithic onwards, since they were used as food by Neanderthals and Paleolithic modern man. The idea of extracting and analyzing legume aDNA was considered beneficial for both basic science and applied research, with an emphasis on genetic resources and plant breeding. The first reported successful and attested extraction of the legume aDNA was done from the sample of charred seeds of pea (Pisum sativum) and bitter vetch (Vicia ervilia) from Hissar, southeast Serbia, dated to 1,350–1,000 Before Christ. A modified version of cetyltrimethylammonium bromide (CTAB) method and the commercial kit for DNA extraction QIAGEN DNAesy yielded several ng μl-1 of aDNA of both species and, after the whole genome amplification and with a fragment of nuclear ribosomal DNA gene 26S rDNA, resulted in the detection of the aDNA among the PCR products. A comparative analysis of four informative chloroplast DNA regions (trnSG, trnK, matK, and rbcL) among the modern wild and cultivated pea taxa demonstrated not only that the extracted aDNA was genuine, on the basis of mutation rate, but also that the ancient Hissar pea was most likely an early domesticated crop, related to the modern wild pea of a neighboring region. It is anticipated that this premier extraction of legume aDNA may provide taxonomists with the answers to diverse questions, such as leaf development in legumes, as well as with novel data on the single steps in domesticating legume crops worldwide. PMID:26635833

  12. Reconsidering domestication of legumes versus cereals in the ancient near east.

    PubMed

    Abbo, Shahal; Saranga, Yehoshua; Peleg, Zvi; Kerem, Zohar; Lev-Yadun, Simcha; Gopher, Avi

    2009-03-01

    In this paper, we discuss, from both biological and cultural perspectives, the ancient human-plant liaison that gave rise to Near Eastern agriculture. We explain the biological aspects of Near Eastern plant domestication by a comparative analysis of legume vs. cereal crop evolution. This comparison is illustrated by the natural distribution, ecological affinity, physiology, population structure, floral biology, growth habit, plant stature, seed dispersal mode, and seed dormancy of both wild and domesticated plants of these crop groups. We discuss the differences between Near Eastern legumes and cereals with regard to each of the above aspects, and we highlight the relevance of these differences with regard to Neolithic decision-making, adoption for farming, and subsequent evolution under domestication. We reached the following conclusions: (1) Near Eastern legumes underwent different evolutionary trajectories under domestication as compared with their companion cereals, despite apparent similarities between selection under domestication of both crop groups. (2) Careful comparison of pea, lentil, and chickpea shows that each of the Near Eastern legume crops has a unique evolutionary history in its own right, and this also holds true for the cereal crops. (3) The evolutionary history of each of the Near Eastern crops, prior to as well as after domestication, is well-reflected in its adaptation profile in present-day cropping systems, which determines each crop's relative economic importance in different world regions (e.g., chickpea is a major pulse in the Indian subcontinent, and pea is a more important crop in temperate regions, while barley has the widest adaptation, extending from high-latitude temperate regions to semi-arid Mediterranean systems). (4) Ancient choice-making as reflected in the founder crops repertoire, involved nutritional considerations that may have outweighed grain yield per area and/or time unit criteria.

  13. Cereal grains, legumes and diabetes.

    PubMed

    Venn, B J; Mann, J I

    2004-11-01

    This review examines the evidence for the role of whole grain foods and legumes in the aetiology and management of diabetes. MedLine and SilverPlatter ('Nutrition' and 'Food Science FSTA') databases were searched to identify epidemiological and experimental studies relating to the effects of whole grain foods and legumes on indicators of carbohydrate metabolism. Epidemiological studies strongly support the suggestion that high intakes of whole grain foods protect against the development of type II diabetes mellitus (T2DM). People who consume approximately 3 servings per day of whole grain foods are less likely to develop T2DM than low consumers (<3 servings per week) with a risk reduction in the order of 20-30%. The role of legumes in the prevention of diabetes is less clear, possibly because of the relatively low intake of leguminous foods in the populations studied. However, legumes share several qualities with whole grains of potential benefit to glycaemic control including slow release carbohydrate and a high fibre content. A substantial increase in dietary intake of legumes as replacement food for more rapidly digested carbohydrate might therefore be expected to improve glycaemic control and thus reduce incident diabetes. This is consistent with the results of dietary intervention studies that have found improvements in glycaemic control after increasing the dietary intake of whole grain foods, legumes, vegetables and fruit. The benefit has been attributed to an increase in soluble fibre intake. However, prospective studies have found that soluble fibre intake is not associated with a lower incidence of T2DM. On the contrary, it is cereal fibre that is largely insoluble that is associated with a reduced risk of developing T2DM. Despite this, the addition of wheat bran to the diets of diabetic people has not improved indicators of glycaemic control. These apparently contradictory findings might be explained by metabolic studies that have indicated improvement

  14. Large-scale microsatellite development in grasspea (Lathyrus sativus L.), an orphan legume of the arid areas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasspea (Lathyrus sativus L., 2n = 14), a member of the family Leguminosae, holds great agronomic potential as grain and forage legume crop in the arid areas for its superb resilience to abiotic stresses such as drought, flood and salinity. The crop could not make much progress through conventional...

  15. Legumes increase rhizosphere carbon and nitrogen relative to cereals in California agricultural plots

    NASA Astrophysics Data System (ADS)

    Bergman, R.; Maltais-landry, G.

    2013-12-01

    Nitrogen (N) is an essential nutrient to plant growth, therefore a sufficient supply is needed for high yields. By using N-fixing plants like legumes in crop rotation, we can increase soil N and yields of following crops. Furthermore, legumes also affect soil carbon (C) and C:N ratios, which impacts nutrient cycling in soils. We assessed the effects of two legumes (vetch, fava bean) and a cereal mixture (oats and wheat) on soil N and C by comparing both rhizosphere and bulk soils. We studied the impacts of these plants with different management types (organic, low-input conventional, unfertilized) to see if plant effects on soil C and N changed across management. We used plots from the Long-Term Research on Agricultural Systems (LTRAS) experiment (Davis, CA) to conduct this experiment, where three plots were under each management type. Within each of these plots, we sampled three micro-plots, where we collected rhizosphere soil from fava bean, vetch, and cereals as well as bulk soil, i.e. non-rhizosphere soil. We collected 108 samples, each of which were dried and ball-milled into a fine, uniform powder. Tin capsules with 15-30mg of soil were then analyzed with a Carlo Erba Elemental analyzer to measure how much N and C was present in each of the samples. The different management types didn't affect the relationship among plants, but soil C and N were highest in organic and lowest in unfertilized plots. We found that N was significantly higher in legume rhizosphere than cereal rhizosphere and bulk soils. Soil C was also higher in legumes vs. cereals and bulk soils, but the only significant difference was with the bulk soils. This ultimately resulted in lower C:N ratios in the rhizosphere of legumes, only vetch, however, had significantly lower soil C:N than cereals. Vetch had higher N, and lower C and C:N than fava bean, but the difference between the two legumes was never significant. Similarly, cereals had higher C and N and lower C:N than bulk soils, although

  16. Increasing seed size and quality by manipulating BIG SEEDS 1 in legume species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant organs such as seeds are primary sources of food for both humans and animals. Seed size is one of the major agronomic traits that have been selected in crop plants during their domestication. Legume seeds are a major source of dietary proteins and oils. Here, we report a novel and conserved ro...

  17. Enhancing Legume Ecosystem Services through an Understanding of Plant-Pollinator Interplay.

    PubMed

    Suso, María J; Bebeli, Penelope J; Christmann, Stefanie; Mateus, Célia; Negri, Valeria; Pinheiro de Carvalho, Miguel A A; Torricelli, Renzo; Veloso, Maria M

    2016-01-01

    Legumes are bee-pollinated, but to a different extent. The importance of the plant-pollinator interplay (PPI), in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: (1) optimal productivity, based on an efficient use of pollinators, and (2) biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the "pest control service" and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: (a) Farming with Alternative Pollinators and (b) Crop Design System.

  18. Grain legume impacts on soil biological processes in Sub-Saharan Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain legumes occupy about 20 million hectares in Africa. The major crops are cowpea (Vigna unguiculata), which is grown on about 11 million hectares mostly in west Africa, and common bean (Phaseolus vulgaris), grown on about 5 million hectares mostly in eastern and southern Africa. These grain le...

  19. Enhancing Legume Ecosystem Services through an Understanding of Plant–Pollinator Interplay

    PubMed Central

    Suso, María J.; Bebeli, Penelope J.; Christmann, Stefanie; Mateus, Célia; Negri, Valeria; Pinheiro de Carvalho, Miguel A. A.; Torricelli, Renzo; Veloso, Maria M.

    2016-01-01

    Legumes are bee-pollinated, but to a different extent. The importance of the plant–pollinator interplay (PPI), in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: (1) optimal productivity, based on an efficient use of pollinators, and (2) biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the “pest control service” and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: (a) Farming with Alternative Pollinators and (b) Crop Design System. PMID:27047514

  20. Comprehensive Comparative Genomic and Transcriptomic Analyses of the Legume Genes Controlling the Nodulation Process.

    PubMed

    Qiao, Zhenzhen; Pingault, Lise; Nourbakhsh-Rey, Mehrnoush; Libault, Marc

    2016-01-01

    Nitrogen is one of the most essential plant nutrients and one of the major factors limiting crop productivity. Having the goal to perform a more sustainable agriculture, there is a need to maximize biological nitrogen fixation, a feature of legumes. To enhance our understanding of the molecular mechanisms controlling the interaction between legumes and rhizobia, the symbiotic partner fixing and assimilating the atmospheric nitrogen for the plant, researchers took advantage of genetic and genomic resources developed across different legume models (e.g., Medicago truncatula, Lotus japonicus, Glycine max, and Phaseolus vulgaris) to identify key regulatory protein coding genes of the nodulation process. In this study, we are presenting the results of a comprehensive comparative genomic analysis to highlight orthologous and paralogous relationships between the legume genes controlling nodulation. Mining large transcriptomic datasets, we also identified several orthologous and paralogous genes characterized by the induction of their expression during nodulation across legume plant species. This comprehensive study prompts new insights into the evolution of the nodulation process in legume plant and will benefit the scientific community interested in the transfer of functional genomic information between species.

  1. Comprehensive Comparative Genomic and Transcriptomic Analyses of the Legume Genes Controlling the Nodulation Process.

    PubMed

    Qiao, Zhenzhen; Pingault, Lise; Nourbakhsh-Rey, Mehrnoush; Libault, Marc

    2016-01-01

    Nitrogen is one of the most essential plant nutrients and one of the major factors limiting crop productivity. Having the goal to perform a more sustainable agriculture, there is a need to maximize biological nitrogen fixation, a feature of legumes. To enhance our understanding of the molecular mechanisms controlling the interaction between legumes and rhizobia, the symbiotic partner fixing and assimilating the atmospheric nitrogen for the plant, researchers took advantage of genetic and genomic resources developed across different legume models (e.g., Medicago truncatula, Lotus japonicus, Glycine max, and Phaseolus vulgaris) to identify key regulatory protein coding genes of the nodulation process. In this study, we are presenting the results of a comprehensive comparative genomic analysis to highlight orthologous and paralogous relationships between the legume genes controlling nodulation. Mining large transcriptomic datasets, we also identified several orthologous and paralogous genes characterized by the induction of their expression during nodulation across legume plant species. This comprehensive study prompts new insights into the evolution of the nodulation process in legume plant and will benefit the scientific community interested in the transfer of functional genomic information between species. PMID:26858743

  2. Biological nitrogen fixation in non-legume plants

    PubMed Central

    Santi, Carole; Bogusz, Didier; Franche, Claudine

    2013-01-01

    Background Nitrogen is an essential nutrient in plant growth. The ability of a plant to supply all or part of its requirements from biological nitrogen fixation (BNF) thanks to interactions with endosymbiotic, associative and endophytic symbionts, confers a great competitive advantage over non-nitrogen-fixing plants. Scope Because BNF in legumes is well documented, this review focuses on BNF in non-legume plants. Despite the phylogenic and ecological diversity among diazotrophic bacteria and their hosts, tightly regulated communication is always necessary between the microorganisms and the host plant to achieve a successful interaction. Ongoing research efforts to improve knowledge of the molecular mechanisms underlying these original relationships and some common strategies leading to a successful relationship between the nitrogen-fixing microorganisms and their hosts are presented. Conclusions Understanding the molecular mechanism of BNF outside the legume–rhizobium symbiosis could have important agronomic implications and enable the use of N-fertilizers to be reduced or even avoided. Indeed, in the short term, improved understanding could lead to more sustainable exploitation of the biodiversity of nitrogen-fixing organisms and, in the longer term, to the transfer of endosymbiotic nitrogen-fixation capacities to major non-legume crops. PMID:23478942

  3. Soil Fertility Map for Food Legumes Production Areas in China

    PubMed Central

    Li, Ling; Yang, Tao; Redden, Robert; He, Weifeng; Zong, Xuxiao

    2016-01-01

    Given the limited resources of fossil energy, and the environmental risks of excess fertilizer on crops, it is time to reappraise the potential role of food legume biological nitrogen fixation (BNF) as sources of nitrogen for cropping systems in China. 150 soil samples across 17 provinces and 2 municipalities of China were collected and analyzed. A distribution map of the soil fertilities and their patterns of distribution was constructed. The pH results indicated that soils were neutral to slightly alkaline overall. The soil organic matter (SOM) and the available nitrogen (AN) content were relatively low, while the available phosphorus (AP) and available potassium (AK) contents were from moderate to high. Production areas of food legumes (faba bean, pea, adzuki bean, mung bean and common bean) were clearly separated into 4 soil fertility type clusters. In addition, regions with SOM, AN, AP and AK deficiency, high acidity and high alkalinity were listed as target areas for further soil improvement. The potential was considered for biological nitrogen fixation to substitute for the application of mineral nitrogen fertiliser. PMID:27212262

  4. Soil Fertility Map for Food Legumes Production Areas in China.

    PubMed

    Li, Ling; Yang, Tao; Redden, Robert; He, Weifeng; Zong, Xuxiao

    2016-01-01

    Given the limited resources of fossil energy, and the environmental risks of excess fertilizer on crops, it is time to reappraise the potential role of food legume biological nitrogen fixation (BNF) as sources of nitrogen for cropping systems in China. 150 soil samples across 17 provinces and 2 municipalities of China were collected and analyzed. A distribution map of the soil fertilities and their patterns of distribution was constructed. The pH results indicated that soils were neutral to slightly alkaline overall. The soil organic matter (SOM) and the available nitrogen (AN) content were relatively low, while the available phosphorus (AP) and available potassium (AK) contents were from moderate to high. Production areas of food legumes (faba bean, pea, adzuki bean, mung bean and common bean) were clearly separated into 4 soil fertility type clusters. In addition, regions with SOM, AN, AP and AK deficiency, high acidity and high alkalinity were listed as target areas for further soil improvement. The potential was considered for biological nitrogen fixation to substitute for the application of mineral nitrogen fertiliser. PMID:27212262

  5. Soil Fertility Map for Food Legumes Production Areas in China.

    PubMed

    Li, Ling; Yang, Tao; Redden, Robert; He, Weifeng; Zong, Xuxiao

    2016-05-23

    Given the limited resources of fossil energy, and the environmental risks of excess fertilizer on crops, it is time to reappraise the potential role of food legume biological nitrogen fixation (BNF) as sources of nitrogen for cropping systems in China. 150 soil samples across 17 provinces and 2 municipalities of China were collected and analyzed. A distribution map of the soil fertilities and their patterns of distribution was constructed. The pH results indicated that soils were neutral to slightly alkaline overall. The soil organic matter (SOM) and the available nitrogen (AN) content were relatively low, while the available phosphorus (AP) and available potassium (AK) contents were from moderate to high. Production areas of food legumes (faba bean, pea, adzuki bean, mung bean and common bean) were clearly separated into 4 soil fertility type clusters. In addition, regions with SOM, AN, AP and AK deficiency, high acidity and high alkalinity were listed as target areas for further soil improvement. The potential was considered for biological nitrogen fixation to substitute for the application of mineral nitrogen fertiliser.

  6. Soil spatial variability and symbiotic nitrogen fixation by legumes

    SciTech Connect

    Reichardt, K. )

    1990-09-01

    The isotope dilution method for the estimation of N{sub 2} fixation by legumes is analyzed, comparing the application of {sup 15}N-enriched fertilizer with {sup 15}N-labeled soil. Soil variability of other dynamic processes in the soil are discussed in light of the distribution of the {sup 15}N label in the system. Field data were collected along six transects, 45 m long, with 30 plots (replicates) each. The legume (Vicia faba L.) was used as a fixing crop, barley (Hordeum vulgare L.) and oil radish (Raphinus sativus L.) as nonfixing standard crops. Isotope methods were also compared with the yield difference method. Results show that isotope methods were very sensitive to the distribution of the label in the soil and that dynamic processes involving N can significantly affect this distribution over a whole field. Best results were obtained with {sup 15}N-labeled soil. The particular site used, having been farmed for more than 20 years with {sup 15}N trials, showed a homogeneous residual {sup 15}N label that made it possible to estimate N{sub 2} fixation without the application of extra label. Estimates of N{sub 2} fixation with the isotope method were well correlated with the yield difference method when fertilizer use efficiency of the fixing and nonfixing crops were similar. Results also indicate that a good reference crop for one method might not be the best for the other method, and one reason for this is the variability of soil parameters and of dynamic processes occurring in the soil.

  7. Scent glands in legume flowers.

    PubMed

    Marinho, C R; Souza, C D; Barros, T C; Teixeira, S P

    2014-01-01

    Scent glands, or osmophores, are predominantly floral secretory structures that secrete volatile substances during anthesis, and therefore act in interactions with pollinators. The Leguminosae family, despite being the third largest angiosperm family, with a wide geographical distribution and diversity of habits, morphology and pollinators, has been ignored with respect to these glands. Thus, we localised and characterised the sites of fragrance production and release in flowers of legumes, in which scent plays an important role in pollination, and also tested whether there are relationships between the structure of the scent gland and the pollinator habit: diurnal or nocturnal. Flowers in pre-anthesis and anthesis of 12 legume species were collected and analysed using immersion in neutral red, olfactory tests and anatomical studies (light and scanning electron microscopy). The main production site of floral scent is the perianth, especially the petals. The scent glands are distributed in a restricted way in Caesalpinia pulcherrima, Anadenanthera peregrina, Inga edulis and Parkia pendula, constituting mesophilic osmophores, and in a diffuse way in Bauhinia rufa, Hymenaea courbaril, Erythrostemon gilliesii, Poincianella pluviosa, Pterodon pubescens, Platycyamus regnellii, Mucuna urens and Tipuana tipu. The glands are comprised of cells of the epidermis and mesophyll that secrete mainly terpenes, nitrogen compounds and phenols. Relationships between the presence of osmophores and type of anthesis (diurnal and nocturnal) and the pollinator were not found. Our data on scent glands in Leguminosae are original and detail the type of diffuse release, which has been very poorly studied. PMID:23574349

  8. The potential of oil-utilizing bacterial consortia associated with legume root nodules for cleaning oily soils.

    PubMed

    Dashti, N; Khanafer, M; El-Nemr, I; Sorkhoh, N; Ali, N; Radwan, S

    2009-03-01

    The surfaces of root nodules of Vicia faba and Lupinus albus (legume crops), were colonized with bacterial consortia which utilized oil and fixed nitrogen. Such combined activities apparently make those periphytic consortia efficient contributors to bioremediation of oily nitrogen-poor desert soils. This was confirmed experimentally in this study. Thus, cultivating V. faba, L. albus and, for comparison, Solanum melongena, a nonlegume crop, separately in oily sand samples resulted in more oil attenuation than in an uncultivated sample. This effect was more pronounced with the legume crops than with the nonlegume crop. Furthermore, in flask cultures, V. faba plants with nodulated roots exhibited a higher potential for oil attenuation in the surrounding water than plants with nodule-free roots. Denaturation gradient gel electrophoresis (DGGE) of polymerase chain reaction amplified 16S rRNA coding genes revealed that periphytic bacteria had DGGE bands not matching those of the oil-utilizing rhizospheric bacteria. Legume nodules also contained endophytic bacteria whose 16S rDNA bands did not match those of Rhizobium nor those of all other individual periphytic and rhizospheric strains. It was concluded that legume crops host on their roots bacterial consortia with a satisfactory potential for oil phytoremediation.

  9. Water-saving ground cover rice production system reduces net greenhouse gas fluxes in an annual rice-based cropping system

    NASA Astrophysics Data System (ADS)

    Yao, Z.; Du, Y.; Tao, Y.; Zheng, X.; Liu, C.; Lin, S.; Butterbach-Bahl, K.

    2014-11-01

    To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS) is being increasingly adopted for rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere-atmosphere exchanges of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE) and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emissions) over a complete year, and the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN) and GCRPS (GUN and GNN), and solely chicken manure (GCM) and combined urea and chicken manure applications (GUM) for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40 and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.09 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN). The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of -1.33 Mg C ha-1 yr-1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80-11.02 Mg CO2-eq ha-1 yr-1 for the conventional paddy and 3.05-9.37 Mg CO2-eq ha-1 yr-1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effects from rice cultivation. Using organic fertilizers for GCRPS considerably reduced annual emissions of CH4

  10. Water-saving ground cover rice production system reduces net greenhouse gas fluxes in an annual rice-based cropping system

    NASA Astrophysics Data System (ADS)

    Yao, Z.; Du, Y.; Tao, Y.; Zheng, X.; Liu, C.; Lin, S.; Butterbach-Bahl, K.

    2014-06-01

    To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS) is being increasingly adopted for the rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere-atmosphere exchanges of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE) and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emission) over a complete year, as well as the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN) and GCRPS (GUN and GNN), solely chicken manure (GCM) and combined urea and chicken manure applications (GUM) for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40% and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.087 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN). The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of -1.33 Mg C ha-1 yr-1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80-11.02 Mg CO2-eq ha-1 yr-1 for the conventional paddy and 3.05-9.37 Mg CO2-eq ha-1 yr-1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effect from rice cultivation. Using organic fertilizers for GCRPS considerably reduced annual emissions

  11. Cumulative impact of a clover cover crop on the persistence and efficacy of Beauveria bassiana in suppressing the pecan weevil (Coleoptera: Curculionidae).

    PubMed

    Shapiro-Ilan, David I; Gardner, Wayne A; Wells, Lenny; Wood, Bruce W

    2012-04-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan. Endemic levels of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin can occur in pecan orchards and contribute to natural control of C. caryae. Commercial formulations of the fungus can also be applied for suppression of C. caryae. We hypothesized that a clover cover crop enhances B. bassiana efficacy and persistence (e.g., by protecting the fungus against abiotic environmental stresses). The hypothesis was tested by conducting field trials in a pecan orchard in Byron, GA, in 2009 and 2010. The study included four treatments arranged in a factorial with two levels of fungus (endemic fungus only, and application of a commercial B. bassiana product), and two levels of clover (white clover, Trifolium repens L., and no clover). Fungal persistence was measured by determining the number of CFUs per gram of soil over time (during 42 d postapplication of B. bassiana in 2009 and 29 d in 2010). Efficacy was measured by capturing naturally emerging C. caryae and subsequently determining mortality and mycosis (over 24 d in 2009 and 17 d in 2010). In 2009, greater prevalence of B. bassiana conidia was detected in plots receiving fungal applications compared with no fungus applications, and no clear effect of clover was observed in plots receiving B. bassiana applications in either year. In 2010, B. bassiana prevalence in the endemic fungus plus clover treatment was higher than fungus without clover, and was similar to plots receiving additional B. bassiana applications. Given that we observed enhanced persistence of endemic B. bassiana in 2010 but not 2009, the impact of clover appears to be a cumulative effect. Mortality of C. caryae (averaged over the sampling periods) ranged between 68-74% in plots receiving B. bassiana applications and 51-56% in plots with endemic fungus only. C. caryae mortality and mycosis data also provided evidence that endemic B. bassiana efficacy was enhanced by clover

  12. Impact of thermal processing on legume allergens.

    PubMed

    Verma, Alok Kumar; Kumar, Sandeep; Das, Mukul; Dwivedi, Premendra D

    2012-12-01

    Food induced allergic manifestations are reported from several parts of the world. Food proteins exert their allergenic potential by absorption through the gastrointestinal tract and can even induce life threatening anaphylaxis reactions. Among all food allergens, legume allergens play an important role in induction of allergy because legumes are a major source of protein for vegetarians. Most of the legumes are cooked either by boiling, roasting or frying before consumption, which can be considered a form of thermal treatment. Thermal processing may also include autoclaving, microwave heating, blanching, pasteurization, canning, or steaming. Thermal processing of legumes may reduce, eliminate or enhance the allergenic potential of a respective legume. In most of the cases, minimization of allergenic potential on thermal treatment has generally been reported. Thus, thermal processing can be considered an important tool by indirectly prevent allergenicity in susceptible individuals, thereby reducing treatment costs and reducing industry/office/school absence in case of working population/school going children. The present review attempts to explore various possibilities of reducing or eliminating allergenicity of leguminous food using different methods of thermal processing. Further, this review summarizes different methods of food processing, major legumes and their predominant allergenic proteins, thermal treatment and its relation with antigenicity, effect of thermal processing on legume allergens; also suggests a path that may be taken for future research to reduce the allergenicity using conventional/nonconventional methods.

  13. Biotechnology: herbicide-resistant crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  14. The spatial genetic differentiation of the legume pod borer, Maruca vitrata F. (Lepidoptera: Pyralidae) populations in West Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The legume pod borer, Maruca vitrata, is an endemic insect pest that causes significant yield loss to the cowpea crop in West Africa, and contributes to food shortages and malnutrition in native human populations. The genetic structure of Maruca vitrata was investigated among five sites from Burkin...

  15. Transcriptome sequencing, and rapid development and application of SNP markers for the legume pod borer Maruca vitrata (Lepidoptera: Crambidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The legume pod borer, Maruca vitrata (Lepidoptera: Crambidae), is an insect pest species that is destructive to crops grown by subsistence farmers in tropical regions of West Africa. We present the de novo assembly of 3729 contigs from 454- and Sanger-derived sequencing reads for midgut, salivary, ...

  16. Evaluating variability of allergens in commodity crops.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crops with significant food allergen issues, include legumes, peanut and soybean, cereal grains, such as wheat and maize, and tree nuts (walnut, Brazil nut, among other phylogenetically diverse species) (Teuber et al. 2006). Officially recognized allergenic proteins may include one or multiple prot...

  17. Determination of Phytoestrogen Content in Fresh-Cut Legume Forage

    PubMed Central

    Hloucalová, Pavlína; Skládanka, Jiří; Horký, Pavel; Klejdus, Bořivoj; Pelikán, Jan; Knotová, Daniela

    2016-01-01

    Simple Summary Phytoestrogens comprise a group of substances negatively influencing the development and function of animal reproductive organs. Their appearance in forage crops can reduce feeding values, cause dietary disorders, and lead to animal health damage. This study evaluated the occurrence of individual phytoestrogens in various species of annual and perennial legumes and their levels in dry forage. It appeared that feeding large amounts of red clover presents a potential risk, but red clover can be replaced with the annual Persian clover, in which markedly lower phytoestrogen levels were detected. Abstract The aim of the study was to determine phytoestrogen content in fresh-cut legume forage. This issue has been much discussed in recent years in connection with the health and safety of feedstuffs and thus livestock health. The experiments were carried out on two experimental plots at Troubsko and Vatín, Czech Republic during June and July in 2015. Samples were collected of the four forage legume species perennial red clover (variety “Amos”), alfalfa (variety “Holyně”), and annuals Persian clover and Alexandrian clover. Forage was sampled twice at regular three to four day intervals leading up to harvest and a third time on the day of harvest. Fresh and wilted material was analyzed using liquid chromatography–mass spectrometry (LC-MS). Higher levels (p < 0.05) of isoflavones biochanin A (3.697 mg·g−1 of dry weight) and formononetin (4.315 mg·g−1 of dry weight) were found in red clover than in other species. The highest isoflavone content was detected in red clover, reaching 1.001% of dry matter (p < 0.05), representing a risk for occurrence of reproduction problems and inhibited secretion of animal estrogen. The phytoestrogen content was particularly increased in wilted forage. Significant isoflavone reduction was observed over three to four day intervals leading up to harvest. PMID:27429009

  18. High residue cover crops alone or with strategic tillage to manage glyphosate-resistant palmer amaranth (amaranthus palmeri) in Southeastern cotton (gossypium hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Wats) is redefining row crop weed management in the Southeast due to its widespread distribution, high competitive ability, copious seed production, and resilience to standard weed management programs. Herbicides alone are failing to p...

  19. Intergrated palmer amaranth management in glufosinate-resistant cotton: I. Soil-inversion, high-residue cover crops and herbicide regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amaranthus control in cotton can be difficult with the loss of glyphosate efficacy, especially in conservation tillage cropping systems. Research was conduction from 2006 to 2008 at EV Smith Research Center, Shorter, Alabama, to determine the level of glyphosate susceptible amaranthus control provi...

  20. Soil acidity amelioration in a no-till system in west Tennessee USA differs by cover crop type and nitrogen application rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation soil management practices may influence the soil acidity. Surface application of lime may be required in no-till systems to ameliorate soil acidity and to improve crop yields. The application of lime may also increase microbial activity on soil. Specifically, the microbial activity of s...

  1. Lime effects on soil acidity, crop yield and aluminum chemistry in inland Pacific Northwest direct-seed cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pH of agricultural soils in the Inland Pacific Northwest (IPNW) has declined below established critical levels for cereal and grain legume crops. Our objective was to assess the effects of broadcast or subsurface banded lime treatments on soil acidity, crop yield, and aluminum (Al) chemistry in ...

  2. Effect of sugarcane cropping systems on herbicide losses in surface runoff.

    PubMed

    Nachimuthu, Gunasekhar; Halpin, Neil V; Bell, Michael J

    2016-07-01

    Herbicide runoff from cropping fields has been identified as a threat to the Great Barrier Reef ecosystem. A field investigation was carried out to monitor the changes in runoff water quality resulting from four different sugarcane cropping systems that included different herbicides and contrasting tillage and trash management practices. These include (i) Conventional - Tillage (beds and inter-rows) with residual herbicides used; (ii) Improved - only the beds were tilled (zonal) with reduced residual herbicides used; (iii) Aspirational - minimum tillage (one pass of a single tine ripper before planting) with trash mulch, no residual herbicides and a legume intercrop after cane establishment; and (iv) New Farming System (NFS) - minimum tillage as in Aspirational practice with a grain legume rotation and a combination of residual and knockdown herbicides. Results suggest soil and trash management had a larger effect on the herbicide losses in runoff than the physico-chemical properties of herbicides. Improved practices with 30% lower atrazine application rates than used in conventional systems produced reduced runoff volumes by 40% and atrazine loss by 62%. There were a 2-fold variation in atrazine and >10-fold variation in metribuzin loads in runoff water between reduced tillage systems differing in soil disturbance and surface residue cover from the previous rotation crops, despite the same herbicide application rates. The elevated risk of offsite losses from herbicides was illustrated by the high concentrations of diuron (14μgL(-1)) recorded in runoff that occurred >2.5months after herbicide application in a 1(st) ratoon crop. A cropping system employing less persistent non-selective herbicides and an inter-row soybean mulch resulted in no residual herbicide contamination in runoff water, but recorded 12.3% lower yield compared to Conventional practice. These findings reveal a trade-off between achieving good water quality with minimal herbicide contamination and

  3. Weed inhibition by sowing legume species in early succession of abandoned fields on Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Li, Jin-Hua; Xu, Dang-Hui; Wang, Gang

    2008-01-01

    A major constraint on vegetation succession on abandoned land is dominance by early successional species. Our aim was to inhibit weeds and alter the initial vegetation succession by the introduction of legume species ( Medicago sativa, Melilotus suaveolens, and Astragalus adsurgens) into abandoned fields on the Loess Plateau, China. Results from our study showed that the addition of legume species strongly affected the dominance pattern of the abandoned-field vegetation. The number of naturally colonizing species was inhibited by the introduction of legume species in the first two growing seasons. The strongest effect on weed inhibition appeared by sowing Melilotus suaveolens. Vegetation cover and above-ground biomass increased after introduction of legume species and the number of naturally colonizing plant species showed a positive correlation with above-ground biomass. Later successional species like Stipa breviflora and Astragalus polycladus appeared three years following the introduction of Melilotus suaveolens, indicating that the course of old-field succession may be accelerated by introducing legume species such as Melilotus suaveolens, at least temporarily.

  4. Leveraging model legume information to find candidate genes for soybean sudden death syndrome using the legume information system.

    PubMed

    Gonzales, Michael D; Gajendran, Kamal; Farmer, Andrew D; Archuleta, Eric; Beavis, William D

    2007-01-01

    Comparative genomics is an emerging and powerful approach to achieve crop improvement. Using comparative genomics, information from model plant species can accelerate the discovery of genes responsible for disease and pest resistance, tolerance to plant stresses such as drought, and enhanced nutritional value including production of anti-oxidants and anti-cancer compounds. We demonstrate here how to use the Legume Information System for a comparative genomics study, leveraging genomic information from Medicago truncatula (barrel medic), the model legume, to find candidate genes involved with sudden death syndrome (SDS) in Glycine max (soybean). Specifically, genetic maps, physical maps, and annotated tentative consensus and expressed sequence tag (EST) sequences from G. max and M. truncatula can be compared. In addition, the recently published M. truncatula genomic sequences can be used to identify M. truncatula candidate genes in a genomic region syntenic to a quantitative trait loci region for SDS in soybean. Genomic sequences of candidate genes from M. truncatula can then be used to identify ESTs with sequence similarities from soybean for primer design and cloning of potential soybean disease causing alleles. PMID:18287696

  5. Tree legumes as feedstock for sustainable biofuel production: Opportunities and challenges.

    PubMed

    Biswas, Bandana; Scott, Paul T; Gresshoff, Peter M

    2011-11-01

    Concerns about future fossil fuel supplies and the environmental effects of their consumption have prompted the search for alternative sources of liquid fuels, specifically biofuels. However, it is important that the sources of such biofuel have minimal impact on global food supplies, land use, and commodity prices. Many legume trees can be grown on so-called marginal land with beneficial effects to the environment through their symbiotic interaction with "Rhizobia" and the associated process of root nodule development and biological nitrogen fixation. Once established legume trees can live for many years and some produce an annual yield of oil-rich seeds. For example, the tropical and sub-tropical legume tree Pongamia pinnata produces large seeds (∼1.5-2g) that contain about 40% oil, the quality and composition of which is regarded as highly desirable for sustainable biofuel production. Here we consider the benefits of legume trees as future energy crops, particularly in relation to their impact on nitrogen inputs and the net energy balance for biofuel production, and also ways in which these as yet fully domesticated species may be further improved for optimal use as biofuel feedstock. PMID:21715045

  6. Declining ring-necked pheasants in the Klamath Basin, California: II. Survival, productivity, and cover

    USGS Publications Warehouse

    Grove, Robert A.; Buhler, D.R.; Henny, Charles J.; Drew, A.D.

    2001-01-01

    Cover condition and its influence on nesting success, survival, and body condition of ring-necked pheasants (Phasianus colchicus) were evaluated at Tule Lake National Wildlife Refuge (TLNWR) and Lower Klamath National Wildlife Refuge (LKNWR). Inadequate nesting cover was responsible for extremely low nest success early in the nesting season at TLNWR. Later in the season at TLNWR, spring-planted crops provided cover to conceal nesting and renesting hens; however, only 0.07 young were produced (to 1 August) per hen during the study. The extremely low reproductive rates were well below those required to maintain a stable population. At TLNWR, most adult mortality during spring and early summer (before crops provided adequate cover) apparently resulted from predation by golden eagles (Aquila chrysaetos). This mortality occurred weeks before insecticide applications. Hard winters (cold temperatures and heavy snowfall) periodically reduce the pheasant population in the Klamath Basin and again greatly reduced numbers during the last year of this study. Unfortunately, pheasant populations declined under the conditions found during this study and were unable to recover from the hard winter of 1992 to 1993. Mean body mass and tarsal length of adult hen pheasants at TLNWR, which is intensively farmed, were less than those for hens at LKNWR, which is not intensively farmed. Results of our study suggest that TLNWR hens may have been nutritionally stressed, and that the amount and distribution of vegetative cover needs to be improved at TLNWR. Habitat management of edge cover along agricultural crops should feature perennial grasses and legumes with small tracts of land interspersed throughout the agricultural fields to provide alternative cover for wildlife in general including pheasants.

  7. Legumes mitigate ecological consequences of a topographic gradient in a northern Mongolian steppe.

    PubMed

    Casper, Brenda B; Goldman, Robert; Lkhagva, Ariuntsetseg; Helliker, Brent R; Plante, Alain F; Spence, Laura A; Liancourt, Pierre; Boldgiv, Bazartseren; Petraitis, Peter S

    2012-05-01

    Topography should create spatial variation in water and nutrients and play an especially important role in the ecology of water-limited systems. We use stable isotopes to discern how plants respond both to ecological gradients associated with elevation and to neighboring legumes on a south-facing slope in the semi-arid, historically grazed steppe of northern Mongolia. Out of three target species, Potentilla acaulis, Potentilla sericea, and Festuca lenensis, when >30 cm from a legume, all showed a decrease in leaf δ(15)N with increasing elevation. This, together with measures of soil δ(15)N, suggests greater N processing at the moister, more productive, lower elevation, and more N fixation at the upper elevation, where cover of legumes and lichens and plant-available nitrate were greater. Total soil N was greater at the lower elevation, but not lichen biomass or root colonization by AMF. Leaf δ(13)C values for P. acaulis and F. lenensis are consistent with increasing water stress with elevation; δ(13)C values indicated the greatest intrinsic water use efficiency for P. sericea, which is more abundant at the upper elevation. Nearby legumes (<10 cm) moderate the effect of elevation on leaf δ(15)N, confirming legumes' meaningful input of N, and affect leaf δ(13)C for two species, suggesting an influence on the efficiency of carbon fixation. Variation in leaf %N and %C as a function of elevation and proximity to a legume differs among species. Apparently, most N input is at upper elevations, pointing to the possible importance of grazers, in addition to hydrological processes, as transporters of N throughout this landscape.

  8. Legumes mitigate ecological consequences of a topographic gradient in a northern Mongolian steppe.

    PubMed

    Casper, Brenda B; Goldman, Robert; Lkhagva, Ariuntsetseg; Helliker, Brent R; Plante, Alain F; Spence, Laura A; Liancourt, Pierre; Boldgiv, Bazartseren; Petraitis, Peter S

    2012-05-01

    Topography should create spatial variation in water and nutrients and play an especially important role in the ecology of water-limited systems. We use stable isotopes to discern how plants respond both to ecological gradients associated with elevation and to neighboring legumes on a south-facing slope in the semi-arid, historically grazed steppe of northern Mongolia. Out of three target species, Potentilla acaulis, Potentilla sericea, and Festuca lenensis, when >30 cm from a legume, all showed a decrease in leaf δ(15)N with increasing elevation. This, together with measures of soil δ(15)N, suggests greater N processing at the moister, more productive, lower elevation, and more N fixation at the upper elevation, where cover of legumes and lichens and plant-available nitrate were greater. Total soil N was greater at the lower elevation, but not lichen biomass or root colonization by AMF. Leaf δ(13)C values for P. acaulis and F. lenensis are consistent with increasing water stress with elevation; δ(13)C values indicated the greatest intrinsic water use efficiency for P. sericea, which is more abundant at the upper elevation. Nearby legumes (<10 cm) moderate the effect of elevation on leaf δ(15)N, confirming legumes' meaningful input of N, and affect leaf δ(13)C for two species, suggesting an influence on the efficiency of carbon fixation. Variation in leaf %N and %C as a function of elevation and proximity to a legume differs among species. Apparently, most N input is at upper elevations, pointing to the possible importance of grazers, in addition to hydrological processes, as transporters of N throughout this landscape. PMID:22108852

  9. Developmental specialisations in the legume family.

    PubMed

    Hofer, Julie M I; Noel Ellis, T H

    2014-02-01

    The legume family is astonishingly diverse; inventiveness in the form of novel organs, modified organs and additional meristems, is rife. Evolutionary changes can be inferred from the phylogenetic pattern of this diversity, but a full understanding of the origin of these 'hopeful monsters' of meristematic potential requires clear phylogenetic reconstructions and extensive, species-rich, sequence data. The task is large, but rapid progress is being made in both these areas. Here we review specialisations that have been characterised in a subset of intensively studied papilionoid legume taxa at the vanguard of developmental genetic studies.

  10. Legume Genome Initiative at the University of Oklahoma

    SciTech Connect

    Bruce A. Roe

    2004-02-27

    Consolidated Appropriations Resolution, 2003 Conference Report for the Department of Energy's Biological and Environmental Research (BER) program provided $481,000 for the Legume Genome Initiative at the University of Oklahoma. These funds were used to support our research that is aimed at determining the entire sequence of the gene rich regions of the genome of the legume, Medicago truncatula, by allowing us to obtain a greater degree of finished BAC sequences from the draft sequences we have already obtained through research funded by the Noble Foundation. During the funding period we increased the number of Medicago truncatula BACs with finished (Bermuda standard) sequences from 109 to 359, and the total number of BACs for which we collected sequence data from 584 to 842, 359 of which reached phase 2 (ordered and oriented contigs). We also sequenced a series of pooled BAC clones that cover additional euchromatic (gene rich) genomic regions. This work resulted in 6 refereed publications, see below. Genes whose sequence was determined during this study included multiple members of the plant disease resistance (R-gene) family as well as several genes involved in flavinoid biosynthesis, nitrogen fixation and plant-microbial symbosis. This work also served as a prelude to obtaining NSF funding for the international collaborative effort to complete the entire sequence of the Medicago truncatula genomic euchromatic regions using a BAC based approach.

  11. Legume genomics: where we have been, where are we going?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the recognition in 2000 that several multi-institutional projects focusing on legume genomics were becoming a reality, the legume research community advocated for organization of an international meeting to address fundamental and applied aspects of legume genetic research. The purposes delinea...

  12. A simulation study of the effects of land cover and crop type on sensing soil moisture with an orbital C-band radar

    NASA Technical Reports Server (NTRS)

    Dobson, M. C.; Ulaby, F. T.; Moezzi, S.; Roth, E.

    1983-01-01

    Simulated C-band radar imagery for a 124-km by 108-km test site in eastern Kansas is used to classify soil moisture. Simulated radar resolutions are 100 m by 100 m, 1 km by 1 km, and 3 km by 3 km, and each is processed using more than 23 independent samples. Moisture classification errors are examined as a function of land-cover distribution, field-size distribution, and local topographic relief for the full test site and also for subregions of cropland, urban areas, woodland, and pasture/rangeland. Results show that a radar resolution of 100 m by 100 m yields the most robust classification accuracies.

  13. De novo assembly of the pennycress (Thlaspi arvense) transcriptome provides tools for the development of a winter cover crop and biodiesel feedstock.

    PubMed

    Dorn, Kevin M; Fankhauser, Johnathon D; Wyse, Donald L; Marks, M David

    2013-09-01

    Field pennycress (Thlaspi arvense L.) has potential as an oilseed crop that may be grown during fall (autumn) and winter months in the Midwestern United States and harvested in the early spring as a biodiesel feedstock. There has been little agronomic improvement in pennycress through traditional breeding. Recent advances in genomic technologies allow for the development of genomic tools to enable rapid improvements to be made through genomic assisted breeding. Here we report an annotated transcriptome assembly for pennycress. RNA was isolated from representative plant tissues, and 203 million unique Illumina RNA-seq reads were produced and used in the transcriptome assembly. The draft transcriptome assembly consists of 33 873 contigs with a mean length of 1242 bp. A global comparison of homology between the pennycress and Arabidopsis transcriptomes, along with four other Brassicaceae species, revealed a high level of global sequence conservation within the family. The final assembly was functionally annotated, allowing for the identification of putative genes controlling important agronomic traits such as flowering and glucosinolate metabolism. Identification of these genes leads to testable hypotheses concerning their conserved function and to rational strategies to improve agronomic properties in pennycress. Future work to characterize isoform variation between diverse pennycress lines and develop a draft genome sequence for pennycress will further direct trait improvement.

  14. De novo assembly of the pennycress (Thlaspi arvense) transcriptome provides tools for the development of a winter cover crop and biodiesel feedstock

    PubMed Central

    Dorn, Kevin M; Fankhauser, Johnathon D; Wyse, Donald L; Marks, M David

    2013-01-01

    Field pennycress (Thlaspi arvense L.) has potential as an oilseed crop that may be grown during fall (autumn) and winter months in the Midwestern United States and harvested in the early spring as a biodiesel feedstock. There has been little agronomic improvement in pennycress through traditional breeding. Recent advances in genomic technologies allow for the development of genomic tools to enable rapid improvements to be made through genomic assisted breeding. Here we report an annotated transcriptome assembly for pennycress. RNA was isolated from representative plant tissues, and 203 million unique Illumina RNA-seq reads were produced and used in the transcriptome assembly. The draft transcriptome assembly consists of 33 873 contigs with a mean length of 1242 bp. A global comparison of homology between the pennycress and Arabidopsis transcriptomes, along with four other Brassicaceae species, revealed a high level of global sequence conservation within the family. The final assembly was functionally annotated, allowing for the identification of putative genes controlling important agronomic traits such as flowering and glucosinolate metabolism. Identification of these genes leads to testable hypotheses concerning their conserved function and to rational strategies to improve agronomic properties in pennycress. Future work to characterize isoform variation between diverse pennycress lines and develop a draft genome sequence for pennycress will further direct trait improvement. PMID:23786378

  15. Grain legume genetic resources for allele mining

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sequencing capacities for higher throughput at significantly lower costs have enabled larger scale genotyping of plant genetic resources. One challenge to sequencing the USDA grain legume collections of pea, chickpea and lentil core accessions is the amount of heterogeneity in the landrace accessio...

  16. 7 CFR 457.169 - Mint crop insurance provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... mint crop. Cover crop. A small grain crop seeded into mint acreage to reduce soil erosion and wind... planted for harvest during a previous crop year. Ground cover. Mint plants, including mint foliage and... coverages provided in these Crop Provisions, you may also elect the Winter Coverage Option in...

  17. Soil quality and the solar corridor crop system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The S...

  18. Soil Quality and the Solar Corridor Crop System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The S...

  19. NPR1 Protein Regulates Pathogenic and Symbiotic Interactions between Rhizobium and Legumes and Non-Legumes

    PubMed Central

    Peleg-Grossman, Smadar; Golani, Yael; Kaye, Yuval; Melamed-Book, Naomi; Levine, Alex

    2009-01-01

    Background Legumes are unique in their ability to establish symbiotic interaction with rhizobacteria from Rhizobium genus, which provide them with available nitrogen. Nodulation factors (NFs) produced by Rhizobium initiate legume root hair deformation and curling that entrap the bacteria, and allow it to grow inside the plant. In contrast, legumes and non-legumes activate defense responses when inoculated with pathogenic bacteria. One major defense pathway is mediated by salicylic acid (SA). SA is sensed and transduced to downstream defense components by a redox-regulated protein called NPR1. Methodology/Principal Findings We used Arabidopsis mutants in SA defense pathway to test the role of NPR1 in symbiotic interactions. Inoculation of Sinorhizobium meliloti or purified NF on Medicago truncatula or nim1/npr1 A. thaliana mutants induced root hair deformation and transcription of early and late nodulins. Application of S. meliloti or NF on M. truncatula or A. thaliana roots also induced a strong oxidative burst that lasted much longer than in plants inoculated with pathogenic or mutualistic bacteria. Transient overexpression of NPR1 in M. truncatula suppressed root hair curling, while inhibition of NPR1 expression by RNAi accelerated curling. Conclusions/Significance We show that, while NPR1 has a positive effect on pathogen resistance, it has a negative effect on symbiotic interactions, by inhibiting root hair deformation and nodulin expression. Our results also show that basic plant responses to Rhizobium inoculation are conserved in legumes and non-legumes. PMID:20027302

  20. The role of the testa during development and in establishment of dormancy of the legume seed

    PubMed Central

    Smýkal, Petr; Vernoud, Vanessa; Blair, Matthew W.; Soukup, Aleš; Thompson, Richard D.

    2014-01-01

    Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the “domestication syndrome.” Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy classes exist among plant species. Physical dormancy (often called hardseededness), as found in legumes, involves the development of a water-impermeable seed coat, caused by the presence of phenolics- and suberin-impregnated layers of palisade cells. The dormancy release mechanism primarily involves seed responses to temperature changes in the habitat, resulting in testa permeability to water. The underlying genetic controls in legumes have not been identified yet. However, positive correlation was shown between phenolics content (e.g., pigmentation), the requirement for oxidation and the activity of catechol oxidase in relation to pea seed dormancy, while epicatechin levels showed a significant positive correlation with soybean hardseededness. myeloblastosis family of transcription factors, WD40 proteins and enzymes of the anthocyanin biosynthesis pathway were involved in seed testa color in soybean, pea and Medicago, but were not tested directly in relation to seed dormancy. These phenolic compounds play important roles in defense against pathogens, as well as affecting the nutritional quality of products, and because of their health benefits, they are of industrial and medicinal interest. In this review, we discuss the role of the testa in mediating legume seed germination, with a focus on

  1. 7 CFR 205.205 - Crop rotation practice standard.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Crop rotation practice standard. 205.205 Section 205... Crop rotation practice standard. The producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops that provide the following functions...

  2. 7 CFR 205.205 - Crop rotation practice standard.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Crop rotation practice standard. 205.205 Section 205... Crop rotation practice standard. The producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops that provide the following functions...

  3. 7 CFR 205.205 - Crop rotation practice standard.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Crop rotation practice standard. 205.205 Section 205... Crop rotation practice standard. The producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops that provide the following functions...

  4. 7 CFR 205.205 - Crop rotation practice standard.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Crop rotation practice standard. 205.205 Section 205... Crop rotation practice standard. The producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops that provide the following functions...

  5. Stress tolerance and stress-induced injury in crop plants measured by chlorophyll fluorescence in vivo: chilling, freezing, ice cover, heat, and high light.

    PubMed

    Smillie, R M; Hetherington, S E

    1983-08-01

    The proposition is examined that measurements of chlorophyll fluorescence in vivo can be used to monitor cellular injury caused by environmental stresses rapidly and nondestructively and to determine the relative stress tolerances of different species. Stress responses of leaf tissue were measured by F(R), the maximal rate of the induced rise in chlorophyll fluorescence. The time taken for F(R) to decrease by 50% in leaves at 0 degrees C was used as a measure of chilling tolerance. This value was 4.3 hours for chilling-sensitive cucumber. In contrast, F(R) decreased very slowly in cucumber leaves at 10 degrees C or in chilling-tolerant cabbage leaves at 0 degrees C. Long-term changes in F(R) of barley, wheat, and rye leaves kept at 0 degrees C were different in frost-hardened and unhardened material and in the latter appeared to be correlated to plant frost tolerance. To simulate damage caused by a thick ice cover, wheat leaves were placed at 0 degrees C under N(2). Kharkov wheat, a variety tolerant of ice encapsulation, showed a slower decrease in F(R) than Gatcher, a spring wheat. Relative heat tolerance was also indicated by the decrease in F(R) in heated leaves while changes in vivo resulting from photoinhibition, ultraviolet radiation, and photobleaching can also be measured. PMID:16663118

  6. A comprehensive draft genome sequence for lupin (Lupinus angustifolius), an emerging health food: Insights into plant-microbe interactions and legume evolution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lupins are important grain legume crops that form a critical part of sustainable farming systems, by reducing the need for fertilizer and providing disease breaks. Narrow-leafed lupin (Lupinus angustifolius L.) is gaining popularity as a human health food, as a non-GM alternative to soybean with the...

  7. Genetic engineering for high methionine grain legumes.

    PubMed

    Müntz, K; Christov, V; Saalbach, G; Saalbach, I; Waddell, D; Pickardt, T; Schieder, O; Wüstenhagen, T

    1998-08-01

    Methionine (Met) is the primary limiting essential amino acid in grain legumes. The imbalance in amino acid composition restricts their biological value (BV) to 55 to 75% of that of animal protein. So far improvement of the BV could not be achieved by conventional breeding. Therefore, genetic engineering was employed by several laboratories to resolve the problem. Three strategies have been followed. A) Engineering for increased free Met levels; B) engineering of endogenous storage proteins with increased numbers of Met residues; C) transfer of foreign genes encoding Met-rich proteins, e.g. the Brazil nut 2S albumin (BNA) and its homologue from sunflower, into grain legumes. The latter strategy turned out to be most promising. In all cases the gene was put under the control of a developmentally regulated seed specific promoter and transferred into grain legumes using the bacterial Agrobacterium tumefaciens-system. Integration into and copy numbers in the plant genome as well as Mendelian inheritance and gene dosage effects were verified. After correct precursor processing the mature 2S albumin was intracellularly deposited in protein bodies which are part of the vacuolar compartment. The foreign protein amounted to 5 to 10% of the total seed protein in the best transgenic lines of narbon bean (Vicia narbonensis L., used in the authors' laboratories), lupins (Lupinus angustifolius L., used in CSIRO, Australia), and soybean (Glycine max (L.) Merr., used by Pioneer Hi-Bred, Inc., USA). In the narbon bean the increase of Met was directly related to the amount of 2S albumin in the transgenic seeds, but in soybean it remained below the theoretically expected value. Nevertheless, trangenic soybean reached 100%, whereas narbon bean and lupins reached approximately 80% of the FAO-standard for nutritionally balanced food proteins. These results document that the Met problem of grain legumes can be resolved by genetic engineering.

  8. Spring wheat production and associated pests in conventional and diversified cropping systems in north central Montana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers in the northern Plains are diversifying and intensifying traditional wheat-based cropping systems by reducing summer fallow and including legume and oilseed crops. This study examined the influence of diversification and intensification on spring wheat yield and quality, and associated ins...

  9. DEVELOPING HERBACEOUS ENERGY CROPS AS FEEDSTOCKS FOR BIOETHANOL PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial herbaceous crops with high biomass yields are promising substrates for producing bioethnaol. A variety of biomasses including cool and warm season grasses and a legume are being evaluated for this purpose. As a first approach, biomass materials were pretreated with dilute-sulfuric acid a...

  10. Late Embryogenesis Abundant (LEA) proteins in legumes.

    PubMed

    Battaglia, Marina; Covarrubias, Alejandra A

    2013-01-01

    Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA) proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan, and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirm the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions. PMID:23805145

  11. Identification of nutrient and physical seed trait QTL in the model legume Lotus japonicus.

    PubMed

    Klein, Melinda A; Grusak, Michael A

    2009-08-01

    Legume seeds have the potential to provide a significant portion of essential micronutrients to the human diet. To identify the genetic basis for seed nutrient density, quantitative trait locus (QTL) analysis was conducted with the Miyakojima MG-20 x Gifu B-129 recombinant inbred population from the model legume Lotus japonicus. This population was grown to seed under greenhouse conditions in 2006 and 2007. Phenotypic data were collected for seed calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn) concentrations and content. Data for physical seed traits (average seed mass and seed-pod allocation values) were also collected. Based on these phenotypic data, QTL analyses identified 103 QTL linked to 55 different molecular markers. Transgressive segregation, identified within this recombinant inbred population for both seed nutrient and physical traits, suggests new allelic combinations are available for agronomic trait improvement. QTL co-localization was also seen, suggesting that common transport processes might contribute to seed nutrient loading. Identification of loci involved in seed mineral density can be an important first step in identifying the genetic factors and, consequently, the physiological processes involved in mineral distribution to developing seeds. Longer term research efforts will focus on facilitating agronomic breeding efforts through ortholog identification in related crop legumes.

  12. Legume genomes: more than peas in a pod.

    PubMed

    Young, Nevin Dale; Mudge, Joann; Ellis, T H Noel

    2003-04-01

    A growing array of sequence-based tools is helping to reveal the organization, evolution and syntenic relationships of legume genomes. The results indicate that legumes form a coherent taxonomic group with frequent and widespread macro- and microsynteny. This is good news for two model legume systems, Medicago truncatula and Lotus japonicus. Indeed, both models have recently been used to clone and characterize genes for nodulation-related receptors that were originally described in legumes with more complex genomes. Studies of legume genomes have also provided insight into genome size, gene clustering, genome duplications and repetitive elements. To understand legume genomes better, it will be necessary to develop tools for studying under-represented taxa beyond the relatively small group of economically important species that have been examined so far.

  13. Legume presence reduces the decomposition rate of non-legume roots, role of plant traits?

    NASA Astrophysics Data System (ADS)

    De Deyn, Gerlinde B.; Saar, Sirgi; Barel, Janna; Semchenko, Marina

    2016-04-01

    Plant litter traits are known to play an important role in the rate of litter decomposition and mineralization, both for aboveground and belowground litter. However also the biotic and abiotic environment in which the litter decomposes plays a significant role in the rate of decomposition. The presence of living plants may accelerate litter decomposition rates via a priming effects. The size of this effect is expected to be related to the traits of the litter. In this study we focus on root litter, given that roots and their link to ecosystem processes have received relatively little attention in trait-based research. To test the effect of a growing legume plant on root decomposition and the role of root traits in this we used dead roots of 7 different grassland species (comprising grasses, a forb and legumes), determined their C, N, P content and quantified litter mass loss after eight weeks of incubation in soil with and without white clover. We expected faster root decomposition with white clover, especially for root litter with low N content. In contrast we found slower decomposition of grass and forb roots which were poor in N (negative priming) in presence of white clover, while decomposition rates of legume roots were not affected by the presence of white clover. Overall we found that root decomposition can be slowed down in the presence of a living plant and that this effect depends on the traits of the decomposing roots, with a pronounced reduction in root litter poor in N and P, but not in the relatively nutrient-rich legume root litters. The negative priming effect of legume plants on non-legume litter decomposition may have resulted from preferential substrate utilisation by soil microbes.

  14. Firewood crops

    SciTech Connect

    Not Available

    1980-01-01

    This report does not suggest a solution to the entire firewood crisis but examines one part of the solution: the selection of species suitable for deliberate cultivation as firewood crops in developing countries. Primary emphasis is placed on species suitable for growing firewood for individual family needs. However, species suited to plantation cultivation for fueling small industrial factories, electric generators, and crop dryers are also considered. Most of the plants are little known in traditional forest production. Some are woody shrubs rather than forest trees, but even these may meet many requirements for small-scale village use. Particular attention was paid to multi-purpose plants that have uses in addition to providing fuel, plants that adapt well to different sites and require little care, plants for problem environments and plants not consumed by goats and wildlife. Special consideration was given to nitrogen-fixing ability, rapid growth, ability to coppice, ability to produce wood of high calorific value that burns without sparks or toxic smoke and ability to grow successfully in a wide range of environments. After an introduction on wood as fuel, more than 60 fuel-wood species for humid tropical, tropical highland and arid and semi-arid regions are presented. The data on existing plants cover their major attributes, description, distribution, use as fuelwood, yield, other uses, environmental requirements, establishment, pest and diseases and limitations. Appendices include technologies for improving the efficiency of fuelwood use, case studies from Ethiopia and the Republic of Korea and a master list of firewood species.

  15. Cover crops in vegetable production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current vegetable production systems require an intensive amount Current vegetable production systems require an intensive amount of work and inputs, and if not properly managed could have detrimental effects on soil and the environment. Practices such as intensive tillage, increased herbicide use, ...

  16. Phytohormone regulation of legume-rhizobia interactions.

    PubMed

    Ferguson, Brett J; Mathesius, Ulrike

    2014-07-01

    The symbiosis between legumes and nitrogen fixing bacteria called rhizobia leads to the formation of root nodules. Nodules are highly organized root organs that form in response to Nod factors produced by rhizobia, and they provide rhizobia with a specialized niche to optimize nutrient exchange and nitrogen fixation. Nodule development and invasion by rhizobia is locally controlled by feedback between rhizobia and the plant host. In addition, the total number of nodules on a root system is controlled by a systemic mechanism termed 'autoregulation of nodulation'. Both the local and the systemic control of nodulation are regulated by phytohormones. There are two mechanisms by which phytohormone signalling is altered during nodulation: through direct synthesis by rhizobia and through indirect manipulation of the phytohormone balance in the plant, triggered by bacterial Nod factors. Recent genetic and physiological evidence points to a crucial role of Nod factor-induced changes in the host phytohormone balance as a prerequisite for successful nodule formation. Phytohormones synthesized by rhizobia enhance symbiosis effectiveness but do not appear to be necessary for nodule formation. This review provides an overview of recent advances in our understanding of the roles and interactions of phytohormones and signalling peptides in the regulation of nodule infection, initiation, positioning, development, and autoregulation. Future challenges remain to unify hormone-related findings across different legumes and to test whether hormone perception, response, or transport differences among different legumes could explain the variety of nodules types and the predisposition for nodule formation in this plant family. In addition, the molecular studies carried out under controlled conditions will need to be extended into the field to test whether and how phytohormone contributions by host and rhizobial partners affect the long term fitness of the host and the survival and

  17. Pre-breeding for diversification of primary gene pool and genetic enhancement of grain legumes

    PubMed Central

    Sharma, Shivali; Upadhyaya, H. D.; Varshney, R. K.; Gowda, C. L. L.

    2013-01-01

    The narrow genetic base of cultivars coupled with low utilization of genetic resources are the major factors limiting grain legume production and productivity globally. Exploitation of new and diverse sources of variation is needed for the genetic enhancement of grain legumes. Wild relatives with enhanced levels of resistance/tolerance to multiple stresses provide important sources of genetic diversity for crop improvement. However, their exploitation for cultivar improvement is limited by cross-incompatibility barriers and linkage drags. Pre-breeding provides a unique opportunity, through the introgression of desirable genes from wild germplasm into genetic backgrounds readily used by the breeders with minimum linkage drag, to overcome this. Pre-breeding activities using promising landraces, wild relatives, and popular cultivars have been initiated at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) to develop new gene pools in chickpea, pigeonpea, and groundnut with a high frequency of useful genes, wider adaptability, and a broad genetic base. The availability of molecular markers will greatly assist in reducing linkage drags and increasing the efficiency of introgression in pre-breeding programs. PMID:23970889

  18. Legume-rhizobia signal exchange: promiscuity and environmental effects

    PubMed Central

    Lira, Mario A.; Nascimento, Luciana R. S.; Fracetto, Giselle G. M.

    2015-01-01

    Although signal exchange between legumes and their rhizobia is among the best-known examples of this biological process, most of the more characterized data comes from just a few legume species and environmental stresses. Although a relative wealth of information is available for some model legumes and some of the major pulses such as soybean, little is known about tropical legumes. This relative disparity in current knowledge is also apparent in the research on the effects of environmental stress on signal exchange; cool-climate stresses, such as low-soil temperature, comprise a relatively large body of research, whereas high-temperature stresses and drought are not nearly as well understood. Both tropical legumes and their environmental stress-induced effects are increasingly important due to global population growth (the demand for protein), climate change (increasing temperatures and more extreme climate behavior), and urbanization (and thus heavy metals). This knowledge gap for both legumes and their environmental stresses is compounded because whereas most temperate legume-rhizobia symbioses are relatively specific and cultivated under relatively stable environments, the converse is true for tropical legumes, which tend to be promiscuous, and grow in highly variable conditions. This review will clarify some of this missing information and highlight fields in which further research would benefit our current knowledge. PMID:26441880

  19. Alternative cropping systems for sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting 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. Research was conducted at the USDA, ARS, Sugarcane Research Unit at Houma, LA to determine the impac...

  20. Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability.

    PubMed

    Zhang, Jie; Yin, Binjie; Xie, Yuhuai; Li, Jing; Yang, Zaibin; Zhang, Guiguo

    2015-01-01

    Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2) involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM) and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a), potentially degradable (b) and the degradation rate constant (c) of 'b' fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP) yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater 'a' fraction, 'b' fraction, 'c' values, and effective degradability (E value) of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn-rye exhibited a greater

  1. Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability

    PubMed Central

    Xie, Yuhuai; Li, Jing.; Yang, Zaibin; Zhang, Guiguo

    2015-01-01

    Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2) involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM) and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a), potentially degradable (b) and the degradation rate constant (c) of ‘b’ fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP) yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater ‘a’ fraction, ‘b’ fraction, ‘c’ values, and effective degradability (E value) of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn

  2. Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability.

    PubMed

    Zhang, Jie; Yin, Binjie; Xie, Yuhuai; Li, Jing; Yang, Zaibin; Zhang, Guiguo

    2015-01-01

    Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2) involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM) and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a), potentially degradable (b) and the degradation rate constant (c) of 'b' fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP) yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater 'a' fraction, 'b' fraction, 'c' values, and effective degradability (E value) of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn-rye exhibited a greater

  3. LegumeIP 2.0--a platform for the study of gene function and genome evolution in legumes.

    PubMed

    Li, Jun; Dai, Xinbin; Zhuang, Zhaohong; Zhao, Patrick X

    2016-01-01

    The LegumeIP 2.0 database hosts large-scale genomics and transcriptomics data and provides integrative bioinformatics tools for the study of gene function and evolution in legumes. Our recent updates in LegumeIP 2.0 include gene and protein sequences, gene models and annotations, syntenic regions, protein families and phylogenetic trees for six legume species: Medicago truncatula, Glycine max (soybean), Lotus japonicus, Phaseolus vulgaris (common bean), Cicer arietinum (chickpea) and Cajanus cajan (pigeon pea) and two outgroup reference species: Arabidopsis thaliana and Poplar trichocarpa. Moreover, the LegumeIP 2.0 features the following new data resources and bioinformatics tools: (i) an integrative gene expression atlas for four model legumes that include 550 array hybridizations from M. truncatula, 962 gene expression profiles of G. max, 276 array hybridizations from L. japonicas and 56 RNA-Seq-based gene expression profiles for C. arietinum. These datasets were manually curated and hierarchically organized based on Experimental Ontology and Plant Ontology so that users can browse, search, and retrieve data for their selected experiments. (ii) New functions/analytical tools to query, mine and visualize large-scale gene sequences, annotations and transcriptome profiles. Users may select a subset of expression experiments and visualize and compare expression profiles for multiple genes. The LegumeIP 2.0 database is freely available to the public at http://plantgrn.noble.org/LegumeIP/. PMID:26578557

  4. Control of crop diseases, third edition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The authors in the Control of Crop Diseases cover a wide range of topics from crop diseases and their diagnosis and eradication to a primer on fungicides and legislation. This wide range of topics, all critical to the topic of crop diseases, thus appeals to a wide audience from molecular biologists,...

  5. [How I got to study legumes].

    PubMed

    Jaffé, W G

    1996-12-01

    In this paper the author presents a brief account of his involvement in the study of legume seeds form a nutritional and toxicological perspective. After observing that the Venezuelan peasants ate diets which often included cooked black beans and a form of corn bread called arepas, he performed nutritional trials which led him to recognize that raw beans contained thermolabile antinutritional factors and that their proteins were complementary to those of corn. Among the antinutritional factors, he isolated a hemagglutinating fraction which later was further characterized. Based on their properties he recognized the existence of four different types of Phaseolus vulgaris cultivars. Research on the nutritive value of bean diets also got him involved in the identification of a growth factor later called vitamin B12. PMID:9221715

  6. Negotiation of mutualism: rhizobia and legumes

    PubMed Central

    Akçay, Erol; Roughgarden, Joan

    2006-01-01

    The evolution and persistence of biological cooperation have been an important puzzle in evolutionary theory. Here, we suggest a new approach based on bargaining theory to tackle the question. We present a mechanistic model for negotiation of benefits between a nitrogen-fixing nodule and a legume plant. To that end, we first derive growth rates for the nodule and plant from metabolic models of each as a function of material fluxes between them. We use these growth rates as pay-off functions in the negotiation process, which is analogous to collective bargaining between a firm and a workers' union. Our model predicts that negotiations lead to the Nash bargaining solution, maximizing the product of players' pay-offs. This work introduces elements of cooperative game theory into the field of mutualistic interactions. In the discussion of the paper, we argue for the benefits of such an approach in studying the question of biological cooperation. PMID:17015340

  7. Biological potential of sixteen legumes in China.

    PubMed

    Yao, Yang; Cheng, Xuzhen; Wang, Lixia; Wang, Suhua; Ren, Guixing

    2011-01-01

    Phenolic acids have been identified in a variety of legumes including lima bean, broad bean, common bean, pea, jack bean, goa bean, adzuki bean, hyacinth bean, chicking vetch, garbanzo bean, dral, cow bean, rice bean, mung bean and soybean. The present study was carried out with the following aims: (1) to identify and quantify the individual phenolic acid and determine the total phenolic content (TPC); (2) to assess their antioxidant activity, inhibition activities of α-glucosidase, tyrosinase, and formation of advanced glycation endproducts; and (3) to investigate correlations among the phytochemicals and biological activity. Common bean possesses the highest antioxidant activity and advanced glycation endproducts formation inhibition activity. Adzuki bean has the highest α-glucosidase inhibition activity, and mung bean has the highest tyrosinase inhibition activity. There are significant differences in phytochemical content and functional activities among the bean species investigated. Selecting beans can help treat diseases such as dermatological hyperpigmentation illness, type 2 diabetes and associated cardiovascular diseases. PMID:22072935

  8. Biological Potential of Sixteen Legumes in China

    PubMed Central

    Yao, Yang; Cheng, Xuzhen; Wang, Lixia; Wang, Suhua; Ren, Guixing

    2011-01-01

    Phenolic acids have been identified in a variety of legumes including lima bean, broad bean, common bean, pea, jack bean, goa bean, adzuki bean, hyacinth bean, chicking vetch, garbanzo bean, dral, cow bean, rice bean, mung bean and soybean. The present study was carried out with the following aims: (1) to identify and quantify the individual phenolic acid and determine the total phenolic content (TPC); (2) to assess their antioxidant activity, inhibition activities of α-glucosidase, tyrosinase, and formation of advanced glycation endproducts; and (3) to investigate correlations among the phytochemicals and biological activity. Common bean possesses the highest antioxidant activity and advanced glycation endproducts formation inhibition activity. Adzuki bean has the highest α-glucosidase inhibition activity, and mung bean has the highest tyrosinase inhibition activity. There are significant differences in phytochemical content and functional activities among the bean species investigated. Selecting beans can help treat diseases such as dermatological hyperpigmentation illness, type 2 diabetes and associated cardiovascular diseases. PMID:22072935

  9. GEOGLAM Crop Monitor Assessment Tool: Developing Monthly Crop Condition Assessments

    NASA Astrophysics Data System (ADS)

    McGaughey, K.; Becker Reshef, I.; Barker, B.; Humber, M. L.; Nordling, J.; Justice, C. O.; Deshayes, M.

    2014-12-01

    The Group on Earth Observations (GEO) developed the Global Agricultural Monitoring initiative (GEOGLAM) to improve existing agricultural information through a network of international partnerships, data sharing, and operational research. This presentation will discuss the Crop Monitor component of GEOGLAM, which provides the Agricultural Market Information System (AMIS) with an international, multi-source, and transparent consensus assessment of crop growing conditions, status, and agro-climatic conditions likely to impact global production. This activity covers the four primary crop types (wheat, maize, rice, and soybean) within the main agricultural producing regions of the AMIS countries. These assessments have been produced operationally since September 2013 and are published in the AMIS Market Monitor Bulletin. The Crop Monitor reports provide cartographic and textual summaries of crop conditions as of the 28th of each month, according to crop type. This presentation will focus on the building of international networks, data collection, and data dissemination.

  10. Nitrogen and phosphorus economy of a legume tree-cereal intercropping system under controlled conditions.

    PubMed

    Isaac, M E; Hinsinger, P; Harmand, J M

    2012-09-15

    Considerable amounts of nitrogen (N) and phosphorus (P) fertilizers have been mis-used in agroecosystems, with profound alteration to the biogeochemical cycles of these two major nutrients. To reduce excess fertilizer use, plant-mediated nutrient supply through N(2)-fixation, transfer of fixed N and mobilization of soil P may be important processes for the nutrient economy of low-input tree-based intercropping systems. In this study, we quantified plant performance, P acquisition and belowground N transfer from the N(2)-fixing tree to the cereal crop under varying root contact intensity and P supplies. We cultivated Acacia senegal var senegal in pot-culture containing 90% sand and 10% vermiculite under 3 levels of exponentially supplied P. Acacia plants were then intercropped with durum wheat (Triticum turgidum durum) in the same pots with variable levels of adsorbed P or transplanted and intercropped with durum wheat in rhizoboxes excluding direct root contact on P-poor red Mediterranean soils. In pot-culture, wheat biomass and P content increased in relation to the P gradient. Strong isotopic evidence of belowground N transfer, based on the isotopic signature (δ(15)N) of tree foliage and wheat shoots, was systematically found under high P in pot-culture, with an average N transfer value of 14.0% of wheat total N after 21 days of contact between the two species. In the rhizoboxes, we observed limitations on growth and P uptake of intercropped wheat due to competitive effects on soil resources and minimal evidence of belowground N transfer of N from acacia to wheat. In this intercrop, specifically in pot-culture, facilitation for N transfer from the legume tree to the crop showed to be effective especially when crop N uptake was increased (or stimulated) as occurred under high P conditions and when competition was low. Understanding these processes is important to the nutrient economy and appropriate management of legume-based agroforestry systems.

  11. Hormonal Control of Lateral Root and Nodule Development in Legumes

    PubMed Central

    Bensmihen, Sandra

    2015-01-01

    Many plants can establish symbioses with nitrogen-fixing bacteria, some of which lead to nodulation, including legumes. Indeed, in the rhizobium/legume symbiosis, new root organs, called nodules, are formed by the plant in order to host the rhizobia in protective conditions, optimized for nitrogen fixation. In this way, these plants can benefit from the reduction of atmospheric dinitrogen into ammonia by the hosted bacteria, and in exchange the plant provides the rhizobia with a carbon source. Since this symbiosis is costly for the plant it is highly regulated. Both legume nodule and lateral root organogenesis involve divisions of the root inner tissues, and both developmental programs are tightly controlled by plant hormones. In fact, most of the major plant hormones, such as auxin, cytokinins, abscisic acid, and strigolactones, control both lateral root formation and nodule organogenesis, but often in an opposite manner. This suggests that the sensitivity of legume plants to some phytohormones could be linked to the antagonism that exists between the processes of nodulation and lateral root formation. Here, we will review the implication of some major phytohormones in lateral root formation in legumes, compare them with their roles in nodulation, and discuss specificities and divergences from non-legume eudicot plants such as Arabidopsis thaliana. PMID:27135340

  12. Hormonal Control of Lateral Root and Nodule Development in Legumes.

    PubMed

    Bensmihen, Sandra

    2015-08-07

    Many plants can establish symbioses with nitrogen-fixing bacteria, some of which lead to nodulation, including legumes. Indeed, in the rhizobium/legume symbiosis, new root organs, called nodules, are formed by the plant in order to host the rhizobia in protective conditions, optimized for nitrogen fixation. In this way, these plants can benefit from the reduction of atmospheric dinitrogen into ammonia by the hosted bacteria, and in exchange the plant provides the rhizobia with a carbon source. Since this symbiosis is costly for the plant it is highly regulated. Both legume nodule and lateral root organogenesis involve divisions of the root inner tissues, and both developmental programs are tightly controlled by plant hormones. In fact, most of the major plant hormones, such as auxin, cytokinins, abscisic acid, and strigolactones, control both lateral root formation and nodule organogenesis, but often in an opposite manner. This suggests that the sensitivity of legume plants to some phytohormones could be linked to the antagonism that exists between the processes of nodulation and lateral root formation. Here, we will review the implication of some major phytohormones in lateral root formation in legumes, compare them with their roles in nodulation, and discuss specificities and divergences from non-legume eudicot plants such as Arabidopsis thaliana.

  13. Biomass production by fescue and switchgrass alone and in mixed swards with legumes. Final project report

    SciTech Connect

    Collins, M.

    1994-06-01

    In assessing the role of biomass in alleviating potential global warming, the absence of information on the sustainability of biomass production on soils of limited agricultural potential is cited as a major constraint to the assessment of the role of biomass. Research on the sustainability of yields, recycling of nutrients, and emphasis on reduced inputs of agricultural chemicals in the production of biomass are among the critical research needs to clarify optimum cropping practice in biomass production. Two field experiments were conducted between 1989 and 1993. One study evaluated biomass production and composition of switchgrass (Panicum virgatum L.) grown alone and with bigflower vetch (Vicia grandiflora L.) and the other assessed biomass productivity and composition of tall fescue (Festuca arundinacea Schreb.) grown alone and with perennial legumes. Switchgrass received 0, 75 or 150 kg ha{sup {minus}1} of N annually as NH{sub 4}NO{sub 3} or was interseeded with vetch. Tall fescue received 0, 75, 150 or 225 kg ha{sup {minus}1} of N annually or was interseeded with alfalfa (Medicago L.) or birdsfoot trefoil (Lotus corniculatus L.). It is hoped that production systems can be designed to produce high yields of biomass with minimal inputs of fertilizer N. Achievement of this goal would reduce the potential for movement of NO{sub 3} and other undesirable N forms outside the biomass production system into the environment. In addition, management systems involving legumes could reduce the cost of biomass production.

  14. Quantitative trait locus analysis of multiple agronomic traits in the model legume Lotus japonicus.

    PubMed

    Gondo, Takahiro; Sato, Shusei; Okumura, Kenji; Tabata, Satoshi; Akashi, Ryo; Isobe, Sachiko

    2007-07-01

    The first quantitative trait locus (QTL) analysis of multiple agronomic traits in the model legume Lotus japonicus was performed with a population of recombinant inbred lines derived from Miyakojima MG-20 x Gifu B-129. Thirteen agronomic traits were evaluated in 2004 and 2005: traits of vegetative parts (plant height, stem thickness, leaf length, leaf width, plant regrowth, plant shape, and stem color), flowering traits (flowering time and degree), and pod and seed traits (pod length, pod width, seeds per pod, and seed mass). A total of 40 QTLs were detected that explained 5%-69% of total variation. The QTL that explained the most variation was that for stem color, which was detected in the same region of chromosome 2 in both years. Some QTLs were colocated, especially those for pod and seed traits. Seed mass QTLs were located at 5 locations that mapped to the corresponding genomic positions of equivalent QTLs in soybean, pea, chickpea, and mung bean. This study provides fundamental information for breeding of agronomically important legume crops.

  15. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula-A Focus on Responses to Fusarium Wilt Disease.

    PubMed

    Thatcher, Louise F; Gao, Ling-Ling; Singh, Karam B

    2016-02-05

    Jasmonate (JA)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume-F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana-F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant) resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula--F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection.

  16. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula-A Focus on Responses to Fusarium Wilt Disease.

    PubMed

    Thatcher, Louise F; Gao, Ling-Ling; Singh, Karam B

    2016-01-01

    Jasmonate (JA)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume-F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana-F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant) resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula--F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection. PMID:27135231

  17. Genetic analysis of tolerance to the root lesion nematode Pratylenchus neglectus in the legume Medicago littoralis

    PubMed Central

    2014-01-01

    Background The nematode Pratylenchus neglectus has a wide host range and is able to feed on the root systems of cereals, oilseeds, grain and pasture legumes. Under the Mediterranean low rainfall environments of Australia, annual Medicago pasture legumes are used in rotation with cereals to fix atmospheric nitrogen and improve soil parameters. Considerable efforts are being made in breeding programs to improve resistance and tolerance to Pratylenchus neglectus in the major crops wheat and barley, which makes it vital to develop appropriate selection tools in medics. Results A strong source of tolerance to root damage by the root lesion nematode (RLN) Pratylenchus neglectus had previously been identified in line RH-1 (strand medic, M. littoralis). Using RH-1, we have developed a single seed descent (SSD) population of 138 lines by crossing it to the intolerant cultivar Herald. After inoculation, RLN-associated root damage clearly segregated in the population. Genetic analysis was performed by constructing a genetic map using simple sequence repeat (SSR) and gene-based SNP markers. A highly significant quantitative trait locus (QTL), QPnTolMl.1, was identified explaining 49% of the phenotypic variation in the SSD population. All SSRs and gene-based markers in the QTL region were derived from chromosome 1 of the sequenced genome of the closely related species M. truncatula. Gene-based markers were validated in advanced breeding lines derived from the RH-1 parent and also a second RLN tolerance source, RH-2 (M. truncatula ssp. tricycla). Comparative analysis to sequenced legume genomes showed that the physical QTL interval exists as a synteny block in Lotus japonicus, common bean, soybean and chickpea. Furthermore, using the sequenced genome information of M. truncatula, the QTL interval contains 55 genes out of which five are discussed as potential candidate genes responsible for the mapped tolerance. Conclusion The closely linked set of SNP-based PCR markers is

  18. Grasses and Legumes for Cellulosic Bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human life has been dependent on renewable sources of bioenergy for many thousands of years, from the time that humans first learned to control fire and utilize wood as the earliest source of bioenergy. Ironically, forage crops represent the next major technological breakthrough in renewable bioene...

  19. Covering Politics.

    ERIC Educational Resources Information Center

    Gruber, Ryan; Wind, Andrew; Trevidi, Neema

    2000-01-01

    Presents four articles considering: (1) the media's role in the coverage of politics; (2) the influence of photography particularly in terms of the president; (3) an event where an Iowa student had a chance to work with professionals while covering politics; and (4) considering scholastic reporters covering national candidates as they learn and…

  20. Covering Crime.

    ERIC Educational Resources Information Center

    Gest, Ted; Krajicek, David; Hackney, Suzette; Moore, Melissa

    2003-01-01

    Presents four brief articles on covering crime. Notes that reporting on crimes requires special skills for student reporters, editors, and photographers. Explains how to gain access to scenes, to develop journalistic ethics, and how to cover crime and its victims. Discusses the relation of race and ethnic issues to crime, and how visual…