Progress 04/28/06 to 04/27/11
Outputs
Progress Report Objectives (from AD-416) Generally, we are designing crop and animal management strategies based on sound biogeochemical principles, that are profitable, and have positive environmental impacts. Specifically, we are developing strategies based on experiments evaluating tillage and cover crop management, crop selection and productivity, forage quality and availability, plant genetics, grazing pressure, animal health and productivity, animal manure application, nutrient cycling, soil quality, carbon storage, and water runoff and quality. Approach (from AD-416) To be able to simultaneously address production and environmental issues, we are taking a multidisciplinary approach to 1) understand biogeochemical mechanisms and processes involved in water and nutrient cycles, 2) evaluate alternative management options and 3) develop management systems to improve the sustainability of agriculture in the region. This requires both field and laboratory investigations, including fescue toxicosis effects on animal physiology. Several field studies will give long-term perspectives and yield realistic relationships between productivity and environmental health cropping studies include: 1) water catchments receiving poultry litter with different tillage management and 2) cover cropping trials based on plant species and method and timing of killing. Pasture studies include 1) evaluation of grazing pressure and organic-inorganic fertilization on soil organic C storage, nutrient runoff, and productivity and 2) water catchments with differences in endophyte association, organic-inorganic fertilization, and presence of cattle. Laboratory analyses from several long-term field studies and soil testing evaluations continued to be processed and verified. Long-term studies remaining active in this project included the Water Quality Study contributing to our objective of deterimining soil responses in cropping systems and Cattle and Cotton Watershed Study contributing to our objective of determining soil responses in integrated crop-livestock systems. Other field studies that were outlined in the project plan and that had contributed to our objectives were terminated this year due to lack of funds and/or reallocation of resources, including the Dawson Field Grazing Study contributing to our objective of determining soil responses in pasture systems and the Pasture-Crop Rotation Study contributing to our objective of determining soil responses in integrated crop-livestock systems. Additional long-term field studies terminated in previous years due to reallocation of resources included the Silage Cropping Intensity Study to meet our objective in determining soil responses in cropping systems and Salem Road Grazing Study to meet our objective in determining soil responses in pasture systems. Soil organic carbon content under various cropping, pasture, and pasture- crop rotation systems is being determined and data are contributing significantly to a growing demand for information on how conservation agricultural systems can contribute to the mitigation of greenhouse gas emissions. Scientists involved with this research project are active in assembling original data, reviewing the literature, and synthesizing available information for technical advisors. Scientific advice derived from this project has been offered to the Soil Science Society of America special committees, Cotton Incorporated, Grassland Carbon Working Group associated with the United Nations Food and Agriculture Organization, the World Bank, Technical Working Group on Agricultural Greenhouse Gases, Global Agriculture Climate Assessment, Field to Market: Keystone Alliance for Sustainable Agriculture, and the USDA-NRCS Conservation Effects Assessment Program for Pasture Lands. This project has been replaced by Project Number 6612-11120-004-00D. Significant Activities that Support Special Target Populations Most forage/livestock operations in the Southern Piedmont are owned by small-farm producers with gross receipts well under $250,000. We are developing conservation agricultural systems appropriate for use by these small-farm producers, including no-tillage planting, cover cropping, land application of manures, and crop-livestock integration. Accomplishments 01 Grazing of pastures improves soil condition of degraded land. Sequestration of soil organic carbon and conservation of nitrogen are of keen scientific and political interests for developing management strategies to help combat climate change resulting from emission of comm greenhouse gases like carbon dioxide and nitrous oxide. Scientists at th USDA-Agricultural Research Service in Watkinsville, Georgia, conducted a 12-year pasture experiment to investigate how compaction and soil organi matter would be affected by: 1) inorganic and organic fertilization; and how forage was utilized. How forage was utilized had an enormous impact on the temporal development of soil properties. When forage was hayed continuously, surface residue was low, soil bulk density was high, and soil organic matter remained relatively unchanged. When forage was graze by cattle, surface residue was low to moderate, soil bulk density was lo to moderate, and soil organic matter was sequestered at high rates. When forage was unharvested (similar to a Conservation Reserve Program management scheme), surface residue was highest, soil bulk density was l (similar to low grazing pressure), and soil organic matter was intermediate between haying and grazing. Cattle grazing of mixed bermudagrass/tall fescue pastures can be considered a viable strategy to rehabilitate millions of acres of degraded cropland in the southeastern USA. Our data negate the perspective that only non-utilization of land will be the best strategy for rehabilitating degraded land. 02 Mechanical aeration captures phosphorus in well-drained soils. Aeration has the potential to reduce phosphorus losses in runoff from grasslands through increased rainfall infiltration, partial incorporation of applie manures, binding of phosphorus with soil minerals, and slowing of runoff flow through increased roughness of the soil surface. Scientists from US ARS in Watkinsville, Georgia, University of Tennessee, University of Georgia, and the USDA Natural Resources Conservation Service compiled an reviewed results from two small-plot aeration studies and two field-scal paired watershed aeration studies. Small-scale rainfall simulations were done on two soil taxa using three types of aeration implements. The-fiel scale studies were conducted in six, 0.7-ha (1.7-acre) bermed field-scal watersheds with varied soil taxa and drainage classes. Small plot studie showed that core aeration reduced total phosphorus (46 %) and dissolved reactive phosphorus (62%) losses from plots fertilized with broiler litt In the field-scale study, aeration reduced dissolved reactive phosphoru losses by 35% in fields with well-drained soils, but not in poorly-drain soils. In summary, soil characteristics such as internal drainage, depth of the subsoil clayey layer, position of shallow BC horizons, compaction aeration implement, and type of manure applied on the grassland surface are likely to interact to determine the overall effectiveness of aeratio on runoff volume and phosphorus losses. 03 Estimating soil organic carbon with a simple model. Rapid and reliable assessments of the potential of various agricultural management systems sequester soil organic carbon are needed to promote conservation and hel mitigate greenhouse gas emissions. A collaborative effort to calibrate soil conditioning index (SCI) scores against soil organic carbon sequestration was developed among scientists with USDA-Agricultural Research Service in Watkinsville, GA, National University in Asuncion Paraguay, and USDA-Natural Resources Conservation Service in Temple, TX. Published soil organic carbon from long-term field studies throughout th Midwest and southeastern USA were compared with simulations run by the S under the umbrella of the Revised Universal Soil Loss Equation (RUSLE2). Across studies, soil organic carbon content increased by 0.435 metric to of carbon dioxide per acre per year per unit change in SCI. The calibration did not differ significantly between the Midwest and southeastern USA regions. These results will have important implications for farmers, crop advisors, scientists, and policy makers interested in carbon trading schemes throughout the 330 million acres of cropland in t USA. 04 Well-managed pastures sequester soil organic carbon. Soils of the southeastern USA have been historically degraded with intensive cultivation that resulted in loss of topsoil and poor fertility. Pasture management has the potential to build soil fertility, restore soil functions, and mitigate greenhouse gas emissions through surface soil organic matter accumulation. A scientist from the USDA Agricultural Research Service in Watkinsville, Georgia, summarized recent literature from the southeastern USA on how pastures affect soil organic carbon. Establishment of perennial grass pastures in the southeastern USA can sequester soil organic carbon at rates of 0.1 to 0.5 tons carbon/acre/ye Soil organic carbon sequestration rate is affected by forage type, fertilization, forage utilization, animal behavior, and soil sampling depth. It can also be spatially affected by animal behavior and by soil depth. Soil organic carbon storage under pastures is important for improving water relations, fertility, and soil quality. With 111 million acres of agricultural land in the southeastern USA, 113 million tons of carbon dioxide/year could be reasonably calculated as potentially sequestered in soil organic matter. Landowners in the southeastern USA have great potential to restore soil fertility and mitigate greenhouse g emissions with adoption of and improvement in pasture management systems 05 Soil carbon is at the core of key ecosystem services. Humans need many things, but unbeknownst to many of us are the intricately critical influences that soil with high organic carbon has on our life support system. Curiously, the growing possibility of trading carbon in a globa marketplace may actually help us better appreciate the enormous value of soil carbon on how our world functions and how we have the influence to preserve and enhance critical ecosystem functions or continue to degrade them with reckless abandonment. With the expected rise in human population and the need for even more food to be produced on already stressed landscapes, widespread adoption of conservation agricultural systems is necessary to build a more resilient global food production system that can also help to mitigate climate change and improve our relationship with Nature. 06 Surface-soil organic matter is important determinant of key ecosystem processes. Stratification of soil porosity and organic matter is common under conservation agricultural systems. A scientist at the USDA- Agricultural Research Service prepared a summary of stratification of so porosity and organic matter for the Encyclopedia of Agrophysics. The volume of soil pores and the concentration of organic matter are greates nearest the soil surface and decline with depth. This characteristic is typical of undisturbed soils under grassland, forest, and conservation- tilled cropland. The quantity of soil organic matter is important to ecosystem functioning. However, stratification of soil organic matter appears to be even more important to ecosystem functioning. Soil qualit and ecosystem functioning could be assessed with calculation of stratification ratio. This article will be useful for undergraduate and graduate students in earth science majors, as well as scientists and an informed public society.
Impacts
(N/A)
Publications
- Franzluebbers, A.J., Stuedemann, J.A. 2010. Surface soil changes during 12 years of pasture management in the Southern Piedmont USA. Soil Science Society of America Journal. 74:2131-2141.
- Buyer, J.S., Zuberer, D.A., Nichols, K.A., Franzluebbers, A.J. 2010. Soil microbial community function, structure, and glomalin in response to tall fescue endophyte infection. Plant and Soil Journal. DOI: 10.1007/S11104- 010-059Z-Y. 339:410-412. 2011.
- Franzluebbers, A.J. 2010. Will we allow soil carbon to feed our needs? Scientific and Technical Review. 1:237-251.
- Franzluebbers, A.J., Causarano, H.J., Norfleet, M.L. 2011. Soil conditioning index (SCI) and soil organic carbon in the Midwest and southeastern USA. Journal of Soil and Water Conservation Society. 66:178- 182.
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) Generally, we are designing crop and animal management strategies based on sound biogeochemical principles, that are profitable, and have positive environmental impacts. Specifically, we are developing strategies based on experiments evaluating tillage and cover crop management, crop selection and productivity, forage quality and availability, plant genetics, grazing pressure, animal health and productivity, animal manure application, nutrient cycling, soil quality, carbon storage, and water runoff and quality. Approach (from AD-416) To be able to simultaneously address production and environmental issues, we are taking a multidisciplinary approach to 1) understand biogeochemical mechanisms and processes involved in water and nutrient cycles, 2) evaluate alternative management options and 3) develop management systems to improve the sustainability of agriculture in the region. This requires both field and laboratory investigations, including fescue toxicosis effects on animal physiology. Several field studies will give long-term perspectives and yield realistic relationships between productivity and environmental health cropping studies include: 1) water catchments receiving poultry litter with different tillage management and 2) cover cropping trials based on plant species and method and timing of killing. Pasture studies include 1) evaluation of grazing pressure and organic-inorganic fertilization on soil organic C storage, nutrient runoff, and productivity and 2) water catchments with differences in endophyte association, organic-inorganic fertilization, and presence of cattle. Soil, plant, animal, and water responses are being collected and evaluated. Botanical composition, forage availability, and cattle performance during the first 6 years of experimentation have been summarized in a publication (Franzluebbers et al., 2009; Forage Grazinglands doi:10.1094/FG-2009-0227-01-RS). Water samples have been collected following storm events. Laboratory processing of the extensive sampling (420 sites x 2 depths) to determine spatial variation of soil properties has been completed and will be statistically analyzed and peer- reviewed reports will be prepared in coming months. A few analyses remain to be completed to be able to analyze and prepare peer-reviewed reports on the temporal changes in soil organic carbon (C) and various soil quality properties and processes, but these analyses should be completed by the end of the 2010 calendar year. A one-year no-cost extension was granted to the investigators from the USDA National Institute for Food and Agriculture administration to complete the analyses that remain. Significant Activities that Support Special Target Populations Most forage/livestock operations in the Southern Piedmont are owned by small-farm producers with gross receipts well under $250,000. We are developing conservation agricultural systems appropriate for use by these small-farm producers, including no-tillage planting, cover cropping, land application of manures, and crop-livestock integration. Accomplishments 01 Organic Carbon can be Sequestered in Soils of the Southeastern United States of America (USA) with Conservation Agricultural Management. Soil of the southeastern USA have been degraded by tillage practices that hav resulted in loss of topsoil and fertility but conservation agricultural management has the potential to rebuild soil fertility, restore soil functions, mitigate greenhouse gas emissions, and increase surface-soil organic matter. A scientist from the United States Department of Agriculture (USDA) Agricultural Research Service in Watkinsville Georgia synthesized recent literature from the southeastern USA to estimate carb sequestration rates with conservation management, evaluate the relationship of surface-soil organic carbon to soil functions, and recommend soil sampling strategies to improve the detection of soil organic carbon sequestration. Surface accumulation of soil organic carbo was common under conservation agricultural management and appears to be linked to the rate of soil organic carbon sequestration, abatement of erosion, and improvement in water quality. With 111 million acres of agricultural land in the southeastern USA, 113 million tons of carbon dioxide per year was estimated as potentially sequestered in soil organi matter with conservation management. These results are valuable for stat and federal conservation agencies seeking to promote conservation practices since landowners in the southeastern USA could potentially restore soil fertility and mitigate greenhouse gas emissions. 02 Soil Conditioning Index has been Calibrated to Soil Organic Carbon in th Southeastern United States of America (USA). Rapid and reliable assessments of the potential of agricultural management systems to sequester soil organic carbon are needed to promote conservation and mitigate greenhouse gas emissions. A collaborative effort to investigate the validity of the soil conditioning index for prediction of soil organ carbon sequestration was developed among scientists with ARS in Watkinsville, Georgia, a former ARS research associate in Beltsville, Maryland (now at the National University in Asuncion, Paraguay), and wit Natural Resource Conservation Service (NRCS) in Temple Texas. Published measurement of soil organic carbon from various studies throughout the southeastern USA were compared with computer simulations of soil organic carbon based on the soil conditioning index and the Revised Universal So Loss Equation. Within a field study, the soil conditioning index was usually highly related to soil organic carbon content. Across studies, soil organic carbon content would increase by 0.25 tons of carbon dioxid per acre per year per unit change in Soil Conditioning Index (SCI). Thes results will have important implications for farmers, crop advisors, scientists, and policy makers interested in carbon trading schemes throughout the 300 million acres of land in the southeastern USA. 03 Soil Microbial Diversity can be Restored with Prairie Restoration. Ther is great diversity of microorganisms in soil and little is known about h cultivation and restoration of native prairie may alter the composition and genetic diversity of bacteria and fungi in soil. A collaborative research effort among scientists at the University of Georgia, Mississip State University, Kansas State University, and (United States Department of Agriculture) USDA-Agricultural Research Service in Watkinsville Georg was developed to test for an effect of cultivation versus restoration of native prairie on soil microbial diversity in soils from the Konza Prair Biological Station near Manhattan, Kansas. Soil organic carbon and nitrogen content simply increased with increasing years of grassland restoration. However, the soil microbial community during restoration wa a transitional bacterial community that differed from either the highly disturbed cropland or the undisturbed original prairie. These results ha important implications for the preservation of global genetic diversity and mitigating the impact of agriculture on the environment. 04 Soil carbon sequestration in United Stated of America (USA) agricultural systems is reviewed. Reducing atmospheric greenhouse gases has been identified as one of the most pressing current environmental issues. In agricultural systems, the sequestration of carbon in soils is thought to be one of the best options for reducing atmospheric concentrations of th greenhouse gas, carbon dioxide. A review article was prepared by scientists from the USDA-Agricultural Research Service in Fort Collins, Colorado, Gainesville Florida, Cheyenne, Wyoming, and Watkinsville, Georgia, as well as from Colorado State University and the USDA-Natural Resources Conservation Service in Davis, California and Lincoln Nebraska The work described the potential of agriculture in the USA to mitigate climate change, primarily through soil carbon sequestration, and also identified critical gaps areas where further research is needed to enhan carbon sequestration capability in cropping systems, grazinglands, agroforestry, horticulture, and turfgrass. The information provides a useful synthesis for policy makers and researchers working to optimize agricultural carbon sequestration and direct further research needed to move forward with an effective carbon sequestration strategy for agriculture.
Impacts
(N/A)
Publications
- Franzluebbers, A.J. 2010. Achieving soil organic carbon sequestration with conservation agricultural systems in the southeastern USA. Soil Science Society of America Journal. 74(2):347-357.
- Morgan, J.A., Follett, R.F., Allen Jr, L.H., Del Grosso, S.J., Derner, J.D. , Dijkstra, F.A., Franzluebbers, A.J., Fry, R., Paustian, K., Schoeneberger, M.M. 2010. Carbon sequestration in agricultural lands of the United States. Journal of Soil and Water Conservation. 65(1):6A-13A.
- Franzluebbers, A.J., Causarano, H.J., Norfleet, M.L. 2010. Calibration of the soil conditioning index (SCI) to soil organic carbon in the southeastern USA. Plant and Soil Journal. DOI:10.1007/s11104-010-0310-9.
- Jangid, K., Williams, M.A., Franzluebbers, A.J., Blair, J.M., Coleman, D.C. , Whitman, W.B. 2009. Development of soil microbial communities during tallgrass prairie restoration. Soil Biology and Biochemistry. On-Line.
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) Generally, we are designing crop and animal management strategies based on sound biogeochemical principles, that are profitable, and have positive environmental impacts. Specifically, we are developing strategies based on experiments evaluating tillage and cover crop management, crop selection and productivity, forage quality and availability, plant genetics, grazing pressure, animal health and productivity, animal manure application, nutrient cycling, soil quality, carbon storage, and water runoff and quality. Approach (from AD-416) To be able to simultaneously address production and environmental issues, we are taking a multidisciplinary approach to 1) understand biogeochemical mechanisms and processes involved in water and nutrient cycles, 2) evaluate alternative management options and 3) develop management systems to improve the sustainability of agriculture in the region. This requires both field and laboratory investigations, including fescue toxicosis effects on animal physiology. Several field studies will give long-term perspectives and yield realistic relationships between productivity and environmental health cropping studies include: 1) water catchments receiving poultry litter with different tillage management and 2) cover cropping trials based on plant species and method and timing of killing. Pasture studies include 1) evaluation of grazing pressure and organic-inorganic fertilization on soil organic C storage, nutrient runoff, and productivity and 2) water catchments with differences in endophyte association, organic-inorganic fertilization, and presence of cattle. Significant Activities that Support Special Target Populations Long-term field studies and soil testing evaluations continued to be investigated. These included the Water Quality Study contributing to Objective 1b, the Dawson Field Grazing Study contributing to Objective 2a, the Pasture-Crop Rotation Study contributing to Objective 3a, and Cattle and Cotton Watershed Study contributing to Objective 3b. Other field studies that were outlined in the project plan and contributed to our objectives have either been terminated (Silage Cropping Intensity Study to meet Objective 1g and Salem Road Grazing Study to meet Objective 2b) or have been redesigned to meet other objectives (nitrogen requirement of cotton under conservation tillage to meet Objective 1c, soil changes under conservation tillage of cotton and corn to meet Objective 1e, and nutrient cycling changes under conservation tillage to meet Objective 1f). Laboratory studies to meet Objective 1a and Objective 1d are continuing at various stages of development. Soil organic carbon content under various cropping, pasture, and pasture- crop rotation systems is being determined and data are contributing significantly to a growing demand for information on how conservation agricultural systems can contribute to the mitigation of greenhouse gas emissions. Scientists involved with this research project are active in assembling original data, reviewing the literature, and synthesizing available information for technical advisors. Advice is being sought from the Chicago Climate Exchange, Georgia Carbon Sequestration Registry, Soil Science Society of America special committees, Cotton Incorporated, Grassland Carbon Working Group associated with the United Nations Food and Agriculture Organization, the World Bank, the Argentinean No-Till Farmers Association, and the USDA-NRCS Conservation Effects Assessment Program for Pasture Lands. Significant Activities that Support Special Target Populations Most forage/livestock operations in the Southern Piedmont are owned by small-farm producers with gross receipts well under $250,000. We are developing conservation agricultural systems appropriate for use by these small-farm producers, including no-tillage planting, cover cropping, land application of manures, and crop-livestock integration. Technology Transfer Number of Web Sites managed: 2
Impacts
(N/A)
Publications
- Franzluebbers, A.J. 2008. Linking soil and water quality in conservation agricultural systems. Electronic Journal of Integrative Biosciences. 6:15- 29.
- Abrahamson Beese, D.A., Causarano, H.J., Williams, J.R., Norfleet, M.L., Franzluebbers, A.J. 2009. Predicting soil organic carbon sequestration in crop production systems of the southeastern USA with EPIC and the soil conditioning index. Journal of Soil and Water Conservation Society. 64:134- 144.
- Franzluebbers, A.J., Stuedemann, J.A. 2008. Soil physical responses to cattle grazing cover crops under conventional and no tillage in the Southern Piedmont USA. International Journal of Soil and Tillage Research. 100:141-153.
- Haney, R.L., Franzluebbers, A.J. 2009. Soil CO2 evolution: Response from arginine additions. Applied Soil Ecology. 42(3):324-327.
- Kamlesh, J., Williams, M.A., Franzluebbers, A.J., Sanderlin, J.S., Reeves, J.H., Jenkins, M., Endale, D.M., Coleman, D.C., Whitman, W.B. 2008. Soil microbial communities are affected by land use and agricultural management in the Southern Piedmont USA. Journal of Soil Biology and Biochemistry. 40:2843-2853.
- Singer, J.W., Franzluebbers, A.J., Karlen, D.L. 2009. Grass-Based Farming Systems: Soil Conservation and Environmental Quality. In: Wedin, W.F., Fales, S., editors. Grasslands: Quietness and Strength for a New American Agriculture. Madison, WI: ASA. p. 121-136.
- Steiner, J.L., Franzluebbers, A.J., Neely, C.L. 2009. Expanding horizons of farming with grass. In: Franzluebbers, A.J., editor. Farming with Grass: Achieving Sustainable Mixed Agricultural Landscapes. Ankeny, IA: Soil and Water Conservation Society. Available: http://www.swcs. org/en/publications/farming_with_grass/ p. 216-234.
- Schomberg, H.H., Wietholter, S., Griffin, T.S., Reeves, D.W., Cabrera, M.L. , Franzluebbers, A.J., Fisher, D.S., Endale, D.M., Novak, J.M., Balkcom, K. S., Raper, R.L., Kitchen, N.R., Locke, M.A., Potter, K.N., Schwartz, R.C., Truman, C.C., Tyler, D.D. 2009. Assessing indices for predicting potential N mineralization in pedogenically distinct soils under different tillage management systems. Soil Science Society of America Journal. 73(5):1575- 1586.
- Franzluebbers, A.J., Stuedemann, J.A. 2008. soil-profile organic carbon and total nitrogen during 12 years of pasture management in the Southern Piedmont USA. Agriculture Ecosystems and the Environment. 129:28-36.
- Franzluebbers, A.J. 2009. Linking soil organic carbon and environmental quality through conservation tillage and residue retention. In: Lal, R. and follett, R.F. (editors), Soil Carbon Sequestration and the Greenhouse Effect, Soil Science Society of America Special Publication Book Chapter, Number 57, 2nd edition.
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Progress 10/01/07 to 09/30/08
Outputs
Progress Report Objectives (from AD-416) Generally, we are designing crop and animal management strategies based on sound biogeochemical principles, that are profitable, and have positive environmental impacts. Specifically, we are developing strategies based on experiments evaluating tillage and cover crop management, crop selection and productivity, forage quality and availability, plant genetics, grazing pressure, animal health and productivity, animal manure application, nutrient cycling, soil quality, carbon storage, and water runoff and quality. Approach (from AD-416) To be able to simultaneously address production and environmental issues, we are taking a multidisciplinary approach to 1) understand biogeochemical mechanisms and processes involved in water and nutrient cycles, 2) evaluate alternative management options and 3) develop management systems to improve the sustainability of agriculture in the region. This requires both field and laboratory investigations, including fescue toxicosis effects on animal physiology. Several field studies will give long-term perspectives and yield realistic relationships between productivity and environmental health cropping studies include: 1) water catchments receiving poultry litter with different tillage management and 2) cover cropping trials based on plant species and method and timing of killing. Pasture studies include 1) evaluation of grazing pressure and organic-inorganic fertilization on soil organic C storage, nutrient runoff, and productivity and 2) water catchments with differences in endophyte association, organic-inorganic fertilization, and presence of cattle. Significant Activities that Support Special Target Populations Long-term field studies continued to be investigated. These included the Water Quality Study contributing to Objective 1b, the Dawson Field Grazing Study contributing to Objective 2a, the Pasture-Crop Rotation Study contributing to Objective 3a, and Cattle and Cotton Watershed Study contributing to Objective 3b. Other field studies that were outlined in the project plan and contributed to our objectives have either been terminated (Silage Cropping Intensity Study to meet Objective 1g and Salem Road Grazing Study to meet Objective 2b) or have been redesigned to meet other objectives (nitrogen requirement of cotton under conservation tillage to meet Objective 1c, soil changes under conservation tillage of cotton and corn to meet Objective 1e, and nutrient cycling changes under conservation tillage to meet Objective 1f). Laboratory studies to meet Objective 1a and Objective 1d are continuing at various stages of development. Soil organic carbon content under various cropping, pasture, and pasture- crop rotation systems is being determined and these data are contributing significantly to a growing demand for information on how conservation agricultural systems can contribute to the mitigation of greenhouse gas emissions. Scientists involved with this research project are active in assembling original data, reviewing the literature, and synthesizing available information for technical advisors. Advice is being sought from the Chicago Climate Exchange, Georgia Carbon Sequestration Registry, and Soil Science Society of America special committees. Research is contributing to the Soil Resource Management National Program (NP202) in Problem Area 3 (Soil carbon measurement, dynamics, and management) and Problem Area 5 (Adoption and implementation of soil and water conservation practices and systems). Research is also contributing to the Global Change National Program (NP204) in Component 1 (Carbon cycle and carbon storage), Problem Area 1 (Cropping system and tillage), Problem Area 3 (Grazinglands, CRP, and buffers), and 5 (Organic carbon transformations) and the Agricultural Systems Competitiveness and Sustainability National Program (NP216) in Component 3 (Integrated whole farm production systems), Problem 1A (Strategies and technologies needed to reduce production costs and risks of economic loss). Significant Activities that Support Special Target Populations Most forage/livestock operations in the Southern Piedmont are owned by small producers with gross receipts well under $250,000. These producers must often supplement their farm income with off-farm employment. Throughout the Southern Piedmont the lowest cost source of nitrogen for forage production is animal manure. However, many producers have soil phosphorus levels that restrict further manure application. Since FY 2005, a USDA-Sustainable Agriculture Research and Education grant to determine alternative forage management practices has been implemented that could (a) increase producer gross income, (b) export phosphorus from these high phosphorus-status farms, and (c) be reasonably implemented by limited-resource producers. Technology Transfer Number of Web Sites managed: 2
Impacts
(N/A)
Publications
- Franzluebbers, A.J., Schomberg, H.H., Endale, D.M. 2007. Soil responses to paraplowing of long-term no-tillage cropland in the Southern Piedmont USA. International Journal of Soil and Tillage Research. 96:303-315.
- Causarnao, H.J., Franzluebbers, A.J., Shaw, J.N., Reeves, D.W., Raper, R.L. , Wood, C.W. 2008. Soil organic carbon fractions and aggregation in the Southern Piedmont and Coastal Plain. Soil Science Society of America Journal. 72:221-230.
- Franzluebbers, A.J., Doraiswamy, P.C. 2007. Carbon sequestration and land degradation. In: Sivakumar, M.V.K., Ndiangui, N. (eds). Climate and Land Degradation, Springer Verlag, Berlin, Germany. p. 343-358.
- Franzluebbers, A.J., Stuedemann, J.A. 2007. Crop and cattle responses to tillage systems for integrated crop-livestock production in the Southern Piedmont, USA. Renewable Agriculture and Food System. 22:168-180
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) Generally, we are designing crop and animal management strategies based on sound biogeochemical principles, that are profitable, and have positive environmental impacts. Specifically, we are developing strategies based on experiments evaluating tillage and cover crop management, crop selection and productivity, forage quality and availability, plant genetics, grazing pressure, animal health and productivity, animal manure application, nutrient cycling, soil quality, carbon storage, and water runoff and quality. Approach (from AD-416) To be able to simultaneously address production and environmental issues, we are taking a multidisciplinary approach to 1) understand biogeochemical mechanisms and processes involved in water and nutrient cycles, 2) evaluate alternative management options and 3) develop management systems to improve the sustainability of agriculture in the region. This requires both field and laboratory investigations, including fescue toxicosis effects on animal physiology. Several field studies will give long-term perspectives and yield realistic relationships between productivity and environmental health cropping studies include: 1) water catchments receiving poultry litter with different tillage management and 2) cover cropping trials based on plant species and method and timing of killing. Pasture studies include 1) evaluation of grazing pressure and organic-inorganic fertilization on soil organic C storage, nutrient runoff, and productivity and 2) water catchments with differences in endophyte association, organic-inorganic fertilization, and presence of cattle. Accomplishments Crop residue is needed to feed the soil under no-tillage silage cropping. Soil degradation is a concern on dairy farms relying on high-quality silage crops as a feedstock. No-tillage management of continuous silage crops on erodible land may not effectively control erosion and improve soil quality, because of the lack of crop residue return to protect the soil surface. A collaborative research effort between the Agricultural Research Service in Watkinsville Georgia, the USDA � Natural Resource Conservation Service in North Carolina, and a farmer in the Piedmont region of North Carolina was conducted from 2000 to 2004 to assess changes in soil quality. The farmer-initiated experimental approach allowed us to evaluate the effectiveness of different crop rotations with different frequencies of silage harvest on soil physical, chemical, and biological properties. Harvesting silage less often and leaving more crop residue on the soil surface was beneficial to most soil properties. A moderately intensive silage cropping system created a more optimum balance between agronomic production and environmental quality. This research will help farmers and agricultural extension specialists to design and implement improved cropping systems to achieve simultaneous goals of production and environmental quality on the 0.5 million acres of corn silage in the southeastern USA. This project is contributing to the Soil Resource Management National Program (NP202) in Problem Area 1 (Understanding and managing soil biology and rhizosphere ecology), Problem Area 2 (Soil management to improve soil structure and hydraulic properties), Problem Area 3 (Soil carbon measurement, dynamics, and management), and Problem Area 5 (Adoption and implementation of soil and water conservation practices and systems). It also will contribute to the Global Change National Program (NP204)in Component 1 (Carbon cycle and carbon storage). The soil conditioning index is useful in predicting soil quality in cotton production systems. Various models are being developed and utilized by scientists and government agencies to quantify the potential for carbon storage in soil. However, testing of models is needed to verify their accuracy and reliability. A collaboration among scientists from the USDA-Agricultural Research Service in Watkinsville Georgia, USDA- Natural Resources Conservation Service, Auburn University, and Texas A&M University tested the performance of a highly technical environmental model (EPIC v. 3060) against a simple predictive model currently used by the USDA-Natural Resources Conservation Service to quantify soil management systems impact on soil quality. Several cotton management systems were evaluated at three locations (Blackland Prairie in Texas, Southern Coastal Plain in South Carolina, and Southern Piedmont in Georgia). Both models predicted low soil quality with conventional tillage production of cotton without a cover crop (traditional management) , but higher soil quality with no-tillage management of cotton with winter cover crop and/or rotation with other high-residue producing crops. Although both models can be used by land managers and policy makers to evaluate soil quality on the 7 million acres of cotton in the southeastern USA, there is still an urgent need to collect field-based measurements of soil quality to fully validate and refine these tools. This project is contributing to the Soil Resource Management National Program (NP202) in Problem Area 3 (Soil carbon measurement, dynamics, and management) and Problem Area 5 (Adoption and implementation of soil and water conservation practices and systems). It also will contribute to the Global Change National Program (NP204) in Component 1 (Carbon cycle and carbon storage). Aeration of well-drained grasslands captures more rainfall and reduces phosphorus losses. Phosphorus (P) losses from organic and inorganic (manures) fertilizers applied to pastures can contribute to eutrophication of surface waters. Management practices are needed to reduce losses of P from fertilized pastures. Scientists from USDA-ARS, J. Phil Campbell Sr., Natural Resource Conservation Service and the Univ. of Georgia worked together to determine the effectiveness of mechanical aeration to reduce overland flow, runoff and nutrient losses that contaminate surface waters. At the plot scale using simulated rainfall, aeration improved retention of rainfall and reduced nutrient losses for two fertilizer sources (inorganic fertilizer and broiler litter). At the field scale, aeration reduced runoff and dissolved P losses on well- drained soils but exacerbated P losses on poorly drained soils. Results from this study are being utilized by the Georgia P-Index Workgroup to calibrate the Georgia P-Index management coefficients for determination of site vulnerability to P losses to surface waters. The Workgroup is made up representatives from the USDA-NRCS, USDA-ARS, the University of Georgia, and the Georgia Dept. of Agriculture. This project contributes to the Soil Resource Management National Program (NP202) in Problem Area 4 (Nutrient management for crop production and environmental protection) and to the Water Resource Management National Program (NP201) in Problem Area 6 (Water quality protection systems). Stream-side pastures with 45% or more forage cover minimize nutrient and sediment transport. Losses of phosphorus (P) and nitrogen (N) to streams and rivers from adjoining pastures contribute to eutrophication of surface water bodies. Collaborators from USDA-ARS, J. Phil Campbell Sr., Natural Resource Conservation Service, University of Georgia, and North Carolina State University used simulated rainfall studies on stream-side grassland fields fertilized with inorganic fertilizers or manures to identify management systems that retain nutrients for use by plants and animals rather than transporting them to surface waters in sediment and run-off. Inorganic fertilizer lost more total P than broiler litter while the opposite was true for N. These results support the use of different nutrient-source weighting factors in risk assessment tools such as state P-Indices, which are used in nutrient management programs. Stream-side vegetative cover of 45% or more was found to be an effective management strategy to reduce sediment, P and N losses from deposited cattle feces and urine. The results of this study are being utilized by the Georgia P- Index Workgroup to support and modify source coefficients of the Georgia P-Index for the determination of site vulnerability to P losses. They are also being utilized by the North Carolina Cooperative Extension Service to develop new best management practices (BMPs). This project contributes to the Soil Resource Management National Program (NP202) in Problem Area 4 (Nutrient management for crop production and environmental protection) and to the Water Resource Management National Program (NP201) in Problem Area 6 (Water quality protection systems). Conservation tillage system reduces nutrient losses in run-off. Losses of phosphorus (P) and nitrogen (N) to streams and rivers from adjoining cropland contribute to eutrophication of surface water bodies. ARS scientists at J. Phil Campbell Sr. Natural Resource Conservation Center, Watkinsville, GA and Southeast Watershed Research Unit, Tifton, GA, in cooperation with University of Georgia scientists simulated rainfall at a constant- and variable-intensity on loamy sand soils managed under conservation (strip-tillage) and conventional tillage. They found that constant-intensity rainfall simulations may over estimate the amount of dissolved nutrients lost to the environment in runoff. Conservation tillage resulted in more losses of dissolved P and N than conventional tillage treatments but conservation tillage systems lost 71% less total N and 67% less total P in runoff than conventional-tillage systems. This information can be used by State Cooperative Extension Systems, USDA-NRCS, environmental consultants, and agricultural producers to promote adoption of conservation tillage as a means of improving water quality, as well as for reducing soil erosion. This project contributes to the Soil Resource Management National Program (NP202) in Problem Area 4 (Nutrient management for crop production and environmental protection) and to the Water Resource Management National Program (NP201) in Problem Area 6 (Water quality protection systems). Spatial variation in soil organic carbon and crop yield predicted with process-based model. Computer simulation models can be useful tools to predict changes in crop yields and environmental consequences from soil management practices. However, these models need to be checked or validated against data from long-term field experiments in order to have confidence in model predictions and improve their usefulness. A collaboration among scientists from the USDA-Agricultural Research Service in Watkinsville Georgia and Auburn Alabama, Auburn University, USDA-Natural Resources Conservation Service in Temple Texas, and Joint Global Change Research Institute in College Park Maryland tested the performance of a highly technical environmental model (EPIC v. 3060) against five years of crop yield and soil data collected from a corn�cotton rotation in central Alabama. The cropping system had additional variables of dairy bedding manure and conventional and conservation tillage systems. The model accounted for 88% of the variation in corn grain and cotton lint yields during the five years. Model predictions were sensitive to landscape position. Predictions of soil organic carbon at the end of five years of the different management schemes were very reasonable, although distribution with depth and within various fractions of organic matter were not wholly adequate. This research demonstrated that EPIC modeling has challenges to overcome, but could be a reasonably accurate tool to predict yield and environmental consequences for the greater than 10 million acres of corn and cotton land in the southeastern USA. This project is contributing to the Soil Resource Management National Program (NP202) in Problem Area 3 (Soil carbon measurement, dynamics, and management). It also will contribute to the Global Change National Program (NP204) in Component 1 (Carbon cycle and carbon storage). Modeling and remote sensing used to predict the effects of conservation management on soil organic matter in West Africa. In the drought-prone Sudan-Sahelian zone of West Africa, agricultural operations are based on relatively low-output systems, which maintain production at subsistence levels. It is getting more difficult to sustain the required food supply for its people, because of land degradation from soil erosion and nutrient mining. Scientists from the USDA Agricultural Research Service in Beltsville MD and Watkinsville GA collaborated with scientists from the University of Hawaii and Institute for Rural Economy in Mali to evaluate management systems for improving soil quality and carbon sequestration. Based on land-use classification, climate variables, soil texture, in-situ soil carbon concentrations and crop growth characteristics, the EPIC-Century model was used to project the amounts of soil carbon sequestered for the region. Under continuous conventional cultivation with minimal fertilization and no residue management, the soil top layer was continuously lost due to erosion. The combination of modeling with land use classification was used to calculate that a modest, but significantly positive amount of carbon could be sequestered with ridge tillage, increased application of fertilizers, and residue management. These findings have important implications for building soil fertility, improving human livelihoods, and sequestering atmospheric carbon throughout West Africa. This project is contributing to the Soil Resource Management National Program (NP202) in Problem Area 3 (Soil carbon measurement, dynamics, and management) and Problem Area 5 (Adoption and implementation of soil and water conservation practices and systems). It also will contribute to the Global Change National Program (NP204) in Component 1 (Carbon cycle and carbon storage). Soil bacterial populations are altered by tall fescue-endophyte associations. With the concern over carbon dioxide emission and its connection with global warming, the United States and other nations have been interested in identifying means to enhance the removal of carbon dioxide from the atmosphere. Tall fescue with endophyte infection has been shown to enhance soil organic carbon accumulation compared to tall fescue pastures without this fungal infection. Previous research indicated that the effect on soil organic carbon from the endophyte infection may have been related to toxic compounds produced by the fungus by altering the functional capability of soil bacteria involved in decomposing plant material. Scientists at the USDA Agricultural Research Service in Watkinsville GA conducted an experiment to directly determine if endophyte infection of tall fescue altered the population and diversity of soil bacteria. Endophyte-infected tall fescue decreased the population of four bacterial groups that are involved in decomposition of plant materials, compared with uninfected tall fescue. This study has identified important groups of bacteria that were affected by endophyte- infected tall fescue and has contributed to a better understanding of the potential mechanisms for enhanced soil organic carbon sequestration. This research will be of keen interest to scientists and government agencies dealing with global warming issues, greenhouse gases, and management of agricultural activities. This project is contributing to the Soil Resource Management National Program (NP202)in Problem Area 1 (Understanding and managing soil biology and rhizosphere ecology) and Problem Area 3 (Soil carbon measurement, dynamics, and management). Moderate grazing pressure can ensure high productivity and avoidance of pasture decline. Bermudagrass is a typical pasture grass in the southeastern USA that can be grazed by beef cattle during the summer. Despite considerable research on cattle performance from bermudagrass, a gap exists in how low and high grazing pressure might affect cattle stocking rate, performance, and production over a number of years. Scientists at the USDA Agricultural Research Service in Watkinsville GA conducted a 5-year grazing study to investigate dynamics in cattle performance and production. During the first couple of years, cattle stocking rate and cattle gain were greater under high than under low grazing pressure. However by the end of five years, stocking rate and cattle gain had become similar, suggesting that high grazing pressure had reduced pasture productivity as a result of changes in plant community composition and surface soil condition. How grazing animals can alter pasture productivity and economic return needs to be a consideration in long-term management strategies on the 46 million acres of pastureland in the southeastern USA. This research will benefit: (a) science- by improving grazing land ecological theory, (b) producers- by improving productivity, and (c) the environment- by reducing land degradation. This project is contributing to the Pasture, Forage, Turf and Rangeland Systems National Program (NP215) in Component 4 (Grazing management: Livestock production and the environment). Significant Activities that Support Special Target Populations Most forage/livestock operations in the Southern Piedmont are owned by small producers with gross receipts well under $250,000. These producers must often supplement their farm income with off-farm employment. Throughout the Southern Piedmont, poultry litter is a readily available source of nitrogen for forage production. However, many producers have soil phosphorus levels that restrict further manure application. Since FY 2005, a USDA-Sustainable Agriculture Research and Education grant to determine alternative forage management practices has been implemented that could (a) increase producer gross income, (b) export phosphorus from these high phosphorus-status farms, and (c) be reasonably implemented by limited-resource producers. Technology Transfer Number of Web Sites managed: 2 Number of Non-Peer Reviewed Presentations and Proceedings: 21 Number of Newspaper Articles,Presentations for NonScience Audiences: 4
Impacts
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Publications
- Abrahamson Beese, D.A., Norfleet, M.L., Causarano, H.J., Williams, J.R., Shaw, J.H., Franzluebbers, A.J. 2007. Effectiveness of the soil conditioning index as a carbon management tool in the southeastern USA based on comparison with EPIC. Journal of Soil and Water Conservation 62:94-102.
- Butler, D.M., Franklin, D.H., Ranells, N.N., Poore, M.H., Green, Jr., J.T. 2006. Ground cover impacts on sediemt and phosphorus export from manured riparian pastures. Journal of Environmental Quality. 35:2178-2185.
- Butler, D.M., Ranells, N.N., Franklin, D.H., Poore, M.H., Green, Jr., J.T. 2007. Ground cover impacts on nitrogen export from manured riparian buffers.Journal of Environmental Quality. 36:155-162.
- Doraiswamy, P.C., McCarty, G.W., Hunt Jr, E.R., Yost, R.S., Doumbia, M., Franzluebbers, A.J. 2006. Modeling soil carbon sequestration in agricultural lands of Mali. Agricultural Systems. doi:10.1016/j.agsy.2005. 09.011.
- Franklin, D.H., West, L.T., Radcliffe, D.E., Hendrix, P.F. 2007. Characteristics and genesis of prefrential flow paths in a Piedmont ultisol. Soil Science Society of America Journal. 71:752-758.
- Franzluebbers, A.J., Brock, B.G. 2007. Surface-soil responses to silage cropping intensity on a typic kanhapludult in the Piedmont of North Carolina. International Journal of Soil and Tillage Research. 93:126-137.
- Causarano, H.J., Shaw, J.N., Franzluebbers, A.J., Reeves, D.W., Raper, R.L. , Balkcom, K.S., Norfleet, M.L., Izaurralde, R.C. 2007. Simulating field- scale soil organic carbon dynamics using EPIC. Soil Science Society of America Journal. 71:1174-1185.
- Potter, T.L., Truman, C.C., Bosch, D.D., Strickland, T.C., Franklin, D.H., Bednarz, C.W., Webster, T.M. 2006. Combined Effects of Constant Versus Variable Intensity Simulated Rainfall and Reduced Tillage Management on Cotton Preemergence Herbicide Runoff. Journal of Environmental Quality. 35:1894-1902.
- Stuedemann, J.A., Franzluebbers, A.J. 2006. Cattle performance and production when grazing bermudagrass at two forage mass levels in the southern Piedmont. Journal of Animal Science. 85(5):1340-1350.
- Franklin, D.H., Cabrera, M.L., West, L.T., Calvert, V.H., Rema, J.A. 2007. Field scale, paired watershed study: aeration to reduce runoff and phosphorus losses from grass lands fertilized with broiler litter. Journal of Environmental Quality. 36:208-215.
- Franklin, D.H., Truman, C.C., Potter, T.L., Bosch, D.D., Strickland, T.C., Bendnarz, C.W. 2007. Inorganic N & P losses from variable and constant intensity rainfall simulations on loamy sand under conventional and stip tillage systems. Journal of Environmental Quality. 36:846-854
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