,REAP Study for Resilient Economic Agricultural Practices in St. Paul, Minnesota Corn stover is an important livestock feed and will probably be a major source of renewable bioenergy, especially in the U.S. Corn Belt. Overly aggressive removal of stover, however, could lead to greater soil erosion and hurt producer yields in the long-run. Good residue management practices could help prevent erosion of valuable topsoil by wind and water while still providing a revenue source for producers, either as livestock feed or for use in renewable bioenergy. Plant residues also contribute to soil structure, nutrient cycling, and help sustain the soil microbiota. Good residue management could also help control the loss of greenhouse gases from agricultural soils that could add to already increasing levels of atmospheric greenhouse gases contributing to global climate change. Cumulative GHG emissions varied widely across locations, by management, and from year-to-year. Despite this high variability, maximum stover removal averaged across all sites, years, and management resulted in lower total emissions of CO2 (-12 ± 11%) and N2O (-13 ± 28%) compared to no stover removal. Decreases in total CO2 and N2O emissions in stover removal treatments were attributed to decreased availability of stover-derived C and N inputs into soils, as well as possible microclimatic differences. Soils at all sites were CH4 neutral or small CH4 sinks. Exceptions to these trends occurred for all GHGs, highlighting the importance of site-specific management and environmental conditions on GHG fluxes in agricultural soils..,

,REAP Study for Resilient Economic Agricultural Practices in West Lafayette, Indiana Corn stover is an important livestock feed and will probably be a major source of renewable bioenergy, especially in the U.S. Corn Belt. Overly aggressive removal of stover, however, could lead to greater soil erosion and hurt producer yields in the long-run. Good residue management practices could help prevent erosion of valuable topsoil by wind and water while still providing a revenue source for producers, either as livestock feed or for use in renewable bioenergy. Plant residues also contribute to soil structure, nutrient cycling, and help sustain the soil microbiota. Good residue management could also help control the loss of greenhouse gases from agricultural soils that could add to already increasing levels of atmospheric greenhouse gases contributing to global climate change. Cumulative GHG emissions varied widely across locations, by management, and from year-to-year. Despite this high variability, maximum stover removal averaged across all sites, years, and management resulted in lower total emissions of CO2 (-12 ± 11%) and N2O (-13 ± 28%) compared to no stover removal. Decreases in total CO2 and N2O emissions in stover removal treatments were attributed to decreased availability of stover-derived C and N inputs into soils, as well as possible microclimatic differences. Soils at all sites were CH4 neutral or small CH4 sinks. Exceptions to these trends occurred for all GHGs, highlighting the importance of site-specific management and environmental conditions on GHG fluxes in agricultural soils.,

,EV Smith Study for Resilient Economic Agricultural Practices in Auburn, Alabama There is a potential in the southeastern US to harvest winter cover crops from cotton (Gossypium hirsutum L.) fields for biofuels or animal feed use, but this could impact yields and nitrogen (N) fertilizer response. An experiment was established to examine rye (Secale cereale L.) residue management (RM) and N rates on cotton productivity. Three RM treatments (no winter cover crop (NC), residue removed (REM) and residue retained (RET)) and four N rates for cotton were studied. Cotton population, leaf and plant N concentration, cotton biomass and N uptake at first square, and cotton biomass production between first square and cutout were higher for RET, followed by REM and NC. However, leaf N concentration at early bloom and N concentration in the cotton biomass between first square and cutout were higher for NC, followed by REM and RET. Seed cotton yield response to N interacted with year and RM, but yields were greater with RET followed by REM both years. These results indicate that a rye cover crop can be beneficial for cotton, especially during hot and dry years. Long-term studies would be required to completely understand the effect of rye residue harvest on cotton production under conservation tillage.,

,Field 70/71 Study for Resilient Economic Agricultural Practices in Ames, Iowa See REAP brochure,

,Bioenergy Cropping Systems Study for Resilient Economic Agricultural Practices in Mandan, North Dakota,Rigorous economic analyses are crucial for the successful launch of lignocellulosic bioenergy facilities in 2014 and beyond. Our objectives are to (1) introduce readers to a query tool developed to use data downloaded from the Agricultural Research Service (ARS) REAPnet for constructing enterprise budgets and (2) demonstrate the use of the query tool with REAPnet data from two field research sites (Ames, IA, and Mandan, ND) for evaluating short-term economic performance of various biofuel feedstock production strategies. Our results for both sites showed that short-term (<3 years) impacts on grain profitability were lower at lower average annual crop residue removal rates. However, it will be important to monitor longer term changes to see if grain profitability declines over time and if biomass harvest degrades soil resources. Analyses for Iowa showed short-term breakeven field-edge biomass prices of $26–$42 Mg−1 among the most efficient strategies, while results for North Dakota showed breakeven prices of $54–$73 Mg−1. We suggest that development of the data query tool is important because it helps illustrate several different soil and crop management strategies that could be used to provide sustainable feedstock supplies.,,

,The Agricultural Collaborative Research Outcomes System (AgCROS) is a growing “network of networks” that presently consists of multiple agricultural data networks: Nutrient Uptake and Outcome Network (NUOnet), the Greenhouse gas Reduction through Agricultural Carbon Enhancement Network (GRACEnet), Resilient Economic Agricultural Practices (REAP), Dairy Agriculture for People and the Planet (DAPP; Dairy Grand Challenge), Soil Health Assessment Network (SHAnet), Agricultural Antibiotic Resistance (AgAR), and the Long-Term Agroecosystem Research (LTAR) Network. By integrating these diverse database networks, AgCROS facilitates the flow of information and increases the cooperation among researchers participating in these networks.,,

,To help enhance USA soil health, and ensure a robust living soil component that sustains essential functions for healthy plants, animals, and environment, and ultimately provides food for a healthy society, the GRACEnet Soil Biology group are working together with the larger USDA-ARS GRACEnet community to provide soil biology component measurements across regions and to eliminate data gaps for GRACEnet and REAP efforts. The Soil Biology group is focused on efforts that foster method comparison and meta-analyses to allow researchers to better assess soil biology and soil health indicators that are most responsive to agricultural management and that reflect the ecosystems services associated with a healthy, functioning soil.,The GRACEnet Soil Biology mission is to produce the soil biology data, including methods of identifying and quantifying specific organisms and processes they govern, that are needed to evaluate impacts on agroecosystems and sustainable agricultural practices. This data collection effort is being accomplished in a highly structured manner to support current and future soil health and antimicrobial resistance research initiatives. The outcomes of the efforts of this team will provide a common biological data platform for several ARS databases, including: GRACEnet/REAP, Nutrient Use and Outcome Network (NUOnet), Long-Term Agroecosystem Research (LTAR) network, soil biology (e.g., MyPhyloDB) databases, and others.,

,On-Farm Residue Removal Study for Resilient Economic Agricultural Practices in Morris, Minnesota Interest in harvesting crop residues for energy has waxed and waned since the oil embargo of 1973. Since the at least the late 1990’s interest has been renewed due to concern of peak oil, highly volatile natural gas prices, replacing fossil fuel with renewable sources and a push for energy independence. The studies conducted on harvesting crop residues during the 1970’s and1980’s focused primarily on erosion risk and nutrient removal as a result early estimates of residue availability focused on erosion control (Perlack et al., 2005). More recently, the focus has expanded to also address harvest impacts on soil organic matter and other constraints (Wilhelm et al., 2007; Wilhelm et al., 2010). In West Central Minnesota, crop residues have been proposed a replacement for natural gas (Archer and Johnson, 2012) while nationally residues are also be considered for cellulosic ethanol production (US DOE, 2011). The objective of the on-farm study was to assess the impact of residue harvest on working farms with different management systems and soils. Indicators of erosion risk, soil organic matter, and crop productivity is response to grain plus cob, or grain plus stover compared to grain only harvest.,

,Alternative Biomass Production Study for Resilient Economic Agricultural Practices in Morris, Minnesota The Tillage Study was established in 1997 to assess the effect of a variety of tillage intensities on soil C. The initial eight treatments included no-tillage, moldboard + disk tillage, chisel tillage, and fall and spring residue management, with or without strip-tillage and strip-tillage + subsoiling (Archer and Reicosky, 2009). In 2004, treatments were reduced to no-tillage, moldboard tillage, and fall and spring residue management without strip-tillage, but all had an early or late planting date. The last comprehensive set of soil samples were collected in 2006. In 2008, the strip-tilled subset of the Tillage Study plots were repurposed for the Alternative Biomass Production Systems study, which was designed to explore alternative strategies to support bioenergy including planting of cellulosic feedstock. The Alternative Biomass Production plots included perennials in an extended 6-year rotation, winter cereal rye cover crops in a corn-soybean rotation, and an alternative Sorghum-Sudan grass hybrid forage system, all of which have and will continue to be monitored for agronomic and soil properties.,