2008 Annual Report 1a.Objectives (from AD-416) 1. Determine effects of cropland and rangeland management practices in the Great Plains on agricultural greenhouse gas intensity (GHGI) (net emissions of CO2, CH4, and N2O per unit of agricultural commodity produced) by: a)quantifying GHGI in field plots under different management practices and, b) applying data and information to project impacts of different management practices on GHGI, via process-based simulation models. 2. Determine land management and climate effects on the size and dynamics of soil organic carbon (SOC) and soil inorganic carbon (SIC) pools by: a) developing methods to measure soil C pools and SOC sequestration. b) measuring SOC pools for long-term continuous no-till with intensive crop management practices under field conditions. c) application of computer models to assess changes in soil carbon stocks resulting from land use and land use change. NEW: Develop network of several ARS locations for GRACEnet (Greenhouse gas Reductions through Agricultural Carbon Enhancement network). These locations will be determined in the near future in consultation with NPS. Lead and coordinate the national ARS project, GRACEnet, a multi-location project to study greenhouse gases (GHGs) in agricultural systems. Coordinate and analyze data from multi-location field studies following standardized protocols to compare net GHG emissions (carbon dioxide, nitrous oxide, methane), carbon (C) sequestration, and broad environmental benefits under different management systems that: typify existing production practices for significant agricultural systems in different parts of the country, maximize C sequestration, minimize net GHG emissions, and meet sustainable production and broad environmental benefit goals (including C sequestration, net GHG emissions, water/soil quality, etc.). Data from multi-location field studies following standardized protocols will be analyzed to compare net GHG emission (Carbon dioxide, nitrous oxide, methane) carbon (C) sequestration, and broad environmental benefits under different management systems that: typify existing production practices for significant agricultural systems in different parts of the country, maximize C sequestration, minimize net GHG emissions, and meet sustainable production and broad environmental benefit goals (including C sequestration, net GHG emissions, water/soil quality, etc). Analyze results from GRACEnet, in cooperation with network participants to: identify practices that balance production and environmental goals related to C sequestration and GHG emissions; identifying ways to produce biofuels crops while meeting environmental goals; develop accurate and easy-to-use models to predict C sequestration and GHG emissions in repsonse to on-farm management decisions; determine how to scale plot estimates of C sequestration and GHG emissions to regional and national scales; use remote imaging to estimate C stocks; and develop fast, accurate, and inexpensive ways to measure or estimate soil C and GHG fluxes. 1b.Approach (from AD-416) Objective 1 a. Greenhouse gas intensity will be quantified in field plots under different management practices to determine the effect of tillage, fertilization, irrigation and crop rotations in irrigated and dryland conditions. The irrigated cropping system incorporates trace gas exchange, soil C, and crop production measurements within an ongoing field plot study that was initiated in 1999. A study to quantify net GWP within an established dryland agricultural management project will be conducted within a project that was established in 1985 in northeastern Colorado. Objective 1 b. Field and laboratory studies will be conducted in or using soils from plots described in 1 a. to identify mechanisms by which soil biological, chemical, and physical processes affect production, emission, and consumption of NO, N2O, CH4, and CO2 in soils. The impact of soil water content and bulk density on trace gas fluxes will be evaluated from field measurements after several years of observations. We will also conduct short-term studies under more controlled conditions, either in field or using intact soil cores. Established procedures which employ highly 15N-enriched fertilizer or 13C-labeled CH4 will be used to determine the effect of soil WFPS on gas exchange. Objective 1 c. Data and information from collected for objectives 1 a and 1 b will be used for DAYCENT model verification to project impacts of different management practices on GHGI, via process-based simulation models. Crop production and ancillary data from the above studies will be used to verify DAYCENT output for irrigated systems. The model will then be used to estimate GHGI for various management scenarios for irrigated systems in the Great Plains. Objective 2a. Soil C pools and SOC sequestration will be determined using new technology such as near- or mid-Infrared diffuse reflectance spectroscopy to determine soil C pool concentrations to provide accurate, yet rapid soil C pool information. Molecular beam mass spectrometry (MBMS) will be used to determine soil C pool concentrations to provide accurate, yet rapid soil C pool information and soil C age. Objective 2b. The impact of agricultural management on soil C and N cycles in long-term continuous no-till with intensive crop management practices under rainfed conditions will be determined in analysis of soils from long-term field experiments. On-farm sites will be selected near and around Richmond, VA that include long-term continuous no-till to compare with long-term conventional tillage sites. This study will allow an evaluation of the change in soil water stable aggregates, water infiltration and retention, and SOC that have occurred following at least 10 yr. Objective 2c. The previously developed databases and those currently being collected will be used to contribute to the calibration and validation of a newly revised Windows-friendly version of the CQESTR computer model for on-farm and farm advisor use and for potential expansion to allow it to begin to address regional estimates of soil C sequestration and changes in C stocks. NEW: Coord. the activities of the network with several ARS locations for GRACEnet 3.Progress Report 5402-11000-007-02S: The methodology to estimate uncertainties in model outputs was published in the most recent EPA GHG inventory and will be submitted for journal publication as will the results of this inventory analyses. Also the latest DAYCENT testing exercise was recently published. This collaborative effort with CSU has been instrumental in completing the recent U.S. Agriculture and Forestry Greenhouse Gas Inventory: 1990-2005 report (August 2008). Sub-objective 1a) quantifying GHGI in field plots under different management practices. GHGI was sampled in 12 different cropping systems of different rotations, tillage intensity, N fertilizer type, and N levels. No-till (NT) cropping systems had significantly lower CO2 and slightly lower N2O emissions than conventional till (CT) systems up until 2005. N2O emissions were significantly less under NT. N2O emissions from polycoated urea had lower emissions than plots with urea ammonium nitrate. A study has been initiated to compare N2O from different types of N fertilizer. Nitrification inhibitors and time-released fertilizers have strong potential to reduce emissions. Sub-objective 1b) Identifying mechanisms by which soil biological, chemical, and physical processes affect production, emission, and consumption of NO, N2O, CH4, and CO2 in soils. (No Report). Study discontinued because of Human limitation following retirement of key scientist. Sub-objective 1c) The DAYCENT biogeochemical model was tested using N2O, crop yield, soil N and C, and other data collected from the plots described in ‘sub-objective 1a’ above. The model properly represented impacts of tillage intensity and N fertilizer on crop yields, soil organic carbon and soil water content. Model runs suggest that CRP land converted to corn for ethanol production provides little, if any, greenhouse gas savings. Reduced tillage and improved fertilizers decrease emissions. Sub-objective 2a) developing methods to measure soil C pools and SOC sequestration. Sub-objective 2b) Continuous NT is a sustainable practice within the Coastal Plain region of VA and its implementation should be encouraged where elimination of tillage is practical. Sub-objective 2c) The DAYCENT model reliably simulated grain yields and soil C levels for most test fields in VA. Long term DAYCENT simulations project that soils can act as a strong carbon sink for about 25 years after conversion to NT. The reported progress directly contributes to accomplishment of ARS Strategic Plan Goal 6, Protect and Enhance the Nation’s Natural Resource Base and Environment. The research conducted provides information under ARS National Program # 204: Global Climate Change for Component I: Carbon Cycle and Carbon Storage and for Component II: Trace Gases – cropping systems 4.Accomplishments 1. U.S. Agriculture and Forestry Greenhouse Gas Inventory Report: Specific-Cooperative Agreement (#58-5402-4-387) was established with Colorado State University to provide access to computer and programmer capabilities for development of the USDA U.S. Agriculture and Forestry Greenhouse Gas Inventory Report. Computer programs were written to compile model inputs, execute simulations, and process model outputs. DAYCENT model results from global scale simulations were included in a recently published paper that compared the economic costs of different GHG mitigation strategies. Impact: Model results have been reviewed and published in the most recent EPA GHG inventory. The reported progress directly contributes to accomplishment of ARS Strategic Plan Goal 6, Protect and Enhance the Nation’s Natural Resource Base and Environment. The research conducted provides information on “interactions between land use, land management, and climate change: relations to carbon sequestration and nitrogen cycling, trace gases, and agroecosystems” under ARS National Program # 204, Global Climate Change. 2. DAYCENT biogeochemical model was used to estimate nitrous oxide emissions for cropped and grazed soils for the US GHG Inventory: New, more rigorous, methodologies were developed to quantify uncertainty which led to much narrower confidence intervals for N2O emissions than reported in previous inventories. Emission estimates, confidence intervals, and methodologies are described in detail in Chapter 3 of the USDA U.S. Agriculture and Forestry Greenhouse Gas Inventory. Impact: The inventory has been reviewed by personnel with the Global Change Program Office and the final print version has been cleared by the Office of Communications. The reported progress directly contributes to accomplishment of ARS Strategic Plan Goal 6, Protect and Enhance the Nation’s Natural Resource Base and Environment. The research conducted provides information on “interactions between land use, land management, and climate change: relations to carbon sequestration and nitrogen cycling, trace gases, and agroecosystems” under ARS National Program # 204, Global Climate Change. 3. Methods for rapid measurement of Soil Organic Carbon (SOC) and SOC pools: Two methods were developed and or tested for rapid measurement SOC. Infrared and pyrolysis molecular beam mass spectrometric (pyMBMS) methods were used and calibrated and or compared to traditional laboratory methods to measure the total SOC, microbial biomass C, particulate organic matter C, mineral associated C, inorganic C (carbonates). Impact: The results of these studies are published and show that both methods can measure total SOC and microbial biomass C. The infrared method (mid) had advantages of being more sensitive for some measures while the pyMBMS method allowed an evaluation of the organic molecules that were associated with various SOC pools, this possibly helping to identify pathways for C cycling and sequestration. The reported progress directly contributes to accomplishment of ARS Strategic Plan Goal 6, Protect and Enhance the Nation’s Natural Resource Base and Environment. The research conducted provides information on “interactions between land use, land management, and climate change: relations to carbon sequestration and nitrogen cycling, trace gases, and agroecosystems” under ARS National Program # 204, Global Climate Change. 5.Significant Activities that Support Special Target Populations None. 6.Technology Transfer Review Publications Beach, R., Deanggelo, B., Rose, S., Li, C., Salas, W., Del Grosso, S.J. 2008. Mitigation potential and costs for global agricultural greenhouse gas emissions. American Journal of Agricultural Economics 38: 109-115.. Del Grosso, S.J., Parton, W.J., Ojima, D.S., Keough, C., Riley, T.H., Mosier, A.R. 2008. Daycent simulated effects of land use and climate on county level n loss vectors in the USA. Follett, R.F. and Hatfield, J.L. (eds). Nitrogen in the Environment: Sources, Problems, and Management 2nd Edition, p. 571-595. Elsevier Science Publishers, The Netherlands. Del Grosso, S.J., Halvorson, A.D., Parton, W.J. 2008. Testing DAYCENT Model Simulations of Corn Yields and Nitrous Oxide Emissions in Irrigated Tillage Systems in Colorado. Journal of Environmental Quality 37:1383-1389. Lal, R., Follett, R.F., Stewart, B., Kimble, J. 2007. Soil Carbon Sequestration to Mitigate Climate Change and Advance Food Security. Soil Science. 172 (12): 943-956. Magrini, K., Follett, R.F., Kimble, J., Davis, M., Pruessner, E.G. 2007. Using Pyrolysis Molecular Beam Mass Spectrometry to Characterize Soil Organic Carbon in Native Prairie Soils. Soil Science. Vol. 172:659-672.