Agroecosystems / Carbon Sequestration Research Focus |
Nebraska Phase I Progress Report
Objectives and Outcomes The growing recognition that human-induced increases in the concentrations of greenhouse constitutes a serious environmental threat – together with the realization that agriculture can play a significant role in mitigating this threat – has stimulated interest, both in the private and the public sector, in pursuing agriculturally-based mitigation strategies. To develop and implement effective mitigation programs, quantification and assessment capabilities are needed. Our Phase I objectives were I) to develop Nebraska datasets detailing climate, soils, irrigation and landuse needed to provide inputs into the Century model; II) to provide a cropland assessment of current rates of carbon sequestration on a state wide basis in Nebraska; III) to assess the potential for increased carbon sequestration with wider adoption of conservation practices and IV) to provide guidance for the necessary data gathering at the county level on land management histories and local conservation practices needed for the Phase II study. This interim phase I assessment uses existing information compiled by USDA/NRCS and other sources, together with a state-of-the-art simulation model capable of integrating climate and soil conditions, landuse change and agricultural management practices and their effects on soil carbon changes over time. The Century model, developed by the Natural Resource Ecology Laboratory/Colorado State University and USDA/ARS, was chosen, based on its ability to incorporate effects of historical landuse and a wide variety of management practices as well as its wide-spread use and recognition in the US and internationally. Products of the phase I research include detailed databases (climate; soils; irrigation; landuse), estimates of current soil carbon sequestration rates by region and estimates of the carbon sequestration potential on Nebraska cropland. The phase II study takes information learned from the regional analysis and provides the basis for collecting local landuse data by local land managers. Upon completion of the phase II study, land managers in Nebraska will have statewide estimates of carbon sequestration, broken out for various landuse and management practices (including grazing impacts) and displayed by maps and county-level tables to show spatial distributions across the state. A database, which can be queried by specific soil and management combinations, for each county in the state, provides a means for local Natural Resource Districts (NRD's) to estimate the effects of current management systems on carbon sequestration and to make projections of carbon sequestration through changes in management and the adoption of conservation practices. NRCS offices will be able to use this database to assist them in the planning process and provide assistance on best management practices. We also expect this tool to be of interest to local agricultural producers, conservation planners, policy makers and business interests. Estimates of current soil carbon sequestration for each NRD can then be submitted to DOE as part of a program on voluntary greenhouse gas mitigation reporting. |