Agroecosystems / Carbon Sequestration Research Focus |
Iowa Final 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 objectives were I) to provide an assessment of current rates of carbon sequestration on a state-wide basis in Iowa, II) to assess the potential for increased carbon sequestration with wider adoption of conservation practices and III) to provide locally-relevant estimates and decision tools for evaluating alternative management strategies with respect to their potential to sequester carbon in soils. The analysis was designed to account for the complex interactions of varying climate, soil and management conditions across the State, both to increase the accuracy of the total estimates for the state as well as to provide locally-relevant information for managers and decision-makers in individual counties/conservation districts. The assessment was initiated using 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, land use 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 land use and a wide variety of management practices as well as its wide-spread use and recognition in the US and internationally. Following an initial project phase utilizing existing information on land use and management practices, the project was expanded to include acquisition and use of locally derived information, through the development of a survey instrument called the Carbon Sequestration Rural Appraisal (CSRA). The objectives of the CSRA were to provide local input about current and historical management practices for use in the modeling and at the same time to provide training and information about greenhouse gas mitigation and carbon sequestration. Products of the research include state-wide estimates of carbon sequestration, broken out for various land use and management practices 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 Soil and Water Conservation Districts 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 conservation district have been submitted to DOE as part of a program on voluntary greenhouse gas mitigation reporting. Finally results of the project have been presented at numerous scientific and public meetings, scientific publications, trade journals and newspaper articles and has led to the initiation of similar projects in other states. |