Integrated Feedstock Supply Systems for Corn Stover Biomass

Technical approach/work plan for task 8: Develop an interactive web-based corn stover biomass planning tool

I-FARM is a database-driven farming systems simulation model and decision tool that predicts economic returns and ecosystem impacts of farm enterprises, integrating both crop and livestock components.  I-FARM was developed by Iowa State University to provide free access to farmers and decision-makers, and currently handles up to 20 users simultaneously. The I-FARM URL is http://i-farmtools.org (van Ouwerkerk et al. 2003).  Free web access to I-FARM provides a powerful and comprehensive farmer decision-making tool. This project will expand I-FARM to address corn stover production and harvest opportunities, providing farmers interested in biomass production with a flexible and valuable decision-making tool. DOE’s recent report Roadmap for Agriculture Biomass Feedstock Supply in the United States identified development of on-farm decision-making tools as a “top priority” research need (U.S. DOE 2003, p. 27). 

I-FARM currently focuses on agroecosystems of the upper Midwest, but through the funding from this project will be expanded to all states with significant corn acreage. The model offers the selection of a range of crops and crop rotations, with the associated practices as tillage, fertilization, planting, weed control, harvesting, and residue removal. Swine, beef and dairy production is modeled based on feed intake, growth rate, grazing or confinement options, and manure management systems. The model provides several outputs including input costs, off-farm sales, economic returns, energy requirements, nutrient flows, and soil erosion impacts.

This DOE-USDA grant will support further development of this model to address farmer decision-making requirements for biomass production.  These will include incorporating the Soil Conditioning Index (SCI), developing a range of biomass production scenarios, implementing a batch processing module to facilitate analysis of large numbers of farms and scenarios, and improving the interface for maximum ease of use by farmers.

The SCI is a decision support tool currently used by the USDA Natural Resource Conservation Service (NRCS) to evaluate crop and soil management practices with respect to impacts on soil organic matter and related soil quality characteristics.  This tool is particularly suitable to address these concerns related to biomass removal in a farmer decision-making framework.  In contrast to sophisticated research model such as CENTURY, the SCI is designed for farmers to understand and use. It is broadly familiar to NRCS staff and other technical service providers, and relies on nationally available databases already integrated in I-FARM. The SCI provides a soil organic matter complement to the RUSLE soil erosion model currently implemented in I-FARM. With the combined package, this tool will provide important feedback to farmers and policymakers with respect to soil sustainability concerns from biomass harvest.

Farm enterprise scenarios will be developed that include a range of biomass production and carbon management strategies.  These scenarios will be formalized as a set of representative farms of several different configurations and sizes, based on agricultural census data for the Midwestern U.S. I-FARM will then be used to analyze these farms to assess economic viability and agroecosystem impacts at the farm scale.  Estimates of farm income, labor requirements, energy use, N, P, and K flows, soil erosion, and soil organic matter changes will be analyzed for the feedstock supply scenarios defined in task 7. For each scenario, assumptions regarding technologies, cost, prices, and policies will be the same as those used in the complementary regional and national economic analysis of task 5.  This analysis will assess economic and agroecosystem impacts in detail at the farm-scale for a range of farm sizes and types. Results of this detailed analysis will identify opportunities for integration and optimization at the farm-scale and aggregated results will be used to calibrate the regional economic model used in task 5. The user-friendly interface and free web access will provide an effective decision-making tool for farmers and their advisors to develop site-specific strategies to respond to expanding opportunities for biomass production.