soil erosion
The residue retention requirement represents the minimum quantity of crop residue (dry tons per acre per year) that must remain on the field to satisfy soil sustainability constraints, including maintenance of soil organic carbon and limits on wind and water erosion. See Metadata description for residue retention coefficients.pdf for more detailed information.
The dataset is comprised of "MuthFiles_Version2025POLYSYS_ChadHellwin.zip" corresponding to the version used in the POLYSYS model for the Billion-Ton Report; Residue removal coefficients to KDF.7z which will open an Excel file (extension .xlsx) by the same name when unzipped; MuthMapping_MDavis-Oct30-2025.7z which when unzipped using 7zip or similar service will deliver several individual maps of the datasets and a Jupyter Notebook (.ipynb extension) to visualize the data and produce the maps delivered in this zipped file.
Note that residue retention values were derived from process-based modeling (EPIC and RUSLE) as reported in Muth et al.(2012). These values are not percentages or fractions. A value of 10 tons/acre/year should be interpreted as: Residue removal is effectively constrained (no removal feasible) under modeled conditions. Values vary by: Crop type, County, Tillage system, Yield scenario, and Year.
For additional information, please see BT16 resources as well as:
Muth, D. J., et al. (2012). Sustainable agricultural residue removal for bioenergy: A spatially comprehensive US national analysis. Applied Energy. http://dx.doi.org/10.1016/j.apenergy.2012.07.028
An Integrated Model for Assessment of Sustainable Agricultural Residue Removal Limits for Bioenergy Systems
Agricultural residues have been identified as a significant potential resource for bioenergy production, but serious questions remain about the sustainability of harvesting residues. Agricultural residues play an important role in limiting soil erosion from wind and water and in maintaining soil organic carbon. Because of this, multiple factors must be considered when assessing sustainable residue harvest limits. Validated and accepted modeling tools for assessing these impacts include the Revised Universal Soil Loss Equation Version 2 (RUSLE2), the Wind Erosion Prediction System (WEPS), and the Soil Conditioning Index. Currently, these models do not work together as a single integrated model. Rather, use of these models requires manual interaction and data transfer. As a result, it is currently not feasible to use these computational tools to perform detailed sustainable agricultural residue availability assessments across large spatial domains or to consider a broad range of land management practices. This paper presents an integrated modeling strategy that couples existing datasets with the RUSLE2 water erosion, WEPS wind erosion, and Soil Conditioning Index soil carbon modeling tools to create a single integrated residue removal modeling system. This enables the exploration of the detailed sustainable residue harvest scenarios needed to establish sustainable residue availability. Using this computational tool, an assessment study of residue availability for the state of Iowa was performed. This study included all soil types in the state of Iowa, four representative crop rotation schemes, variable crop yields, three tillage management methods, and five residue removal methods. The key conclusions of this study are that under current management practices and crop yields nearly 26.5 million Mg of agricultural residue are sustainably accessible in the state of Iowa, and that through the adoption of no till practices residue removal could sustainably approach 40 million Mg. However, when considering the economics and logistics of residue harvest, yields below 2.25 Mg ha−1 are generally considered to not be viable for a commercial bioenergy system. Applying this constraint, the total agricultural residue resource available in Iowa under current management practices is 19 million Mg. Previously published results have shown residue availability from 22 million Mg to over 50 million Mg in Iowa.