Identifying marginal land for Multifunctional Perennial Cropping Systems in the Upper Sangamon River watershed, Illinois

Abstract

Conservation-oriented land practices have long been a strategy for mediating the environmental issues resulting from conventional agriculture. However, there is limited economic support and incentive for landowners to transition the sensitive marginal lands that need mitigation the most. To improve this approach, information tools built out of landowner preferences may help facilitate successful long-term adoption of diverse systems that achieve production and conservation goals, such as Multifunctional Perennial Cropping Systems (MPCs). Previous work has recognized MPCs to have the potential for providing both ecosystem services and perennial crops such as fruits, nuts, and grasses on land that landowners would otherwise consider marginal. To prioritize efforts for implementation of MPCs and provide tailored information to landowners, this study introduces a suitability model that identifies marginal land based on soil erosion, crop productivity, and other land traits that are important to landowners. Information provided by this tool can inform land management decisions. The land traits were spatially analyzed using a geographic information system (GIS) and parameterized to encode the magnitude of each variable's effect on MPCs suitability. Applied in the Upper Sangamon River watershed, central Illinois, we identified 18,685 ha of highly suitable cropland for MPCs. An 8.5 m spatial resolution allowed identification of subfield suitability areas, in addition to locating target regions of extensive occurrences of high suitability. The distribution of target areas was often located where crop productivity was low and topographic potential for erosion was high. For 26,743 ha of cropland, potential erosion was estimated to be greater than the soil loss standard, particularly in the northeastern section of the watershed where there was higher relief and peri-urban or riparian areas surrounding cropland. In a scenario in which landowners would implement MPCs on identified target regions, simulated soil erosion was reduced by 56% across the watershed. The model provides a simple and effective management tool for identifying priority areas for MPCs implementation, giving landowners and researchers actionable information to improve upon conservation strategies for marginal cropland.