LAUSR

Soil health is a pathway through which farm and environmental outcomes can be improved together on agricultural landscapes, and management to improve soil health is increasingly recognized as a strategy for agricultural producers to adapt to climate change-related impacts such as erosion and flooding. Many incentive programs exist or are in development to support the adoption of practices that promote soil health for these reasons, but few on-farm trials have compared the intersections of farmer versus researcher observations of soil health or of soil health compared with climate adaptation. The purpose of our study was to assess soil health outcomes and adaptation to simulated climate change in response to cover cropping on working farms enrolled in a Minnesota NRCS funded EQIP incentive program. This incentive program required the inclusion of diverse cover crop mixtures into existing farm crop rotations. We conducted farmer surveys, NRCS protocol field soil assessments and NRCS recommended laboratory assays on farms from across the state of Minnesota in a paired design comparing fields on the same or adjacent farms, of the same soil mapping unit. While 85% of farmers reported improvements in soil attributes or productivity, most field and laboratory assessments produced a high amount of variability in responsiveness to cover cropping. Despite this variability, we saw a significant decrease in bare ground and significant increases in earthworm counts, cellobiohydrolase microbial activity, and the Visual Assessment of Soil Structure (VESS). While researcher measurements did not show improvement in physical characteristics or infiltration other than the VESS field assessment, 67% of farmers reported Improvements to the physical structure of the soil, associated with improved outcomes such as earlier planting dates and consistent crop growth across fields. When 5+ species of cover crops were present, the percentage of reported improvements went up to over 80%. We also found no significant improvement to climate change adaptation measured by nutrient or sediment loss after a simulated storm event. Together, our results suggest that while variable, adding a diverse annual cover crop mix to increase continuous cover can improve characteristics associated with soil health, and that there needs to be a stronger focus in understanding variation in realized soil health outcomes on farms, including more co-creation of research with farmer partners. This article is protected by copyright. All rights reserved.