Cover crops, chemicals, and emissions in Pottawatomie County, Kansas, USA

Abstract

Cover crops have numerous benefits, including enhanced erosion control, forage biomass, nitrogen fixation, nutrient recycling, weed suppression, water management, temperature moderation, and carbon sequestration. Still, the adoption of cover crops by farmers is significantly influenced by their individual goals and preferences, their specific agroecological contexts, and larger agro-industrial structures and systems. Farmers in Pottawatomie County, Kansas, planted cover crops on 8.2% of the county’s cropland in 2022 (nearly twice the national average). This study sought to understand what these farmers were looking for in cover crops by specifically choosing to interview them. Utiliz­ing information gleaned from inter­views with 22 farmers and/or cover crop experts, I was able to thematically analyze the resulting data. Coding revealed that many interviewees were on the “chemical herbicide treadmill” for cover crop suppression and/or termination. I used this infor­mation as a theoretical framework to inform descriptive analyses of farm characteristics, crop types, farmland use, and emissions. After compar­ing trends and themes, I found that interviewees looked for cover crops to be affordable if not prof­itable, suitable for use as a supplement forage biomass/nutrition for cattle, and ideally subsidized by cost-share programs (~US$50/acre). Weather and labor availability and labor cost were also key influ­ences. When grazing or crimping cover crops was not an option for their suppression or termination, interviewees preferred using herbicides over mini­mum tillage. This preference was reflected in the 1997–2022 county-level trends of increased herbi­cide application rates and expenses, notable changes in the primary cropland type from hay(lage) to corn and soybeans, and accelerated leaching emissions. Finally, I discussed implications for adopting soil health principles that trended more organic than regenerative, and offered resources for cover crop education, outreach, and cost share.