Scaling up agricultural conservation: Predictors of cover crop use across time and space in the US upper Midwest

Scaling up cover crop use will increase crop diversity on agricultural lands and help achieve sustainable production and environmental wellbeing. To increase the total acreage planted to cover crops, more farmers need to use cover crops on a larger proportion of their farms (extent) and for a longer time (longevity), suggesting the importance of spatial and temporal scales of adoption. The adoption literature lacks attention to the spatial and temporal precision of practice measures and misses opportunities to identify consistent or diverse mechanisms for scaling up conservation practices. To fill this gap, we used data from 1,724 corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) farms in Illinois, Indiana, Michigan, and Ohio to study three measures of cover crop usage: the use of cover crops in a single year on a specific field, the percentage of acres planted to cover crops on a farm in a single-year, and years of cover crop use. Our models included key biophysical, operational, policy, social, and psychological factors. We hypothesize that predictors of cover crop adoption and intensity and longevity of use differ. Our results revealed five factors that performed consistently across measures (perceived benefits of cover crops, knowledge, profitability goals, no-till, and rotational diversity), while the effects of the other seven factors varied, including sustainability goals that were only associated with the longevity of use. Policy programs that aim at increasing cover crop use should consider which aspect of scaling-up is being targeted, then focus on corresponding factors that can better tailor policy and education programs to farmer motivations and decision-making contexts.