Farmers' heterogeneous perceptions of marginal land for biofuel crops in US Midwestern states considering biophysical and socioeconomic factors

Planting bioenergy crops on marginal land is critical for avoiding competition with food crop production. While many studies have estimated marginal land availability using various methods, only a few studies have considered the role of socioeconomic factors in affecting perceptions about the availability of marginal land. This study analyzes land-use survey data to examine the determinants of farmers' perceptions of marginal land availability on their farms. We find that farmers' perceptions are affected by a combination of unfavorable biophysical (e.g., soil water capacity, temperature variability, and slope) and socioeconomic factors, of which farm size appears to be significant. Interestingly, we identify different determinants of perceptions among farmers that claim to have marginal land and those that do not; the former are determined mainly by unfavorable biophysical factors, while the latter are mainly explained by small farm size. We further apply a prediction model that is trained by a machine learning algorithm to Midwestern states, and derive maps of marginal land likelihood and associated dominant influencing factors. The results suggest that marginal land is primarily under pastureland and grassland cover and in the Dakotas and Nebraska; there is also some marginal land under crop production in the Corn Belt. Our findings contribute to improving understanding of the complex determinants of heterogeneous perceptions of marginal land and can inform the design of more targeted policies for bioenergy crop adoption.