Exploring the relationship between agricultural intensification and changes in cropland areas in the US

Abstract

Rapid increase in human population, per capita food consumption (i.e., meat-intensive diet), and biofuel production further drives increasing demand for land. One critical solution is agricultural intensification of crop yield (i.e., crop production per unit area) improvement on the existing croplands. Therefore, the pressure to convert other land for food production can be reduced. Here, we used a panel data of the three most important crops (i.e., corn, soybean, and wheat) in the US Midwest to explore trends of change in agricultural yields and cropland areas at both county and crop levels during 1974–2008. We then utilized mapping to visualize and explicitly examine the spatial patterns of land-sparing and agricultural expansion. Finally, we related cropland area changes to changes in yield and other factors that may impact the contraction/expansion of cropland areas. We detected agricultural expansion with yield increases when considering all counties together. However, cropland area increases were less rapid than rises in crop production. Counties located at the southern periphery of the Corn Belt experienced land-sparing, whereas counties located at the western margin of the Corn Belt, that are more arid and potentially require higher input, exhibited highest agricultural expansion. Higher crop prices and USDA farm subsidies were associated with agricultural expansion.