This research uses hierarchical Bayesian models to estimate the relationship between landscape-scale agricultural diversity and the yields of corn, soy, and winter wheat in the coterminous United States. We find that the yields of corn and winter wheat increase by as much as 20% in highly diversified agricultural systems. Our findings also indicate that (1) crop production is more responsive to the number of distinct crop types cultivated on a landscape than their cultivated extent and that (2) increasing diversity in agricultural systems that are already diverse brings the highest yield gains. Our models provide strong evidence at national and regional scales that agricultural diversification-an intervention with known ecosystem benefits-can increase crop production.