Environmental Impacts of Agricultural Intensification: Evidence from Brazil’s Double-cropping Boom

This article examines the environmental impacts of agricultural intensification in Brazil, particularly the significant expansion of a double-cropping system involving soybeans and corn, which has transformed Brazil into the world’s leading exporter of corn. We use econometric models with instrumental variables to assess the impact of double-cropping on pesticide runoff and land-use change, focusing on regions near tropical forests. Our results indicate that double-cropping reduces pesticide runoff by acting as a cover crop that limits chemical leaching, although the effect size is small. In our analysis of land-use change, we observe notable regional variation. In traditional agricultural zones, double-cropping has minimal influence on cropland expansion due to high land-conversion costs. However, in frontier areas where land conversion barriers are lower, double-cropping significantly drives cropland expansion. We estimate that 44% of the cropland expansion in the frontier region would not have occurred without the practice of double-cropping. This finding suggests that the recent growth of second-crop corn for ethanol production may have more substantial environmental impacts than previously anticipated.