Growing two crops a year in the same field improves schools, helps advance public sanitation, raises median income, and creates jobs.

New research finds that double cropping — planting two crops in a field in the same year — is associated with positive signs of economic development for rural Brazilians.

The research focused the state of Mato Grosso, the epicenter of an agricultural revolution that has made Brazil one of the world’s top producers of soybeans, corn, cotton, and other staple crops. That Brazil has become an agricultural powerhouse over the last decade or so is clear. What has been less clear is who is reaping the economic rewards of that agricultural intensification — average Brazilians or wealthy landowners and outside investors.

Leah VanWey, associate professor of sociology at Brown University and the study’s lead author, says her results suggest at least one type of agricultural intensification — double cropping…