Recent research by the Conservation Tillage Information Center shows American farmers are beginning to use cover crops in their rotations to conserve moisture, boost yields of subsequent cash crops, fight erosion and add organic matter to their farm fields. With estimates predicting 20 million acres of U.S. cropland to be seeded to cover crops by 2020, the trend amounts to a significant new agronomic enterprise in many areas, even if cover crops are not considered a cash crop.