NASA Harvest partner scientists from Stanford have published new research on the use of satellites to detect cover crop practices in the Midwestern United States and how they might impact yield. The article, Satellite detection of cover crops and their effects on crop yield in the Midwestern United States, indicates that the practice of planting winter cover crops has seen renewed interest as a solution to environmental issues with the modern maize- and soybean-dominated row crop production system of the U.S. Midwest. The study examines whether cover cropping patterns can be assessed at scale using publicly available satellite data, reviewing spatial and temporal trends in cover crop occurrence on maize and soybean fields in the Midwest since 2008.
The researchers found that despite increased regard and funding for cover crops as well as a 94% increase in cover crop acres planted from 2008-2016, increases in winter vegetation have been more modest. Cover cropping was combined with satellite-predicted yields, associating these areas with low relative maize and soybean production and poor soil quality, consistent with farmers adopting the practice on fields most in need of purported cover crop benefits. When controlling for invariant soil quality, cover cropping resulted in some benefits, with average yield increases of 0.65% for maize and 0.35% for soybean. Given these modest impacts on yields, the authors determined that greater incentives or reduced costs of implementation are needed to increase adoption of this practice for the majority of maize and soybean acres in the U.S.