While the wide use of cover crops in rotations with corn in the last decade has resulted in reductions in nutrient pollution and sedimentation, the introduction of cover crops has muddled growers' decision-making regarding how much nitrogen fertilizer to apply to meet their cash crop demands. Researchers at Penn State's College of Agricultural Sciences say they have developed a new decision-support tool that credits nitrogen mineralization from cover crops and soil organic matter.

After harvest in the fall, farmers take the harvested crops to market or store them on their farm. They don't take the whole plant from the field, though. The leftover parts of the plant, like the stalk and leaves from corn, remain in the field. This debris is called crop residue. Read more in this article from Phys.org and the American Society of Agronomy.