Why grow a field of plants that will not be harvested?

After a food crop is harvested, a field may still be planted with rye, clover or another cover crop. Its main job is to protect and improve the soil between harvests. Growing it can be useful even when it will never become a crop for sale.

Leaves soften the impact of falling rain. Roots help hold soil in place, while stems and plant remains slow water moving over the surface. That can reduce the amount of soil carried away. Living roots also take up some nutrients that might otherwise leave the field with draining water.

Below ground, roots and the substances they release support soil organisms. Later, when cover-crop material breaks down, part of the captured nutrients can return to the soil. A legume cover crop can also work with nitrogen-fixing bacteria, adding nitrogen-containing material to this cycle. Different cover crops do these jobs differently; one mixture does not suit every place.

Timing matters. A cover crop left growing too long can compete with the next crop for water or become difficult to manage. Farmers choose how and when to end its growth. The field is not merely waiting between harvests. Its living cover is helping determine how much water, soil and usable nutrients will remain when the next crop begins.