Winter Rye Covers the Bare Field
After the corn is harvested, a field can look finished, with the stalks cut and the soil left bare. Some farmers, however, complete one more important job before winter arrives. They scatter the seeds of a cover crop, often a grass called rye, which they never plan to sell.
Bare soil is easily lost, because heavy rain can wash it downhill and strong wind can blow the dry top layer away. Soil takes an extremely long time to form, so losing it is a serious problem for any farm. Rye sprouts quickly in cool weather, and its roots spread through the ground like a net that holds the soil in place.
The green leaves help, too. They shade the ground in spring, which makes it harder for weeds to sprout. Rye can keep growing slowly through a cold season when most plants have stopped.
Before the next crop is planted, the farmer cuts the rye or turns it under with a plow. As the plants rot, they add organic matter to the soil. That material feeds the tiny creatures living there and helps the ground hold water like a sponge.
A cover crop costs seed and work, so a farmer must plan for it. Many decide it is worth the effort because it protects the most valuable thing the farm owns, the soil.