Soil is not a renewable resource; it must be protected and preserved by treating it properly. Many people are aware that farmers take precautions to protect soil such as limiting their tillage and driving on fields as little as possible. But did you know that cover crops are a sustainable farming practice that helps preserve and nourish soil?
Much of the awareness that soil must be protected came from hard lessons learned during the devastating droughts on the Canadian prairies in the 1920s and 30s. Drought made it impossible to grow anything in soil that had been mismanaged and over-cultivated. Families went hungry in the midst of fields that had once sustained them and farmers watched helplessly as topsoil blew away in the unrelenting wind.
The drought years led to establishing various agencies to create drought-alleviation programs, most notably the Prairie Farm Rehabilitation Administration in 1935. From the research and work of such programs came new cultivation practices that have since grown and expanded as scientists, researchers and farmers have learned more.
Today, soil preservation is an important part of sustainable farming. Growing cover crops after harvesting a commodity crop, or even at the same time as a commodity crop, helps to preserve and restore soil. The new crop is one that grows quickly to cover the ground, restricting weed growth and soil erosion, and breaks down to nourish the soil over the winter. Some crops deter pests and disease; for example, red clover can suppress the life cycle of an insect that likes wheat, removing a generation of pests without using an insecticide and with the added benefit of not driving on the field and compacting the soil to deliver the spray.
Cover crops are also beneficial to lake and waterways, as they reduce the amount of water draining off a field during rainfall, keeping the water in the soil and keeping topsoil, fertilizer and organic matter out of the water. When tillage radishes are planted as a cover crop, their long taproot actually breaks up the soil, preventing compaction and improving drainage, which prepares the soil for the spring crop. Besides radishes, cover crops include red clover, sunflowers, winter wheat, oats, alfalfa and rye.
Bonus benefit! Cover crops are also good for bees! Flowering cover crops can provide pollen and nectar to support bee health and reproductive potential.