Although cover crops have been used for centuries, today’s modern farmer has grown up in a generation which has replaced the use of cover crops with widespread use of fertilizers and herbicides. Cover crops have an important role in successful farming systems. However, there are some drawbacks to consider, such as seeding cost, pest harboring, possible spring burndown, and yield reductions. Choosing the right cover crop for your needs is critical to success.
The main purpose of a cover crop is to benefit the soil and/or future crops. Some of the primary benefits from cover crops include:
- Soil quality improvements—Soil tilth is improved whenever a plant establishes roots and grows into compacted areas. Water infiltration is improved as well. When a field lays fallow for a period of time, the surface tends to seal and water will run off. Also, beneficial organisms and microorganisms in the soil thrive when fresh plant material is decomposing. Organic matter levels tend to improve with the addition of cover crops.
- Erosion control—Cover crops reduce wind and water erosion on all types of soils. By having the soil held in place by cover crops during the fall, winter, and early spring, loss of soil from erosion is greatly reduced.
- Fertility improvements—Legumes can add substantial amounts of available nitrogen to the soil. Non-legumes can be used to take up excess nitrogen from previous crops and recycle the nitrogen as well as available phosphorus and potassium to the following crop.
- Suppress weeds—A dense stand of winter rye or other cover crop can suppress weeds by soil shading. Allelochemicals from cover crops suppress the growth of other plants.
- Insect control—Beneficial insects, such as lady beetles or ground beetles, may be encouraged by planting cover crops.