Why plant a cover crop?

When nature is left unattended, it knows what it is doing.  The ground is absolutely covered with plants.  Those plants cover, protect and hold the soil in place keeping it from the forces of erosion.  Animals feed off of those plants and deposit their droppings on the soil.  When the plants die, they feed the life in the soil.  Cover cropping, also know as green manure cropping, follows the same principle. Some of the primary benefits from cover crops include:

1. 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. Cover crops protect the soil surface and reduce sealing. Also, beneficial organisms in the soil, such as earthworms, thrive when fresh plant material is decomposing. Organic matter levels tend to improve with the addition of cover crops.
2. 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.
3. 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. This is very important after manure application, because cover crops can reduce leaching of nutrients.
4. 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.
5. Insect control--Beneficial insects, such as lady beetles or ground beetles, may be encouraged by planting cover crops.