The main purpose of a green cover crop is to benefit the soil and other crops in the rotation. Usually the green cover crop is not intended for harvest, feed or sale. Some of the main benefits from cover crops include:
- Improving soil quality: 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, due to weathering the surface tends to seal and water will run off. Cover crops protect the soil surface and reduce soil sealing and capping. Soil biology is enhanced assisting the growth of beneficial organisms, such as bacteria, soil mycorrhizae, and deep burrowing earthworms in particular thrive when fresh plant material is decomposing. Organic matter levels tend to improve with the inclusion of cover crops in a crop rotation.
- 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 autumn, winter, and early spring period, loss of soil and associated nutrients from erosion is greatly reduced.
- Fertility improvements: Legumes can add substantial amounts of available nitrogen to the soil. Non-legumes can be used to mop up excess nitrogen left over from previous crops and recycle available phosphorus and potassium to the following crop. This is very important after manure application because cover crops can reduce leaching of nitrate in particular.
- Suppress weeds: A dense stand of a green cover crop, such as rye or mustard, can suppress weed growth by soil coverage and shading. A combination of natural plant competition and plant root exudates, or allelochemicals, from cover crops suppress the growth of other weed species.
- Insect control: Beneficial predators such as ladybirds, ground beetles and farm birds, who feed on aphids and field slugs, will also be encouraged by planting cover crops.
Geraghty Consulting have developed an indepth knowledge on the use of cover crops in commercial crop production systems. We can provide farmers with a range of options to include cover crops in field rotations that will reduce the cost of other farm inputs in succeeding cash crops.