Benefits of cover crops
Cover crops offer many benefits not just soil erosion protection.
There are definite benefits in including cover crops in your crop rotation. You can grow some of your nitrogen needs, improve water infiltration, reduce soil erosion, and reduce weed pressure and soil crusting. The biggest advantage is improved soil structure through increased soil organic matter.
Soil structure is defined as the way which the individual particles of sand, silt and clay are assembled. Soil organic matter is made up of humus, crop residue and roots, and the soil microbial world. The microbial world is bacteria, fungi, protozoa, nematodes and other organisms.
The predominate species of microbes in a tilled field are bacteria. Bacteria can be broken down to aerobic and anaerobic. In tilled fields the aerobic bacteria (live in the presence of oxygen) are the most abundant and break down crop residue quickly along with soil organic matter if enough food is present. In wet tilled fields (compaction) the anaerobic bacteria are the main bacteria. They are slow at breaking down crop residue. If you plow and you had corn in that field two years ago and today you turn up corn stalks that look like they have not deteriorated, anaerobic bacteria is the cause.
In no-till fields with cover crops, researchers are finding mycorrhizal fungi. These fungi thrive when there is a constant presence of living roots. What researchers have found is a symbiotic relationship between these fungi and the plant. This relationship allows the fungi to develop special glue called glomalin which helps develop macroaggregates which in turn leads to better soil structure.
Special thanks to Florian Chirra, Ohio State University Extension, for contributing to this article.