Cover crops have been used to preserve and improve soil since ancient times. Ancient Chinese manuscripts recorded probably more than 3,000 years ago document the use of green manure crops, a type of cover crop usually grown to help maintain soil organic matter and increase nitrogen availability to the next main crop. There are many more instances where the use of cover crops by ancient cultures has been documented or understood. Without doubt, it is known that the use of cover crops can be very beneficial for farmers.
As we are nearing the end of the vegetable production season, silage has or will be chopped soon, and other crops will be harvested, many farmers may want to consider putting in a cover. Here are a few of my favorite recommendations:- Crimson Clover: although it is getting somewhat late to put in Crimson Clover, this cover crop has the benefit of fixing much nitrogen and adding organic matter to the soil. Planting is not recommended after August 20th for elevations greater than 2,500 ft. For those that are under 2,500 ft in elevation, it can be planted as late as early to mid September.
- Oats: A great way to get a good winter cover, but oats are not cold hardy. They will die out in the coldest weather, but leave a good amount of covering residue. When tilled in, this does add organic matter back into the soil. Cover crop oats should be planted by September 30 in Yancey County.
- Brassica sp. (turnips): Need a crop to help address compaction issues? Try planting some of the bulb type turnips. Forage turnips are also a great way to get some cover in the winter. The foliage of turnips when plowed in can greatly benefit soil organic matter. Plant as late as October 15th.
- Cereal or Winter Rye: One of the easiest winter cover crops to establish and it establishes quickly. Decomposing residue is known to have an allelopathic effect on weeds (i can chemically supress the germination of weeds seeds). However, be mindful that this cover crop can grow out of control in the spring which may make plowing/tilling difficult if delayed too far into the spring. It can also make no-till planting challenging due to the thick crop residue that remains after burn down. Plant cereal rye as late as October 15th.
- Annual ryegrass: Grows very well in the fall if it is established early enough. Annual ryegrass can develop an extensive root system which provides very effective erosion control. It also adds a considerable organic matter. Some varieties are more susceptible to winter kill. It also can become a weed to some crops in the following production season. Plant annual ryegrass as late as mid September in elevations below 2,500 ft.
- Cover crop wheat: offers great cover in the late winter months. Adds organic matter to the soil when plowed in. Should be plowed in prior to seed set in the spring if possible. Tends to die down prior to early spring crop planting. Can be planted as late as October 10th.
- Triticale: Offers the best benefits of wheat and cereal rye. Establishes very quickly and can be planted late. Can have fairly significant growth and biomass production in the spring months like cereal rye.
References:
Magdoff and H.V. Es. 2009. "Building Better Soils for Better Crops". 3rd editionCastillo et. al. 2020. "Planting Guide for Forage Crops in North Carolina. AG-266. Available online.
