Andrew Frankenfield
Keep your goals in mind when selecting cover crops and cover crop mixtures.
Cover crops can help improve soil quality, save manure nitrogen or fix nitrogen for the following crop, supply rescue forage and can lead to improved ground and surface water quality. Cover crops have a host of benefits, but there isn’t a single species that does it all. You need to determine what your goal is for your field and select a cover crop species that will do that. Secondly you need to plant it at the appropriate time so it has sufficient time to do what you intended it to do. Cover crops are just like cash crops, they respond well to moderate to high fertility and good available moisture; a field that has low fertility will have a marginal cover crop growth as well. Fields with a history of manure applications or planned applications are excellent locations for cover crops.

Dwarf BMR Forage Sorghum, Annual ryegrass, Crimson Clover and Radishes seeded late July 2013 after Sweet corn. Mixture was green chopped for cattle feed in September. Remaining annual ryegrass and crimson clover over wintered and was burned down in April.
What’s your goal?
- Nitrogen fixation (legumes)
- Nitrogen scavenging (grasses taking up and storing leftover N from soil)
- Soil Building (organic matter and soil structure improvement)
- Erosion Fighting (soil-holding ability of roots and vegetation)
- Weed Fighting
- Forage/Grazing
- Quick Growth
- Alleviate Compaction
- Reduce Nematodes
Attract Beneficial Insects
What goals cover crops achieve
Nonlegumes/Grasses (Annual ryegrass, Barley, Oats, Rye, Wheat, Buckwheat and Sorghum-sudan)
Roles: Most scavenge nitrogen, improve soil organic matter and soil structure, prevent erosion and provide forage. Grasses have relatively quick growth.
Legumes (Berseem clover, Cowpeas, Crimson clover, Field peas, Hairy vetch, Medics, Red clover, Subterranean clover, Sweet clovers, White clover and Woollypod vetch)
Roles: Fix nitrogen, improve soil organic matter and soil structure, prevent erosion and provide forage.
Legumes typically have slower growth than grasses.
Brassicas (Mustards, Radish and Rapeseed)
Roles: Prevent erosion, suppress weeds and soilborne pests, alleviate soil compaction and scavenge nutrients
You likely have heard that mixtures of different cover crop species are good, but what is a good mixture and how do you plant it?
Again it comes down to the time of the year and your location. Generally it is a good idea to plant at least one grass and one legume species and to have one of them survive the winter to provide the soil protection over winter with an actively growing crop come spring time. Also consider adding a brassica to the grass and legume mixture for more diversity. There are many premixed cover crop mixtures on the market. Some of them are listed below.