Resilient crop yields can be maximized by improving soil health, which is enhanced with cover crops. Long-term advocates have found that adding cover crops to their rotation adds a critical amount of additional carbon to the soil.
Cover crops should be considered as part of the overall crop rotation, and especially on soils with lower organic matter, or on fields with short rotations and little return of crop residue or manure.
Cover crops can provide multiple benefits to the soil. Cover crop species selection will depend on the goal or expected benefit from a cover crop. Matching cover crop choices to function lists some of the reasons for including cover crops in a rotation and lists the potential cover crops that best meet these goals. (More detailed information can be found in the Soil Management section)
Table 1. Matching Cover Crop Choices to Function
| Cover Crop Function | Cover Crop Options |
| nitrogen production | legumes – red clover and other clovers, alfalfa, peas, vetch |
| nitrogen scavenging | fall uptake – daikon radish and other brassicas, oats, barleywinter/spring uptake – cereal rye, winter wheat |
| weed suppression | fast growing/shading plants –brassicas (i.e. diakon radish), winter rye, buckwheat |
| building soil structure | fibrous root systems – oat, barley, rye, wheat, triticale, ryegrass or clovers |
| reducing compaction | most cover crops will assist in reducing compactionmoderate compaction – diakon (oilseed) radish more severe compaction requires strong, dense tap roots over time – alfalfa, sweet clover |
| biomass return to soil | fall seeded – spring cereals, diakon radishsummer-seeded – millets, sorghum, sudangrass, sorghum-sudan grass |
| erosion protection (wind, water) | most cover crops, once established – winter rye, winter wheat, spring cereals (seeded early) |
| emergency forage | fall – oat, barley, wheat, rye, forage brassicas (turnips)summer – millet, sorghum, sudangrass, sorghum-sudangrass, |
| livestock grazing | |
| nematode suppression | cutlass mustard, sudans/sorghums (Sordan 79, Trudan 8) pearl millet (CRPM 101), marigold (Crackerjack, Creole), oilseed radish (Adagio, Colonel)Not all cover crops have the ability to suppress nematode populations; some can act as hosts. Cover crop activity is variety and nematode-specific |