Sustainable Crop Rotations with Cover Crops

Cover Crops Rotations after Cash Grain Crop Cover crops offer many benefits for agriculture that include erosion control; reduced compaction and nutrient leaching; increased water infiltration; improved soil biodiversity; weed control and disease suppression; increased carbon sequestration and maximum nutrient recycling; improved air, soil, and water quality; and wildlife enhancement. Every cover crop species has its own niche and attributes for agricultural production. A wrong combination of cover crops may exert negative attributes, so a thorough understanding of cover crops selection and management is needed to minimize negative outcomes. Legume cover crops are commonly used for nitrogen contribution because of their inherent capacity to fix atmospheric N (inert gas) into usable form to be used by succeeding crops. Common legume cover crops include cowpea, winter pea, crotalaria, red clover, sweet clover, hairy vetch, soybeans, and alfalfa. On the other hand, grass cover crops include cereal rye, annual ryegrass, Sorghum Sudan grass, oats, wheat, spelt, teff, triticale, and barley. Grass cover crops are widely used for soil erosion control, forages, improving soil structure and reducing compaction, carbon sequestration, recycling nutrients, and weed control. The Brassicas include oilseed radish, tillage radish, or forage radish, turnips, kale, mustard, and rape. They are good for reducing compaction, recycling nutrients, and weed control and disease suppression. Buckwheat is neither a legume nor grass but is a fast-growing summer cover crop and is excellent for nutrient recycling (e.g. phosphorus), honeybees, and allelopathy. The following sections provide information about specific attributes of different cover crops grown after each cash crop.