1. Cover Crops To Provide Nitrogen
Cover crops add nitrogen to soils through one of two methods: nitrogen fixing and nitrogen scavening. Nitrogen-fixing legumes such as clover, vetch, and peas convert atmospheric nitrogen in soil into forms that can be used by your plants. Nitrogen scavenging plants capturing excess nitrogen before it can run-off, and store the nitrogen in plant tissues. Excellent nitrogen scavengers include radish, rye, sudangrass, and sorghum-sudan hybrids. Grains are also good scavengers.
2. Cover Crops To Improve Soil Structure
One of the best cover crops for aerating compacted soils and improving water infiltration is tillage radish, or daikon radish. Clover, vetch, rye, sudangrass, sorghum-sudan hybrids, and mustards all promote healthy soil structure. These cover crops produce byproducts that help soil particles adhere to one another resulting in a good crumbly textured soil.
3. Cover Crops To Add Organic Matter or Biomass
Organic matter provides many benefits to soils. Most cover crops provide some amount of organic matter to soils, but plants differ in the benefits they provide. Succulent plants, such as legumes (clover, patridge pea, and vetch), break down quickly in soils. They provide nutrients, but leave behind little lasting biomass. Fibrous plant tissues such as grasses and grains, break down more slowly. They will tie up nutrients, but build stable humus, or organic matter, in soils. Perennial clovers such as white and red clover can provide both benefits, with the leaves breaking down quickly while the roots and stems contribute to biomass accumulation.
4. Cover Crops To Reduce Soil Erosion
Cover crops that provide good cover and a dense root system help stabilize soils and combat erosion. Clovers, annual ryegrass, Austrian winter peas, crown vetch, sudangrass, sorghum-sudan hybrids, rapeseed, mustards, and cowpeas are good cover crops for erosion protection.