Cover crops can be utilized in a cropping system to absorb and recycle soil nutrients. This ability can be useful when excess fertilizer has been applied to a cash crop and remains available in the soil. Without a cover crop, the fertilizer nutrients may soon become unavailable due to leaching or surface runoff. In the same way, when manure is applied to the soil, a cover crop can absorb nutrients contained in the manure before leaching or runoff occurs. A cover crop with fast growing ability is capable of producing large amounts of biomass in a short period of time. The amount of capturing and recycling of excess soil nutrients in plant biomass is one of the most important features when comparing cover crop species of grasses, legumes, and brassicas. Research conducted in Ohio has shown that oilseed radish cover crop significantly reduces soil nitrate levels by 70% when compared to no cover crop after manure application. Also 9.8 tons per acre of dry matter biomass has absorbed 603 lbs/acre of nitrogen, 126 lbs/acre of phosphorus, and 1060 lbs/acre of potassium. Due to its fleshy composition (and low carbon:nitrogen ratio), the oilseed radish plant material easily decomposes and nutrients become available for the following cash crop.
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