cover crop, green temporary crop grown to prevent or reduce erosion and to improve the soil by building up its organic content. Green-manure crops are usually classed as cover crops. In orchards a cover crop is sometimes used to check the growth of some fruits when they reach maturity by supplying a plant that will compete with the tree for the nutriment in the soil. Cover crops are often the first means used to rehabilitate land that has become run down as the result of poor farming practices and neglect. Leguminous plants (e.g., clovers, vetches, and soybeans) and nonleguminous (e.g., rye, barley, wheat, and turnips) are used. See catch crop.