Role of Annual Legume Cover Crops in Efficient Use of Water and Nitrogen

Winter cover crops of either grasses or legumes are compatible with conservation tillage methods and offer several important benefits that protect and improve the soil and can increase production efficiency. This chapter describes the methods of using annual legume winter cover crops in various cropping systems, mainly continuous grain, aims to evaluate the effects of these cover crops on soil water conservation and use. It examines the transformations and plant availability of Nitrogen (N) from several adapted species of annual legume cover crops. M. S. Smith et al. indicated several ways in which legume winter cover crops may affect the plant-soil water relationships of the summer crop. Dry matter yields and N concentration provide a measurement of the N content of the aboveground portion of a cover crop. The yield response to legume cover crops is greatest at low or zero N rates, as would be expected.