Winter annual cover crops have been used in rotation with summer crops for many years in North Carolina, but now there are some interesting new applications of this practice. Early experiments date from the 1940s and show several important benefits of planting winter annual cover crops, chief among them erosion control, addition of nitrogen (N) to the soil for use by a subsequent crop, removal of N from the soil to prevent nutrient loading, buildup of soil organic matter, and buildup of residue that acts as a mulch for water conservation or retention.