Cool-season leguminous cover crops

The agroecological benefits of cover crops, particularly legumes, are well-documented. The environmental and economic costs of intensive synthetic nitrogen fertilizer use highlight the need for more sustainable crop management practices. Legumes have been used as a primary source of nitrogen in farming for thousands of years. For example, Columella, a Roman agricultural writer of the first century, stated that ‘Where no kind of manure is to be had, I think the cultivation of lupines [Lupinus spp.] will be found the readiest and best substitute. If they are sown about the middle of September in poor soil, and then plowed in, they will answer as well as the best manure.’