Melilotus officinalis Cool season legume cover crop. (yellow) Long taproots (often larger and longer than carrots) that open soils and mine insoluble minerals (such as Potassium and Phosphorus), returning them to the soil in plant-available form. Often used in rotation with grain or corn and valued for hay. Great for grazing. Grows to 2'-6' and will fix up to 125 lb of Nitrogen per acre if given adequate Calcium and Phosphorus.
Annual sweet white clover (SCL370) is more tolerant of heavy and poorly drained soils, naturalizes along creeks and streams, and is best for the deep South-Texas to Georgia. Biennial yellow (SCL365) withstands drier sites. Both do best on neutral or alkaline loams and require at least 17" of rainfall per season. Tolerates temperatures to 0°F. Seed at 0.5-1 lb/1000 sq ft or 12-20 lb/acre.