Glycine max This edible legume is a great nitrogen fixer during the hot summer growing season, making up to 130 pounds of available nitrogen per acre. Performs best when irrigated at planting time, as this helps to get this legume prepared for the summer heat. For green manure, rototill soybeans into the soil when 50% of the plants have flowered. If you wish to harvest the beans, let them fully mature and dry in the pod. Grows to 24 inches, tolerating almost any soil. Sow spring to summer. Recommended seeding rate: 2–3 pounds per 1000 square feet; 50 pounds per acre.

Available only in the contiguous US.