The researchers studied different grass and legume mixtures in Northern Rhodesia to see how they affect herbage yields and soil quality. They found that grass/legume mixtures produced more herbage and protein compared to grass alone. The legumes did not transfer nitrogen underground to the grass. Maize grown after legume treatments had higher nitrogen levels and yields. Cattle weight gains were similar with different hay types. Adding legumes to grass improved digestibility and protein content. Grass/legume mixtures had higher nitrogen yields than grass alone, but still lower than in temperate regions. The success of tropical grass/legume pastures depends on how well the legumes can fix nitrogen.