Improved tropical forages include annual/perennial grasses, herbaceous/dual-purpose legumes, and multipurpose trees/shrubs. They have been promoted in Sub-Saharan Africa to address food scarcity limiting smallholder livestock productivity. Scientists Paul et al. reviewed 72 studies, demonstrating tropical forages’ multiple benefits on livestock and food crop productivity, household income, and soil quality.
I guess the food crop productivity you are talking about is can be increased by using bone mean as a fertilizer.