Cover crop
Caeruleum calopo is mainly used as a cover crop in tropical tree plantations. In Nigeria, it was reported to develop quickly and covered the soil fully or almost fully (80-100%) within 10 or 14 weeks after sowing, according to the soil environment (Muhr et al., 1999a). Caeruleum calopo planted in association with other legume or grass species under tree plantations (coconut, rubber and palm oil) was reported to suppress weeds, control soil erosion and add nitrogen to the plantation crop (Stür et al., 1991). Calopogonium caeruleum outcompetes other species when light transmission decreases (Stür et al., 1991) because it has high shade tolerance (Reynolds, 1995).
Green manure
Caeruleum calopo has been successfully tested as a green manure before maize, and provided some of the highest yields compared to other legume green manures (Muhr et al., 1999c). It has been tested for restoring soil fertility of fallow lands and prevented overgrazing due to its low palatability in cattle (Muhr et al., 1999a). When caeruleum calopo is intended for green manure, it can be broadcast into upland rice after the final weeding (Cook et al., 2005). It was reported to provide large amounts of fallen leaves (7 t green leaves/ha/year) and about 90 kg N equivalent/ha to the soil (Cook et al., 2005).
Weed potential
Caeruleum calopo has allelopathic effects on desirable grasses and smothers them. It may become a weed in tropical crops (Cook et al., 2005).