Researchers in Ethiopia studied how planting maize with different legumes affects maize yield. They tested cowpeas, lablab, cassia, and centro in different combinations. They found that planting cowpeas and lablab after maize increased maize yield by 43% and 36% respectively. Maize yield also increased with higher planting density, but not proportionally. Intercropping maize with legumes was better than growing maize alone. They recommend planting cowpeas and lablab after maize, while cassia and centro can be planted together with maize. The best maize planting density was around 55,000 plants per hectare.