Abstract
The effect of Mussoorie rock phosphate-enriched compost, 'Phosphocompost' (containing 8.0 wt % P205), on yield and P uptake in red gram (Cajanus cajan (L.) Millsp.) was studied. The phosphocompost was superior to single superphosphate in its effects on yield, P and N uptake and nitrogenase activity of the nodules. Humic acid solubilized the rock phosphate and was considered one of the factors responsible for better availability of phosphate on composting.