Soil phosphomonoesterase enzyme activities and phosphate fractions from rhizosphere soils were studied at maximum tillering and panicle initiation stages for three hybrid and two inbred high yielding varieties of rice in a pot culture net-house experiment receiving green manure (Sesbania) and farmyard manure. The P mobilization pattern under integrated nutrient management was also studied. Pusa RH21, a hybrid rice cultivar, showed higher soil alkaline phosphomonoesterase activities, higher plant biomass yield and more P uptake than other cultivars. Under different fertilizer treatments, higher plant biomass and soil phosphomonoesterase (both acid and alkaline) activities at panicle initiation stage of the crop were observed in the green-manure-applied pots. Among the enzymatic activities that were compared, alkaline phosphomonoesterase activity at panicle initiation stage was found to be most significantly correlated to plant biomass yield and P uptake. Selection for this property may be used in rice hybridization programmes to develop better P-efficient cultivars.