Although the phosphorus (P) pools and cycles in grassland ecosystems can be significantly impacted by livestock grazing, very few studies have looked at the effects of grazing intensity on the soil P pools. Grazing has been known to reduce soil P availability. However, the mechanisms behind this have been rarely studied. Here, a long-term trial in the Indian semi-arid pastureland was arranged to examine impact of different grazing pressures, i.e. heavy (HG), medium (MG), and low (LG) in pastureland on soil P fractions. Soil samples were taken from surface and sub-surface layers and analysed for soil P dynamics, microbial activity, and diversity. Total soil P increased significantly (P < 0.05) under MG and HG by 18 and 39 % over control at the surface layer, respectively. Plant available P under LG and HG was significantly (P < 0.05) higher (by similar to 11 and 15 %) than control at the surface layer. In the grazed plots, plant available P at the surface soil layer was similar to 10 % greater than subsurface soil layer. MG and HG significantly enhanced the iron, aluminium, and calcium bound P. The population of P solubilizing bacteria under LG was similar to 48 and 75 % higher than MG and HG, respectively in surface layer. The P adsorption maxima and adsorption energy declined significantly (P < 0.05) under LG, but increased under HG over control at both soil layers. Excessive grazing pressure on grasslands might detrimentally affect the sustainability of ecological functions. To rejuvenate damaged grasslands and manage P effectively in semiarid regions and elsewhere, it is urgently necessary to optimise grazing pressure.