Phosphorus deficiency and low availability are a major constraint to agricultural production system due to strong adsorption and precipitation of P after addition to soil. Use of different organic materials, including manures, composts, crop residues and other rural and urban wastes to enhance phosphorous biological cycling in the soil. The addition of crop residues influences P availability via different mechanisms. Soil microbes play a vital role in soil P dynamics by P uptake, solubilization, and mineralization. Therefore, better understanding the relationship between type and amount of P amendment, size, and activity of microbial biomass in the soil is key for better management of soil P and other nutrients.