Phosphorous is another nutrient that is critically important for legumes and the clover plants that are fixing nitrogen, but all plants need phosphorous as they do nitrogen. Legumes need a higher level of P fertility than the neighbouring grass plants. Phosphorus is vital for plant growth, and is a component of the nucleic acid structure of plants and bio-membranes. Therefore, it is important in cell division and tissue development. It is also involved in the energy metabolism of cells and is required for the biosynthesis of primary and secondary metabolites in plants. Legume crops requires less nitrogen but application of phosphorus and potassium plays a vital role in getting high yield per unit area. The application of phosphorus increases dry matter at harvest, number of pods plant -1 , seeds pod -1 , 1000 grain weight, seed yield and total biomass of mung bean. The experimental results of different authors stated that the highest number of pod plant -1 and grain yield of soyabean were obtained from maximum level of phosphorus as compared to other treatments. common bean crop dependent on nitrogen fixation needs more inorganic phosphorus than the same crop provided with mineral nitrogen. Common beans are therefore especially susceptible to low soil phosphorus when accompanied by low soil. Phosphorus also plays an important role in biological nitrogen fixation, for the symbiotic fixation of nitrogen to occur, the roots have to interact with compatible rhizobia in the soil and factors that affect root growth or the activity of the host plant would affect nodulation. however, the rate of phosphorus is varied from place to place, or it's governed by the amount of P status in the soil. Since, legume crops demanding more P than other nutrient, we have to apply it obtained best grain yield.