Department of Soil Science, CCS HAU, Hisar, Haryana, 125001, India.
A high grade quality rock phosphate is an essential requirement for manufacturing of phosphatic fertilizers. In India, 15.3 mt of indigenous deposits of high grade rock phosphate could meet hardly 35% of the total demand and remaining demand is met through its import. In view of escalating cost of P fertilizers, it becomes necessary to generate technologies by which P from indigenous low grade rock phosphate can be solubilized and utilized as a source of P fertilizer. Various amendments which have been explored world over in order to increase the solubility and availability of low grade rock phosphate includes: composting with farm manure, green manuring, partial acidulation of rock phosphate, use of phosphorus solubilizing organisms, use of rock phosphate along with some chemicals etc.
