The alluvial soils vary in nature from that of sandy loam to clay. They are usually rich in potash but poor in phosphorous. Even otherwise phosphates are available in water or soil in a very small fraction. The reasons are phosphates take the longest time among all other minerals for its complete recycling. Even during the recycling process if not immediately used, a portion of available phosphates gets converted into other compounds which again takes much time for it to come into the cycle.