Phosphorus fractions -their key role in soil management

Abstract

Phosphorus (P) is a critical macronutrient influencing soil fertility and crop productivity in India. In Indian soils, phosphorus exists in both organic and inorganic fractions, each differing in availability and mobility. The primary inorganic fractions include calcium-bound, iron-bound, and aluminum-bound phosphates, while organic phosphorus occurs mainly as inositol phosphates, phospholipids, and nucleic acids. Indian soils, being largely acidic or alkaline with low native phosphorus reserves, exhibit strong fixation tendencies that reduce available P. Management practices such as integrated use of fertilizers and organic amendments influence the distribution and transformation of these fractions. Studies indicate that phosphorus fractions vary with soil type, climatic conditions, and cropping systems, and their dynamics play an important role in sustaining long-term fertility of soil and productivity. Hence knowledge about the fractions contributes to a better understanding of phosphorus dynamics in soils and its implications for agricultural productivity and environmental sustainability.