Vol. 10, Issue 6 (2021)

Author(s):
GK Surya Krishna, V Sai Surya Gowthami, Charankumar GR, T Giridhara Krishna and CH Sujani Rao

Abstract:
Studying the soil phosphorus (P) fractions is critical for elucidating the processes underlying soil P accumulation in cropping systems and mitigating the risk of P loss to the environment. Long-term cultivation with various fertilizer treatments and cropping systems can have a significant effect on the availability of P as well as its fractionation. External application of phosphorus fertilizer to soils of intensive cropping systems also surpass the P requirements of crops, accumulating P in the soil in chemically stable and insoluble forms that may become available to plants in subsequent years. The relative solubility of inorganic soil P fractions determines how the liable pool is replenished when it is exhausted by plant P removal. The inclusion of inorganic fertilizers with organic manures improved the labile P pools by means of improving the soil organic content and nutrient availability under multiple cropping systems there by reduced the non-labile pools of phosphorus. However, partial substitution of inorganic fertilizer with organics resulted in a substantial increase in almost all P fractions in soil. Thus, knowledge of the various inorganic fractions of soil P and their distribution within the soil is critical for determining the long-term availability of P to crops and formulating sound fertilizer recommendations. This will benefit not only the bioavailability of soil P, but also the reduction of water contamination caused by runoff P.