Vol. 10, Issue 12 (2021)

Author(s):
Mallesh KU and KT Gurumurthi

Abstract:
A field experiment was conducted at AHRS, Kathalagere, during kharif 2014, to study the effect of different sources of phosphorus with and without PSF on release of available phosphorus and its influence on growth and yield of rice. The effect of different sources and levels of phosphorus @ 40, 50 and 60 kg ha^-1 P₂O₅ as rock phosphate applied in the form of nutriphos with or without PSF were tried along with single super phosphate in a randomized complete block design comprising eight treatments replicated thrice. The application of different sources of phosphorus with and without PSF treatment significantly increased the values of saloid – P and Ca – P fraction in soil at harvest stages. Higher values of saloid – P and Ca – P fractions were recorded in treatments involving P levels with PSF treatment compared to application of only P levels. The highest saliod-P (21.23 mg kg^-1) was recorded with the treatment where P applied in the form of SSP + PSF. The lowest was recorded in treatment where 40 kg ha^-1 P₂0₅ through rock phosphate in the form of nutriphos (15.77 mg kg^-1). Significant increases in Al - P, Fe – P, red – P, occl – P, organic – P and total - P fractions in soil due to P levels with and without PSF treatment. Higher values of Al - P, Fe – P, red – P, occl – P, organic – P and total - P fractions were recorded in treatments involving P levels without PSF treatment compared to the application of only P levels with PSF treatment. The highest aluminum-P (123.17 mg kg^-1) was recorded in the treatment where phosphorus applied in the form of SSP. The lowest aluminum-P was recorded in treatment where40 kg ha^-1 P₂0₅ through rock phosphate in the form of nutriphos + PSF (106.44 mg kg^-1).