Status of Available Phosphorus and Forms of Phosphorus in Soil under Major Cropping Systems of Y.S.R. Kadapa District, A.P.

An investigation was carried out to study different forms of phosphorus under major cropping systems in Y.S.R. Kadapa district of Southern Zone of Andhra Pradesh. Five soil samples from each cropping system at 0-15 cm depth collected from each cropping system to study their physicochemical properties, status of available P2O5 and different forms of P. Majority of the soils were moderately alkaline in reaction, non-saline, free lime content indicating that these soils are moderately calcareous, medium to high in available P2O5. Highest mean values for available P2O5 (182.41 kg ha-1), Al-P (80.82 mg kg-1), Ca-P (118.55 mg kg-1) and total-P (434.35 mg kg-1) were recorded in groundnut monocropping system whereas for saloid P (23.01 mg kg-1), Fe-P (69.82 mg kg-1) and other forms of P (228.35 mg kg-1) highest mean values were recorded under sunflower-sesame, groundnut-groundnut and fallow-bengal gram cropping systems, respectively.