Study of different phosphorus fractions and their relationship with soil properties under major cropping systems in Y.S.R. Kadapa district, A.P.

Abstract

Phosphorus fractionation study in soils of Y.S.R. Kadapa district, A.P, was studied in relation to soil properties in which 5 soil samples collected from each major cropping system were analysed for different physico-chemical properties and different P fractions. The sequential distribution of different forms of P under major cropping systems in surface soils followed the order: Ca-P > Fe-P > Al-P > Sal-P ( Fallow-Bengalgram), Al-P > Ca-P > Sal-P > Fe-P (Sunflower-Sesame), Ca-P > Fe-P > Al-P > Sal-P (Paddy-Paddy), Ca-P > Al-P > Fe-P > Sal-P (Groundnut monocropping), Al-P > Fe-P > Ca-P > Sal-P (Groundnut-Groundnut). Soil reaction (pH) showed positive and significant correlation with other forms of P (r= 0.413*), available P2O5 showed positive and significant correlation with Al-P (r= 0.893**), Fe-P (r= 0.823**), Ca-P (r= 0.766**) and total-P (r= 0.651**). Al-P showed positive and significant correlation with Fe-P (r= 0.916**), Ca-P (r= 0.473*) and total-P (r= 0.554**) whereas Fe-P showed significant and positive correlation with Ca-P (r= 0.543**) and total-P (r= 0.643**). Ca-P showed positive and significant correlation with total-P (r= 0.705**), total-P showed positive and significant relation with other forms of P (r= 0.790**).