Studies on forms and distribution of phosphorus in the different soil series of a sub-watershed in northern dry zone of Karnataka

Abstract

A study was undertaken during 2018-19 in the soils of Babaleshwar East sub-watershed of Vijayapura district which belongs to Northern dry zone of Karnataka to study the forms of phosphorus and their relationship with soil properties. Thirteen soil series were identified in the study area, one representative soil profile was selected from each soil series and horizon-wise soil samples were analyzed for different fractions of phosphorus. Saloid-P, Fe-P, Al-P, Org-P and available-P decreased with profile depth in all the soil series and were positively and significantly correlated with organic carbon. Reductant soluble-P, occluded -P and Ca-P and total-P did not follow definite trend in most of the soil series. Occluded-P was negatively correlated with free CaCO3, whereas Ca-P and total-P were significantly and positively correlated with free CaCO3. Fe-P, Al-P and reductant soluble -P significantly and negatively correlated with pH and free CaCO3. Among the inorganic phosphorus fraction Ca-P was dominant as the soils are under semi-arid region.