Forms and distribution of phosphorus in Ebonyi State, Southeastern Nigeria

Abstract

This study was carried out to determine the forms and distribution of phosphorus (P) fractions in Ebonyi State, Southeastern Nigeria.  Fifteen soil samples from five selected local Governments of the State were collected with soil auger at three depths (0-20 cm, 20-40 cm and 40-60 cm). These were subjected to physico-chemical analysis, while the different fractions of P were determined using standard method. Results obtained indicated that the total soil P varied from 351.11 to 671.61 mg/kg, organic P from 80.00 to 149 mg/kg, available P from 6.70 to16.30 mg/kg and all these P fractions decreased with soil depth. The active inorganic P forms had values that varied from 13.14 to 67.70 mg/kg for Al-P, 32.00 to187 mg/kg for Fe-P and 1.00 to 3.99 mg/kg for Ca-P. The relative abundance of the various P forms were in the order inactive  P>Fe-P>Al-P>Ca-P and these decreased down the soil profile. Available P correlated significantly with Al-P, but its interaction with Fe-P could not reach significance level. The higher correlation coefficient between available P and Al-P indicated that Al-P contributes more to soil available P and hence soil productivity with respect to P. Identification of the amount of the various P forms will aid in making efficient soil management policies and practices in respect to P fertilization in this agro-ecological zone.