Phosphorus Fractions Evaluation in the Soils of the Southern Guinea Savannah of Nigeria

Background and Objective: The amount of phosphorus (P) available for plant nutrition may be influenced by the different P fractions in the soil. Hence, an investigation of the different fractions of phosphorus in the soils of Jama’a and Samaru Kataf was carried out. Materials and Methods: In each location, 10 soil samples were collected and subjected to routine analysis and sequential extraction of phosphorus using the modified Chang and Jackson Method. Data were subjected to descriptive analysis as well as correlation. Results: The soils were found to be sandy loam and strongly acidic. The total P was 587.0 mg kg‾1 and 506.0 mg kg‾1 in the soils of Jama’a and Samaru Kataf, respectively. The fractions were observed to be in the order residual-P>calcium-P>occluded P>saloid-P>Fe-P>Al-P>occluded Fe and Al-P for soils of Jama’a while for Samaru Kataf, the fractions were residual-P>occluded P>Fe-P>calcium-P> Al-P>saloid-P>occluded Fe and Al-P. Significant and positive correlations was observed between pHKCl Al-P (r = 0.51*), Fe-P (r = 0.50*) as well as occluded Fe and Al-P (r = 0.49*) while the correlation was positive and highly significant with occluded P (r = 0.67**) and Ca-P (r = 0.74**). Conclusion: The high percentage of residual P observed in these soils is an indication of a high degree of weathering in both locations