Phosphorus Fractions in Relation to Soil Properties and Genesis in Alfisols and Inceptisols of Himachal Pradesh

The forms of phosphorus in fourteen soil profiles of Kangra valley of Himachal Pradesh were studied in relation to soil properties and genesis. In Alfisols, amount of total phosphorus decreased with increasing depth whereas in Inceptisols surface layer contained lower amount as compared to subsurface soils. Reductant soluble phosphorus (red-P) constituted the dominant fraction in Alfisol and Ca-P in Inceptisol. Inorganic fractions of phosphorus were found to be correlated with pH but the relationship varied in the two orders. The effect of organic carbon, clay contents, and oxides was inconsistent on the amount of phosphorus fractions. It could be concluded on the basis of relative abundance of P fractions that soil profiles from Alfisol were more mature and those from Inceptisol showed varying degree of maturity.