Distribution of Organic Phosphorus in Humus fractions in Some Soils of Uttar Pradesh

Maximum amount of organic phosphorus content in humic acid and fulvic acid was noted in greyish black soil of bhabhar (foot-hills) group. Asa whole, fulvic acid fraction contained the highest proportion of organic P (19.05%) followed by β-humus (12.7%), humic acid (5.9%) and hymatomelanic acid (0.3%). Major portion of organic phosphorus was associated with non-humic matter of the soil. Mar (black clay), a heavy textured soil in the Bundelkhand region showed maximum concentration of organic P in non-humic portion. Organic phosphorus associated with non-humic matter was found to be positively correlated with the finer particles (clay and silt) of the soil.