Studies on Composition of Humus in Different Soil Groups of Uttar Pradesh

Various humus fractions, viz, humic acid, fulvic acid, hymatomelanic acid, β-humus and huminwere fractionated in different soils of Uttar Pradesh. Maximum concentration of humic acid was noted in surface layer of greyish black soil of bhabhar (foot-hills) group. Mar (black clayey) soil of Bundelkhand region contained the highest amount of hymatomelanic acid while raker (coarse grained reddish) soil of the same area showed the lowest content of both humic and hymatomelanic acids. Fulvic acid content was maximum in the calcareous soil of alluvial tract. Saline-alkali soil did not contain hymatomelanic acid. On the whole, fulvic acid formed the major portion of humic matter, the others in decreasing order being humin, β-humus, humic acid and hymatomelanic acid. Humic acid was more in surface than in sub-surface soil while reverse was the case with the fulvic acid fraction.