Studies on the Nature and Composition of Humus in Some Outer Himalayan Soils of Uttar Pradesh

Content and qualitative composition of humus was studied to characterise soil profiles from Musoorie hills (U.P.) formed over different parent materials and under different vegetation. Distribution of C in various humus fractions, its variation within the profile and its accumulation in illuvial horizons has progressed with the process of podzolization. Differences in the nature of humus were also seen in these soils. The humus of the soils over limestones under conifers was found more humic in nature with greater condensation of aromatic rings in them and thus more mature as compared to that of soils developed over shales under oak, which contained higher content of fulvic acids and fulvic acid-like humic acids of more peripheral chains as expressed by lower C_ha/C_fa ratio and lower extinction coefficient values.