Abstract

Humin extracted from eight profiles representing typical soil groups in Rajasthan was studied for elementary composition, functional groups, spectra under visible ranges and coagulation threshold values. Variation in C, N and S contents and functional groups of humin of different soils were in ranges comparable with those reported elsewhere. Variation in elemental composition of humin appeared to be related with the stage of humification, E4/E6 ratio and coagulation threshold values indicated that humin of Banswara (black) and Kota soils were similar in behaviour to humic acid. Humin of Jaipur. Ganga- nagar, Sirohi. Udaipur, Banswars (red) and Chittor soils was characterised by wider E4/ E6 ratio and higher coagulation threshold values indicating their resemblance to fulvic acid.

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