**National Academy of Agricultural Research Management, Rajendranagar, Hyderabad, Andhra Pradesh, 500030
***A.P. Agricultural University, Rajendranagar, Hyderabad, Andhra Pradesh, 500030
GB. Pant University of Agriculture and Technology, Pantnagar, Nainital, U.P., 263145
Present addresses: *National Bureau of Soil Survey and Land Use Planning, Nagpur, Maharashtra, 440006
Humic and fulvic acids isolated from representative soil samples of Beni and Khamia series (Aquic Hapludoll) and from Patharchatta series (Typic Hapludoll) in tarai (foot-hill) region exhibited minimum heterogeneity with respect to their elemental composition, molecular weight, functional groups and spectral properties, the former having relatively higher values than the latter. The humic and fulvic acids obtained from surface samples (0—15 cm) showed higher total acidity than the corresponding fractions from the sub-surface horizons (15—30 cm), the molecular weights being around 1100 and 680, respectively. UV-spectral studies showed a featureless absorption spectra with neither maxima nor minima but with high absorption values at 200 to 350 nm wavelengths.
Humic acid, fulvic acid, functional group, absorption spectra
