Department of Soil Science and Agricultural Chemistry, University of Agricultural Sciences, GKVK, Bangalore, 560065.
1Present address: Department of Biochemistry, UAS, GKVK, Bangalore, 500065.
Humic and fulvic acids extracted from coirdust-based composts were characterized by chemical methods and infrared spectroscopic analysis. The E4/E6 ratios of FAs were found slightly higher than HAs indicating that FAs were less aromatic than HAs. When organic additives were incorporated during composting, the resultant HA was more aliphatic in nature and also more labile. Carbon content of HA varied from 38.44 to 42.18 per cent and that of FA from 30.11 to 36.36 per cent. Per cent N content varied from 2.12 to 5.18 in HAs and 0.91 to 2.52 in FAs. The general shape of IR spectra of HAs and FAs isolated from compost resembled those reported for HAs and FAs isolated from peat samples (Type A). Wider absorption band in the region 3400 cm−1 was seen for all samples. The finger print regions for 1725 to 1200 cm−1 were perturbed due to micronutrient incorporation.
Lignin, humic acids, fulvic acids, infrared spectra
