Abstract

Five surface (0-15 cm) soils from West coast tropical evergreen forest belonging to red ferrallitic type of Kerala, India was taken and used for comparing the efficiency of organic matter fractionation with 0. 5 N NaOH, 0. 1 M Na4P2O7, 0. 5 N NaF and 0. 5 N Na2CO3 + 0. 5 N NaHCO3 mixture in the ratio 2: 1 extractants. Quantities of humic acid (HA), fulvic acid (FA), their ash, and carbon (C) and nitrogen (N) contents were determined and the UV and IR spectra of HA and FA recorded. Sodium hydroxide extracted the most HA and FA from the soils. The measured C and N contents were comparable for the different extractants. The spectra of HA and FA extracted with NaOH had stronger absorption bands than those HA and FA extracted using the other extractants. On the basis of efficiency NaOH was the best from the point of view of yield