TOTAL CARBOHYDRATES OF THE SOIL MICROBIAL BIOMASS IN 0.5 M K2SO4 SOILEXTRACTS

The relationship between total carbohydrates and organic C found in th e extracts of non-fumigated soils and in the extractable fraction afte r CHCl3 fumigation was investigated in a group of 58 arable, 24 grassl and and 26 forest soils. We evaluated also the effects of soil conditi ons and the form of land use on these relationships. The content of mi crobial biomass carbohydrate C (E(CHC)) ranged from 4.3 to 261.4 mu g C g(-1) soil and was significantly correlated (r = 0.88) with microbia lly-derived C (E(C)). The E(CHC)-to-E(C) ratio was mainly affected by the pH but also by soil organic C and total N, but not directly by the form of land use. Due to the large, pH-dependent variations in the E( CHC)-to-E(C) ratio, no conversion factor can be proposed for the estim ation of biomass C by measuring carbohydrate C. For this reason, the p ossibility of monitoring shifts in the microbial community structure s eems more valuable. Copyright (C) 1996 Elsevier Science Ltd