Effect of electrolyte concentration on glucose decomposition in soil

Abstract

The influence of the electrolyte concentration of the soil solution on the ability of the soil biomass to decompose glucose was assessed by determining the residual glucose content of soil samples in a laboratory incubation experiment. For three amounts of glucose addition (0, 3.5 and 70 mg glucose g-1 soil), the electrolyte concentration of the soil solution was varied between that of deionized water and a 0.10 M CaCl2 solution. A significant decrease in the rate of glucose decomposition was only noted once the concentration of Ca2+ in the soil solution reached 0.10 M; however, after 125 h incubation, the extent Of glucose decomposition was not significantly influenced by changes in Ca2+ concentration. Therefore, increases in the electrolyte concentration of soils amended with gypsum or agricultural lime are not likely to inhibit the activity of the microbial biomass and its ability to decompose organic residues.