Physiological activity variations in microbial biomass resulted from agricultural exploitation of hemihydromorphic soils of Central Caucasus (in boundaries the plains of Kabardino-Balkaria)

The results of fundamental studies on the soil biological properties in the plains of Kabardino-Balkaria concerning metabolic activity of the soil microbial biomass are represented. The data obtained by the physiological estimation method of basal respiration rate and substrate-induced respiration rate make it possible to determine decrease of basal respiration activity and substrate-induced respiration activity to 37% on average and 60% on average correspondingly. The calculation of microbial biomass carbon content in cultivated soils shows reduction of this parameter from high to average level and decrease in reserves of microbial biomass carbon to 53% on average. Agrogenic processes involve microbial fraction reduction of the organic soil carbon from 4,8-6,2% to 2,0-3,5%. Ecophysiological indicators: microbial respiration coefficients (QR and QR’) and the parameter of specific microbial biomass respiration (qCO2) testify to the medium degree of metabolic reduction in microbial cenoses of agrogenic soils.