Investigation of the intensity of organic matter microbial decomposition in arid steppe soils of South-Western Transbaikal by application methods

To assess the effect of climatic factors on the enzymatic (protease and cellulase) activity of microbial communities, we studied the intensity of model substrates (cellulose and protein) decomposition under field conditions. The highest intensity of model substrates decomposition was observed in 2016 - the period of favorable hydrothermal conditions: the average annual rate for protein and cellulose was 0.095- 0.169 and 0.032-0.045% per day respectively. In more dry 2015, the lowest indices of their decomposition were 0.022 0.082 and 0.008-0.023% per day, respectively. Depending on the climatic conditions of South-Western Transbaikal, we noted certain common features of model substrates decomposition in different periods of the research. In the summer-autumn period hydrothermal indices was more favorable for activity of microorganisms (the optimum temperatures coincided with the highest moisture content): the decomposition rate of protein and cellulose was 0.051-0.520% per day and 0.014-0.110% per day respectively. We highlighted the low actual cellulolytic activity (0.001-0.160% per day) of the investigated soils, despite the relatively high potential of their cellulolytic ability (0.18-1.34% per day). Higher rates of canvas decomposition in the open environment were observed in underhumus horizons of the investigated soils, which are less prone to aridization and insolation.