Changes in soil biota and its relationships with soil properties across different land-use types

Abstract

The purpose of this paper was to determine the changes in soil biota from typical chernozems across different land-use types, as well as to determine its interdependence with the soil properties. In the paper were investigated loamy-clayey typical chernozems in the following variants: arable; 15 years under the fallow; 60 years under the fallow. It was established that the parameters of the biological indices decrease on the soil profile with the depth. It was observed that in arable soils the main fauna mass is concentrated in the layer 20-60 cm. Also, due to the strong compaction of these soils, there is an abrupt decrease in the number of invertebrates and the change of microfauna structure. The content of microbial biomass gradually decreases with depth in all studied soil profiles. There is a significant decrease of the microbial biomass content in arable chernozems compared to the other soils. These values range from 280.7 μ g C g-1 soil in the 0-25 cm layer to 217.8 μ g C g-1 soil in the 35-50 cm layer. Due to the lower number of bacteria, actinomycetes and fungi in arable soils, there is a considerable prevalence of microorganisms decomposing humus. Interaction of soil biota and its metabolites with soil vegetation leads to structure improvement, formation of valuable agronomic aggregates and increase of their hydrostability. A close correlation between the biomass indices, the number of microorganisms and the structure of typical chernozems in the former 0-25 cm arable layer was found, where the restoration process is more intense, the layer being degraded more strongly. Analogic legitimacy was detected for microbiological indices and water stable aggregates content and structuring coefficient.