Biological activity of sod-podzolic soils in the long term experiment with different agrotechnical methods

Abstract

The effect of long-term application of grain-fallow-plow crop rotation with various legume densities, permanent cultivation of winter rye and barley, continuous bare fallow on the ecological and physiological state of the microbial community of sod-podzolic heavy loam soil was investigated. Biological activity indexes of soil microbiocenoses such as potential intensity of СО2 emission, microbial biomass gross respiration rate, metabolic coefficient, nitrogen fixation were assessed. It has been shown that the best humus state of soil and significant increase in the total nitrogen content provides the introduction of organic fertilizer (manure) in the “Crop rotation of 28,6% of legumes”. The ratio of the microbial biomass in sod-podzolic heavy loam soil organic matter varies from 1,50 to 3,24%. Application of mineral fertilizers leads to insignificant decrease in the carbon content of microbial biomass and raising of labile organic carbon. The decrease of metabolic activity in microbial communities has been determined in all variants of long-term study regardless of agrotechnical techniques. It has been established that permanent intensive cultivation of crops either with or without crop rotation leads to stability interference of the Cis-Urals soil microbiocenosis.