Научный журнал

The article presents the results of the long-term application of mineral (MS) and organomineral (OMS) fertilizer systems on the cellulolytic activity of soddy-podzolic soil in the Central Non-Black soil region. The study was conducted in 2023 on the basis of a long-term stationary field experiment (SSh-2) at the Experimental Station of the All-Russian Research Institute of Agrochemistry named after D.N. Pryanishni kov (Shebantsevo village, Domodedovo urban district, Moscow oblast) during the cultivation of winter wheat, barley, and green manure (white mustard). It was found that the application of mineral fertilizers increased the application-measured cellulolytic activity under winter wheat by 2.95 times relative to the control (from 5.18% to 15.30%), while the organomineral system combined with micronutrients and magnesium increased it by 3.46 times (up to 17.92%). Differences between the treatments were not statistically significant (LSD₀₅ = 8.83%); however, both treatments were significantly higher than the control. Under barley, the maximum increase in the index was 1.4 times (from 11.79% to 16.49%); however, analysis of variance revealed no statistically significant differences between the treatments (F = 0.94; p = 0.496). At the same time, cellulase enzyme activity under OMS decreased by a factor of 1.06–1.32 relative to the control (by 6–24%), which is explained by the mechanism of catabolite repression — a temporary suppression of the synthesis of energy-costly enzymes in the presence of readily available organic matter from green manure. The multidirectional nature of the changes apparently reflects the metabolic plas ticity of the microbial community, which is consistent with 16S rRNA sequencing data showing the absence of long-term structural rear rangements of the microbiocenosis.