The Effect of Biological Decomposers on Soil Carbon Sequestration to Mitigate Soil Degradation

Soil degradation is one of the most significant challenges in modern agriculture. The loss of humic substances leads to a decrease in soil fertility and resistance to water and wind erosion, making soils more prone to the impacts of global climate change. One of the key strategies to combat soil degradation is the implementation of soil conservation practices aimed at increasing organic matter content in the soil.

Under conditions of a long-term stationary field experiment on typical low-humus chornozem, the effect of microbial products — plant residues biodecomposers — on the sequestration of labile carbon compounds in the soil under prolonged monoculture maize cultivation was investigated. An increase in the labile carbon content in the soil was observed in variants using the biodecomposers Ecostern Classic and Ecostern Bacterial + Ecostern Trichoderma by 0.11% and 0.18%, respectively, compared to the control. The obtained data on the increase in labile carbon content were confirmed by the dynamic determination of the organic matter transformation coefficient, the increase of which indicates enhanced microbiological processes in the soil and the predominance of organic matter synthesis processes over its mineralization. Thus, when biodecomposers were used, this indicator was significantly higher than in the control throughout the study period.

Focusing on the survival of the fungal bioagent from the Ecostern Classic and Ecostern Trichoderma products in the soil, the dynamics of the Trichoderma genus fungi population were monitored. The results showed an increase in the population of this micromycete in variants with the application of Ecostern Classic by an average of 19 thousand CFU/g of soil and, with the combined application of Ecostern Bacterial and Ecostern Trichoderma, by 34 thousand CFU/g of soil, compared to 28 thousand CFU/g of soil in the control. This indirectly indicates the survival of this bioagent included in the bioproducts.

During the determination of the soil eco-physiological diversity index using the BIOTREX technology (Community-Level Physiological Profiling method), it was found that in the control soil samples, the index was 3.66, whereas with the use of biodecomposers, it increased to 4.87–5.61, depending on the studied variant. Additionally, according to the BIOTREX assessment, the use of biodecomposers not only enhanced soil biodiversity but also improved its biological activity. The application of biodescomposers ensured an increase in maize grain yield compared to the control by 3.2 t/ha in the variant with Ecostern Classic and by 1.76 t/ha with the combined application of Ecostern Bacterial and Ecostern Trichoderma.

It was found that the application of a biodecomposer on corn residues accelerates their transformation and ensures the sequestration of labile carbon compounds. Microbial decomposers also enhance microbiological processes in the soil, leading to a predominance of organic matter synthesis over its mineralization, which is crucial for mitigating soil degradation.