Effect of spring wheat straw, Mikotop and NaturAgro EcoGrow products on soil biological properties, yield and quality of soybean seeds

Abstract

Soil processes are directly or indirectly related to organic matter which is more actively formed and accumulated in the soil when straw is applied. Many researchers consider the use of biological destructors based on various microorganisms to be a technique that accelerates straw decomposition on the first year. The goal of the research conducted on chernozem soils of the Central soil-economic zone was to study the features of C-CO₂ emission, the formation of labile humus and soil biological activity when applying different rates of spring wheat straw only and straw treated with Mikotop and NaturAgro EcoGrow products in commercial soybean crops. Wheat straw was applied at a rate of 0.85 and 1.9 t ha, both untreated and treated with the biological products. The microorganism counting, the direction and activity of microbiological processes, and the content of labile humus were carried out according to standard methods adopted in the scientific community. It was found that when treating a double straw rate with NaturAgro EcoGrow, the accumulated C-CO₂ emission increased to 103.82 g m² in 74 days; when straw only was applied at a rate of 1.9 t ha - 128.08 g m²; and when inoculated with Mikotop - to 116.78 g m². The intensity of C-CO₂ losses is directly dependent on the amount of precipitation and the hydrothermal coefficient - r = 0.78, the coefficient of organic matter mineralization, coefficients of oligotrophy and cellulase activity (r = 0.63–0.68). The increase of the total microbial count and decreased immobilization coefficient lead to the change of C-CO₂ emission and decreasing amount of labile humus in the soil which indicates the predominance of soil humification processes especially when applying straw treated with Mikotop and NaturAgro EcoGrow biological products. The transformation of the organic matter of straw under the influence of the biological products Mikotop and NaturAgro EcoGrow increases the yield of soybean grain from 2.67 t ha to 2.74-3.0 t ha, or by 6.7-12.0%. At the same time, the protein content increases from 33.1% to 36.5-39.6%, and thousand-grain weight - from 175.26 to 178.3-206.6 g with higher efficiency when applying a double rate of straw treated with Mikotop.