Abstract:
Ensuring sustainable crop production while maintaining soil fertility is a critical challenge in the context of global climate change and increasing agricultural intensification. One promising approach involves the use of biological agents to accelerate the decomposition of plant residues and improve soil quality. This study explores the impact of post-harvest mulching combined with plant residue destructors on the decomposition rate of oilseed flax stubble, nitrogen availability, and the microbiological activity of arable soils. The research was conducted during the 2023–2024 growing season under rainfed conditions on middle-loamy dark chestnut soil using a systematic field experiment with four replications. Two experimental factors were considered: the application of various microbial cellulose destructors and the use or absence of surface mulching after flax harvest. Results showed that the combined application of biological destructors and mulching significantly enhanced the decomposition of plant biomass – by 202–289% relative to untreated control plots – due to the activity of cellulose-degrading microorganisms. This process led to improved nutrient cycling, with the content of mobile nitrogen compounds in the topsoil increasing by 62.2–78.9%. Concurrently, the biological activity of ammonifying microbial populations rose by 32.0–58.9%, indicating enhanced microbial-driven nitrogen transformation. A slight positive effect was also observed in plots where only water was applied to the stubble, attributed to temporary increases in humidity that stimulated native aerobic cellulose-degrading microbes. Importantly, the improved soil conditions resulting from this integrated approach contributed to a 4.1–9.8% increase in grain yield of the su b sequent winter wheat crop. Among the tested microbial products, the most effective preparation included a synergistic blend of humic and fulvic acids, amino acids, phytoenzymes, and essential macro- and micronutrients.
