Spatial variability of soil organic matter in the agroforestry system of the dry-steppe zone, Volgograd Region, Russia

Understanding the spatial variability of soil organic matter (OM) in agroforestry landscapes is crucial for optimizing agricultural productivity and environmental sustainability. Protective forest belts significantly influence soil properties, yet their impact remains understudied. This research aims to assess OM distribution under agroforestry systems, addressing knowledge gaps in soil fertility management and precision farming. The study of the theory of spatial variability of soil organic matter in agroforestry landscapes is important for the improvement of precision farming technologies and the theory of yield programming. The present study was conducted during 2022-2024 at Federal Scientific Center of Agroecology of the Russian Academy of Sciences, Russia to determine the influence of protective forest strips on the processes of spatial distribution of soil organic matter and quantitative assessment of variability of its content is an actual scientific direction for sustainable agriculture in the conditions of chestnut soils of the dry-steppe zone. Studies at the "Kachalino" test site in Volgograd, Russia, analyzed low-moist loamy soils and protective forest strips (planted 1985–1992). Key indicators, including tree height, species composition, and openness, were assessed. It was established that agroforest landscapes have three ecological zones differentiated by soil formation processes, which were identified at various distances from the forest belts. The first zone of intensive soil formation is located directly in the forest belt with an average soil OM content of 2.27%. The second zone, a zone of moderate soil formation, includes agrarian cenosis, spreads at a distance of up to 10H, has an average soil OM content of 1.55%. The third zone, the zone of weakly automorphous soil formation - includes agrarian cenoses at a distance of 15-20N from PFB, has an average value of 1.35%.