Physical and microbiological aspects of the soil seed bed in the early formation of the barley root system (Hordeum vulgare L.): tomographic studies

Barley seeds (Mikhailovsky sort) in a model physical experiment with a two-layer density soil bed (the range of soil density from 0.7 to 1.2 g/cm³) of silty loam arable soil (Albic Glossic Retisols (Lomic, Cutanic), Moscow Region) were placed for germination at the boundary of different-density layers at optimum moisture content. During the period from planting to 7-10 days. the dynamics of the root system development was studied using an x-ray microtomograph “Bruker SkyScan 1172G” (Belgium) while simultaneously studying the composition of soil biota, which was reconstructed from microbial markers (fatty acids and their derivatives).The roots of the germinating seed mastered the entire pore space of the soil, regardless of the density zones studied in experiments. The number of bacteria increases by the fifth day with a noticeable dominance of actinobacteria (aerobacteria Actinobacteria spp., Rhodococcus equi) and Firmicutes (anaerobes Ruminococcus sp.) due to the destruction of the seed coat with its subsequent decrease on the seventh day.