Relationship between root-derived biopore structure and biopore sheath soil bacteria in various cover crops under compacted soils

Soil pore structure has an important effect on microbial communities, yet the quantitative relationship between biopore characteristics formed by different cover crops and biopore sheath soil microbial communities remains unclear. In this study, we explored the characteristics of biopores formed by different cover crops and their effects on soil microbial communities in biopore sheath under soil compaction. Three cover crops, including ryegrass, hairy vetch and oilseed rape were grown in soil columns filled with a bulk density of 1.2 g cm-3 at the upper 50 mm soil layer and 1.5 g cm-3 at the lower 80 mm soil layer. The biopore structure and the soil microbes in the biopore sheath formed by different cover crops were analyzed using X-ray computed tomography and high-throughput sequencing techniques, respectively. Our results suggested that more biopores were formed by ryegrass in the lower part of the soil column than by hairy vetch and oilseed rape.