Effect of intercropping of paulownia and buckwheat on soil microbial biodiversity and enzymatic activity

The aim of this study was to capture microbiological changes in the soil environment during intercropping of paulownia with buckwheat using randomized block method experiment conducted at Wroclaw University of Environmental and Life Sciences in 2019–2022. The soil samples were characterized by measuring abundance of microorganisms determining the microbial and fungal community structure using Illumina MiSeq sequencing, the activity of dehydrogenase (DHA) and total glomalin-related soil proteins (T-GRSP). In addition, we assessed the buckwheat roots' colonisation by fungi, as well as yield and biometric traits of the plant. The calculated alpha indicators of the bacterial microbiome diversity and abundance show higher bacterial diversity in the intercropping samples, when compared to the control site. NGS (Next-Generation Sequencing) analysis showed that Actionobacteria, Proteobacteria and Acidobacteria were dominant in the microbiome in every variant of the experiment, regardless of the crop. By contrast, the mycobiome was dominated by fungi classified as the Ascomycota and Mortierellomycota. At the first sampling date (T1), intercropping sample analysis showed significant increase in DHA activity, but not in glomalin concentration. As a rule, the biometric traits’ values were higher when buckwheat was intercropped with paulownia compared to the control culture, both in terms of buckwheat yield and the total kernels of weight per plant.