The microbiome structure and shifts in surface and subsurface soil horizon of Haplic Luvisol under different crops cultivation

Abstract

The presented study investigated the comparative approach to evaluate prokaryotic and fungal soil communities in association with various plant crops along the genetic soil horizon using a high-throughput sequencing technique, with special emphasis on subsoils. We evaluate the diversity, abundance and structure of soil microbiome through the depth profiles in Haplic Luvisol (Cutanic) soil collected from lucerne, pear orchard, vineyard, and wheat crop. The structure of soil microbial communities differed due to crop type as well as depth of soil layer. Additionally, some basic physicochemical properties (e.g. total organic carbon - TOC, total nitrogen - TN, dissolved organic carbon - DOC, dissolved nitrogen – DN, pH, clay content) as well as mass and morphological parameters of the plant roots were determined. The highest clay content was noted in illuvial (Bt) horizons (in all profiles). The content of the studied C and N forms was the highest in the Ap horizon and in some subsurface layers and generally decreased with depth. Generally, the highest TOC, TN and DOC content was noted in the orchard profile, while the lowest occurred in the vineyard profile. The opposite trend was found for available Mg content. In turn, the highest DN was determined in the winter wheat profile. Overall, the decrease of the abundances of the most dominant phyla with depth was observed. Using a holistic approach via microbiome investigation of bacterial and fungal communities along soil horizon in a long-term land use with different plant cultivation, we showed that land management not only affect α-diversity but also shift the structure and the composition of bacterial and fungal communities in response to land use, in particular we identified the highest values of biodiversity indicators were found under lucerne and the lowest under vineyard. Future work needs to include the importance of soil type in shaping soil microbial communities under the same land use and plant cultivation, especially under subsurface soil layers.