Vineyard reclamation alters soil properties and microbial community in desertified land

The reclamation of non-productive desertified land is a crucial step towards addressing the issue of a deteriorating ecological environment and expanding the cultivable land area. The effectiveness of soil nutrition and the quality of the environment can be determined by changes in microbial composition and diversity. This study aims to investigate the impact of desertification and reclamation years on microbial composition and diversity, as well as to comprehend the primary soil physicochemical factors that influence the composition of microflora in soil. Soil samples from one naturally deserted land and four vineyards with different reclamation years of 5, 10, 15 and 20 years were collected using the cutting ring method. The diversity and composition of microbial communities in these samples were assessed using metagenomic sequencing. The results revealed significant variations in soil microbial community diversity and composition. The most common phyla of bacteria were Proteobacteria, Actinobacteria, and Acidobacteria, while the most common phyla of fungi were Ascomycota, Mortierellomycota, and Basidiomycota. The principal co-ordinates analysis (PCoA) demonstrated that the composition of the bacterial and fungal community tended to stabilization with increasing reclamation years. The Linear discriminant analysis Effect Size (LEfSe) technique identified biomarkers in vineyards with varying reclamation years. The coexistence network revealed the different topological structures of fungi and bacteria in various soil layers. The network of fungi and bacteria in the topsoil had higher density than that in the subsurface soil. Mantel test analysis indicated that available phosphorus (AP) and total phosphorus (TP) exhibited a significant positive correlation with the alpha-diversity of bacterial communities in the topsoil, while bulk density (BD) and soil organic carbon (SOC) had an extremely significant positive correlation with the alpha-diversity of fungi communities in the topsoil. The Redundancy analysis (RDA) further revealed that microbial community composition was driven by BD, pH, and SOC. These findings suggest that viticulture in desertified locations can enhance soil physicochemical characteristics and microbial diversity, thereby improving the soil quality of reclaimed land.