Planting Cyperus esculentus augments soil microbial biomass and diversity, but not enzymatic activities

The planting of Cyperus esculentus, a member of the grass family Cyperaceae which includes nut sedge weeds, is being increasingly promoted in northern China's semi-arid and arid regions. Yet the effects of planting C. esculentus upon soil quality and soil microbial characteristics of sandy land remain unclear. This study examined the short-term (1 year) impact of this grass species on soil microbial biomass indices, enzymatic activities, and microbiome characteristics in the Horqin Sandy Land area of China. The results show that planting C. esculentus could increase microbial biomass in the form of carbon (MBC), nitrogen (MBN), and phosphorus (MBP), but it negligibly influenced the enzymatic activities of soil β-1,4-glucosidase (BG), cellobiohydrolase (CBH), leucine aminopeptidase (LAP), and β-1,4-N-acetaminoglycosidase (NAG). Over 1 year, we found that planting C. esculentus significantly increased the soil bacterial richness and diversity of sandy land, yet also altered community composition of soil bacteria and eukaryotes in way that could promote their homogenization. In this respect, the relative abundances of Acidobacteria and Proteobacteria significantly decreased and increased, respectively; hence, they may be considered for use as important indicators of soil nutrient-rich conditions. Overall, the results could be explained by greater soil organic carbon (SOC) and total nitrogen (TN), mainly derived from cumulative plant litter input to soils, which then increased the sandy soil's C:N ratio. Future research should focus on exploring the long-term effects of planting C. esculentus on soil quality and soil microbial characteristics of sandy lands in China and abroad.