Soil-like Substrate Technology Improves Soil Nutrient Content and Enzyme Activity, Enhancing Soil Microbial Community Structure and Restoring Soils in Ecologically Sensitive Areas of the Loess Plateau.

The study assessed the impact of soil-like substrate technology on soil nutrient cycling, enzyme activities, and microbial community structure to evaluate its potential for ecological restoration in the highly sensitive areas of the Loess Plateau. Soil nutrients and enzyme activities were measured before and after applying the technology and at various soil depths. Microbial diversity and community structure were analyzed using Illumina PE150 sequencing. In the -20 cm depth layer (RLS), soil nutrient content and enzyme activity were significantly higher than in the control (CK). Compared with CK, total nitrogen and organic matter in RLS increased by 1.35 and 1.03 times, respectively. Urease and invertase activities increased by 1.15 and 1.35 times, respectively. Microbial community analysis showed changes in Actinomycetes, Alphaproteobacteria, and Thermoleophilia populations. The surface layer (0-6 cm, SS) had higher nutrient content and enzyme activity than deeper layers. The microbes in the SS layer were significantly different from those in the substratum layer (6-12 cm, BS) and the vegetation mat substrate layer (12-20 cm, PS). The top three most abundant phyla were Nocardioidaceae, Micrococcaceae, and Unclassified-Frankiales. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that microbes in the surface layer were mainly involved in carbohydrate and amino acid metabolism. Correlation analysis revealed significant relationships between environmental factors and microbial communities. Soil-like substrate technology enhances soil nutrients, enzyme activity, and microbial community structure, providing evidence for restoring the "soil-vegetation-microorganism" system in the Loess Plateau.