Spatiotemporal Evolution of Soil Quality Under Long-Term Apple Cultivation of the Taihang Mountains, China

The present study aims to investigate the impact of long-term apple production and orchard management practices on soil quality in gneiss mountainous regions. In this study, the microbial community (as measured by phospholipid fatty acid analysis) and soil physicochemical properties (bulk density, organic matter, nitrogen, phosphorus, potassium) were determined in soil samples collected from apple plantations of various ages (0-, 8-, 22-, 29- and 36-year) in Gangdi Village, Xingtai, China. The soil samples were collected from depths of 0-20, 20-40, and 40-60 centimetres. The findings of the study demonstrated that with an increase in the duration of apple cultivation, there was a decline in soil bulk density and an enhancement in porosity. Initially, the content of soil nutrients such as organic matter, nitrogen, and phosphorus increased, reaching a subsequent state of stability, accompanied by a decline in pH. The soil microbial biomass demonstrated a significant increase, accompanied by discernible alterations in the composition of the microbial community. Organic matter was found to be the primary factor influencing the structure and diversity of microbial communities. It is evident from forward analysis that the soil Gram-Negative and Actinomycetes communities are predominantly influenced by Soil pH, bulk density, and total phosphorus. In contrast, the Gram-Positive and Eukaryote communities are relatively less affected by soil environmental factors. It is noteworthy that the soil bacterial community exhibited a higher degree of sensitivity to the duration of apple cultivation in comparison to the fungal community. A marked vertical differentiation in soil quality indicators is evident, with the enhancement in surface soil quality exceeding that of deeper layers.