Effects Of Planting Structure On Soil Water-Stable Aggregates, Microbial Biomass And Enzyme Activity In A Catchment Of Loess Plateau Terraces, China

Terraces have been widely used to control soil erosion on the Loess Plateau of China. Soil water-stable aggregates, microbial biomass and enzyme activity play key roles in soil fertility and quality. However, the impact of plant structure on soil water-stable aggregates, microbial biomass and enzyme activity remain unclear despite their importance for sustainable ecological agriculture. In this study, the effects of three traditional plant types (Triticum aestivum (TA), Zea mays (ZM) and Solanum tuberosum (ST)) and two novel economic plant types (Malus domestica (MD) and intercropped field (Solarium tuberosum and Malus domestica, SM)) were evaluated on similar terraces of the Loess Plateau. We investigated the water-stable soil aggregation, microbial biomass and enzyme activity and attempted to determine their contributions to the quality of terraced soils, examined the links on Loess Plateau terraces. Our results showed that the different plant types had significant effects on soil quality. The total nitrogen (TN) and total phosphorus (TP) contents, mean weight diameter (MWD) and geometric mean diameter (GMD) values, and invertase, urease and microbial biomass carbon (MBC) levels were highest in the SM samples and were lowest in the ST samples. Growing apples instead of traditional crops significantly improved the availability of soil nutrients, soil water-stable aggregates, microbial biomass and enzyme activity. Soil organic carbon (SOC), soil moisture, ammonium nitrogen and pH were identified as the primary factors affecting the water-stable soil aggregate and microbial activity characteristics across all plant types in the dryland terraces of Loess Plateau. These observations indicate that scientifically-driven land management could be used to increase soil structural stability and could have a distinct impact on the soil nutrients and biological characteristics.