Straw incorporation improves soil health by maintaining ecosystem multi-functionality at relatively high levels in semi-humid regions

Straw incorporation is an essential practice for enhancing agroecosystem functionality, mitigating agricultural greenhouse gas emissions, and achieving sustainable agriculture. However, the responses of the soil health index (SHI) and ecosystem multi-functionality (EMF) to short-term effects of straw incorporation in semi-humid regions remain poorly understood. Thus, this study investigated the short-term effects of straw incorporation rates on soil functions and soil health in a semi-arid region with high soil organic matter content. The results demonstrated that straw incorporation significantly reduced soil pH but substantially improved soil structural stability, total nutrients, available nutrients, microbial biomass, and enzyme activity compared to no-straw incorporation. It also significantly enhanced the SHI: the highest SHI (1.388) was observed at a straw incorporation rate of 13.5 t hm -2 , followed by 9 t hm -2 (1.282); the lowest SHI (0.605) was recorded at 1.125 t hm -2 . Seasonal dynamics revealed that SHI exhibited a rapid initial increase, followed by fluctuations within a narrow range as the growing season progressed. EMF showed a dose-dependent response to straw incorporation rates, initially increasing with greater straw inputs, but slightly declining at the highest rates. EMF for the 9 and 13.5 t hm -2 treatments were not significantly different, and both exceeded the control by over fourfold. Therefore, straw incorporation in the short term directly promoted soil carbon and nutrient cycling, biodiversity maintenance, and aggregate stability by altering straw residue dynamics and decomposition processes, directly translating to elevated soil health. The optimal straw incorporation rate in this study in this region was 9–13.5 t hm -2 .