Recently, the Agricultural Clean Watershed Innovation Team at the Institute of Environment and Sustainable Development in Agriculture, CAAS, discovered that long-term application of organic manure and straw mulching can restore eroded environments and microbial functions, thereby significantly enhancing the soil multifunctionality in eroded sloping farmland. The related findings have been published in the Agriculture Ecosystems & Environment.

Soil erosion and degradation significantly reduce the water retention capacity, nutrient content and biodiversity of soil, leading to the weakening or even loss of soil ecological functions. Although the application of organic manure and straw can mitigate the stress on the soil environment caused by man-made accelerated erosion, the mechanism by which they restore the multifunctionality of degraded soil through the regulation of microbial communities and functional genes remains unclear.

This study, based on long-term sloping farmland located experiments, reveals for the first time the long-term effect and dynamic mechanism of organic materials in improving soil multifunctionality in eroded sloping farmland. The results indicate that the combined application of organic manure and straw mulching significantly reduce runoff and sediment loss, while increasing soil nutrient retention and the content of water-stable aggregates. The improvement in soil environment enhances the stability of microbial communities, increases the Shannon index of microbial functions, and enriches the carbon (such as bcrB/C/D) and nitrogen (such as amoB/C, napA, and nirB) cycling genes, thereby further improving the soil multifunctionality. Soil erosion environments and microbial functions, especially carbon and nitrogen cycling, are critical factors affecting soil multifunctionality. In the process of soil restoration, key microbial groups such as Proteobacteria play a key role in stabilizing community structure and maintaining community functions. In this study, multidimensional mechanism analyses including soil physicochemical properties, microbial community structure, functional genes, and network analysis were integrated to clarify the systematic path through which organic materials synergistically enhance soil multifunctionality by "reducing erosion - improving environment - optimizing microbial functions". This is crucial for protecting the ecological integrity of sloping farmland and promoting sustainable agricultural development.

This study was supported by the National Key Research and Development Program, the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences, and the National Natural Science Foundation of China.

Linkage: https://www.sciencedirect.com/science/article/pii/S0167880925000477