Long-term"Organic Substitution of Mineral Fertilizer"Enhances Ecological Network Complexity and Stability of Detritus Micro-food Web in Red Soil
[Objective]This paper investigated the effects of organic substitution of mineral fertilizer(called organic substitution)on the complexity and stability of soil detritus micro-food web,aiming to provide a scientific basis for sustainable soil nutrient management.[Method]Based on a long-term field experiment in the red soil region of southern China,the response of community composition and diversity of soil detritus micro-food web to long-term organic substitution was examined by using high-throughput sequencing technology,and the effect of long-term organic substitution on ecological network complexity and stability of soil detritus micro-food web was evaluated by co-occurrence network analysis.[Result]The long-term organic substitution significantly altered the community composition of soil bacteria,fungi,protozoa,and the overall micro-food web,and increased species richness of soil bacteria,fungi,protozoa,nematodes,and the overall microbiota community of the micro-food web.Most topological parameters such as average degree,average clustering coefficient,connectivity and modularity of ecological network of each functional group showed higher under the organic substitution.The robustness of ecological network of each functional group was higher and the vulnerability of ecological network of bacteria,protozoa,nematodes and the overall micro-food web was lower under the organic substitution,compared to conventional fertilization treatment.[Conclusion]The results showed that long-term organic substitution increased the species diversity of soil bacteria,fungi,protozoa,nematodes and the overall community of the micro-food web,and enhanced ecological network complexity and stability of the micro-food web,which would potentially improve soil functioning.
Organic substitution of mineral fertilizerSoil micro-food webNematodeProtozoaMicrobesEcological network