Study on the Mechanism of Carbonization and Microbial Interaction of Rice Straw Mud under Autumn Thin Pulp Rotary Rake Returning to Field.

Rice straw decomposes under unique seasonal freeze-thaw cycles, which are of great significance in agricultural ecosystems at high latitudes and altitudes. This process not only promotes the transformation of organic matter into mud like carbon substances, but also changes the microbial interaction network, ultimately affecting soil carbon cycling. To this end, we conducted a mesh bag experiment, combining high-throughput sequencing of bacterial 16S rRNA gene and fungal ITS2, to analyze the morphological characterization, chemical composition, and extracellular enzymes of rice straw, in order to study the decomposition rate and nutritional dynamics of rice straw, as well as the temporal dynamics of the microbial community that decomposes rice straw residue. This experiment was conducted under field conditions influenced by natural seasonal climate scenarios. The research results under these different returning methods were compared. We assume that: (I) freeze-thaw cycles under different returning methods will promote the carbonization of rice straw sludge, increase its nutrient release rate and enzyme production; (Ii) The microbial community will adjust its response to environmental factors and effective chemical nutrients in rice straw residues under different returning methods, providing feedback on the decomposition rate under different returning methods; (Iii) Different returning methods will reshape the soil microbial interaction network over time; And the carbonization process of straw like mud (Iv) is influenced by freeze-thaw cycles as the microbial network regenerates and provides feedback on different returning strategies.