Abstract:

To investigate the impact of integrated rice-fish system on soil microbial diversity, this study conducted a comparative analysis of soil microorganisms under integrated rice-fish and rice monoculture systems using 16S sequencing technology. The results revealed significant differences in the relative abundances of Chloroflexi and Acidobacteriota in soil samples during the first and second months. At the genus level, the relative abundance of Acidobacteriales was significantly lower during the first and second months under the integrated rice-fish system than under the rice monoculture system. Notably, the abundance of Bacillus under the integrated rice-fish system system significantly decreased by the fourth month compared with rice monoculture, whereas Clostridium sensu stricto increased throughout all periods. Diversity and functional enrichment analyses demonstrated that the chao diversity index of soil microorganisms under the integrated rice-fish system increased dramatically from the first to the fourth month, surpassing the improvement observed in the rice monoculture system. Furthermore, significant functional differences were idenjpgied in metabolic pathways such as chemoheterotrophy, aerobic chemoheterotrophy, fermentation, nitrogen fixation, methylotrophy, hydrocarbon degradation, methanotrophy, and animal parasites or symbionts. Specifically, the integrated rice-fish system exhibited enhanced enrichment of nitrogen-fixation and fermentation functional microorganisms. These findings indicate that integrated rice-fish system significantly enhances soil microbial diversity, fertility, and improves soil ecological benefit benefits.

Key words: integrated rice-fish system, soil microorganisms, microbial diversity, ecology