水稻根际促生菌微胶囊菌剂的制备及促生作用OA

To promote the widespread application of plant growth-promoting rhizobacteria composite microbial agents in agricultural production,reduce fertilizer use,and achieve green,sustainable agricultural development,used phosphate-solubilizing Pantoea eucalypti R8,potassium-solubilizing Enterobacter sichuanensis K25,and nitrogen-fixing Bacillus zanthoxyli N2 as research strains.The fermentation conditions for the composite microbial agents were optimized using single-factor,orthogonal,and response surface methodology.Microcapsules were prepared using sodium alginate and CaCl2,and their growth-promoting effect on rice was verified in pot experiments.The results showed that the optimal fermentation medium for the composite microbial agent was molasses 20.00 g·L-1,corn steep powder 20.00 g·L-1,yeast extract 3.00 g·L-1,K2HPO4 1.50 g·L-1,NaCl 3.00 g·L-1.The optimal fermentation conditions were temperature 31.0℃,pH 6.95,inoculation volume 3.3%,and liquid loading volume 30.0 mL.The bacterial concentration reached 1.02×1012 cfu·mL-1 after optimization,which was 5.05 times higher than in the unoptimized state.The optimal preparation ratio for microcapsule was 3%SA-3%CaCl2,with an embedding rate of 86.74%and good sustained-release performance.In the pot experiment,the rice treated with the microcapsule showed significantly higher plant height,root length,dry weight,and single-plant yield than the control group(P＜0.05),with 67.86%increase in plant dry weight and 22.45%increase in single-plant yield.The rice composite microbial agent microcapsules prepared exhibited significant growth-promoting effects and great application potential,providing theoretical and technical support for the preparation and application of microbial fertilizers,and plays a positive role in promoting the development of green agriculture.