Effects of nitrogen-fixing cyanobacteria complex microbial inoculant and growth-promoting bacteria SM 13 on yield and quality of rice with straw turnover

【Objective】The effects of nitrogen-fixing cyanobacteria complex microbial inoculant and growth-promoting bacteria SM13 on rice yield and quality were investigated with straw turnover, which provided a theoretical basis for the application of microbial fertilizer.【Method】The rice variety Longjing 31 was used as the tested material. Four treatments were designed, namely, conventional fertilization(CK), treatment applied with nitrogen-fixing cyanobacteria complex microbial inoculant(LZ), treatment applied with growth-promoting bacterium SM13(SM), treatment applied with both of nitrogen-fixing cyanobacteria complex microbial inoculant and growth-promoting bacterium SM13(SL). The leaf area and dry matter weight of rice in the main growing stages were measured, the spike traits and yield of rice were investigated after maturity, and the processing, appearance, nutrition, and taste quality of rice were measured after the physical and chemical properties of rice were stabilized, and the effects of different treatments on rice yield and rice quality were compared and analyzed.【Result】Compared with CK treatment, the dry matter weight of rice under LZ treatment was significantly increased by 26.40% at the grain filling stage(P<0.05, the same below), SL treatment significantly reduced the seed setting rate of primary branches, and LZ treatment significantly reduced the 1000-grain weight of secondary branches. The yield of SM, SL and LZ increased by 10.00%, 9.80% and 8.78% compared with CK, respectively. There was no significant effect on rice processing, appearance and nutritional quality by the single application of nitrogen-fixing cyanobacteria complex microbial inoculant, growth-promoting bacteria SM13 and the combination of the two(P>0.05). But SM and SL treatments significantly improved rice taste quality compared with CK treatment, the texture and taste values increased by 7.23%, 4.87% and 7.22%, 5.74% respectively compared with CK. Correlation analysis indicated that there were different levels of correlation between yield and rice spike traits. There was extremely significant positive correlation between yield and panicle weight(P<0.01), and significant positive correlation between yield and secondary branch number.【Conclusion】The application of nitrogen-fixing cyanobacteria complex microbial inoculants and growth-promoting bacteria SM13 has the potential to increase rice yield with straw turnover, and growth-promoting bacteria SM13 can enhance rice taste quality to a certain extent.