[Straw Composts with Composite Inoculants and Their Effects on Soil Carbon and Nitrogen Contents and Enzyme Activity]

The utilization of straw resources is of great significance to agricultural environmental protection and sustainable agricultural development. Based on the isolated 15 high-efficient cellulose degrading bacteria in the laboratory, the composite inoculants (JFB-1) which can effectively degrade crop straw were screened, and the effects of straw composts with the composite inoculants on soil carbon and nitrogen contents and enzyme activity were studied. The results showed that the composite inoculants could accelerate straw decomposition for 1-2 d during single fermentation period, and the organic matter contents in straw composts reached 403.5-515.1 g·kg^-1, while the ratio of carbon and nitrogen decreased from 10.53 to 15.30. The pot experiments found that the application effects of rice straw composts were generally better than those of corresponding asparagus straw composts. Compared with the control compost of rice straw, when the application amount of rice straw compost using the composite inoculants was 150 g·kg^-1, the contents of soil organic matter and total nitrogen increased by 33.5% and 7.3%, and soil urease and cellulase activities increased by 16.7% and 30.8%, respectively. Compared with no fertilization treatment, the application of straw composts could improve soil microbial community structure, and increase microbial diversity indices. When the application amount of rice straw compost using the composite inoculants was 100 g·kg^-1, the biomass of common Chinese cabbage cultivated for 30 d increased by 46.4% compared to the control compost of rice straw. These results indicated that the composite inoculants have great application potential in straw composts.