Effects of different microbial inoculants on the characteristics of straw decomposition and nutrient release and extracellular enzyme activities

雨晴 王 ^1,2 Mingcong Zhang ^2* Lei Lu ² Chen Wang ² 佳宁 王 ³ Yang Hu ² Siyan LI ² Wei Xie ² Xiwen Hu ⁴ Haiqing Guo ⁵

• ¹ 黑龙江八一农垦大学, 黑龙江省, China
• ² College of Agricultural, Heilongjiang Bayi Agricultural University, Heilongjiang, China
• ³ Department of Foreign Language, Kunlun Tourism College, Harbin, China, Harbin, China
• ⁴ Nadanbo Township Comprehensive Service Center, Dongfeng County, Liaoyuan City, Jilin Province, China, JiLin, China
• ⁵ Lindian County Agricultural Machinery Comprehensive Service Center, Lindian County, Daqing City, Heilongjiang Province, China, Daqing, China

Understanding the relationship between the different microbial inoculants and straw decomposition is crucial for achieving high yield in agriculture. This study investigated the effects of different microbial inoculants on nutrient release characteristics and extracellular enzyme activities. A pot experiment was conducted in two growing seasons (2023 and 2024), and the soybean (Glycine max L. Merrill) cultivar was Nongqing 28, corn straw as the test straw, and Bacillus sp. ND1 and Bacillus sp. ND2 as the test fungicides. The following treatments were used: straw + no microbial agent application (CK), straw + Bacillus sp. ND1 application (T1), straw + Bacillus sp. ND2 application (T2), and straw + application of 1:1 Bacillus sp. ND1 and Bacillus sp. ND2 compound bacteria (T3). The results indicated that, compared with the CK treatment, the T1, T2 and T3 treatments resulted in a significant increase in the straw decomposition rate; a gradual decrease in the hemicellulose content; a gradual increase in the nitrogen, phosphorus and potassium release rates from straw; a gradual increase in the extracellular enzyme activities; and a gradual increase of the soybean yield in the R2, R4, R6 and R8 periods. Compared with the T1 and T2 treatments, the T3 treatment R8 period resulted in a significant increase in the straw decomposition rate; the R4 and R6 periods resulted in a significant decrease in the straw nitrogen release rate and phosphorus release rate; the R2 and R4 periods of straw exo-beta-1,4-glucanase content and straw xylanase content increased significantly.Compared with that in the CK treatment, the yield of soybean in the T3 treatment increased by 24.00%-28.00% (P<0.05). In summary, T3 treatment can accelerate straw decomposition and nutrient release rates, increase soybean yield, and provide a theoretical basis for optimizing the straw decomposition effect and rational utilization of organic resources by promoting the activity of extracellular enzymes and the degradation of straw cellulose, hemicellulose and lignin.