| Title | Effects of Continuous Straw Returning on Soil Functional Microorganisms and Microbial Communities |
|---|---|
| Author | Yunpeng Guan1, Meikang Wu2, Songhao Che1, Shuai Yuan1, Xue Yang1, Siyuan Li1, Ping Tian2, Lei Wu1, Meiying Yang1*, and Zhihai Wu2 |
| Address | 1College of Life Sciences, Jilin Agricultural University, Changchun 130118, People’s Republic of China, 2Faculty of Agronomy, Jilin Agricultural University, Changchun 130118, People’s Republic of China |
| Bibliography | Journal of Microbiology, 61(1),49-62, 2023, |
| DOI | 10.1007/s12275-022-00004-6 |
| Key Words | Straw return · Enzyme activity · Microbial community · Degradability · Rice · Soil nutrients |
| Abstract | This study examined the changes in soil enzymatic activity, microbial carbon source metabolic diversity, and straw decomposition rates in paddy fields treated with 1, 2, or 3 years of straw returning (SR1–SR3). The soil’s ability to decompose straw and cellulolytic bacteria increased with the number of treatment years (1: 31.9% vs. 2: 43.9% vs. 3: 51.9%, P < 0.05). The numbers of Azotobacter, Nitrobacteria, cellulolytic bacteria, and inorganic phosphate bacteria increased progressively with the numbers of straw returning years. Cellulolytic bacteria and inorganic phosphate bacteria were significantly positively correlated with the decomposition rate (r = 0.783 and r = 0.375, P < 0.05). Based on 16S sequencing results, straw returning improved the microbial diversity of paddy soils by increasing unclassified bacteria and keeping dominant soil microorganism populations unchanged. The relative importance of individual microbial taxa was compared using random forest models. Proteobacteria, ammoniating bacteria, and potassium dissolving bacteria contributed to peroxidase activity. The significant contributors to phosphate monoesterase were Acidobacteriota, Desulfobacterota, ammoniating bacteria, cellulolytic bacteria, and potassium-dissolving bacteria. Proteobacteria, ammoniating bacteria, cellulolytic bacteria, and potassium-dissolving bacteria contributed to urease activity. Desulfobacterota, ammoniating bacteria, cellulolytic bacteria, and potassium-dissolving bacteria contributed to the neutral invertase activity. In conclusion, soil microbial community structure and function were affected within 2 years of straw returning, which was driven by the combined effects of soil organic carbon, available nitrogen, available potassium, and pH. With elapsing straw returning years, soil properties interacted with soil microbial communities, and a healthier soil micro-ecological environment would form. |