Lyu Fu-Ze, Yang Ya-Li, Bao Xue-Lian, Zhang Chang-Ren, Zheng Tian-Tian, He Hong-Bo, Zhang Xu-Dong, Xie Hong-Tu
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Ying Yong Sheng Tai Xue Bao. 2023 Apr;34(4):903-912. doi: 10.13287/j.1001-9332.202304.033.
To investigate the effects of no-tillage and different amounts of stover mulch on soil microbial community composition and their residues, we set up a field experiment of different amounts of stover mulch under no-tillage on the long-term maize conservation tillage station located in the Mollisols area of Northeast China (built in 2007), including without stover mulch (NT0), 1/3 stover mulch (NT1/3), 2/3 stover mulch (NT2/3) and full stover mulch (NT3/3), and the conservation tillage (plowing without stover mulch, CT) as control. We analyzed phospholipid fatty acid, amino sugar biomarker and soil physicochemical properties at different soil layers (0-5 cm, 5-10 cm, 10-20 cm). The results showed that compared to CT, no-tillage without stover mulch (NT0) did not affect soil organic carbon (SOC), total nitrogen (TN), dissolved organic carbon and nitrogen (DOC, DON), water content, microbial community and their residue. The main effects of no-tillage and stover mulch were found in the topsoil. Specifically, the NT1/3, NT2/3 and NT3/3 significantly increased SOC content by 27.2%, 34.1% and 35.6%, respectively, phospholipid fatty acid content was significantly increased under NT2/3 and NT3/3 by 39.2% and 65.0%, respectively, and NT3/3 significantly increased the content of microbial residue-amino sugar by 47.2% in the depth of 0-5 cm compared with CT. The variations in soil properties and microbial community induced by no-tillage and different amounts stover mulch decreased with soil depth, with almost no difference in the 5-20 cm soil layer. SOC, TN, DOC, DON, and water content were the main factors influencing the composition of the microbial community and the accumulation of microbial residue. Microbial biomass was positively correlated with microbial residue, particularly fungal residue. In conclusion, all stover mulch treatments promoted SOC accumulation to different degrees. When there is sufficient stover, it is advisable to opt for no-tillage with full stover mulch, as it is most conducive to the increases of soil microbial biomass, microbial residue and SOC. In case when the amount of stover is inadequate, however, no-tillage with 2/3 stover mulch can still improve soil microbial biomass and SOC content. This study would provide practical guidance for stover management in conservation tillage and sustainable agricultural development in the Mollisols area of Northeast China.
为探究免耕及不同量秸秆覆盖对土壤微生物群落组成及其残留物的影响，我们在中国东北黑土区（建于2007年）的长期玉米保护性耕作试验站开展了免耕条件下不同量秸秆覆盖的田间试验，包括无秸秆覆盖（NT0）、1/3秸秆覆盖（NT1/3）、2/3秸秆覆盖（NT2/3）和全量秸秆覆盖（NT3/3），并以传统耕作（翻耕且无秸秆覆盖，CT）作为对照。我们分析了不同土层（0 - 5厘米、5 - 10厘米、10 - 20厘米）的磷脂脂肪酸、氨基糖生物标志物及土壤理化性质。结果表明，与CT相比，无秸秆覆盖的免耕（NT0）对土壤有机碳（SOC）、全氮（TN）、溶解性有机碳和氮（DOC、DON）、含水量、微生物群落及其残留物均无影响。免耕和秸秆覆盖的主要影响体现在表层土壤。具体而言，NT1/3、NT2/3和NT3/3分别使SOC含量显著增加27.2%、34.1%和35.6%，NT2/3和NT3/3下的磷脂脂肪酸含量分别显著增加39.2%和65.0%，与CT相比，NT3/3使0 - 5厘米深度的微生物残留物 - 氨基糖含量显著增加47.2%。免耕和不同量秸秆覆盖引起的土壤性质和微生物群落变化随土壤深度降低，在5 - 20厘米土层几乎无差异。SOC、TN、DOC、DON和含水量是影响微生物群落组成和微生物残留物积累的主要因素。微生物生物量与微生物残留物呈正相关，尤其是真菌残留物。总之，所有秸秆覆盖处理均不同程度地促进了SOC积累。当秸秆充足时，建议选择全量秸秆覆盖的免耕方式，因为这最有利于土壤微生物生物量、微生物残留物和SOC的增加。然而，当秸秆量不足时，2/3秸秆覆盖的免耕仍可提高土壤微生物生物量和SOC含量。本研究将为东北黑土区保护性耕作中的秸秆管理及可持续农业发展提供实践指导。
