Zhao Jinxi, Hu Yanyu, Wang Jing, Gao Wanjing, Liu Deyao, Yang Miaoyin, Chen Xin, Xie Hongtu, He Hongbo, Zhang Xudong, Lu Caiyan
Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
Sci Total Environ. 2024 Oct 20;948:174716. doi: 10.1016/j.scitotenv.2024.174716. Epub 2024 Jul 14.
Reducing greenhouse gas (GHG) emissions from agricultural ecosystems is vital to mitigate global warming. Conservation tillage is widely used in farmland management to improve soil quality; however, its effects on soil GHG emissions remain poorly understood, particularly in high-yield areas. Therefore, our study aimed to evaluate the effects of no-tillage (NT) combined with four straw-mulching levels (0 %, 33 %, 67 %, and 100 %) on GHG emission risk and the main influencing factors. We conducted in-situ observations of GHG emissions from soils under different management practices during the maize-growing season in Northeastern China. The results showed that NT0 (705.94 g m) reduced CO emissions by 18 % compared to ridge tillage (RT, 837.04 g m). Different straw mulching levels stimulated NO emissions after rainfall, particularly under NT combined with 100 % straw mulching (2.89 kg ha), which was 45 % higher than that in any other treatments. The CH emissions flux among different treatments was nearly zero. Overall, straw mulching levels had no significant effect on the GHG emissions. During the growing season, soil NH-N (< 20 mg kg) remained low and decreased with the extension of growth stage, whereas soil NO-N initially increased and then decreased. More importantly, the results of structural equation modeling indicate that: a) organic material input and soil moisture are key factors affecting CO emissions, b) nitrogen fertilizer and soil moisture promote NO emissions, and c) climatic factors exert an inexorable influence on the GHG emissions process. Our conclusions emphasize the necessity of incorporating precipitation-response measures into farmland management to reduce the risk of GHG emissions.
减少农业生态系统中的温室气体（GHG）排放对于缓解全球变暖至关重要。保护性耕作在农田管理中被广泛应用以改善土壤质量；然而，其对土壤温室气体排放的影响仍知之甚少，尤其是在高产地区。因此，我们的研究旨在评估免耕（NT）结合四种秸秆覆盖水平（0%、33%、67%和100%）对温室气体排放风险及主要影响因素的作用。我们在中国东北地区玉米生长季对不同管理措施下土壤的温室气体排放进行了原位观测。结果表明，与垄作（RT，837.04 g m）相比，NT0（705.94 g m）使CO排放量减少了18%。不同的秸秆覆盖水平在降雨后刺激了NO排放，特别是在NT结合100%秸秆覆盖的情况下（2.89 kg ha），比其他任何处理都高出45%。不同处理间的CH排放通量几乎为零。总体而言，秸秆覆盖水平对温室气体排放没有显著影响。在生长季，土壤NH-N（<20 mg kg）含量较低且随生长阶段的延长而降低，而土壤NO-N含量先增加后降低。更重要的是，结构方程模型的结果表明：a）有机物质输入和土壤湿度是影响CO排放的关键因素，b）氮肥和土壤湿度促进NO排放，c）气候因素对温室气体排放过程有不可忽视的影响。我们的结论强调了在农田管理中纳入降水响应措施以降低温室气体排放风险的必要性。
