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| 稻麦轮作农田排水控制与秸秆还田对土壤有机碳累积的协同影响模拟 |
| Simulating the synergistic effect of drainage control and straw return on soil organic carbon accumulation in rice-wheat rotation fields |
| 投稿时间：2026-01-25 修订日期：2026-07-03 |
| DOI： |
| 中文关键词: 秸秆还田 排水强度 土壤有机碳 DNDC模型 DRAINMOD模型 |
| 英文关键词: straw return drainage intensity Soil Organic Carbon DNDC model DRAINMOD model |
| 基金项目:国家自然科学(52379050) |
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| 摘要点击次数: 192 |
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| 中文摘要: |
| 为阐明排水农田水位调控与秸秆还田措施对耕层土壤有机碳（SOC）累积过程的协同影响，本研究基于江苏省扬州市沿运灌区稻麦轮作农田地下水位埋深的实地观测数据，结合研究区气象、土壤、以及田间管理资料，联合运用田间水文模型DRAINMOD与土壤碳氮循环模型DNDC，探究了不同排水控制强度（无控排、弱控排和强控排）及秸秆还田模式（水稻和小麦秸秆还田总量1~12 t?hm-2?a-1）下农田耕层SOC的动态累积过程。模型检验结果表明，输入DRAINMOD模型对地下水位更为准确的模拟结果，可有效提升DNDC模型对排水农田SOC累积过程的模拟精度。基于30 a长序列气象数据的情景模拟结果表明，耕层SOC累积增长率随秸秆还田量增加显著递增；模拟期末，农田耕层（0~20cm）SOC含量由初始值17.1 g?kg-1增至18.4~25.1 g?kg-1；相同秸秆还田水平下，SOC累积速率随农田排水控制强度增加（即土壤排水强度降低）而提高，但该调控效应存在显著的年际差异。在枯水年与平水年，提高农田排水控制强度有利于促进秸秆还田条件下耕层SOC的累积；在丰水年，提高排水控制强度反而会减缓耕层SOC累积过程。因此，在优化秸秆还田方案的同时，科学适配农田排水管理方案，可促进农业粮食生产与农田固碳能力提升的协同发展。 |
| 英文摘要: |
| To clarify the synergistic effects of controlled drainage and straw returning on the accumulation process of soil organic carbon (SOC) in the topsoil, this study adopted field-observed groundwater depth data from rice-wheat rotation farmlands in the Yanyun irrigation district of Yangzhou City, Jiangsu Province. Combined with meteorological, soil and field management data of the study area, the hydrological model DRAINMOD and soil carbon-nitrogen cycle model DNDC were jointly applied to investigate the dynamic accumulation of topsoil SOC under different controlled drainage intensities (uncontrolled drainage, weakly-controlled drainage, and strongly-controlled drainage) and straw returning patterns (total rice and wheat straw input ranging from 1 to 12 t?hm-2?a-1). Model validation revealed that embedding the more accurate groundwater table outputs from DRAINMOD into DNDC could effectively improve the simulation accuracy of SOC accumulation in drained farmlands. Simulations based on long-term meteorological data indicated that the growth rate of topsoil SOC increased significantly with the rise of straw returning amount under combined treatments of varied controlled drainage and straw returning. During the 30-year simulation period, the SOC content in the 0-20 cm topsoil increased from the initial value of 17.1 g?kg-1 to a range of 18.4-25.1 g?kg-1. At the same straw returning rate, the SOC accumulation rate rose with increasing controlled drainage intensity (i.e., actual drainage flux declined). The simulation results also demonstrated that the regulatory effect of controlled drainage intensity on topsoil SOC accumulation exhibited distinct interannual variations. In dry and normal years, intensified controlled drainage effectively promoted SOC accumulation under straw returning. Conversely, increasing controlled drainage intensity reduced the SOC accumulation rate in wet years with abundant precipitation. Therefore, optimized straw return combined with rationally regulated field drainage can achieve synergistic promotion of grain production and farmland carbon sequestration. |
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