为探究涝渍胁迫下农田生态系统碳平衡关系, 在五道沟实验站设立典型试验区, 以冬小麦拔节期为研究时段开展控制试验, 设置涝、渍试验组和正常试验组, 测量不同情景下冬小麦碳通量, 并分析其变化趋势。研究结果表明: 在正常情景下, 拔节期冬小麦碳通量表现为碳汇, 13 时碳通量最低, 晴天碳通量低于阴雨天, 连续阴雨天后的初晴日碳通量大幅降低; 涝渍情景可以降低拔节期冬小麦的碳通量, 其中涝水情景的影响更为明显, 第 3 d 后涝渍情 景对冬小麦碳通量影响明显减弱。碳通量随温度呈三次曲线变化, 在正常和渍水情景下冬小麦碳通量在 7 ℃左右 达到最高点; 在涝水情景下 5 ℃ 左右达到最高点。拔节期碳的累积主要用于植株茎部生长, 渍水 3 d 为降低碳通量 且不影响植株生长的最佳时点。研究成果可为维持农田生态系统碳平衡和建设生态灌区提供科学依据。

In order to explore the relationship between carbon balance of farmland ecosystem under waterlogging stress, a typical test area was set up in Wudaogou experimental station, and the winter wheat jointing stage was used as the research period to carry out the control experiments. The surface/ subsurface waterlogging test and the normal test were set to measure and analyze the changing trend of the carbon flux under different conditions. T he results show that: under normal conditions, the carbon flux of winter wheat in the jointing stage is carbon sink, with the lowest carbon flux is at 13 o’clock, the carbon flux on a sunny day is lower than that on a rainy day, the carbon flux o n a sunny day after continuous rainy days is reduced, the waterlogging co ndition can reduce the carbon flux of winter wheat in the jointing stage, the influence of the surface waterlogging condition is more obvious, and the effect of the water logging condition on the winter wheat carbon flux after the third day is significantly weakened. Moreover, the temperature is another important factor affecting the carbon flux of winter wheat in the jointing stage.T he carbon flux changes with the temperature in cubic curves. Under normal and waterlogging scenarios, the carbon flux of winter wheat reaches the highest point around 7 ℃ . In the case of surface waterlogging , it reaches the highest point around 5 ℃ . T he results of the research can provide scientific evidence for keeping the carbon balance of farmland ecosystems and constructing the ecological irrigated areas.

国家自然科学基金( 51579101; 51879106 ; 51709111) ; 国家重点研发计划( 2016YFC0401401) ; 河南省科技创新杰出青年支持计 划( 184100510014)