以涝渍连续抑制天数为冬小麦排水指标的试验

为了探讨在冬小麦抽穗开花期以涝渍连续抑制天数作为排水指标的可能性，该文利用测坑试验研究了冬小麦抽穗开花期不同涝渍处理对其生理指标及产量的影响，建立了作物相对产量Ry（涝渍胁迫处理下小麦产量与对照的比值）与涝渍连续抑制天数CSDI的关系模型。结果表明，涝渍处理对冬小麦光合速率、气孔导度和蒸腾速率具有明显的抑制作用，在地表水累积深度SFW相同的情况下，地下水埋深小于50 cm的累积深度SEW50越大，冬小麦减产越严重；在单纯受渍情况下，冬小麦相对产量Ry随SEW50的增大而呈减小的趋势，但各处理之间差异不显著。冬小麦相对产量Ry与SEW50和CSDI均具有较好的线性关系；涝害权重系数CW是一个随涝渍状态而变的状态变量，说明在涝渍连续情况下，用涝渍连续抑制天数作为控制排水指标比较合理。

Study on continuous days of water logging and excessive soil water as drainage index of wheat

To explore the possibility of taking continuous stress-day from surface and subsurface water logging (CSDI) as drainage index during the heading and flowering period of winter wheat, influence of different continuous stress-day from surface and subsurface water logging during heading and flowering period on yield of winter wheat by test pits was studied. Model about relative crop yield and CSDI was established. The results showed that water logging and excessive soil water markedly inhibited leaf photosynthesis stomatal conductance and transpiration rate. The bigger of continuous dynamic state of groundwater, the more serious yield reduction was at the same cumulative depth of surface water. The relative yield decreased with the increase of continuous dynamic state of groundwater, however, the difference among the treatments was not significant. There was better linear relationship between crop relative yield and SEW50 and CSDI. Weight coefficient of water logging (CW) was a state variable which changed with status of surface and subsurface water logging. It was showed that the utilization of CSDI was reasonable in determination of controlled drainage index under the condition of continuous stress from surface and subsurface water logging.