调亏灌溉对冬小麦生理机制及水分利用效率的影响

Effect of regulated deficit irrigation on physiological mechanism and water use efficiency of winter wheat

在人工控制试验条件下 ,采用子母盆栽土培法 ,以冬小麦为试验材料进行了调亏灌溉试验研究。结果表明 ,适时适度的水分调亏显著抑制蒸腾速率 ,而光合速率下降不明显 ,复水后光合速率又具有超补偿效应 ,光合产物具有超补偿积累 ,且有利于向籽粒运转与分配 ;抑制营养生长 ,促进生殖生长。冬小麦调亏灌溉的适宜时段为三叶—返青 ,调亏度为 4 0 %～6 0 %田间持水率 (θF) ,历时约 5 5 d;平均比对照增产 0 .88%～ 8.2 5 % ,节水 12 .80～ 18.5 5 % ,水分利用效率提高 15 .96 %～32 .98%。

Under the condition of control test, by cultivating in pots containing soil, with winter wheat as material, the Regulated Deficit Irrigation (RDI) was studied. The results showed that RDI in winter wheat was a practical technology for water saving, high yield and high efficiency. Under appropriate amount of water deficit at right stages, the transpiration rate decreased obviously, and the photosynthesis rate diminution was not obvious. There were super compensation effects in photosynthesis and photosynthetic products accumulation after rewatering. The proportion of photosynthetic products distributed in the grains tends to increase. RDI was able to control vegetative growth, and promote reproductive growth. The indexes of RDI for water saving and high yield in winter wheat as are follows: the stage of regulated water deficit was three leaves-returning green stages, the amount of water deficit was 40%~60%, and the water deficit duration was 55 days, RDI increased yield by 0.88% ~8.25%, water consumption decreased by 12.80%~18.55%, water use efficiency increased by 15.96%~32.98% as compared with that of conventional irrigation.