调亏灌溉对玉米需水规律和水分生产效率的影响

The effect of regulated deficit irrigation on waterconsumption regulation and water production efficiency of maize

在山西省洪洞县霍泉灌区通过大田试验、研究了苗期调亏灌溉对玉米需水规律和水分生产效率的影响。结果表明：调亏处理玉米在苗期、拔节期及抽雄期需水量减少，叶面积、蒸腾速率和光合速率下降，在灌浆期则相对增加，作物的总需水量减少。叶面积、蒸腾速率和棵间蒸发减少是调亏灌溉需水量降低的主要原因。调亏灌溉能够延缓灌浆期叶片衰老，提高光合速率，使光合同化物向籽粒分配的比例增加。调亏灌溉处理产量有所下降，但水分生产效率提高。

The effect of regulated deficit irrigation (RDI) imposed on maize in seedling stage on water consumption and water production efficiency (WPE) was studied based on the field experiment conducted in huoquan Irrigation district, Shanxi province during 1997 and 1998. The results indicated that RDI photosynthesis rate in seedling stage, jointing stage and heading stage, but reletively increased in filling stage. Total water consumption was lower than the control treatment mainly because RDI reduced leaf area, transpiration and soil evaporation. RDI could suspend leaf senescence and increase photosynthesis rate in the filling stage. Photosynthesis products distributing to grain tended to increase. Grain yield was rarely lower but WPE was higher than control treatment under RDI.