控制性分根交替滴灌对玉米蒸腾日变化和WUE的影响

Effect of Controlled Roots-Divided Alternative Drip Irrigation for Maizeon Daily Variation of Transpiration Rate and Water Use Efficiency

以盆栽玉米为试材,对控制性分根交替滴灌供水方式下,夏玉米蒸腾速率和水分利用效率(WUE)的日变化特征及其对产量水平上的WUE和地上生物量的影响进行了试验研究,以探索夏玉米在这种新型供水方式下的节水机理和节水效应。结果表明,晴好天气下,AI1和CK蒸腾速率的日变化特征基本一致,均呈不对称的浅“M”型,且上午变化幅度大于下午,AI2蒸腾速率的日变化呈以12:00时为轴的“M”型对称曲线。就1天的平均蒸腾速率而言,AI1和CK相差不大,绝对差值仅为0.01 mmol/(m2.s),表明AI1可在减少作物灌水量的同时而不降低作物的蒸腾速率,AI2和CK相比,差异显著,仅为CK的89.5%。产量水平上的WUE,AI2虽明显高于CK,但其生物量下降明显(仅为CK的52.5%),AI1不但WUE明显高于CK,且生物量差异不大,生物量仅下降9%而耗水量减少25%。初步表明控制性分根交替滴灌是一种高效可行的节水新技术。

Daily variation of transpiration rate and WUE of maize under controlled root-divided alternative drip irrigation were studied through potted experiment in order to investigate water saving mechanism and effect of the new irrigation method. The result indicated that daily variation of transpiration rate of maize showed same asymmetric shallow ＂M＂ type and the change range of a. m. was higher than that of p. m on the fine day in AI1 and CK disposal, while it showed symmetrical ＂M＂ type, which took 12：00 as axial, in AI2 disposal. As to the daily average transpiration rate, All was as much as that of CK and the absolute difference was only 0. 01 mmol/（m^2·s）, which showed that AI1 could reduce the quantity of irrigation while maintain the transpiration rate. Compared with CK, the transpiration of AI2 was merely 89. 5% of CK. Though the yield WUE of AI2 was higher than CK, ifs biology yield reduced clearly, merely 89. 5% of CK Not only the yield WUE of AI1 was higher than CK, but also its biology yield had little difference with CK. All of the data proved that controlled root divided alternative drip irrigation was a practicable water ,saving technology.