调亏灌溉对夏玉米光合生理特性的影响

Effect of Regulated Deficit Irrigation on Physiological and Photosynthetic Characteristics of Summer Maize and Its Optimized Combination of Agronomic Techniques

在移动式防雨棚下,采用子母盆栽土培法和池栽微区试验相结合的方法,以夏玉米(Zea mayL.)为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(Tr),而光合速率(Pn)下降不明显,复水后Pn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。玉米节水高产的调亏灌溉指标是:调亏时段为三叶一心—拔节(七叶一心),调亏度为45%FC(Fieldwater capacity,FC)~65%FC,历时21d;或拔节—抽穗调亏,调亏度为60%FC^65%FC,历时21d;平均比对照增产25.24%,节水15.41%,水分利用效率提高45.05%。根据3因子正交旋转组合设计综合试验资料,分别建立了经济产量(Y)及水分利用效率(WUE)数学模型。

Under the eondition of mobile rain-proof shelter, by cultivating in pots containing soil in combination with the pond culture, with summer maize （Zea may L. ） as material, the experiment in regulated deficit irrigation （RDI） was conducted, The results showed that RDI in summer maize was a practicable technology for watersaving, high-yield and high-efficiency. Under appropriate amount of water deficit at right stages, Tr decreased obviously, and Pn diminution was not obvious. There were superrcompensation effects in photosynthesis and photosynthetic products accumulation after re-watering. 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 summer maize as are follows; the stage of regulated water deficit is three leaves jointing, the amount of water deficit is 45%FC～65 %FC, or regulated water deficit during jointing-heading, the amount of water deficit is 60%FC～65%FC, and the water deficit duration is 21days. RDI increased yield by 25.24%, water consumption decreased by 15.41%, water use efficiency （WUE） increased by 45.05% as compared with conventional irrigation. Two mathematical models were established based on the data from three-factor quadratic rotational regression design experiment. Various optimal schemes for the combination of RDI and agronomic techniques under various objectives were worked out by computerizing simulation.