调亏灌溉对冬小麦光合生理特性的影响及其优化农艺技术组合

Effect of Regulated Deficit Irrigation on Physiological and Photosynthetic Characteristics of Winter Wheat and Its Optimized Combination with Agronomic Techniques

在移动式防雨棚条件下．采用子母盆栽土培法和池栽微区试验相结合的方法，以冬小麦品种93中6为试验材料进行了调亏灌溉（Regulated deficit irrigation，RDI）试验研究，旨在了解调亏灌溉对小麦不同生育阶段生长动态、蒸腾速率（Tr）、光合速率（Pn）、光合产物积累与分配以及最终籽粒产量和水分利用效率（WUE）的影响，寻求适宜的调亏生育阶段（时期）和调节亏水度，为建立冬小麦RDI模式及其配套优化农艺方案提供理论依据。结果表明，适时适度的水分调亏显著抑制Tr，而Pn下降不明显；复水后Pn又具有超补偿效应，光合产物具有起补偿积累，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40％FC（Field water capacity，FC）～60％FC，历时约55d；平均比对照增产0．88％～8．25％，节水12．80％～18755％，水分利用效率提高15．96％～32．98％。通过三因子正交旋转组合设计综合分析试验资料，分别建立了经济产量（Y）及水分利用效率（WUE）的数学模型。对模型的解析结果表明，当实施RDI时，可适当提高作物群体指标，并与施肥等其它农艺技术相结合，可以补偿RDI的负面效应。对所建数学模型进行目标联合仿真寻优，获得不同决策目标下RDI与农艺技术结合的优化方案。

Under the condition of mobile rain-proof shelter, by cultivating in pots containing soil in combination with the pond culture, with winter wheat （Triticum aestivum L. ） as material, the experiment in Regulated Deficit Irrigation （RDI） to investigate the effects of RDI on growth dynamic of plants was conducted. Photosynthetic rate （Pn）, transpiration rate （Tr）, distribution and accumulation of photosynthet- ic products, grain yield, and water use efficiency （WUE）, was investigated to seek the right stages of RDI and the amount of water deficit, and to offer theoretical basis for the establishment of RDI model in winter wheat and its optimized combination with agronomic techniques. A two-factor（RDI stages and the amount of water deficit） randomize-block design and a three-factor （the amount of water deficit, fertilizer level, and sowing rate）quadratic rotational regression combination design were adopted in experiments in pots and in pond culture, respectively. The results showed that RDI in winter wheat was a practicable technology for water-saving, 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 super-compensation effects on 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 winter wheat as are follows： the stages of regulated water deficit is three-leaves-returning green stages, the amount of water deficit is 40% field water capacity （FC） -60% FC, and the water deficit duration is S S days, RDI increased grain yield by 0.88%- 8.25%, water Consumption decreased by 12.80%- 18. 55%, Water use efficiency（WUE） increased by 15.96%-32.98% as compared with that of conventional irrigation. Two mathematical models were established based on the data from three-factor quadratic rotational regression design experiment. The result of analyzing the models indicated that plant density should be increased moderately and combined with other agronomic techniques while RDI was applied. Various optimal schemes for the combination of RDI and agronomic techniques under various objectives were worked out by simulation.