灌水处理对冬小麦生理生长特性等的影响研究

通过对冬小麦不同生育期进行有限灌溉的大田试验,研究不同水分处理对冬小麦的土壤水分变化、株高、叶面积指数、光合特性、产量以及水分利用效率的影响。结果表明:①灌水量越大,含水量变化的土层深度越大;并且土层深度越大,含水量的变化越小。②开花期灌水对缺水处理叶面积指数和株高的补偿效应明显。③各处理的光合特性日变化趋势一致,蒸腾速率和气孔导度日变化趋势均是双峰曲线,光合速率日变化趋势均是单峰曲线,均有"午休"现象。④开花水有利于籽粒的形成,只灌开花水也可获得较高产量。但产量与总灌水量之间呈抛物线关系。⑤单叶和产量水平的水分利用效率均随灌水量的不同而不同。总灌水量越大,叶片水分利用效率越大,灌溉水利用效率越低,水分利用效率越低。⑥综合考虑,全生育期只灌1次75 mm开花水的处理最合理。

Effects of Limited Irrigation on Physiological Characteristics and WUE of Winter Wheat

According to a limited irrigation experiment conducted in dry land field at different growth stages of winter wheat,the influence of different water supply treatments on the soil water changes,plant height,leaf area index,photosynthetic characteristics,yield and water use efficiency(WUE).The results showed that: ① with the increase of irrigation quantity,the influence depth of soil layer becomes deeper and soil water changes decrease with the soil depth increasing;② the irrigation on anthesis has a significant compensation effect on leaf area index and plant height under water stress.③ The tendency of diurnal variation of photosynthetic characteristic of every water supply treatment is the same.The transpiration rate and stomatal conductance both present a form of bimodal curve and the diurnal variation of photosynthetic rate single peak curve and midday depression is obvious.④ Flowering water is beneficial to form grain and higher yield can be achieved only by supplying water on anthesis;and it showed a parabola relationship between yield and the total irrigation volume.⑤ The water use efficiency of single leaf and yield vary with the variation of irrigation quantity.The irrigation water use efficiency and water use efficiency decrease with the total irrigation volume increasing but leaf water use efficiency increase with it.⑥ Comprehensive consideration,it is most reasonable to supply water of 75 mm on anthesis during the whole growth period.