不同灌水深度对冬小麦生长及产量的影响

为了给华北平原丘陵地区的冬小麦节水灌溉提供科学依据,试验分析了4个不同灌水深度处理对冬小麦光合日变化、株高、叶面积指数和籽粒产量的影响。试验以灌水深度为控制因子,设4个处理,即:地表灌溉(T1)、灌水深度为根系分布的60%(T2)、灌水深度为根系分布的75%(T3)、灌水深度为根系分布的90%(T4),每个处理4次重复。结果表明:不同灌水深度条件下,冬小麦净光合速率、蒸腾速率和气孔导度日变化呈"M"形的双峰曲线,存在明显的"午休"现象,而胞间CO2浓度则呈"W"形的双峰曲线,深层灌的午睡现象不如地表灌的明显,且4项光合指标在同一时刻均要比地表灌的高;随灌水深度的增加,株高逐渐增大,叶面积指数呈先增大后减小的趋势,而灌水深度过大则会使影响植株后期的株高增长,使叶面积指数下降增快;适当增加灌水深度可明显提高小麦收获指数,使产量增加,但产量并不是随灌水深度的增加而增加。

Effects of Different Irrigation Depth on Growth and Production of Winter Wheat

In order to provide a scientific basis for water-saving irrigation of winter wheat in the north plain hilly region of China,the test analyzes the influence of four different irrigation depths on diurnal variation of photosynthesis of winter wheat in shooting stage, winter wheat plant height,leaf area index and the grain yield.Using water depth as the control factor,the test sets four treatments, namely the surface irrigation (T1),the 60% of root system distribution water depth (T2),the 75% of root system distribution wa-ter depth (T3),and the 90% of root system distribution water depth (T4).There are four repeats for each treatment.The results show that:under the condition of different irrigation depths,net photosynthetic rate,transpiration rate and stomatal conductance of winter wheat present “M”type of double-peaks curve with a clear “midday depression”phenomenon,while the CO2 concentration presents a “W”type of double-peaks curve,and the four indicators of deep irrigation are less obvious than those of surface irrigation at the same time.With the increase of irrigation depth,the plant height gradually increases,the leaf area index shows a trend of in-crease first and then decrease;too large irrigation depth will make the plant grow slow at later growth stage and the leaf area index drop rapidly.The appropriate increase of irrigation depth can significantly improve the wheat harvest index and enhance the yield, but the production does not increase with the increase of the water depth.