隔沟交替灌溉对棉花生长、产量和水分利用效率的调控效应

为了探讨旱区农业高效节水新途径，于2004—2006年在甘肃石羊河流域干旱荒漠绿洲区田间，研究了常规沟灌、固定隔沟灌溉、隔沟交替灌溉对棉花生长、产量和水分利用效率的调控效应，结果表明，隔沟交替灌溉对棉花株高抑制作用较明显，而对蕾铃等生殖生长的影响较小，该技术能够调整棉花营养生长与生殖生长的关系，有效控制作物生长冗余，调节光合产物在根冠间的比例和分配，优化根冠比；可以在保持相同光合速率水平下大大降低叶片蒸腾损失，提高叶片水分利用效率，使霜前花比例提高，产量水平的水分利用效率分别较常规沟灌和固定隔沟灌提高17.22%和18.59%。在西北旱区棉花上应用隔沟交替灌溉技术具有较大的节水增产潜力。

Responses of Cotton Growth, Yield, and Water Use Efficiency to Alternate Furrow Irrigation

To explore new high-efficient water-saving irrigation methods in arid areas,a field experiment was carried out to investigate the effects of alternate furrow irrigation in partial root zone on growth,yield and water use efficiency of cotton(Gossypium hirsutum L.) in an oasis region of Shiyang River Basin,Gansu province in 2004-2006.Planting with mulching and in furrows was applied with three partial root zone irrigation methods,i.e.conventional furrow irrigation(CFI,all furrows watered),fixed furrow irrigation(FFI,fixed one of every two furrows watered),and alternate furrow irrigation(AFI,neighboring two furrows alternatively watered) under three irrigation levels(225,300,450 m3 ha-1 in 2004;225,300,375 m3 ha-1 in 2005;and 240,360,480 m3 ha-1 in 2006) for each method in the three years.The results indicated that AFI shortened the cotton plant height,had no significant effect on reproductive growth such as bud and boll,and maintained the balance between vegetative and reproductive growth with reducing redundant growth.It regulated the distribution of photosynthesis products and ratio between root and shoot.AFI reduced `luxury' transpiration without much reduction in photosynthetic rate,resulting in higher water use efficiency.In the three years,AFI always achieved the highest seed cotton yield under the three irrigation levels.Higher yield and reduced water loss also resulted in a higher water use efficiency(WUE) for the AFI treatment.Furthermore,percentage of pre-frost seed cotton yield under AFI was higher which meant better lint quality.Seed cotton WUE was improved by 17.22% and 18.59% as compared with CFI and FFI at the same irrigation levels of 37.5 mm in 2005.The results suggest that AFI should be a useful water-saving irrigation method in the arid region where cotton production is heavily dependent on irrigation.