两种施肥水平下根区局部灌溉对甜玉米水分利用的效应

Effect of Partial Root-zone Irrigation on the Growth and Water Use of Sweet Corn under Two Fertilization Level

根区局部灌溉如分根区交替灌溉和部分根干燥灌溉是新的高效节水技术。研究了两种施肥水平条件下根区局部灌溉对甜玉米叶片光合、叶面积、干物质积累和水分利用的影响。结果发现,与常规均匀灌水相比,根区局部灌溉高、低肥处理的蒸腾速率分别降低19.01%和17.50%,光合速率分别提高8.88%和18.34%,叶片水分利用效率分别提高34.69%和43.45%。随着甜玉米生育期的推进,各灌溉处理间的叶面积差异逐渐缩小;单株干物重分别下降15.14%和24.38%,蒸散量(即作物耗水量)分别下降31.28%和29.58%;冠层水分利用效率分别提高23.48%和7.40%。这表明较高肥条件下根区局部灌溉的冠层水分利用效率提高较多,因而根区局部灌溉技术的节水效应要与合理施肥相结合才能发挥更好的作用。

Partial root-zone irrigation (PRI) such as alternate partial root-zone irrigation (APRI) and partial root-zone drying (PRD) is a new high-efficient water saving technique. Effect of partial root-zone irrigation on the photosynthesis, leaf area, dry mass accumulation and water use of sweet corn under two fertilization levels was studied in this paper. The author found that compared with conventional irrigation for whole root zone (CI), under high and fertilization for PRI ,mean transpiration rate reduced 19.01% and 17.50% ,photosynthesis rate increased by 8.88% and 18.34%,leaf water use efficiency (WUE) increased by 34.69% and 43.45%,respectively.With the advance of sweat corn growth stages, the difference of leaf area for different irrigation treatments lessened gradually, mean dry mass reduced 15.14% and 24.38%,mean evapotranspiration (i.e. water use ) reduced 31.28% and 29.58%,while canopy WUE increased 23.48% and 7.40%. The result indicated that partial root-zone irrigation increased more canopy WUE under higher fertilization, so the water saving effect of partial root-zone irrigation should combine with rational fertilization.