水肥处理对玉米叶片水分利用效率及其光合特性的影响

Effect of water-fertilizer on maize's water use efficiency and photosynthesis characteristic

采用田间小区试验方法,研究了水肥处理对玉米叶片水分利用效率及光合特性的影响。结果表明,在不同的水肥处理下,整个生育期内净光合速率、水分利用效率、叶片气孔导度、蒸腾速率的变化基本一致。在中水(90 m3.hm-2)、中肥(其中N、P、K分别为160、60、110 kg.hm-2)情况下,玉米叶片净光合速率(Pn)、水分利用效率(WUE)在开花期达到最大;叶片气孔导度(Gs)、蒸腾速率(E)在抽雄期达到最大。中水、高肥(N、P、K分别为240、90、170 kg·hm-2)情况下,蒸腾速率与气孔导度之间的相关性显著高于中水、低肥(其中N、P、K分别为80、30、50 kg·hm-2)和中水、中肥处理下的蒸腾速率与气孔导度之间的相关性;蒸腾速率与气孔导度间存在线性关系,呈正相关,气孔导度的变化影响着蒸腾速率的变化。

Field trials were conducted to study the maize＇s water use efficiency and synthesis characteristic under different conditions of water and fertilizer. The results showed that under the condition of medium level demand of water （90m^3·hm^-2） and fertilizer （N, P, K was 160, 60, 110 kg·hm^-2, respectively）, the photosynthetic rate （Pn） and water use efficiency （WUE） were the highest at the blooming stage; in tasseling stage, the stomatal conductance （Gs） and the transpiration rate （E） were the highest. The trends of the photosynthetic rate, transpiration rate, water use efficiency and stomatal conductance observed under the different water and fertilizer were indentical respectively in the period of growth. The correlation between transpiration rate and stomatal conductance in medium level demand of water and high level demand of fertility （N, P, K was 240, 90, 170kg·hm^-2, respectively） was significantly higher than in medium level demand of water and low fertility （N, P, K was 80, 30, 50 kg·hm^-2, respectively） and in medium level demand of water and fertilizer significantly; there was a direct correlation, linar relationship between the transpiration rate and the stomatal conductance, the stomatal conductance＇ changes affected the transpiration rate＇s