水分与氮素对南疆膜下滴灌棉花水分利用效率与蒸腾速率的影响

The Effects of Water and Nitrogen on Water Use Efficiency and Transpira-tion Rate in Mulched-cotton by Drip Irrigation in South-Xinjiang

研究了不同滴水量(2 850、3 900、4 950 m3/hm2)与施氮量(0、180、270、360 N kg/hm2)条件下南疆膜下滴灌棉花蕾期、花铃期与盛铃期功能叶水分利用效率WUE与蒸腾速率E。结果表明,在蕾期、花铃期水分与氮素对棉花叶片水分利用效率WUE无显著影响;在盛铃期,WUE显著地受到水分的影响,施氮、施氮与水分的交互作用对WUE无显著影响。在盛铃期时,滴水量为4 950 m3/hm2时WUE显著高于滴水量为3900、2 850 m3/hm2时的WUE,后两者之间的WUE无显著差异。不同处理棉花叶片蒸腾速率E在蕾期均高于花铃期和盛铃期。在蕾期,水分与氮素对蒸腾速率无显著影响;在花铃期,水分对蒸腾速率E的影响达到了显著水平,最高滴水量处理的蒸腾速率也最高,而施氮、水分与施氮的交互作用对蒸腾速率E无显著影响。在盛铃期,最高滴水量4 950 m3/hm2条件下,蒸腾速率E显著地受到施氮的影响,施氮量最高时,其蒸腾速率也最高。南疆膜下滴灌棉花水分利用效率、蒸腾速率的大小与棉田冠层环境因子密切相关,其中,温度是最主要的影响因子。WUE与叶片温度、空气温度、空气饱和差、胞间CO2与空气CO2浓度比呈现出极显著的负相关关系,WUE与光合有效辐射PAR呈显著负相关关系,WUE与空气相对湿度、空气CO2浓度呈现出极显著的正相关关系。蒸腾速率与空气温度、叶片温度、光合有效辐射PAR呈现出极显著的正相关关系。蒸腾速率与空气CO2浓度、胞间CO2与空气CO2浓度比呈现出极显著的负相关关系。

This experiment studied the effects of water and nitrogen on water use efficiency and transpiration rate in mulched-cotton by drip irrigation in South-Xingjiang China. The water application rate was 2 850 ,3 900 ,4 950 m^3/hm^2, and the nitrogen application rate was 0,180,270, 360 Nkg/hm^2. Using the li-6400 portable photosynthesis system （ U. S Li-COR）, cotton leaf water use efficiency （WUE） and transpiration rate （E） were gained from budding to bolling stage. The results showed that in budding and early boiling stage, water and nitrogen application had no significant effects on the WUE. But at later boiling stage, WUE was significantly effected by water application and not by nitrogen and nitrogen water interaction. When irrigation 4 950 m^3/hm^2, the WUEwas the highest and it was higher than that of irrigation 2 850,3 900 m^3/hm^2. In all treatments the transpiration rate in budding stage were higher than that of at bolling stage. In budding water and nitrogen had no significant effects on transpiration rate, in later bolling water had significant effect on transpiration rate, the more irrigation ,the more the transpiration rate. But the nitrogen and nitrogen water interaction had no significant effects on transpiration rate. Under irrigation 4 950 m^3/hm^2, transpiration rate was notable effected by nitrogen application, and the more nitrogen, the more transpiration rate. In South-Xingjiang, mulched cotton by drip irrigation the leaf WUE and transpiration rate were related by environmental factors and temperature was the key one. The relationship between WUE and environmental factors such as leaf temperature, air temperature, VPD, ratio of intercellular CO2 concentration to ambient CO2 concentration （Ci/Ca） were significant （P〈0.01） negative. WUE had significant （P〈0. 05） negative relationship of PAR. WUE had significant （P 〈 0. 01） positive relationship. The relationship between transpiration rate and environmental factors such as air temperature, leaf temperature, PAR were significant （P〈0.01） positive. The relationship between transpiration rate and air CO2 concentration, ratio of intercellular CO2 concentration to ambient CO2 concentration （Ci/Ca） were significant （P〈0.01） negative.