The Effects of Water and Nitrogen on Water Use Efficiency and Transpira-tion Rate in Mulched-cotton by Drip Irrigation in South-Xinjiang
WU Wei-mo~1,DONG He-lin~2,WANG Ping~3,CHEN Kang-wei~3 and WEI Changzhou~4 (1.Institute of Plant Science and Technology,Tarim University,Alar Xinjiang 843300;China;2.Cotton Research Institute of CAAS,Anyang Henan 455004,China;3.12 Regiment,Xinjiang Construction Corps,Alar Xinjiang 843300 China;4.Institute of Agriculture of Shihezi University,Shihezi 832003,China)
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 li6400 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 bolling stage,water and nitrogen application had no significant effects on the WUE.But at later bolling 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 WUE was 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 CO_2 concentration to ambient CO_2 concentration(Ci/Ca) were significant(P0.01) negative.WUE had significant(P0.05) negative relationship of PAR.WUE had significant(P0.01) positive relationship.The relationship between transpiration rate and environmental factors such as air temperature,leaf temperature,PAR were significant(P0.01) positive.The relationship between transpiration rate and air CO_2 concentration,ratio of intercellular CO_2 concentration to ambient CO_2 concentration(Ci/Ca) were significant(P0.01) negative.
【Fund】： 农业部948重大国际合作资助项目(2003-253);; 农业部农业产业结构调整重大研究专项(04-07-03B)资助
【CateGory Index】： S562
【CateGory Index】： S562