灌溉制度对甜瓜/向日葵间作系统叶片水分状况和水分利用效率的影响

Effects of Irrigation System on Leaf Water Status and Water Use Efficiency of Melon/Sunflower Intercropping System

为优化甜瓜/向日葵间作模式节水灌溉关键技术,提高绿洲灌区灌溉水分利用效率。试验以甜瓜和向日葵为试材,研究9种灌溉制度下甜瓜/向日葵间作系统和2种作物单作的叶片水分状况和水分利用效率。结果表明,甜瓜/向日葵间作系统的水分效率显著高于甜瓜单作和向日葵单作,分别提高30.3%和107.8%,间作显著提高了甜瓜成熟期叶片的水分饱和亏,对相对含水量无显著影响,却降低了向日葵开花期和成熟期叶片的相对含水量和水分饱和亏。间作不同灌溉次数下,灌水8次和灌水9次有利于提高间作系统的水分利用效率。间作不同灌水定额下,灌水8次和灌水9次处理下,灌水定额为225 m^(3)/hm^(2)的水分利用效率显著高于灌水定额为450 m^(3)/hm^(2)、和300 m^(3)/hm^(2),分别提高47.8%、21.4%和37.6%、31.0%。间作不同间作灌溉次数下,灌水7次有利于提高甜瓜成熟期叶片的相对含水量,灌水8次有利于提高甜瓜成熟期叶片水分饱和亏和向日葵成熟期叶片水分饱和亏,灌溉次数对向日葵叶片相对含水量无显著影响。间作不同灌水定额下,灌水定额为225 m^(3)/hm^(2)有利于提高甜瓜叶片的相对含水量、水分饱和亏和向日葵叶片的相对含水量,灌溉定额对向日葵叶片水分饱和亏无显著影响。在河西绿洲灌区甜瓜/向日葵间作系统条件下获得较高水分利用效率和改善叶片水分状况较适宜的灌溉制度为全生育期灌水8次、灌水定额225 m^(3)/hm^(2)。

To optimize the water-saving irrigation technology of melon/sunflower intercropping mode,and improve irrigation water use efficiency in the oasis area,a field experiment comprising monoculture and intercropping of two crops(melon and sunflower)was conducted under nine irrigation systems to study the leaf water status and water use efficiency.The results showed that the water efficiency of the intercropping system was significantly higher than that of the melon and sunflower monoculture,increasing by 30.3%and 107.8%,respectively.Intercropping significantly increased the water saturation deficit of melon leaves at maturity stage and had no significant effect on relative water content,but reduced the relative water content and water saturation deficit of sunflower leaves at flowering and maturity stages.Under different irrigation times of intercropping,8 times of irrigation and 9 times of irrigation were beneficial to improving the water use efficiency of the intercropping system.Under different irrigation quotas,the water use efficiency of the irrigation quota of 225 m^(3)/hm^(2) was significantly higher than that of 450 m^(3)/hm^(2) and 300 m^(3)/hm^(2) under the 8-time and 9-time treatments with an increase of 47.8%and 21.4%and 37.6%and 31.0%,respectively.Under different intercropping irrigation times,7 times irrigation was helpful to increasing the relative water content of melon leaves at maturity stage,and 8 times irrigation was helpful to increasing the water saturation deficit of both melon leaves and sunflower leaves at maturity stage,while the intercropping irrigation times had no significant effect on relative water content.Under different irrigation quotas for intercropping,the irrigation quota of 225 m^(3)/hm^(2) was beneficial to increasing the relative water content and water saturation deficit of melon leaves and relative water content of sunflower leaves,but the irrigation quota had no significant effect on sunflower leaf water saturation deficit.Under the melon/sunflower intercropping system in the Hexi oasis region,the more suitable irrigation system is to irrigate 8 times during the whole growth period with the water quota of 225 m^(3)/hm^(2).