为了解不同间作条件下枣树的光合生理特性,为绿洲枣农复合系统的优化配置提供依据,选择了枣树/玉米和枣树/紫花苜蓿两种有代表性的间作方式,用LI-6400光合作用测定系统测定了不同间作条件下枣树叶片气体交换参数的日变化。结果表明,枣树/玉米间作地(简称玉米地)和枣树/紫花苜蓿间作地(简称苜蓿地)的田间主要气象因子有显著不同;两间作地枣树叶片的净光合速率(Pn)、蒸腾速率(E)日变化都呈典型的单峰曲线;苜蓿地枣树的Pn最高值持续时间短暂,全天水分利用效率(WUE)较低,而玉米地枣树WUE较高。以上结果说明,间作枣树的WUE直接受种间关系影响,枣树和深根性的紫花苜蓿间作效果较差,而枣树和玉米间作则具有更高的水分利用效率和光能利用效率。
In order to understand the photosynthetic physiological characteristics of Chinese jujube under different intercropping conditions and provide a basis for optimizing the allocation of the oasis jujube-crop complex system, we chose jujube/maize and jujube/clover intercropping system as two representative intercropping modes. We measured the daily changes of jujube leaf gas exchange parameters in their fitting period with LI - 6400 photosynthesis system. The results showed that, the main meteorological factors in the fields were significantly different between the two intercropping conditions. The net photosynthetic rate and transpiration rate presented a typical single-peak curve. The jujube, which intercropped with clover, had a sharply decreased net photosynthetic rate and a lower water use efficiency all day. Whereas the ones intercropped with maize had higher water use efficiency. These results showed that, the water use efficiency of cropped jujube, was significantly affected by the interactions between the intercropping species. Clovers with deep roots were not fit to be intercropped with jujube, whereas jujube intercropped with maize could achieve higher water use efficiency and light use efficiency. The appropriate distance in jujube/maize cropping system and the different intercropping modes to enhance the productivity of jujube were both worthy of further study.