Photosynthetic characteristics of Ziziphus jujuba under different intercropping conditions.

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.