The differential effect of N availability in the alleviation of salt stress and protection of photosynthesis was studied by observing gas exchange parameters, PSII‘, Rubisco activity and photosynthetic NUE. The effect of N on photosynthetic characteristics wasอdifferent in the presence or absence of salt stress. In the absence ofอsalt stress, 5 mM N and 10 mM both increased net photosynthesisอby 8% and 37%, but 20 mM N decreased net photosynthesis by 26% compared to the respective control. In contrast, supplementation of 20 mM N resulted in the alleviation of salt stress and promoted net photosynthesis by 25% compared to control, whereas 10 mM N could minimize the effects of salt stress on photosynthetic characteristics (Table 1).