Abstract:

A pot experiment was conducted with 2 typical varieties of flue-cured tobacco (K326 and NC89), and 2 nitrogen levels and 2 water treatments. The effects of soil water deficit on photosynthetic characteristics and nitrogen metabolism were analyzed. The mechanism of response of tobacco plant under over-application of nitrogen to soil water deficit. The aim of the experiment was to provide the theory for improvement the quality of by using water to control the nitrogen uptaking. The results were as follows: Soil drying decreased the photosynthetic rate and transpiration rate, and heavy use of nitrogen inhibited this descend. The synergistic effect of nitrogen and water improved the leaf quality. water deficit significantly decreased the uptake of nitrate, inhibited the activity of nitrate reductase, and decreased the total nitrogen contents of middle leaves and upper leaves. Therefore soil water deficit effectively inhibited the nitrogen metabolism at mature stage.