Influence of super absorbent polymer in spray seeding on photosynthesis and transpiration of Amorpha fruticosa.

The Li-6400 portable photosynthesis system was used for the dynamic research of photosynthesis and transpiration rate of Amorpha fruticosa in July of 2008,and the effect of super absorbent polymers on the photosynthesis and transpiration was studied.The results indicated that the photosynthesis and transpiration rates of the plants growing in eight types of substrates displayed the similar diurnal change mode,i.e.,the two-peak pattern.The peak values of photosynthetic rate occurred at 10:00 and 16:00,and the lowest values appeared at 6:00 and 18:00 respectively.The first peak of transpiration rate occurred at 11:00,one hour late than the peak photosynthetic rate,but the second peak transpiration rate showed at 14:00,two hours ahead of the second peak photosynthetic rate.The results showed that different dosages of super absorbent polymer made the photosynthesis and transpiration rate of A.fruticosa displaying at three levels.Too much or too little of the polymer dosage all led negative effect on photosynthesis and transpiration of the plants.The experiment results showed that the 0.15%,0.20%,0.30% of the super absorbent polymer were the three appropriate dosages for the growth of A.fruticosa plants.