Comparison Study on Soil Nutrient and Photosynthetic Characteristics of Ferula ferulaeoides at Different Growth Periods

Abstract

In this paper,the dynamic changes of soil water content,pH,organic substance and soil nutrient,as well as the diurnal variations of net photosynthetic rate,transpiration rate and water use efficiency of Ferula ferulaeoides at different growth periods were studied.We found that the soil water content,organic substance and soil nutrient showed downward tendency with the growth of F.ferulaeoides while the pH was reverse,but changed slightly.In different soil depths,the soil water content and pH gradually increased with the soil depth,while organic substance and soil nutrient gradually reduced.The net photosynthetic rates at three growth periods varied in a double-peak curve and presented obvious phenomenon of "midday rest" at 14:00,with the daily mean values of leaf expansion periodmaturation periodfruit period;The transpiration rates appeared to vary in a single-peak curve and had the highest value at 14:00,with the daily mean values of leaf expansion periodfruit periodmaturation period;The water use efficiency showed a increased tendency at growth period and had the lowest value at 14:00,with the diurnal mean values of maturation periodfruit periodleaf expansion period.The correlation analysis revealed that stomatal conductance,photosynthetic active radiation had positive correlation with photosynthetic rate;Light intensity had evident positive correlation with transpiration rate.