Study on Transpiration Rate of Walnut under Different Soil Water Content in Semi-Arid Region Loess Plateau

Walnut is one of the most important economic trees in semi-arid region loess plateau.This paper studied the relationship between the transpiration rate of walnut seedlings and the outside factors(sunshine and water) and the inside factors(leaf water potential and stomatal resistance).Then it made the equations of the transpiration rate and the factors.The results indicated that the transpiration rate was mostly affected by the soil water content when it was about 15%.So that,the transpiration can be controlled in order to enhance the water utilization efficiency of plants.