Abstract: In order to understand the effects of sand burial on survival,yield and the photosynthetic response of two main crops in the Horqin Sand Land,net photosynthetic rates,stomatal conductance,transpiration rate and water use efficiency of maize (Zea mays) and green bean (Vigna radiata) in different sand burial depths were studied after they were buried 5,10,15 days,survival rate and yield were recorded at the end of the growing period.The results show that:(1) compared to green bean,maize has stronger ability to resist sand burial.12.5% of maize seedlings can survived after burial depth exceeds their plant height,while no seedlings of green bean survived after the burial depth reached to 100% of its seedling height;(2) after the burial depth increased to 25% of seedling height,yield of both maize and green bean decreased,however,the green bean decreased much more than the maize;(3) net photosynthetic rates of two species decreased sharply with increased burial depth,indicating that sand burial was very harmful to the photosynthetic system of plants.However,compared to green bean,maize has better photosynthetic adaptation to sand burial stress by taking stomata closure,decreasing the transpiration rate,increasing the water use efficiency and recovering the net photosynthetic rate to a certain extent when the burial depth and time increased.

Key words: Horqin Sandy Land, sand burial, crops, yield, photosynthesis characteristics