As quality forage, Alfalfa is cultivated in the large-scale of various regions, especially arid and semi-arid regions in northwest of China. Water use efficiency of alfalfa has extremely important practical significance because of water consumption and water shortage in northwest region.
Currently on the water use efficiency of alfalfa, the study is almost the leaves and yield levels while the study about ecological systems level is rarely reported. Net ecosystem CO2 exchange, actual evaporation and oth...