Effects of different irrigation methods on the production and WUE of alfalfa

The study was undertaken at Hong Sha-wo village in Zhang-Ye irrigation area of He-xi corridor during March to October in 2003,to find the various regulations and the relationship between alfalfa top biomass and soil water content in different irrigation methods,furrow irrigation,separating furrow irrigation,border irrigation and traditional irrigation as control.The results are showed as following,in the first year of alfalfa growth,the soil water content of separating furrow is the highest than any treatments,the soil water content of furrow irrigation is higher than that in border irrigation and that in traditional irrigation,the soil water content of border irrigation is the lowest in the seedling stage and the early period of vegetative growth of alfalfa,the variation of soil water content in different irrigation are becoming smaller with extension of alfalfa growth stage and decreased rainfall,for example,in 0～120 cm layer the average soil water content of traditional irrigation,border irrigation,furrow irrigation and separating furrow irrigation are 6.3%,5.7%,7.8% and 8.9% respectively(measured on July 1,2003).The top dry biomass weight of traditional irrigation and of border irrigation are higher than that in furrow irrigation and that in separating furrow irrigation in every key growth stage of alfalfa.The water use efficiency(WUE) in border irrigation is highest among treatments,the WUE in traditional irrigation is lower than that in border irrigation,but higher than that in furrow irrigation and that in separating furrow irrigation in all alfalfa growth stage,for example,WUE in traditional irrigation,in border irrigation,in furrow irrigation and in separating furrow irrigation are 4.20,4.49,3.67 and 3.56\respectively.