Effects of regulated deficit irrigation on biomass and nutrient quality of different alfalfa varieties
[Objective]In order to explore the most suitable water-saving irrigation technology for alfalfa pro-duction in the desert irrigation area of Gansu province,this study examined the effects of regulated deficit irrigation on above-ground biomass,nutrient quality,and water productivity of different varieties of alfalfa,focusing on the triple goals of high yield,high quality and efficient water conservation.[Method]Twelve alfalfavarieties were selected as experimental materials and subjected to three irrigation treatments:moderate water stress (T1:45％～55％ of field water capacity),mild water stress (T2:55％～65％ of field water capacity) and full irrigation (T3:65％～75％ field water capacity). Full irrigation was used as the control.Differences in yield and nutrient indices of the different variet-ies under these water treatments were observed to identify suitable varieties and irrigation techniques for water-saving alfalfa production in this region.[Result]The results indicated that water productivity followed this pattern:mild water stress[23.01 kg/(hm2·mm)]>full irrigation[20 kg/(hm2·mm)]>moderate water stress[18 kg/(hm2·mm)].Water productivity under mild water stress increased by 15％,while it decreased by 10％ under moder-ate water stress .Among the varieties,WL319HQ achieved the highest water productivity under all three water treat-ments,with the highest productivity under mild water stress,outperforming the other two treatments by 3.8 and 5.7 kg/(hm2·mm),respectively. Under full irrigation and mild water stress,WL319HQ also had significantly higher yields compared to the other tested varieties.However,under moderate water stress,the total yield of alfalfa was sig-nificantly lower than under the other two treatments (P<0.05),with Gannong 3 achieving the highest yield under these conditions.Across all experimental groups,WL319HQ had the highest crude protein and crude fat contents,the lowest acid detergent fiber and neutral detergent fiber contents,and the highest relative feeding value,significantly out-performing other varieties under other water stress treatments.[Conclusion]Planting WL319HQ under mild water stress(55％～65％ of field water capacity) in the desert irrigation areas of Gansu was beneficial for improving grass-land ecological productivity.
万方数据
维普
