河西走廊洋葱节水灌溉制度研究OA

[Objective]The Hexi Corridor is a semi-arid region in Northwestern China,where water scarcity limits agricultural production,making improving irrigation water efficiency essential.Long-day onion is an important cash crop in the region,but its optimal water-saving irrigation remains elusive.This paper aimed to fill this knowledge gap,and experimentally explore suitable water-saving irrigation scheduling for long-day onion in this region.[Method]The experiment was conducted in a field,with the Hongjin red onion cultivar as the model plant.The experiment consisted of five irrigation treatments:3 000 m3/hm2(T1),3 675 m3/hm2(T2),4 350m3/hm2(T3),5 025 m3/hm2(T4),5 700m3/hm2(T5);the control was irrigation of 7 650 m3/hm2(CK).During the experiment,we measured the growth traits,yield and quality of the onion in each treatment.[Result]Compared with CK,reducing irrigation amount in the treatments did not result in significant effects on dry matter content,but reduced soil bulk density and increased soil porosity.Compared with CK,T1-T5 increased root activity by 6.72%,8.06%,31.45%,15.32%,and 46.77%,respectively,and reduced malondialdehyde by 4.93%,3.07%,28.95%,7.07%,and 62.57%,respectively.Reducing irrigation amount led to a decrease in onion yield.Compared with CK,T5 decreased onion yield and contents of soluble sugar,soluble protein,vitamin C,and onion oil by 11.19%,5.18%,2.54%,1.17%,and 2.70%,respectively,while increasing water use efficiency and irrigation water use efficiency by 11.59%and 19.21%,respectively.In T5,the discard rate of onion was 3.46%,while its water waste rate was only 3.28%.[Conclusion]Comprehensive analysis indicates that the optimal irrigation amount for long-day onion in the study region is 5 700 m3/hm2,which can be used as an improved irrigation strategy for red onion production in the Hexi Corridor and regions with similar soil type and climate.