土壤质地和灌溉水量对黑河中游地区甜高粱生长特征及水生产力的影响

Effects of soil texture and irrigation on growth characteristics and water productivity of sweet sorghum in the middle reaches of Heihe River

甜高粱已成为干旱和盐碱等边际性土壤区农业可持续发展的重要作物之一,针对河西走廊荒漠绿洲区水资源短缺与土地贫瘠等问题,本研究以黑河中游边缘绿洲为研究区,通过5个土壤(砂壤土S1、S2,砂土S3、S4,壤砂土S5)和3个灌溉处理(28.6%节水灌溉,14.3%节水灌溉I2,常规充分灌溉I3)的田间试验,进行不同土壤条件下节水灌溉对甜高粱生长特征及灌溉水生产力的影响研究,探讨了河西走廊荒漠绿洲区甜高粱适宜种植土壤与灌溉措施。结果表明,在充分灌溉处理下,甜高粱生长特征指标、生物量和灌溉水生产力均低于节水灌溉(I1、I2)。其中,I1和I2茎秆生物量分别较充分灌溉处理增加了7.81%和3.57%,总生物量增加了6.30%和3.17%。此外,I1和I2甜高粱灌溉水生产力为3.63 kg·m^-3和2.94 kg·m^-3,分别较充分灌溉处理的2.44 kg·m^-3提高了48.8%和20.4%。因此,充分灌溉不会提高甜高粱产量,却会显著降低灌溉水生产力。同时,除茎秆汁液锤度外,甜高粱其它生长特征和灌溉水生产力表现为S1>S5>S2>S4>S3。表明甜高粱适合种植于砂壤土和壤砂土,且适当的水分胁迫有利于甜高粱糖分含量的积累与生物产量的提高。

Sweet sorghum has become one of the important crops for sustainable development of agriculture in drought and saline areas.In a desert oasis area with water shortage and poor land of Hexi Corridor,we planted sweet sorghum in different soils with varied irrigation amounts to figure out the feasible soil and irrigation measures for the area.The study area was located at the edge of Heihe River.Five soils(sandy-loam soil,S1 and S2;sandy soil,S3,S4;loam-sandy soil,S5)and 3 irrigation measures(28.6%water-saving irrigation,I1;14.3%water-saving irrigation,I2;conventional full-irrigation,I3)were implemented by a field experiment to investigate the effects of water-saving irrigation on the growth characteristics of sweet sorghum and irrigation water productivity under different soil conditions.The results showed that the growth,yield and irrigation water productivity of sweet sorghum with I3 treatment were significantly reduced than those of I1 and I2 treatments;while the stalk biomass with I1 and I2 treatments increased by 7.81%and 3.57%,and the total biomass increased by 6.30%and 3.17%,respectively.The irrigation water productivity with I1 and I2 treatments was 3.63 kg·m^-3 and 2.94 kg·m^-3,48.8%and 20.4%higher than 2.44 kg·m^-3 of I3,respectively.Full-irrigation could not increase sweet sorghum yield,but significantly reduced irrigation water productivity.Except for the stem juice brix,other growth characteristics of sweet sorghum and irrigation water productivity were in an order of S1>S5>S2>S4>S3.Sweet sorghum was suitable for planting in sandy-loam soil or loamy-sand soil,and reasonable water stress would be conducive to the sugar content accumulation and biomass increase in sweet sorghum.