微咸水灌溉模式对向日葵产量和品质的影响

Impact of Brackish Water Irrigation on Yield and Quality of Sunflower

为研究干旱半干旱灌区向日葵利用微咸水进行灌溉的适宜矿化度及可行性,采用淡+咸+咸畦灌模式,在向日葵苗期采用淡水灌溉,现蕾期、灌浆期采用不同矿化度微咸水2.5 g/L(KX2)、3.0 g/L(KX3)、3.5 g/L(KX4)、4.0 g/L(KX5)进行灌溉,并以全生育期淡水灌溉(KX1)为对照,研究微咸水灌溉对向日葵品质和产量的影响。结果表明:葵花籽粒中的蛋白质和油酸随着灌溉水矿化度的增加而增加,亚油酸和脂肪随着灌溉水矿化度的增加而减小,棕榈酸和硬脂酸随着灌溉水矿化度的增加呈现先增加后减小的趋势,VE随着灌溉水矿化度的增加呈现先增加后减小再增加的趋势。部分品质指标之间具有比较强的相关性,其中,蛋白质与油酸、亚油酸之间有较强的相关性,脂肪与脂肪酸各组成指标(亚麻酸除外)、VE之间有较强的相关性,脂肪酸各组成指标中除了棕榈酸与其他脂肪酸指标相关性不显著外,其他脂肪酸指标之间具有较强的相关性。并且脂肪-油酸、亚油酸-蛋白质呈正“S”变化趋势,脂肪-亚油酸呈倒“S”变化趋势;脂肪-VE、油酸-蛋白质是正相关线性关系,亚油酸-油酸是负相关线性关系,且亚油酸和油酸的相关度很高。不同处理籽粒品质指标平均综合得分排名依次为:KX5>KX4>KX2>KX3>KX1,品质指标综合得分随着灌溉水矿化度的增加而增大,不同处理向日葵平均产量依次为:KX3>KX1>KX2>KX4>KX5,产量随着灌溉水矿化度的增加而减小。因此,当灌溉水矿化度为3.5 g/L时,既不会造成向日葵大幅度地减产,又能提高其品质,是比较合理可行地微咸水灌溉浓度。

It is important to study the applicability and appropriate mineralization degree of brackish water used for irrigating sunflower in arid and semiarid regions.Taking freshwater irrigation as control(KX1),another four irrigation treatments were designed,which irrigate with freshwater in the seedling stage and brackish water of different mineralization degree in the budding and grain-filling stages,i.e.,2.5 g/L(KX2),3.0 g/L(KX3),3.5 g/L(KX4)and 4.0 g/L(KX5).Yield and quality indexes of sunflower were measured to analyze their responses to mineralization degree of irrigation water.With the increase of mineralization degree,protein and oleic acid contents of the sunflower seed tend to increase,linoleate and fat contents tend to decrease,while palmitic acid,and stearic acid contents increase first and then decrease,vitamin E contents increase first,then decrease and then increase again.There exist strong correlations among part quality indexes,such as protein content with oleic acid content,fat content with fatty acid components(except linolenic acid)and vitamin E,fatty acid component with another fatty acid component except palmitic acid.The relationships of fat vs.oleic acid contents and linoleate vs.protein contents show sigmoid shape,while those of fat vs.linoleate contents show inverse sigmoid shape.Meanwhile,oleic acid content is linearly and negatively correlated with linoleate content,while the relationships of fat vs.vitamin E and oleic acid vs.protein contents are linearly and positively correlated.Based on integrated assessment results of sunflower seed quality,the irrigation treatments are ranked in the order of KX5>KX4>KX2>KX3>KX1,which tend to increase with mineralization degree of irrigation water.While the sunflower yields are ranked in the order of KX3>KX1>KX2>KX4>KX5,which tend to decrease with mineralization degree of irrigation water except KX3.Considering both yield and quality,the irrigation treatment with mineralization degree of 3.5 g/L is appropriate for irrigation of sunflower in the study region,which results in higher sunflower seed quality and yield.