| Water shortage and soil salinization have become important reasons restricting the sustainable development of agriculture in Hetao irrigation area.Therefore,the response mechanism of sunflower yield and quality to water and nitrogen regulation under different drainage conditions and its impact on the law of soil water and salt transport are studied,and then the water and fertilizer system adapted to local conditions is put forward to achieve the purpose of saving water,increasing production,regulating quality and improving salinized soil.It can provide technical measures and theoretical support for irrigation and drainage management and water and fertilizer regulation for the high-quality and efficient development of sunflower planting industry in Hetao irrigation area.This study takes the edible sunflower widely planted in Hetao irrigation area as the research object,a two-year field experiment was carried out in Bayannur Academy of agriculture and animal husbandry,Inner Mongolia from 2019 to 2020.The soil and crop indexes were comprehensively evaluated by entropy weight TOPSIS method and principal component analysis（PCA）.The main conclusions are as follows:（1）The irrigation amount was 330mm,210mm and 120mm,and the average desalination rate of 0-160cm soil layer was 22.57%,21.56%and 19.87%respectively,which was significantly higher than that of non drainage treatment（26.65%,10.76%and 18.44%）;After two years of irrigation and leaching,the degree of soil salinization in the sunflower root zone（0-60cm）changed from moderate to mild.The soil salinization type of 60-160cm soil layer before and after irrigation and leaching under the subsurface drainage treatment was mild.Under the condition of high irrigation and low irrigation,the type of soil salinization changed from mild to moderate.The implementation of subsurface drainage and the increase of irrigation water can not reduce the soil p H.（2）Increasing nitrogen fertilizer to 210kg/hm2 significantly increased plant height and stem diameter,but decreased chlorophyll content.Irrigation at budding stage could prolong the expression of superoxide dismutase（SOD）and peroxidase（POD）activities during the growth period,thus ensuring the normal growth of plants.（3）Under the condition of subsurface drainage,330mm irrigation and 105kg/hm2nitrogen topdressing treatment not only ensured high yield,but also maintained a high level of nitrogen partial productivit（PFP）.The interaction of water and nitrogen had a significant effect on the contents of protein,crude fat and amino acid components（except lysine）in sunflower seed kernel,and the effect of nitrogen topdressing was significantly greater than that of irrigation.Through the comprehensive analysis（PCA）of sunflower yield,seed protein,crude fat and 8 kinds of amino acid components under water and nitrogen regulation under the condition of subsurface drainage and under different drainage conditions,Under the condition of subsurface,210mm irrigation and 210kg/hm2 nitrogen topdressing(I210N210)were the best treatments.Compared with the conventional treatment（330mm irrigation without drainage）,the contents of seed protein,crude fat,arginine,valine,lysine,phenylalanine,leucine,isoleucine and methionine increased by 0.95%,0.54%,0.132%,0.042%,0.013%,0.048%,0.057%,0.044%and 0.011%respectively,and the yield of sunflower decreased slightly.（4）Principal component analysis（PCA）and entropy weight TOPSIS model were used to comprehensively evaluate 14 indexes of soil desalination,sunflower yield,water and fertilizer utilization efficiency and seed kernel quality under water nitrogen regulation treatment under subsurface drainage and water regulation treatment under different drainage conditions.Under the condition of subsurface,210mm irrigation and 210kg/hm2 nitrogen topdressing(I210N210)were the best treatments.Compared with conventional treatment,the irrigation amount was reduced by 120mm,the desalination rate was increased by 25.64%,and the protein The content of amino acid components increased. |
