【摘要】 【目的】探究钙/铝基改良剂对内蒙古河套灌区盐碱土质量和向日葵产量的影响，为该区盐碱地综合治理提供理论依据和技术支撑。【方法】在内蒙古鄂尔多斯市开展两年（2022—2023年）田间小区定位试验，设置对照（CK）及钙基（Ca-based）、铝基（Al-based）和钙铝复合（Ca+Al-based）3种改良剂处理，系统分析收获期0—20 cm土层盐碱指标、养分含量及向日葵农艺性状与籽粒产量；采用主成分分析法构建土壤质量指数（SQI），并结合结构方程模型解析改良剂对SQI和向日葵产量的影响路径。【结果】与CK相比，3种改良剂均能提高SQI和向日葵产量。其中，Ca+Al-based处理在降低土壤pH值（0.09—0.24单位）、钠吸附比（14.3%—24.9%）及提高土壤速效磷（72.7%—147.0%）、硝态氮（0.6%—89.6%）等方面的效果最优，其SQI和产量也较CK显著提高了51.0%—58.0%和30.0%—51.4%。而Ca-based处理的效果次之，其SQI提高了36.3%—51.0%，产量仅在2022年提高了29.3%。值得注意的是，含钙处理（Ca+Al-based和Ca-based）虽使土壤电导率较CK升高了16.0%—70.4%，但主要源于水溶性Ca²⁺、Mg²⁺、SO₄^2-等离子浓度的增加，未对作物产生盐害。结构方程模型表明，改良剂通过直接调控土壤盐碱和养分指标，间接提升SQI和向日葵产量。其中，土壤盐碱障碍消减对向日葵产量的贡献率（79.2%）高于养分的提高对产量的贡献率（20.8%）。【结论】钙铝复合改良剂通过协同增效作用，显著改善盐碱地质量并提高向日葵产量，适于在内蒙古河套灌区及生态条件类似区域的盐碱地上推广应用。更多还原

【Abstract】 【Objective】This study aimed to investigate the effects of calcium-and/or aluminum-based soil amendments on soil quality and sunflower yield in the Hetao Irrigation District of Inner Mongolia,China,so as to provide a theoretical support and technical guidance for the comprehensive governance of saline-alkali lands in the region.【Method】A two-year （2022-2023） field experiment was conducted in Ordos City,Inner Mongolia,with four treatments:control （CK）,calcium-based amendment （Ca-based）,aluminum-based amendment （Al-based）,and calcium+aluminum-based amendment （Ca+Al-based）.The experiment systematically assessed soil salinity indices and nutrient content in the 0-20 cm soil layer,as well as sunflower agronomic traits and grain yield at harvest.The soil quality index （SQI） was constructed using principal component analysis,and structural equation modeling was employed to reveal the effects of the amendments on SQI and sunflower yield.【Result】Compared with CK,all three soil amendments improved the SQI and sunflower yield.Among the treatments,the Ca+Al-based amendment demonstrated the most promising results,specifically reducing soil pH by 0.09-0.24 units and sodium adsorption ratio by 14.3%-24.9%,and increasing soil available phosphorus by 72.7%-147.0%and nitrate nitrogen by 0.6%-89.6%.Consequently,it increased the SQI by 51.0%-58.0%and sunflower seed yield by 30.0%-51.4%compared with CK.The Ca-based treatment was less pronounced,with SQI increasing by36.3%-51.0%and yield increasing only in 2022 （29.3%）.Notably,soil electrical conductivity increased by 16.0%-70.4%under the Ca-based and Ca+Al-based treatments,primarily due to an increase in water-soluble Ca²⁺,Mg²⁺,and SO₄^2-concentrations,and did not lead to salt damage in plants.In addition,structural equation modeling revealed that the amendments exerted their effects by directly regulating soil salinity and nutrient indices,which indirectly increased SQI and yield.Furthermore,the contribution of soil salinity reduction to yield （79.2%） was greater than that of nutrient improvement （20.8%）.【Conclusion】The Ca+Al-based amendment demonstrated a synergistic effect in significantly improving soil quality and sunflower yield,making it a suitable option for further application in the Hetao Irrigation District of Inner Mongolia and similar ecological regions.更多还原