Abstract: To optimize the alfalfa-maize intercropping system in the Hexi Irrigation District and identify the suitable maize cultivars， 10 maize （Zea mays L.） cultivars were used to compare their agronomic traits， yield performance， and nutritional quality under sole-cropping and intercropping conditions. Structural equation modeling and a multi-criteria decision-making model were further employed for integrated analysis. The results showed that cultivar， cropping pattern， and their interaction had highly significant effects on plant height， stem diameter， effective plant density， fresh weight per plant， and dry matter yield （P<0.01）. Under intercropping， ‘Jinzhangye 1706’ had the highest dry matter yield （27.12 t·hm^-2）. ‘Tunyu 168’ had the highest ear fresh weight （522.33 g）， and its fresh weight per plant reached 1.32 kg. ‘Ganyu 23’ had the highest number of green leaves and the highest crude protein （CP） content （10.77%）. Structural equation modeling indicated that the pathways by which agronomic traits affected dry matter yield and relative feed value （RFV） differed between planting patterns. Based on the multi-criteria decision-making results， cultivar selection for the intercropping system should comprehensively consider agronomic traits， yield and nutritional quality. Among the tested cultivars， ‘Ganyu 23’ ‘Jinzhangye 1706’ and ‘Tunyu 168’ can be selected as optimal cultivars for the alfalfa/maize intercropping system in this region.

Key words: Alfalfa, Intercropping, Maize, Variety screening

摘要： 为优化河西灌区紫花苜蓿-玉米套作体系并筛选适宜玉米品种，本试验以10个玉米（Zea mays L.）品种为材料，比较其在单作和套作条件下的农艺性状、产量及营养品质，结合结构方程模型和多准则决策模型进行综合分析。结果表明：品种、种植模式及其互作对株高、茎粗、有效株数密度、单株鲜重和干物质产量的均有极显著影响（P<0.01）。套作下‘金张掖1706’干物质产量最高（27.12 t·hm^-2）。‘屯玉168’穗鲜重最高（522.33 g），单株鲜重达到了1.32 kg。‘甘玉23’绿叶数最多，粗蛋白（Crude protein，CP）含量也最高（10.77%）。结构方程模型结果表明不同种植模式下农艺性状对干物质产量和相对饲喂价值（Relative feed value，RFV）的作用路径存在差异。结合多准则决策模型结果，套作体系中玉米品种筛选应综合考虑农艺性状、产量及营养品质，其中‘甘玉23’‘金张掖1706’和‘屯玉168’可作为该区域套作体系的优选品种。

关键词: 紫花苜蓿, 套作, 玉米, 品种筛选