Abstract: To explore the synergistic improvement of productivity and nutritional quality in oat （Avena sativa） -based mixed sowing systems in alpine regions， this study selected four high-quality forage species （‘Lanjian No.3’ common vetch（Vicia sativa）， ‘Qinghai No.13’ broad bean（Vicia faba）， ‘Qingjian No.1’ forage pea（Pisum sativum）， and ‘Feed rape No.2’（Brassica napus）） for mixed sowing with ‘Qingyin No.1’ oat at five seeding ratios （2∶8， 4∶6， 5∶5， 6∶4， and 8∶2）. Aboveground biomass and forage nutritional ingredients/quality/values were measured， and land equivalence ratio， relative yield， and competition ratio were calculated. The TOPSIS model was employed to perform a comprehensive evaluation of mixed sowing performance. The results showed that different forage combinations exhibited significant differences in yield， quality， and interspecies competition. The oat + forage pea （4∶6） mixture yielded the highest dry matter yield （10 368.73 kg·ha^-1）， with significantly higher crude protein yield and land equivalence ratio values compared to oat monoculture. The oat + common vetch （8∶2） mixture ranked second in dry matter yield （9432.63 kg·ha^-1）. In terms of competitiveness， oat + broad bean and oat + common vetch mixtures at 2∶8 ratios showed higher relative yield and competitive advantages. Monocultures of broad bean and forage pea exhibited higher crude protein content， while ‘Feed rape No.2’ monoculture had the highest crude fat content. Mixing oat with other legumes significantly reduced crude fiber content， thereby enhancing forage feeding value. Structural equation modeling revealed that seeding ratio exerted direct positive effects on yield， nutrient content， feeding value， and species competition， and indirectly promoted yield improvement by mediating nutrient-competition interactions. TOPSIS-based comprehensive evaluation identified the oat + forage pea （4∶6） mixture as the most advantageous combination in terms of both productivity and nutritional quality， making it the preferred forage intercropping model for alpine pastoral systems.

Key words: Alpine regions, Mixed method, Mixed proportion, Yield, Nutritional quality

摘要： 为探讨高寒区燕麦（Avena sativa）混播系统生产力与营养品质的协同提升效应，本研究选用4种优质饲草（‘兰箭3号’箭筈豌豆（Vicia sativa）、‘青海13号’蚕豆（Vicia faba）、‘青建1号’饲用豌豆（Pisum sativum）、‘饲油2号’油菜（Brassica napus））与‘青引1号’燕麦按5种比例（2∶8，4∶6，5∶5，6∶4，8∶2）混播，测定地上生物量及营养成分，计算土地当量比、相对产量和竞争比，并采用TOPSIS模型对混播效应进行综合评价。结果表明：不同混播组合在产量、品质及种间关系方面差异显著。燕麦与饲用豌豆4∶6混播时干草产量最高（10 368.73 kg·ha^-1），且粗蛋白产量和土地当量比也显著高于燕麦单播；燕麦与箭筈豌豆8∶2混播时干草产量次之（9432.63 kg·ha^-1）。在竞争性方面，燕麦与蚕豆或箭筈豌豆2∶8混播组合表现出较高的相对产量和竞争优势。单播蚕豆和豌豆的粗蛋白含量较高，单播油菜的粗脂肪含量较高。燕麦与其他饲草混播时降低了饲草的粗纤维含量，提升了饲喂价值。结构方程模型显示，混播比例对产量、营养成分、饲喂价值及竞争关系均具有直接正向作用，并通过调控营养与竞争关系间接促进产量提升。TOPSIS综合评价表明，燕麦与饲用豌豆4∶6混播组合在产量与品质方面兼具优势，是高寒区优选的饲草混播模式。

关键词: 高寒地区, 混播方式, 混播比例, 产量, 营养品质