Abstract Sustainable development of livestock production is challenged by the shortage of forage resources on the Qinghai-Tibetan plateau (QTP). Common vetch-oat intercropping is used on the QTP and in other alpine regions to obtain substantial forage yield, but few common vetch cultivars have been evaluated in intercropping systems. A three-year field experiment in the eastern QTP was carried out to compare plant growth, photosynthetic rate (Pn), radiation use efficiency (RUE), aboveground biomass, land equivalent ratio (LER), and competition ratio of oat row intercropping with three new common vetch cultivars (Lanjian No. 1, Lanjian No. 2, Lanjian No. 3) under low-input conditions. Compared to sole cropping at seed densities of 141 and 667 plants m–2, for common vetches and oats, respectively, alternate row intercropping with each species at half these densities significantly increased the Pn (by 15–19%) of oat, and reduced the Pn (by 12–26%) of common vetch. Moreover, row intercropping significantly increased intercepted photosynthetically active radiation and RUE (by 44%) for oat but significantly decreased these for common vetch (by 34%). Among common vetch cultivars, at both flowering and maturity stages, Lanjian No. 2 (1.21, 1.15) and Lanjian No. 3 (1.27, 1.21) had greater LER than the later-maturing Lanjian No. 1 (1.07, 1.01) when intercropped. Oat row intercropping with Lanjian No. 2 and Lanjian No. 3 increased forage production compared to sole cropping oat or common vetch on the QTP. These findings provide scientific support for common vetch-oat intercropping as a sustainable approach to increasing forage production from cropland in alpine regions.

中文翻译：

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紫云英栽培品种优化光合性能提高青藏高原燕麦行间作产量

摘要 青藏高原（QTP）牧草资源短缺，给畜牧生产可持续发展带来挑战。在青藏高原和其他高山地区使用常见的紫云英-燕麦间作以获得可观的牧草产量，但很少有普通紫云英品种在间作系统中进行过评估。在青藏高原东部进行了为期三年的田间试验，比较了燕麦行间作与三种植物的生长、光合速率 (Pn)、辐射利用效率 (RUE)、地上生物量、土地当量比 (LER) 和竞争比。低投入条件下的紫云英新品种（蓝尖1号、蓝尖2号、蓝尖3号）。与种子密度分别为 141 和 667 株 m–2 的单一种植相比，对于常见的野豌豆和燕麦，以这些密度的一半与每个物种交替行间作显着增加了燕麦的 Pn（15-19%），并降低了普通紫云英的 Pn（12-26%）。此外，行间作显着增加了燕麦的截获光合有效辐射和 RUE（44%），但显着降低了普通紫云英（34%）。在常见的紫云英品种中，在开花和成熟阶段，间作时蓝尖2号（1.21、1.15）和蓝尖3号（1.27、1.21）的LER均高于晚熟蓝尖1号（1.07、1.01） . 与青藏高原上的单作燕麦或普通紫云英相比，燕麦行间作蓝尖 2 号和蓝尖 3 号提高了牧草产量。