Abstract:

It is difficult to meet forage demands in alpine ecological zones. To address this issue， we evaluated the comprehensive performance of 10 oat （Avena sativa） varieties in terms of yield， nutritional quality， and soil improvement potential. Using variance analysis， structural equation modeling （SEM）， and technique for order preference by similarity to ideal solution （TOPSIS） analysis， we assessed the adaptability of the ten oat varieties and their soil interaction mechanisms. The ultimate goal of this research was to provide scientific evidence to underpin the development of the grassland-livestock industry in the Qinghai Lake-Gonghe Basin region. It was found that the oat varieties ‘Monida’， ‘Forage’， and ‘Haymaker’ exhibited significant yield advantages， with the fresh grass yield ranging from 50.20 to 54.78 t·ha^-1 and the hay yield ranging from 18.68 to 21.48 t·ha^-1. Among the tested varieties， ‘Esker’ had the lower fresh-dry ratio （1.67）， and ‘Everleaf’ had the lower stem-leaf ratio （2.19）. We detected differences in nutritional value among the varieties： ‘Model’ and ‘Everleaf’ had the higher crude protein contents （8.23%-8.45%）， whereas ‘Monida’ and ‘Esker’ were notable for their high ether extract levels （4.94% and 4.85%， respectively）. ‘Baler 2’ exhibited outstanding fiber characteristics， with the lower levels of crude fiber， neutral detergent fiber， and acid detergent fiber， and the higher relative feed value and total digestible nutrient value， indicative of excellent forage quality. In terms of soil impact， plots planted with ‘Baler 2’ and ‘Fuxing’ showed higher soil phosphorus levels， while those planted with ‘Model’ had elevated total nitrogen and carbon contents. Correlation analysis suggested that high-yielding oat varieties were generally associated with superior nutritional profiles and favorable soil ecological feedback. The SEM results revealed that oat variety influenced yield and nutritional traits through both direct effects （path coefficients： 0.4088-0.4368） and indirect， soil-mediated effects （0.0725-0.6885）. The TOPSIS comprehensive evaluation identified ‘Model’ as the top-performing variety （score： 0.580）， exhibiting high yield， superior nutrition， and strong soil feedback potential. Therefore， ‘Model’ is recommended as a priority oat variety for the restoration of degraded grassland and for forage-livestock development in the Qinghai Lake-Gonghe Basin region.

Key words: Qinghai Lake area, oat, yield, nutritional value, soil physicochemical properties