The Qaidam Basin is a typical inland arid saline basin in China， characterized by high soil salinity and harsh plant growth conditions. Soil amendment is therefore of great significance for the rational development and utilization of saline-alkali land. This study focused on oat （Avena sativa） grown with the application of four soil amendments （single superphosphate， potassium humate， cattle manure+desulfurized gypsum， and attapulgite） to analyze oat production performance and nutritional quality， aiming to identify the ideal soil amendment for saline-alkali soils in the Qaidam Basin. The results showed that oat treated with single superphosphate achieved greater plant height， stem diameter， and forage yield， measuring 107.57 cm， 3.47 mm， and 1001.00 g·m^-2， respectively. Oat treated with potassium humate exhibited higher crude fat and water-soluble carbohydrate content， at 3.15% and 25.40% respectively， while its acid detergent fiber and neutral detergent fiber content were lower. Piecewise Structural Equation Modeling （SEM） analysis indicated that the soil amendments affected nutritional quality by influencing forage yield and stem diameter. The TOPSIS multi-criteria decision model demonstrated that oat treated with single superphosphate had superior production performance and nutritional quality， which is the ideal soil amendment for application in saline-alkali soils of the Qaidam Basin.

Soil amendments  /  Qaidam Basin  /  Oat  /  Nutritional quality  /  Comprehensive evaluation