Effects of Long‐Term Straw Return on Physiological Traits and Grain Yield of Wheat Under Spring Low‐Temperature Stress

Spring low‐temperature stress (SLTS) is an important constraint on winter wheat production under increasing climate variability, but whether long‐term straw return can maintain physiological stability under SLTS remains unclear. A long‐term field experiment was established in 2008 in the Huaihe River Basin of China. Four straw‐management treatments were compared: no straw return, maize straw ploughing‐in, wheat straw mulching and wheat straw mulching combined with maize straw ploughing‐in. Wheat physiological traits and grain yield were evaluated during a natural mild SLTS event in the 2024–2025 growing season. Straw‐return treatments maintained higher root activity, more stable chlorophyll status, stronger antioxidant and osmotic regulation and lower oxidative damage than no straw return. Across straw‐return treatments, hydrogen peroxide and malondialdehyde contents were 11.3%–53.4% and 6.8%–37.8% lower, respectively. These physiological advantages were accompanied by improved young‐spike growth, biomass accumulation and grain yield. Wheat straw mulching showed the highest comprehensive principal component analysis score and increased grain yield by 19.2% compared with no straw return. These findings describe treatment‐associated physiological and yield performance during one natural mild SLTS event and provide a basis for further evaluation of straw‐return management across additional events and years.