Abstract
Plastic‐mulched drip irrigation is widely used in arid regions, but it may aggravate root‐zone hypoxia and salinity. A two‐year field experiment based on two two‐factor designs was conducted in Xinjiang, China, during 2023 and 2024 to investigate the combined effects of irrigation‐water temperature (10°C–15°C and 20°C–25°C), aeration method (5 mg L −1 (no aeration)) and 18 mg L −1 (micro‐nano aeration) and humic acid application (0 and 0.5% of fertigation mass) on processing tomato growth, yield, fruit quality, root‐zone soil conditions and greenhouse gas fluxes. Micro‐nano aeration and humic acid significantly increased yield and improved fruit quality, with maximum yields of 198.1–205.9 t ha −1 . Irrigation‐water warming increased single fruit weight by 4% and soluble sugar content by 8%–10%. These responses were associated with improved soil oxygen and water availability and reduced effective salinity. Aeration and humic acid increased CO 2 and N 2 O emissions but also promoted CH 4 uptake. Structural equation modelling showed that soil oxygen and temperature were the main drivers of plant growth and lycopene accumulation. The combined application of warmed irrigation water, micro‐nano aeration and humic acid was an effective strategy for improving processing tomato production in arid regions.