Optimized irrigation management is crucial even in humid regions due to rainfall variability and uneven distribution during the growing season, which may cause transient water stress. In this study, A factorial experiment in a randomized complete block design with three replications was conducted at the growth season 2024-2025. Treatments included three water stress levels: no-water stress (NWS), irrigation withheld at flowering (WSF), and irrigation withheld at pod-filling (WSP), and four shade net levels (0%, 30%, 50%, and 80%). Results showed that WSF and WSP reduced seed yield by approximately 12% and 27%, respectively, compared to NWS. The 30% shade net increased seed yield by about 14% and improved water productivity compared to 50%, 80%, and no shade treatments. Water stress at pod-filling (WSP) increased oleic acid and decreased linoleic and particularly linolenic acids by up to 28%. Dense shading (80%) reduced biomass by about 27% and negatively affected some quality traits. Overall, the findings indicate that combining appropriate irrigation management with mild shading (30%) can be an effective strategy to enhance yield, improve water productivity, and maintain soybean seed quality in humid regions.