Iranian Journal of Irrigation & Drainage

Iranian Journal of Irrigation & Drainage

Effects of Water Stress and Shade Net on Water Productivity, Seed Quality and Yield of Soybean in Humid Region

Articles in Press

Document Type : Original Article

Authors
Saeid Shiukhy 1
Sahhar Batebi 2
Bahareh Shamgani Mashhadi 3
saviz Batebi 2
1 Assistant Professor of Agro-meteorology, Department of Water Engineering, Faculty of Agricultural Engineering, Sari Agricultural sciences and Natural Resources University, Sari, Iran.
2 4- Graduate student of Science in Greenhouse Crop Production, Department of Horticulture, Faculty of Agricultural Sciences, Sari University of Agricultural Sciences and Natural Resources, Mazandaran, Iran.
3 Ph.D. candidate of Agro-meteorology, Department of Water Engineering, Faculty of Agricultural Engineering, Sari Agricultural sciences and Natural Resources University, Sari, Iran.
10.22034/idj.2026.570848.2662
Abstract
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.
Keywords
Pod-filling
Biomass
Irrigation withheld
Linolenic acid
Water management
Iranian Journal of Irrigation & Drainage

Articles in Press, Accepted Manuscript
Available Online from 23 May 2026