{"paper_id":"243a070f-b443-4f48-ade9-c58699e051e1","body_text":"Coupling WOFOST and HYDRUS-1D to simulate daily maize growth, water– salt dynamics and stress responses under salinity gradients in salinized farmland | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Coupling WOFOST and HYDRUS-1D to simulate daily maize growth, water– salt dynamics and stress responses under salinity gradients in salinized farmland Jing Zhang, Xiaojing Shen, Run Wu, Jingyu Ji, Fenjie Shang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9142790/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Soil salinization constrains agricultural productivity across approximately 950 million hectares worldwide. In the Yellow River irrigation district of Ningxia, secondary salinization severely depresses maize yields. Existing crop–water–salt models lack day-by-day bidirectional coupling between salt transport and crop growth, over-simplify salt stress representation, and amplify stress through multiplicative integration. To address these gaps, we developed a fully coupled WOFOST–HYDRUS-1D model linking the Richards equation and convection–dispersion equation with crop photosynthesis, transpiration, and assimilate partitioning through a modified Maas–Hoffman function. Salt stress is transmitted via three physiological pathways, and the combined stress factor is computed using Liebig’s law of the minimum. The model was calibrated with 43 sampling points spanning low-to-high salinity gradients (1.49–6.79 g kg⁻¹) in Huinong District during 2024, and independently validated with 30 points (1.29–7.75 g kg⁻¹) in 2025. Calibration yielded R² = 0.883, RMSE = 0.744 t ha⁻¹, NRMSE = 10.96%, and NSE = 0.795; validation gave R² = 0.824, RMSE = 0.753 t ha⁻¹, NRMSE = 11.13%, and NSE = 0.810, confirming strong inter-annual parameter stability. Under high salinity (> 4 g kg⁻¹), simulated mean yield declined to 3.75 t ha⁻¹, a 53% reduction compared with low-salinity conditions. Compared with the standard WOFOST model (R² = 0.450, RMSE = 1.399 t ha⁻¹), the coupled model substantially improved accuracy.These results show that the coupled model can improve yield prediction under salinity stress and provide a useful tool for irrigation scheduling and water–salt management in salinized farmland. WOFOST model HYDRUS-1D model salt stress soil water–salt transport Richards equation Maas–Hoffman function inter-annual validation Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 20 Apr, 2026 Reviews received at journal 17 Apr, 2026 Reviews received at journal 06 Apr, 2026 Reviewers agreed at journal 20 Mar, 2026 Reviewers agreed at journal 18 Mar, 2026 Reviewers agreed at journal 18 Mar, 2026 Reviewers invited by journal 18 Mar, 2026 Editor assigned by journal 17 Mar, 2026 Submission checks completed at journal 17 Mar, 2026 First submitted to journal 16 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-9142790\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":608299831,\"identity\":\"8db54ddf-219b-4ff0-8343-c2aa89c7d364\",\"order_by\":0,\"name\":\"Jing Zhang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Ningxia University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Jing\",\"middleName\":\"\",\"lastName\":\"Zhang\",\"suffix\":\"\"},{\"id\":608299833,\"identity\":\"33de643f-36b8-4c00-80e9-158490b9b67b\",\"order_by\":1,\"name\":\"Xiaojing 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01:54:25\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-9142790/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-9142790/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":105055291,\"identity\":\"0b1fa533-0f1c-4b52-a400-ab77a464125f\",\"added_by\":\"auto\",\"created_at\":\"2026-03-20 11:26:59\",\"extension\":\"pdf\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":1346176,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"SubmittedPapertoIrrigationScience.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-9142790/v1_covered_b1de3d81-11b5-4167-928b-c775806f12e4.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Coupling WOFOST and HYDRUS-1D to simulate daily maize growth, water– salt dynamics and stress responses under salinity gradients in salinized 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In the Yellow River irrigation district of Ningxia, secondary salinization severely depresses maize yields. Existing crop\\u0026ndash;water\\u0026ndash;salt models lack day-by-day bidirectional coupling between salt transport and crop growth, over-simplify salt stress representation, and amplify stress through multiplicative integration. To address these gaps, we developed a fully coupled WOFOST\\u0026ndash;HYDRUS-1D model linking the Richards equation and convection\\u0026ndash;dispersion equation with crop photosynthesis, transpiration, and assimilate partitioning through a modified Maas\\u0026ndash;Hoffman function. Salt stress is transmitted via three physiological pathways, and the combined stress factor is computed using Liebig\\u0026rsquo;s law of the minimum. The model was calibrated with 43 sampling points spanning low-to-high salinity gradients (1.49\\u0026ndash;6.79 g kg⁻\\u0026sup1;) in Huinong District during 2024, and independently validated with 30 points (1.29\\u0026ndash;7.75 g kg⁻\\u0026sup1;) in 2025. Calibration yielded R\\u0026sup2; = 0.883, RMSE\\u0026thinsp;=\\u0026thinsp;0.744 t ha⁻\\u0026sup1;, NRMSE\\u0026thinsp;=\\u0026thinsp;10.96%, and NSE\\u0026thinsp;=\\u0026thinsp;0.795; validation gave R\\u0026sup2; = 0.824, RMSE\\u0026thinsp;=\\u0026thinsp;0.753 t ha⁻\\u0026sup1;, NRMSE\\u0026thinsp;=\\u0026thinsp;11.13%, and NSE\\u0026thinsp;=\\u0026thinsp;0.810, confirming strong inter-annual parameter stability. Under high salinity (\\u0026gt;\\u0026thinsp;4 g kg⁻\\u0026sup1;), simulated mean yield declined to 3.75 t ha⁻\\u0026sup1;, a 53% reduction compared with low-salinity conditions. Compared with the standard WOFOST model (R\\u0026sup2; = 0.450, RMSE\\u0026thinsp;=\\u0026thinsp;1.399 t ha⁻\\u0026sup1;), the coupled model substantially improved accuracy.These results show that the coupled model can improve yield prediction under salinity stress and provide a useful tool for irrigation scheduling and water\\u0026ndash;salt management in salinized farmland.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Coupling WOFOST and HYDRUS-1D to simulate daily maize growth, water– salt dynamics and stress responses under salinity gradients in salinized farmland\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2026-03-20 11:26:21\",\"doi\":\"10.21203/rs.3.rs-9142790/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2026-04-20T19:02:22+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-04-18T03:42:29+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-04-06T08:30:43+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"68795907787501535499595036047583592355\",\"date\":\"2026-03-20T08:43:44+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"280640380465096436655961584388770740616\",\"date\":\"2026-03-18T13:24:37+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"10043693705591763224162173816218510217\",\"date\":\"2026-03-18T06:42:04+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2026-03-18T06:33:52+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2026-03-17T11:51:17+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2026-03-17T07:55:28+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Irrigation Science\",\"date\":\"2026-03-17T01:48:39+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"irrigation-science\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"irsc\",\"sideBox\":\"Learn more about [Irrigation Science](http://link.springer.com/journal/271)\",\"snPcode\":\"271\",\"submissionUrl\":\"https://submission.nature.com/new-submission/271/3\",\"title\":\"Irrigation Science\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"88f40a04-77da-41f6-85f0-f9ff93985b02\",\"owner\":[],\"postedDate\":\"March 20th, 2026\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"under-review\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2026-05-11T16:08:15+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2026-03-20 11:26:21\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-9142790\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-9142790\",\"identity\":\"rs-9142790\",\"version\":[\"v1\"]},\"buildId\":\"XKTyCvWXoU3ODBz1xrDgd\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}