Climate-driven losses in soybean suitability threaten iron and zinc supply for millions in the Global South

Climate-driven losses in soybean suitability threaten iron and zinc supply for millions in the Global South | 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 Article Climate-driven losses in soybean suitability threaten iron and zinc supply for millions in the Global South Ejovi A Abafe, Nick W Smith, Thomas M R Maxwell, Warren C McNabb This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7332463/v2 This work is licensed under a CC BY 4.0 License Status: Posted Version 2 posted You are reading this latest preprint version Show more versions Abstract Recent studies have documented the growing impact of climate change on global agriculture. Yet, the nutritional impacts of these changes remain largely overlooked, especially for key crops like soybeans, one of the world’s richest plant sources of iron and zinc, nutrients for which over a billion people remain at risk of deficiency. Here, drawing on advances in spatial modelling and nutrient mapping, we present the first global assessment showing that projected climate-driven declines in soybean suitability by 2050 will substantially reduce iron and zinc supply for millions of people in sub-Saharan Africa and Southeast Asia, where deficiencies are already widespread. In Southern Africa alone, lost soybean-derived nutrients correspond to the annual requirements of more than six million people for iron and four million for zinc. By contrast, gains accrue mostly in higher-income temperate regions, where deficiency burdens are generally lower. These findings highlight a new frontier in climate adaptation: agricultural strategies must incorporate a nutrition lens, and global nutrition initiatives must integrate climate foresight. Earth and environmental sciences/Climate sciences/Climate change/Projection and prediction Scientific community and society/Agriculture Scientific community and society/Social sciences/Climate change/Climate-change impacts/Environmental health Scientific community and society/Developing world Food system resilience global nutrition climate change soybean production crop suitability Micronutrient deficiency micronutrient supply Nutrition–sensitive agriculture Spatial modelling Agro-ecological suitability Figures Figure 1 Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 2 posted You are reading this latest preprint version Show more versions 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7332463","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":547020496,"identity":"9e471a76-1f24-4a66-9e85-70204f72fafb","order_by":0,"name":"Ejovi A Abafe","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBAC+wbGNgYGGwY54rUYMDAfY2BIYzAmRQtbGkhLYgMJWnjMHvxIsElf23788YePbQzy/A28hz/g02LPwGNu2JOQlrvtTI6Z5Mw2BsMZB/gSDAjZIsH743DutgM5bMy8bQyMGxh4DBLwa+H/Jvkn4X+62fnnjz//bWOwB2k5QMgWaZ6EAwlmNxIMpIEBngjUYtiAVwszj7mxTEKy4bYbb8wke85JJM84zIM/xO3be8wevkmwkzc7n/74w48yG9v+9h5jvCHGwIzMYWSTQBMhDP6QpnwUjIJRMApGBgAAaMhFC1JQ/nEAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0002-2019-4856","institution":"1 Sustainable Nutrition Initiative®, Riddet Institute, Massey University, Palmerston North 4410, New Zealand. 2 School of Food Technology and Natural Sciences, Massey University, Palmerston North 4410, New Zealand","correspondingAuthor":true,"prefix":"","firstName":"Ejovi","middleName":"A","lastName":"Abafe","suffix":""},{"id":547155767,"identity":"10c5acda-bbf4-4475-9544-89cf85f70957","order_by":1,"name":"Nick W Smith","email":"","orcid":"https://orcid.org/0000-0002-6230-4355","institution":"1 Sustainable Nutrition Initiative®, Riddet Institute, Massey University, Palmerston North 4410, New Zealand. 3 The New Zealand Institute for Plant and Food Research Ltd, 23 Batchelar Road, Palmerston North 4410, New Zealand","correspondingAuthor":false,"prefix":"","firstName":"Nick","middleName":"W","lastName":"Smith","suffix":""},{"id":547155768,"identity":"3f9916e5-3143-4ae2-abfb-badfbc982dbf","order_by":2,"name":"Thomas M R Maxwell","email":"","orcid":"https://orcid.org/0000-0001-9204-1667","institution":"4 Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, Christchurch, New Zealand","correspondingAuthor":false,"prefix":"","firstName":"Thomas","middleName":"M R","lastName":"Maxwell","suffix":""},{"id":547155769,"identity":"5114618b-e25f-4d0d-a8dc-533c6bc3d9ab","order_by":3,"name":"Warren C McNabb","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+UlEQVRIiWNgGAWjYBACgwM8Bsw8DAcS+EnQwlfA3APUItlAvBb+D8xngFoMDhCvhXfj5zM1d/KMrx1+/PFHxWEG/vYDbA9/4NFidoB3s3TOsWfFZrfTzKR5zhxmkDiTwG4ggV/LNuYctsOJ224nmDEzth1mYLjBwCZhgFcLjxmzzb/DiZtnp3/++PPfYQZ5kJYEPFrsQVpk2w4nbpDOMZDgbTjMYADScgCPFsvDPMbSsn3PiiVu55RJ8xxL5zE8k9iGN8QNjvcYfub5diePf3b65o8/aqzl5I4fPiaJL8QYmFG5zTwMDIz47MAEdSSpHgWjYBSMgpEBAIKYVRoDwCHDAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-2514-6551","institution":"1 Sustainable Nutrition Initiative®, Riddet Institute, Massey University, Palmerston North 4410, New Zealand","correspondingAuthor":true,"prefix":"","firstName":"Warren","middleName":"C","lastName":"McNabb","suffix":""}],"badges":[],"createdAt":"2025-08-09 08:35:09","currentVersionCode":2,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-7332463/v2","doiUrl":"https://doi.org/10.21203/rs.3.rs-7332463/v2","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":96660553,"identity":"5bcdf0bc-e0dd-4af6-8307-e01abe4737e8","added_by":"auto","created_at":"2025-11-24 18:19:25","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":200719,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGlobal soybean suitability under historical and future climate scenarios.\u003c/strong\u003e (a) Baseline suitability for soybean cultivation under historical climate conditions (WorldClim v2.1, 1970–2000); (b) projected suitability by 2050 under the SSP2-4.5 climate scenario. Suitability was modelled using MaxEnt, with occurrence data derived from the Spatial Production Allocation Model (SPAM) for the years 2010 and 2020 \u003csup\u003e43\u003c/sup\u003e. Models were trained with all 19 bioclimatic variables (BIO1–BIO19), representing temperature and precipitation. Future projections (b) used downscaled WorldClim v2.1 data for SSP2-4.5 (2050) \u003csup\u003e90\u003c/sup\u003e. Continuous suitability probabilities (0 – 1) were reclassified into six categories: Unsuitable (≤0.04), Marginal (\u0026lt;0.19), Low (\u0026lt;0.34), Moderate (\u0026lt;0.54), High (\u0026lt;0.74), and Very High (≤1.00). See Table S1d for full classification details.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 1c | Projected country-level changes in soybean climatic suitability and harvested area by 2050 (SSP2-4.5)\u003c/strong\u003e. Projected gains and losses in soybean climatic suitability (% change) and harvested area (hectares) at the country level by 2050, based on MaxEnt model projections under the SSP2-4.5 climate scenario. Country boundaries were defined using the Global Administrative Areas (GADM) database (\u003ca href=\"https://gadm.org/\"\u003ehttps://gadm.org\u003c/a\u003e). For transcontinental countries (e.g., Russia, Türkiye), reported values represent the mean of their separate continental components. Percentage changes are relative to baseline and may overstate impacts in countries with very small or no baseline soybean area, where large proportional changes reflect negligible absolute areas in the SPAM \u003csup\u003e43\u003c/sup\u003e dataset.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFig. 1d | Global distribution of soybean harvested area, 2010–2020. \u003c/strong\u003eSpatial distribution of global soybean harvested area based on SPAM data, pooling 2010 and 2020 to capture recent cultivation patterns and minimize temporal bias. Values indicate total harvested area per ~10 km grid cell (hectares); values may exceed the cell’s physical area (10,000 ha) in regions with multiple cropping cycles. Country and subnational boundaries for mapping and summary statistics were defined using the Global Administrative Areas (GADM) database (\u003ca href=\"https://gadm.org/\"\u003ehttps://gadm.org\u003c/a\u003e). SPAM integrates national and subnational statistics, remote sensing, and ancillary spatial data to generate spatially explicit crop distribution maps \u003csup\u003e43\u003c/sup\u003e.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7332463/v2/84b9a64c1386c7aa9fe40837.jpg"},{"id":96710343,"identity":"29793a1f-647a-4820-9695-a6b4a679db54","added_by":"auto","created_at":"2025-11-25 10:10:29","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":897775,"visible":true,"origin":"","legend":"","description":"","filename":"Climatedrivenlossesinsoybean.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7332463/v2_covered_63662af2-f681-45bb-a5c2-41b7a66408ec.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"Climate-driven losses in soybean suitability threaten iron and zinc supply for millions in the Global South","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":true,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Food system resilience, global nutrition, climate change, soybean production, crop suitability, Micronutrient deficiency, micronutrient supply, Nutrition–sensitive agriculture, Spatial modelling, Agro-ecological suitability","lastPublishedDoi":"10.21203/rs.3.rs-7332463/v2","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7332463/v2","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eRecent studies have documented the growing impact of climate change on global agriculture. Yet, the nutritional impacts of these changes remain largely overlooked, especially for key crops like soybeans, one of the world’s richest plant sources of iron and zinc, nutrients for which over a billion people remain at risk of deficiency. Here, drawing on advances in spatial modelling and nutrient mapping, we present the first global assessment showing that projected climate-driven declines in soybean suitability by 2050 will substantially reduce iron and zinc supply for millions of people in sub-Saharan Africa and Southeast Asia, where deficiencies are already widespread. In Southern Africa alone, lost soybean-derived nutrients correspond to the annual requirements of more than six million people for iron and four million for zinc. By contrast, gains accrue mostly in higher-income temperate regions, where deficiency burdens are generally lower. These findings highlight a new frontier in climate adaptation: agricultural strategies must incorporate a nutrition lens, and global nutrition initiatives must integrate climate foresight.\u003c/p\u003e","manuscriptTitle":"Climate-driven losses in soybean suitability threaten iron and zinc supply for millions in the Global South","msid":"","msnumber":"","nonDraftVersions":[{"code":2,"date":"2025-11-24 18:19:20","doi":"10.21203/rs.3.rs-7332463/v2","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}},{"code":1,"date":"2025-11-05 14:15:46","doi":"10.21203/rs.3.rs-7332463/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"50558684-a384-40f2-a291-3c76710f3081","owner":[],"postedDate":"November 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":58197002,"name":"Earth and environmental sciences/Climate sciences/Climate change/Projection and prediction"},{"id":58197003,"name":"Scientific community and society/Agriculture"},{"id":58197004,"name":"Scientific community and society/Social sciences/Climate change/Climate-change impacts/Environmental health"},{"id":58197005,"name":"Scientific community and society/Developing world"}],"tags":[],"updatedAt":"2025-11-05T14:15:47+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-24 18:19:20","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v2","identity":"rs-7332463","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7332463","identity":"rs-7332463","version":["v2"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}