{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:27:33Z","timestamp":1760059653760,"version":"build-2065373602"},"reference-count":66,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T00:00:00Z","timestamp":1751414400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Operacional Competitividade e Internacionaliza\u00e7\u00e3o program","award":["POCI-01-0247-FEDER-069670","LISBOA-01-0247-FEDER-069670"],"award-info":[{"award-number":["POCI-01-0247-FEDER-069670","LISBOA-01-0247-FEDER-069670"]}]},{"name":"Operacional Regional de Lisboa 2020 program","award":["POCI-01-0247-FEDER-069670","LISBOA-01-0247-FEDER-069670"],"award-info":[{"award-number":["POCI-01-0247-FEDER-069670","LISBOA-01-0247-FEDER-069670"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Biosciences"],"abstract":"<jats:p>The intensification of olive growing has raised environmental concerns, particularly regarding nutrient loss from excessive fertiliser use. In line with the European Union\u2019s Farm to Fork strategy, which aims to halve the soil nutrient losses by 2030, this study evaluates the effectiveness of two sensor-based approaches\u2014proximal sensing with a FLAME spectrometer and remote sensing via UAV-mounted multispectral imaging\u2014compared with foliar chemical analyses as the reference standard, for diagnosing the nutritional status of olive trees. The research was conducted in Elvas, Portugal, between 2022 and 2023, across three olive cultivars (\u2018Azeiteira\u2019, \u2018Arbequina\u2019, and \u2018Koroneiki\u2019) subjected to different fertilisation regimes. Machine learning (ML) models showed strong correlations between sensor data and nutrient levels: the multispectral sensor performed best for phosphorus (P) (determination coefficient [R2] = 0.75) and potassium (K) (R2 = 0.73), while the FLAME spectrometer was more accurate for nitrogen (N) (R2 = 0.64). These findings underscore the potential of sensor-based technologies for non-destructive, real-time nutrient monitoring, with each sensor offering specific strengths depending on the target nutrient. This work contributes to more sustainable and data-driven fertilisation strategies in precision agriculture.<\/jats:p>","DOI":"10.3390\/applbiosci4030032","type":"journal-article","created":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T06:10:26Z","timestamp":1751436626000},"page":"32","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Multi-Sensor Comparison for Nutritional Diagnosis in Olive Plants: A Machine Learning Approach"],"prefix":"10.3390","volume":"4","author":[{"given":"Catarina","family":"Manuelito","sequence":"first","affiliation":[{"name":"INIAV I.P., Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Polo de Elvas, Estrada de Gil Vaz, Apartado 6, 7351-901 Elvas, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-3483-6646","authenticated-orcid":false,"given":"Jo\u00e3o de","family":"Deus","sequence":"additional","affiliation":[{"name":"INIAV I.P., Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Polo de Inova\u00e7\u00e3o de Dois Portos, Quinta da Almoinha, 2565-191 Dois Portos, Portugal"}]},{"given":"Miguel","family":"Dam\u00e1sio","sequence":"additional","affiliation":[{"name":"INIAV I.P., Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Polo de Inova\u00e7\u00e3o de Dois Portos, Quinta da Almoinha, 2565-191 Dois Portos, Portugal"},{"name":"GI-1716, Proyectos y Planificaci\u00f3n, Departamento Ingenier\u00eda Agroforestal, Escola Polit\u00e9cnica Superior de Enxe\u00f1ar\u00eda, Universidade de Santiago de Compostela, R\u00faa Benigno Ledo s\/n, 27002 Lugo, Spain"}]},{"given":"Andr\u00e9","family":"Leit\u00e3o","sequence":"additional","affiliation":[{"name":"SISCOG SA, Sistemas Cognitivos, Campo Grande, 378-3\u00ba, 1700-097 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6947-4368","authenticated-orcid":false,"given":"Lu\u00eds Alcino","family":"Concei\u00e7\u00e3o","sequence":"additional","affiliation":[{"name":"VALORIZA\u2014Research Center for Endogenous Resource Valorization, Polytechnic Institute of Portalegre, 7300-110 Portalegre, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5101-0036","authenticated-orcid":false,"given":"Roc\u00edo","family":"Arias-Calder\u00f3n","sequence":"additional","affiliation":[{"name":"Institute for Regional Development (IDR), Agroforestry and Cartography Precision, Castilla-La Mancha University, Campus Universitario s\/n, 02071 Albacete, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5941-0336","authenticated-orcid":false,"given":"Carla","family":"In\u00eas","sequence":"additional","affiliation":[{"name":"INIAV I.P., Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Polo de Elvas, Estrada de Gil Vaz, Apartado 6, 7351-901 Elvas, Portugal"}]},{"given":"Ant\u00f3nio Manuel","family":"Cordeiro","sequence":"additional","affiliation":[{"name":"INIAV I.P., Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Polo de Elvas, Estrada de Gil Vaz, Apartado 6, 7351-901 Elvas, Portugal"}]},{"given":"Eduardo","family":"Fernandes","sequence":"additional","affiliation":[{"name":"SISCOG SA, Sistemas Cognitivos, Campo Grande, 378-3\u00ba, 1700-097 Lisboa, Portugal"}]},{"given":"Lu\u00eds","family":"Albino","sequence":"additional","affiliation":[{"name":"SISCOG SA, Sistemas Cognitivos, Campo Grande, 378-3\u00ba, 1700-097 Lisboa, Portugal"}]},{"given":"Miguel","family":"Barbosa","sequence":"additional","affiliation":[{"name":"SISCOG SA, Sistemas Cognitivos, Campo Grande, 378-3\u00ba, 1700-097 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3753-2399","authenticated-orcid":false,"given":"Filipe","family":"Fonseca","sequence":"additional","affiliation":[{"name":"SISCOG SA, Sistemas Cognitivos, Campo Grande, 378-3\u00ba, 1700-097 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9054-5108","authenticated-orcid":false,"given":"Jos\u00e9","family":"Silvestre","sequence":"additional","affiliation":[{"name":"INIAV I.P., Instituto Nacional de Investiga\u00e7\u00e3o Agr\u00e1ria e Veterin\u00e1ria, Polo de Inova\u00e7\u00e3o de Dois Portos, Quinta da Almoinha, 2565-191 Dois Portos, Portugal"},{"name":"GREEN-IT Bioresources4sustainability, ITQB NOVA, Av. da Rep\u00fablica, 2780-157 Oeiras, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,2]]},"reference":[{"key":"ref_1","unstructured":"Pinto, L., Cabral, R., and Gon\u00e7alves, J.M. 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