{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T03:03:03Z","timestamp":1770692583459,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,2,7]],"date-time":"2026-02-07T00:00:00Z","timestamp":1770422400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000844","name":"European Space Agency","doi-asserted-by":"publisher","award":["4000117474\/16\/NL\/NDe"],"award-info":[{"award-number":["4000117474\/16\/NL\/NDe"]}],"id":[{"id":"10.13039\/501100000844","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Data"],"abstract":"<jats:p>This data descriptor presents a dataset comprising crop and soil parameters measured in winter wheat fields near the town of Knezha, Bulgaria. The data were collected as part of a project evaluating the potential of vegetation indices derived from Sentinel-2 satellite imagery to predict biophysical and biochemical crop parameters. The core dataset consists of measurements obtained from 20 m \u00d7 20 m field plots and includes a broad range of parameters: leaf area index, fraction of absorbed photosynthetically active radiation, vegetation cover fraction, chlorophyll content, above-ground biomass, plant nitrogen content, biological yield, surface soil moisture, spectral reflectance, plant density, crop height, visual assessments of disease or pest damage, and data on weed occurrence. The dataset is complemented by unmanned aerial vehicle imagery, crop calendars, and field management information. The main soil types in the study area were characterized through soil profiles, while meteorological data were obtained from an automated weather station. The data were collected during the 2016\u20132017 and 2017\u20132018 agricultural seasons. The dataset is freely available for download and serves as a valuable resource for researchers in remote sensing\u2014particularly for validating satellite-derived products\u2014as well as for specialists involved in winter wheat monitoring, modeling, and agronomic studies.<\/jats:p>","DOI":"10.3390\/data11020035","type":"journal-article","created":{"date-parts":[[2026,2,9]],"date-time":"2026-02-09T10:45:31Z","timestamp":1770633931000},"page":"35","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["In Situ Crop and Soil Data and UAV Imagery from Winter Wheat Fields in a Bulgarian Site"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4821-8231","authenticated-orcid":false,"given":"Petar","family":"Dimitrov","sequence":"first","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-4705-1023","authenticated-orcid":false,"given":"Eugenia","family":"Roumenina","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-5437-1060","authenticated-orcid":false,"given":"Georgi","family":"Jelev","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6248-0148","authenticated-orcid":false,"given":"Lachezar","family":"Filchev","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"given":"Alexander","family":"Gikov","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4607-3064","authenticated-orcid":false,"given":"Ilina","family":"Kamenova","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"given":"Iliana","family":"Ilieva","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9265-9539","authenticated-orcid":false,"given":"Dessislava","family":"Ganeva","sequence":"additional","affiliation":[{"name":"Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Blok 1, 1113 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9053-5372","authenticated-orcid":false,"given":"Milena","family":"Kercheva","sequence":"additional","affiliation":[{"name":"Institute of Soil Science, Agrotechnologies and Plant Protection \u201cNikola Poushkarov\u201d, Agricultural Academy, 7 Shose Bankya St., 1331 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4491-5646","authenticated-orcid":false,"given":"Martin","family":"Banov","sequence":"additional","affiliation":[{"name":"Institute of Soil Science, Agrotechnologies and Plant Protection \u201cNikola Poushkarov\u201d, Agricultural Academy, 7 Shose Bankya St., 1331 Sofia, Bulgaria"}]},{"given":"Veneta","family":"Krasteva","sequence":"additional","affiliation":[{"name":"Institute of Soil Science, Agrotechnologies and Plant Protection \u201cNikola Poushkarov\u201d, Agricultural Academy, 7 Shose Bankya St., 1331 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7155-5594","authenticated-orcid":false,"given":"Viktor","family":"Kolchakov","sequence":"additional","affiliation":[{"name":"Institute of Soil Science, Agrotechnologies and Plant Protection \u201cNikola Poushkarov\u201d, Agricultural Academy, 7 Shose Bankya St., 1331 Sofia, Bulgaria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8820-4689","authenticated-orcid":false,"given":"Emil","family":"Dimitrov","sequence":"additional","affiliation":[{"name":"Institute of Soil Science, Agrotechnologies and Plant Protection \u201cNikola Poushkarov\u201d, Agricultural Academy, 7 Shose Bankya St., 1331 Sofia, Bulgaria"}]},{"given":"Nevena","family":"Miteva","sequence":"additional","affiliation":[{"name":"Institute of Soil Science, Agrotechnologies and Plant Protection \u201cNikola Poushkarov\u201d, Agricultural Academy, 7 Shose Bankya St., 1331 Sofia, Bulgaria"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1111\/j.1365-3180.1974.tb01084.x","article-title":"A decimal code of the growth stages of cereals","volume":"14","author":"Zadoks","year":"1974","journal-title":"Weed Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"739","DOI":"10.1029\/2018RG000608","article-title":"An overview of global leaf area index (LAI): Methods, products, validation, and applications","volume":"57","author":"Fang","year":"2019","journal-title":"Rev. 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