{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T22:20:12Z","timestamp":1779402012358,"version":"3.53.1"},"reference-count":32,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,6,4]],"date-time":"2021-06-04T00:00:00Z","timestamp":1622764800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100007636","name":"Deutsche Bundesstiftung Umwelt","doi-asserted-by":"publisher","award":["AZ 33702"],"award-info":[{"award-number":["AZ 33702"]}],"id":[{"id":"10.13039\/100007636","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Knowing the exact nutrient composition of organic fertilizers is a prerequisite for their appropriate application to improve yield and to avoid environmental pollution by over-fertilization. Traditional standard chemical analysis is cost and time-consuming and thus it is unsuitable for a rapid analysis before manure application. As a possible alternative, a handheld X-ray fluorescence (XRF) spectrometer was tested to enable a fast, simultaneous, and on-site analysis of several elements. A set of 62 liquid pig and cattle manures as well as biogas digestates were collected, intensively homogenized and analysed for the macro plant nutrients phosphorus, potassium, magnesium, calcium, and sulphur as well as the micro nutrients manganese, iron, copper, and zinc using the standard lab procedure. The effect of four different sample preparation steps (original, dried, filtered, and dried filter residues) on XRF measurement accuracy was examined. Therefore, XRF results were correlated with values of the reference analysis. The best R2s for each element ranged from 0.64 to 0.92. Comparing the four preparation steps, XRF results for dried samples showed good correlations (0.64 and 0.86) for all elements. XRF measurements using dried filter residues showed also good correlations with R2s between 0.65 and 0.91 except for P, Mg, and Ca. In contrast, correlation analysis for liquid samples (original and filtered) resulted in lower R2s from 0.02 to 0.68, except for K (0.83 and 0.87, respectively). Based on these results, it can be concluded that handheld XRF is a promising measuring system for element analysis in manures and digestates.<\/jats:p>","DOI":"10.3390\/s21113892","type":"journal-article","created":{"date-parts":[[2021,6,7]],"date-time":"2021-06-07T01:56:40Z","timestamp":1623031000000},"page":"3892","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Determination of Nutrients in Liquid Manures and Biogas Digestates by Portable Energy-Dispersive X-ray Fluorescence Spectrometry"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7041-555X","authenticated-orcid":false,"given":"Michael","family":"Horf","sequence":"first","affiliation":[{"name":"Abteilung Technik im Pflanzenbau, Leibniz-Institut f\u00fcr Agrartechnik und Bio\u00f6konomie (ATB), Max-Eyth-Allee 100, D-14469 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4890-9574","authenticated-orcid":false,"given":"Robin","family":"Gebbers","sequence":"additional","affiliation":[{"name":"Abteilung Technik im Pflanzenbau, Leibniz-Institut f\u00fcr Agrartechnik und Bio\u00f6konomie (ATB), Max-Eyth-Allee 100, D-14469 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sebastian","family":"Vogel","sequence":"additional","affiliation":[{"name":"Abteilung Technik im Pflanzenbau, Leibniz-Institut f\u00fcr Agrartechnik und Bio\u00f6konomie (ATB), Max-Eyth-Allee 100, D-14469 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Markus","family":"Ostermann","sequence":"additional","affiliation":[{"name":"Fachbereich 1.4, Bundesanstalt f\u00fcr Materialforschung (BAM), Zweiggel\u00e4nde Adlershof, Richard-Willst\u00e4tter-Stra\u00dfe 11, D-12489 Berlin, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Max-Frederik","family":"Piepel","sequence":"additional","affiliation":[{"name":"Fachgebiet Pflanzenern\u00e4hrung und Pflanzenbau, Fakult\u00e4t Agrarwissenschaften und Landschaftsarchitektur, Hochschule Osnabr\u00fcck, Am Kr\u00fcmpel 31, D-49090 Osnabr\u00fcck, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6046-2803","authenticated-orcid":false,"given":"Hans-Werner","family":"Olfs","sequence":"additional","affiliation":[{"name":"Fachgebiet Pflanzenern\u00e4hrung und Pflanzenbau, Fakult\u00e4t Agrarwissenschaften und Landschaftsarchitektur, Hochschule Osnabr\u00fcck, Am Kr\u00fcmpel 31, D-49090 Osnabr\u00fcck, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1255\/jnirs.462","article-title":"Comparison of transflectance and reflectance to analyse hog manures","volume":"13","author":"Saeys","year":"2005","journal-title":"J. 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