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dc.contributor.advisorHummel, John W.eng
dc.contributor.advisorSudduth, Kenneth A., 1958-eng
dc.contributor.authorKim, Hak Jin, 1969-eng
dc.date.issued2006eng
dc.date.submitted2006 Summereng
dc.descriptionThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.eng
dc.descriptionTitle from title screen of research.pdf file viewed on (April 26, 2007)eng
dc.descriptionIncludes bibliographical references.eng
dc.descriptionVita.eng
dc.descriptionThesis (Ph.D.) University of Missouri-Columbia 2006.eng
dc.descriptionDissertations, Academic -- University of Missouri--Columbia -- Biological engineering.eng
dc.description.abstractAutomated sensing of soil macronutrients (i.e., N, P, and K) would allow more efficient mapping of soil nutrient variability for variable-rate nutrient management. This study reports on the development of a sensor array consisting of three different ion-selective electrodes (ISEs) for simultaneous determination of soil macronutrients. The sensitivity and selectivity of PVC membrane-based ISEs with tetradodecylammonium nitrate (TDDA) and valinomycin for sensing nitrate and potassium, respectively, and of cobalt rod-based phosphate ISEs were satisfactory for measuring N, P, and K ions over typical ranges of soil concentrations. The nitrate ISEs, when used in conjunction with the Kelowna extractant (0.25M CH₃COOH + 0.015M NH₄F), provided soil NO₃-N values similar to those obtained with standard methods (i.e., automated ion analyzer and 1M KCl extractant). However, the soil K values obtained with the K ISEs and Kelowna extractant were about 50% lower than those obtained with an ICP spectrometer and Mehlich III extractant due to decreased K extraction by the Kelowna solution. The ISE-P values for soil were about 63% lower than ICP-P values (ICP and Mehlich III) due to both decreased P estimates in soil extracts by cobalt electrodes and reduced P extraction by the Kelowna solution. Nevertheless, strong linear relationships (r² > 0.78**) existing between the two methods would make it possible to use the K and P ISEs for soil K and P sensing.eng
dc.identifier.merlinb58469898eng
dc.identifier.oclc123564382eng
dc.identifier.urihttps://hdl.handle.net/10355/4471
dc.identifier.urihttps://doi.org/10.32469/10355/4471eng
dc.languageEnglisheng
dc.publisherUniversity of Missouri--Columbiaeng
dc.relation.ispartofcollectionUniversity of Missouri--Columbia. Graduate School. Theses and Dissertationseng
dc.sourceSubmitted by University of Missouri--Columbia Graduate School.eng
dc.subject.lcshSoil mappingeng
dc.subject.lcshSoils and nutrition -- Managementeng
dc.titleIon-selective electrodes for simultaneous real-time analysis for soil macronutrientseng
dc.typeThesiseng
thesis.degree.disciplineBiological engineering (MU)eng
thesis.degree.grantorUniversity of Missouri--Columbiaeng
thesis.degree.levelDoctoraleng
thesis.degree.namePh. D.eng


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