{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T03:48:08Z","timestamp":1773805688841,"version":"3.50.1"},"reference-count":123,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2019,10,3]],"date-time":"2019-10-03T00:00:00Z","timestamp":1570060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","award":["031A564E"],"award-info":[{"award-number":["031A564E"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Characterization of spatial soil variability is key for a better understanding of soils. To arrive at such information geophysical techniques have been used in the last two decades. Due to its easy handling, the geophysical sensor EM38 has widely been used to characterize agricultural areas. The theoretical background and usage of the EM38 is described, and based on multifaceted applications, the interpretation of the results as well as optimized steps for using it are outlined. Common principles and models of the apparent electrical conductivity (ECa) and strengths and limitations of this technique (calibration and temperature effects) are described as well as additional applications, such as the magnetic susceptibility, a comparison of measurements in vertical and horizontal modes, the use of weighted depth information and the influence of measurement conditions are addressed. Further a comparison of EM38 with other proximal soil sensors and fusion with other devices is described. The study reveals that EM38 is useful because the readings can reflect many different soil parameters.<\/jats:p>","DOI":"10.3390\/s19194293","type":"journal-article","created":{"date-parts":[[2019,10,4]],"date-time":"2019-10-04T04:12:52Z","timestamp":1570162372000},"page":"4293","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":36,"title":["Theory and Guidelines for the Application of the Geophysical Sensor EM38"],"prefix":"10.3390","volume":"19","author":[{"given":"Kurt","family":"Heil","sequence":"first","affiliation":[{"name":"Chair of Plant Nutrition, Technical University Munich, Emil-Ramann-Str. 2, D-85350 Freising, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4106-7124","authenticated-orcid":false,"given":"Urs","family":"Schmidhalter","sequence":"additional","affiliation":[{"name":"Chair of Plant Nutrition, Technical University Munich, Emil-Ramann-Str. 2, D-85350 Freising, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2019,10,3]]},"reference":[{"key":"ref_1","unstructured":"Sperl, C. (1999). Erfassung der Raumzeitlichen Variation des Bodenwassergehaltes in Einem Agrar\u00f6kosystem Mit dem Ground-Penetrating-Radar, Technische Universit\u00e4t M\u00fcnchen. Diss. TU M\u00fcnchen. FAM-Bericht 37."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1016\/S0016-7061(00)00047-1","article-title":"Soil resistivity: A non-invasive tool to map soil structure horizonation","volume":"97","author":"Tabbagh","year":"2000","journal-title":"Geoderma"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.compag.2004.11.017","article-title":"Multi-dimensional electromagnetic modeling and inversion with application to near-surface earth investigations","volume":"46","author":"Pellerin","year":"2005","journal-title":"Comput. Electron. Agric."},{"key":"ref_4","unstructured":"L\u00fcck, E., R\u00fchlmann, J., and Spangenberg, U. (2005). Physical Background of EC Mapping: Laboratory, Theoretical and Field Studies, ECPA."},{"key":"ref_5","unstructured":"Gebbers, R., and L\u00fcck, E. (2005, January 9\u201312). Comparision of geoelectrical methods for soil mapping. Proceedings of the 5th European Conference on Precision Agriculture (5ECPA) and Precision Livestock Farming (2ECPLF), Uppsala, Sweden."},{"key":"ref_6","first-page":"455","article-title":"Application of soil electrical conductivity to precision agriculture: Theory, principles, and guidelines","volume":"95","author":"Corwin","year":"2003","journal-title":"Agron. J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1011","DOI":"10.3390\/s19051011","article-title":"Improving In-Situ Estimation of Soil Profile Properties Using a Multi-Sensor Probe","volume":"19","author":"Xiaoshuai","year":"2019","journal-title":"Sensors"},{"key":"ref_8","first-page":"333","article-title":"Height above ground corrections of EM38 reading s of soil apparent electrical conductivity. Short communication","volume":"56","author":"Korsaeth","year":"2006","journal-title":"Acta Agric. Scand. Sect. B Soil Plant Sci."},{"key":"ref_9","unstructured":"McNeill, J.D. (1980). Electromagnetic Terrain Conductivity Measurements at Low Induction Numbers, Geonics Limited. Technical Note 6."},{"key":"ref_10","unstructured":"Blumenstein, O., and Schachtzabel, H. (2000). Geophysik f\u00fcr Landwirtschaft und Bodenkunde. Stoffdynamik in Geosystemen, University of Potsdam. [7th ed.]."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Khongnawang, T., Zare, E., Zhao, D., Srihabun, P., and Triantafilis, J. (2019). Three-Dimensional Mapping of Clay and Cation Exchange Capacity of Sandy and Infertile Soil Using EM38 and Inversion Software. Sensors, 19.","DOI":"10.3390\/s19183936"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"651","DOI":"10.2136\/sssaj1976.03615995004000050017x","article-title":"Effects of Liquid-Phase Electrical Conductivity, Water Content and Surface Conductivity on Bulk Soil Electrical Conductivity","volume":"4","author":"Rhoades","year":"1976","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_13","unstructured":"Durlesser, H. (1999). Bestimmung der Variation Bodenphysikalischer Parameter in Raum und Zeit Mit Elektromagnetischen Induktionsverfahren, FAM-Bericht 35. [Ph.D. Thesis, Technische Universit\u00e4t M\u00fcnchen]."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2953","DOI":"10.1029\/92WR01560","article-title":"A helicopter-borne electromagnetic survey to delineate groundwater recharge rates","volume":"28","author":"Cook","year":"1992","journal-title":"Water Resour. Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1015","DOI":"10.2136\/sssaj1992.03615995005600040003x","article-title":"Depth profiles of electrical conductivity from linear combinations of electromagnetic induction measurements","volume":"56","author":"Cook","year":"1992","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"715","DOI":"10.4141\/cjss88-069","article-title":"Estimating spatial variations of soil water content using noncontacting electromagnetic inductive methods","volume":"68","author":"Kachanoski","year":"1988","journal-title":"Can. J. Soil Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1071\/SR9900453","article-title":"Estimating average rootzone salinity from electromagnetic induction (EM-38) measurements","volume":"28","author":"Slavich","year":"1990","journal-title":"Aust. J. Soil Res."},{"key":"ref_18","first-page":"54","article-title":"The electrical resistivity log as an aid in determining some reservoir characteristics","volume":"146","author":"Archie","year":"1942","journal-title":"Trans. Am. Min. Metall. Pet. Eng."},{"key":"ref_19","unstructured":"Maxwell, J.C. (1881). A Treatise on Electricity and Magnetism, Clarendon Press. [2nd ed.]."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4832","DOI":"10.1063\/1.340476","article-title":"Electrical conduction in clay bearing sandstones at low and high salinities","volume":"63","author":"Sen","year":"1988","journal-title":"J. Appl. Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.compag.2004.11.001","article-title":"Soil properties influencing apparent electrical conductivity: A review","volume":"46","author":"Friedman","year":"2005","journal-title":"Comput. Electron. Agric."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"575","DOI":"10.1103\/PhysRev.24.575","article-title":"A mathematical treatment of the electric conductivity and capacity of disperse systems, I. The electric conductivity of a suspension of homogeneous spheroids","volume":"24","author":"Fricke","year":"1924","journal-title":"Phys. Rev."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1520\/JAI13087","article-title":"Generalized Archie\u2019s Law for Estimation of Soil Electrical Conductivity","volume":"2","author":"Shah","year":"2005","journal-title":"J. ASTM Int."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"433","DOI":"10.2136\/sssaj1989.03615995005300020020x","article-title":"Soil Electrical Conductivity and Soil Salinity: New Formulations and Calibrations","volume":"53","author":"Rhoades","year":"1989","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2771","DOI":"10.1029\/91WR01095","article-title":"Theoretical prediction of electrical conductivity in saturated and unsaturated soil","volume":"27","author":"Mualem","year":"1991","journal-title":"Water Resour. Res."},{"key":"ref_26","unstructured":"G\u00fcnzel, F. (1994). Geoelectrical Examination of Groundwater Contaminations Considering the Influence of Clay and Water Content on the Electrical Conductivity of the Subsoil. [Bachelor\u2019s Thesis, Universit\u00e4t M\u00fcnchen]."},{"key":"ref_27","first-page":"503","article-title":"Obtaining \u2018useful\u2019 high-resolution soil data from proximally-sensed electrical conductivity\/resistivity (PSEC\/R) surveys","volume":"5","author":"McBratney","year":"2005","journal-title":"Precis. Agric."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1097\/00010694-200106000-00003","article-title":"Influence of soil properties on electrical conductivity under humid water regimes","volume":"166","author":"Auerswald","year":"2001","journal-title":"Soil Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2564","DOI":"10.1103\/PhysRevLett.57.2564","article-title":"New Pore-Size Parameter Characterizing Transport in Porous Media","volume":"57","author":"Johnson","year":"1986","journal-title":"Phys. Rev. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"469","DOI":"10.2136\/sssaj1980.03615995004400030006x","article-title":"Effect of ESP, cation exchange capacity, and soil solution concentration on soil electrical conductivity","volume":"44","author":"Shainberg","year":"1980","journal-title":"Soil Sci. Am. J."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1216","DOI":"10.2136\/sssaj1980.03615995004400060017x","article-title":"Determination of Soil Solution Electrical Conductivity from Bulk Soil Electrical Conductivity Measurements by the Four Electrode Method","volume":"44","author":"Nadler","year":"1980","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.cageo.2011.06.017","article-title":"Characterisation of soil texture variability using the apparent soil electrical conductivity at a highly variable site","volume":"39","author":"Heil","year":"2012","journal-title":"Comput. Geosci."},{"key":"ref_33","first-page":"490","article-title":"Interpretation of electrical conductivity patterns by soilproperties and geological maps for precision agriculture","volume":"10","author":"Brenning","year":"2008","journal-title":"Precis. Agric."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1071\/SR98084","article-title":"Investigation of dryland salinity using the electrical image method","volume":"37","author":"Acworth","year":"1999","journal-title":"Aust. J. Soil Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/j.jappgeo.2011.07.005","article-title":"Low induction number, ground conductivity meters: A correction procedure in the absence of magnetic effects","volume":"75","author":"Beamish","year":"2011","journal-title":"J. Appl. Geophys."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Dane, J.H., and Topp, G.C. (2002). Indirect measurement of solute concentration: Nonintrusive electromagnetic induction. Methods of Soil Analysis, Part 4, SSSA. SSSA Book Ser. 5.","DOI":"10.2136\/sssabookser5.4"},{"key":"ref_37","unstructured":"Geonics, E.M. (2002). EM38 Ground Conductivity Meter Operating Manual, Geonics Limited Ontario."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Dabas, M., and Tabbagh, A. (2003). A comparison of EMI and DC methods used in soil mapping theoretical considerations for Precision Agriculture. Precision Agriculture, Wageningen Academic Publishers.","DOI":"10.3920\/9789086865147_017"},{"key":"ref_39","unstructured":"Penttinen, S., Alakukku, L., H\u00e4nninen, P., and Jaakkola, A. (2003, January 1\u20134). Response Functions of EM38 and EM31 and 3-Layer Model of Cultivated Soil. Proceedings of the Nordic association of Agricultural Scientists 22nd Congress, Turku, Finland."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/j.compag.2014.11.014","article-title":"Comparison of the EM38 and EM38-MK2 electromagnetic induction-based sensors for spatial soil analysis at field scale","volume":"110","author":"Heil","year":"2015","journal-title":"Comput. Electron. Agric."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.compag.2004.11.002","article-title":"Characterizing soil spatial variability with apparent soil electrical conductivity: I. Survey protocols","volume":"46","author":"Corwin","year":"2005","journal-title":"Comput. Electron. Agric."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/S0168-1699(00)00185-X","article-title":"Accuracy issues in electromagnetic induction sensing of soil electrical conductivity for precision agriculture","volume":"31","author":"Sudduth","year":"2001","journal-title":"Comput. Electron. Agric."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.compag.2004.11.003","article-title":"Characterizing soil spatial variability with apparent soil electrical conductivity, Part II Case study","volume":"46","author":"Corwin","year":"2005","journal-title":"Comput. Electron. Agric."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.compag.2004.10.005","article-title":"Apparent soil electrical conductivity measurements in agriculture","volume":"46","author":"Corwin","year":"2005","journal-title":"Comput. Electron. Agric."},{"key":"ref_45","unstructured":"Johnson, K. (2006). Conductivity (EM) survey: A survival manual. Remote Sensing in Archaeology\u2014An Explicity North American Perspective, University of Alabama."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1023\/B:PRAG.0000022359.79184.92","article-title":"Effect of daily temperature fluctuations on soil electrical conductivity as measured with the Geonics EM38","volume":"5","author":"Brevik","year":"2004","journal-title":"Precis. Agric."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"339","DOI":"10.2136\/sssaj2004.3390","article-title":"Minimizing Drift in Electrical Conductivity Measurements in High Temperature Environments using the EM-38","volume":"68","author":"Robinson","year":"2004","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jappgeo.2010.10.004","article-title":"Comparing performance of instrumental drift correction by linear and quadratic adjusting in inductive electromagnetic data","volume":"73","author":"Santos","year":"2011","journal-title":"J. Appl. Geophys."},{"key":"ref_49","unstructured":"Keller, G.V., and Frischknecht, F.C. (1966). Electrical Methods in Geophysical Prospecting, Pergamon Press."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2401","DOI":"10.1029\/95WR01949","article-title":"Noninvasive soil water content measurement using electromagnetic induction","volume":"31","author":"Sheets","year":"1995","journal-title":"Water Resour. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1097\/SS.0b013e318189397f","article-title":"The temperature correction for the electrical resistivity measurements in undisturbed soil samples: Analysis of the existing conversion models and proposal of a new model","volume":"173","author":"Besson","year":"2008","journal-title":"Soil Sci."},{"key":"ref_52","unstructured":"Rhoades, J.D., Chanduvi, F., and Lesch, S. (1999). Soil Salinity Assessment. Methods and Interpretation of Electrical Conductivity Measurements, FAO. Irrigation and drainage paper No 57."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1007\/s11119-009-9156-7","article-title":"Comparing temperature correction models for soil electrical conductivity measurement","volume":"12","author":"Ma","year":"2011","journal-title":"Precis. Agric."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1071\/SR06093","article-title":"An electromagnetic induction method for monitoring variation in soil moisture in agroforestry systems","volume":"45","author":"Huth","year":"2007","journal-title":"Aust. J. Soil Res."},{"key":"ref_55","unstructured":"Johnson, J.K. (2006). Magnetic Susceptibility. Remote Sensing in Archaeology: An Explicitly North American Perspective, University of Alabama Press."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1111\/j.1365-2389.2010.01261.x","article-title":"Sensitivity of multi-coil frequency domain electromagnetic induction sensors to map soil magnetic susceptibility","volume":"61","author":"Simpson","year":"2010","journal-title":"Eur. J. Soil Sci."},{"key":"ref_57","unstructured":"Ernenwein, E.G., and Hargrave, M.L. (2009). Archaeological Geophysics for DoDField Use: A Guide for New and Novice Users, Corps of Engineers. Funded by the Environmental Security Technology Certification Program; Project 200611: Streamlined Archaeogeophysical Data Processing and Integration for DoD Field Use."},{"key":"ref_58","unstructured":"McNeill, J.D. (1986). Rapid, Accurate Mapping of Soil Salinity Using Electromagnetic Ground Conductivity Meters, Geonics Limited. Technical Note TN-18."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.jappgeo.2003.08.022","article-title":"Implications of magnetic backgrounds for unexploded ordnance detection","volume":"54","author":"Butler","year":"2003","journal-title":"J. Appl. Geophys."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.jappgeo.2009.03.006","article-title":"Comparison between electromagnetic induction and fluxgate gradiometer measurements on the buried remains of a 17th century castle","volume":"68","author":"Simpson","year":"2009","journal-title":"J. Appl. Geophys."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1002\/gea.10042","article-title":"Geophysical indicators of culturally emplaced soils and sediments","volume":"17","author":"Dalan","year":"2002","journal-title":"Geoarchaeology"},{"key":"ref_62","first-page":"603","article-title":"Application of high-resolution geophysical methods to archaeology. Archaeological geology of North America","volume":"4","author":"Wynn","year":"1990","journal-title":"Geol. Soc. Am."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/S0065-2113(08)60257-6","article-title":"Geostatistical Analysis of a soil salinity data set","volume":"58","author":"Bourgault","year":"1997","journal-title":"Adv. Agron."},{"key":"ref_64","unstructured":"Schmidhalter, U., Zintel, A., and Neudecker, E. (2001, January 18\u201320). Calibration of electromagnetic induction measurements to survey the spatial variability of soils. Proceedings of the 3rd European Conference Precision Agriculture, Montpellier, France."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"2075","DOI":"10.2136\/sssaj2005.0405","article-title":"Incorporating Electromagnetic Induction Methods into Regional Soil Salinity Survey of Irrigation Districts","volume":"70","author":"Robinson","year":"2006","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1080\/15324989709381490","article-title":"Nondestructive assessment of rangeland soil depth to petrocalcic horizon using electromagnetic induction","volume":"11","author":"Boettinger","year":"1997","journal-title":"Arid. Soil Res. Rehabil."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"2055","DOI":"10.1080\/00103629809370093","article-title":"Use of non-contacting electromagnetic inductive method for estimating soil moisture across a landscape","volume":"29","author":"Khakural","year":"1998","journal-title":"Commun. Soil Sci. Plant Anal."},{"key":"ref_68","unstructured":"Heath, J., Challis, P., and Norman, C. (1999). Manual for Calibration of EM38. Agriculture Victoria-Natural Resources and Environment, Institute of Sustainable Irrigated Agriculture, ILRI."},{"key":"ref_69","unstructured":"Dalgaard, M., Have, H., and Nehmdal, H. (2001, January 18\u201320). Soil clay mapping by measurements of electromagnetic conductivity. Proceedings of the 3rd European Conference on Precision Agriculture, Montpellier, France."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"469","DOI":"10.2307\/4003336","article-title":"Soil depth assessment of sagebrush grazing treatments using electromagnetic induction","volume":"51","author":"Bork","year":"1998","journal-title":"J. Range Manag."},{"key":"ref_71","unstructured":"Norman, C.P. (1990). Training Manual on the Use of the EM38 for Soil Salinity Appraisal, Department of Agriculture and Rural Affairs. Technical Report Series No. 181."},{"key":"ref_72","unstructured":"Slavich, P. (2001, January 3\u20135). Ground based electromagnetic induction measures of soil electrical conductivity. Applications and models to assist interpretation. Proceedings of the Conference Held at Yanco Agricultural Institute, Electromagnetic Techniques for Agricultural Resource Management, Yanco, New South Wales, Australia."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.2136\/sssaj2006.0323","article-title":"Using the EM38DD Soil Sensor to delineate claylenses in a sandy forest soil","volume":"71","author":"Cockx","year":"2007","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"586","DOI":"10.2136\/vzj2008.0123","article-title":"Can Apparent Electrical Conductivity Improve the Spatial Characterization of Soil Organic Carbon?","volume":"8","author":"Martinez","year":"2009","journal-title":"Vadose Zone J."},{"key":"ref_75","unstructured":"Vanderlinden, K., Mart\u00ednez, G., Gir\u00e1ldez, J.V., and Muriel, J.L. (2010, January 1\u20136). Characterizing Soil Management Systems using Electromagnetic Induction. Proceedings of the 19th World Congress of Soil Science, Soil Solutions for a Changing World August 2010, Brisbane, Australia."},{"key":"ref_76","unstructured":"Stamatiadis, S., Lynch, J.M., and Schepers, J.S. (2004). Mapping soil electrical conductivity, Remote Sensing for Agriculture and the Environment."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"1763","DOI":"10.2136\/sssaj2010.0056","article-title":"Repeated Electromagnetic Induction Surveys for Improved Soil Mapping in an Agricultural Landscape Pedosphere","volume":"74","author":"Zhu","year":"2010","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/j.jappgeo.2005.10.001","article-title":"The influence of soil moisture on magnetic susceptibility measurements","volume":"59","author":"Maier","year":"2006","journal-title":"J. Appl. Geophys."},{"key":"ref_79","doi-asserted-by":"crossref","unstructured":"Gebbers, R., L\u00fcck, E., and Heil, K. (2007, January 3\u20136). Depth sounding with the EM38-detection of soil layering by inversion of apparent electrical conductivity measurements. Proceedings of the 6th European Conference on Precision Agriculture, Skiathos, Greece.","DOI":"10.3920\/9789086866038_010"},{"key":"ref_80","unstructured":"Zhdanov, M.S., and Keller, G.V. (1994). The Geoelectrical Methods in Geophysical Exploration, Elsevier. Methods in Geochemistry and Geophysics 31."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.2136\/vzj2011.0035","article-title":"Quantitative two-layer conductivity inversion of multi-configuration electromagnetic induction measurements","volume":"10","author":"Mester","year":"2011","journal-title":"Vadose Zone J."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"1004","DOI":"10.2136\/sssaj1997.03615995006100040002x","article-title":"Tikhonov Regularization of Electrical Conductivity Depth Profiles in Field Soils","volume":"61","author":"Borchers","year":"1997","journal-title":"SSSAJ"},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"517","DOI":"10.2136\/sssaj1982.03615995004600030014x","article-title":"An improved technique for determining soil electrical conductivity\u2014Depth relations from above-ground electromagnetic measurements","volume":"46","author":"Corwin","year":"1982","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"288","DOI":"10.2136\/sssaj1984.03615995004800020011x","article-title":"Measurement of inverted electrical conductivity profiles using electromagnetic induction","volume":"48","author":"Corwin","year":"1984","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"315","DOI":"10.4141\/cjss86-032","article-title":"A rapid method for estimating weighted soil salinity from apparent soil electrical conductivity measured with an aboveground. Electromagnetic induction meter","volume":"66","author":"Wollenhaupt","year":"1986","journal-title":"Can. J. Soil Sci."},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1007\/BF00189989","article-title":"Estimation of field scale leaching rates from chloride mass balance and electromagnetic induction measurements","volume":"11","author":"Slavich","year":"1990","journal-title":"Irrig. Sci."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1016\/S0016-7061(00)00039-2","article-title":"Two soil profile reconstruction techniques","volume":"87","author":"McBratney","year":"2000","journal-title":"Geoderma"},{"key":"ref_88","first-page":"549","article-title":"Inversion of electrical conductivity data with Tikhonov regularization approach: Some considerations","volume":"46","author":"Deidda","year":"2003","journal-title":"Ann. Geophys."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.geoderma.2012.11.005","article-title":"Mapping the three-dimensional variation of soil salinity in a rice-paddy soil","volume":"195","author":"Li","year":"2013","journal-title":"Geoderma"},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1071\/SR09013","article-title":"2-dimensional soil and vadosezone representation using an EM38 and EM34 and a laterally constrained inversion model","volume":"47","author":"Triantafilis","year":"2009","journal-title":"Aust. J. Soil Res."},{"key":"ref_91","doi-asserted-by":"crossref","unstructured":"Li, H.Y., Li, F.H., Shi, Z., and Huang, M.X. (2010, January 23\u201324). Three Dimensional Variability of Soil Electrical Conductivity Based on Electromagnetic Induction Approach. Proceedings of the Artificial Intelligence and Computational Intelligence (AICI), International Conference on IEEE, Sanya, China.","DOI":"10.1109\/AICI.2010.284"},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"553","DOI":"10.3997\/1873-0604.2010037","article-title":"Electromagnetic induction calibration using apparent electrical conductivity modelling based on electrical resistivity tomography","volume":"8","author":"Rings","year":"2010","journal-title":"Near Surf. Geophys."},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"481","DOI":"10.3997\/1873-0604.2014012","article-title":"Calibration of frequency-domain electromagnetic devices used in near-surface surveying","volume":"12","author":"Thiesson","year":"2000","journal-title":"Near Surf. Geophys."},{"key":"ref_94","doi-asserted-by":"crossref","first-page":"WA125","DOI":"10.1190\/1.3467936","article-title":"Efficient loop antenna modeling for zero-offset, off-ground electromagnetic induction in multilayered media","volume":"75","author":"Moghadas","year":"2010","journal-title":"Geophysics"},{"key":"ref_95","doi-asserted-by":"crossref","first-page":"2732","DOI":"10.1002\/2013WR014864","article-title":"Three-dimensional imaging of subsurface structural patterns using quantitative large-scale multiconfiguration electromagnetic induction data","volume":"50","author":"Rudolph","year":"2014","journal-title":"Water Resour. Res."},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1016\/j.compag.2009.05.009","article-title":"Height-above-ground effects on penetration depth and response of electromagnetic induction soil conductivity meters","volume":"68","author":"Morris","year":"2009","journal-title":"Comput. Electron. Agric."},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1023\/A:1026319307801","article-title":"Differences in EM-38 readings taken above crop residues versus readings taken with instrument-ground contact","volume":"4","author":"Brevik","year":"2003","journal-title":"Precis. Agric."},{"key":"ref_98","unstructured":"Heckman, E. (2005). Geophysical Methodologies and Test Site for Battlefield Archaeology. [Master\u2019s Thesis, University of Arkansas]."},{"key":"ref_99","unstructured":"Ernenwein, E.G., and Hargrave, M.L. (2007). Archaeological Geophysics for DoDField Use: A Guide for New and Novice Users, Environmental Security Technology Certification Program, Corps of Engineers."},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"983","DOI":"10.1046\/j.1365-2478.1997.650303.x","article-title":"A novel mobile multipole system (MUCEP) for shallow (0\u20133 m) geoelectrical investigation: The \u2018Vol-de-canards\u2019 array","volume":"45","author":"Panissod","year":"1998","journal-title":"Geophys. Prospect."},{"key":"ref_101","unstructured":"Kimble, J.M., Doolittle, J., Taylor, R., Windhorn, R., and Gerken, J. (2001). The Use of EMI and Electrical Instruments for Estimating Soil Properties to Help in Mapping. AGU Fall Meeting Abstracts, American Geophysical Union."},{"key":"ref_102","doi-asserted-by":"crossref","first-page":"7","DOI":"10.2136\/sssaj2008.0079","article-title":"Comparing the EM38DD and DUALEM-21S sensors for depth-to-clay mapping","volume":"73","author":"Saey","year":"2008","journal-title":"SSSAJ"},{"key":"ref_103","doi-asserted-by":"crossref","first-page":"135","DOI":"10.2113\/JEEG15.3.135","article-title":"Mapping Depth to Argillic Soil Horizons Using Apparent Electrical Conductivity","volume":"15","author":"Sudduth","year":"2010","journal-title":"J. Environ. Eng. Geophys."},{"key":"ref_104","first-page":"175","article-title":"Comparing three geophysical tools for locating sand blows in alluvial soils of southeast Missouri","volume":"57","author":"Doolittle","year":"2002","journal-title":"J. Soil Water Conserv."},{"key":"ref_105","unstructured":"Sudduth, K.A., Kitchen, N.R., and Drummond, S.T. (2003). Soil conductivity sensing on claypan soils: Comparison of electromagnetic induction and direct methods. Applications of Electromagnetic Methods Agriculture, Geonics Limited."},{"key":"ref_106","doi-asserted-by":"crossref","first-page":"179","DOI":"10.3997\/1873-0604.2009011","article-title":"Comparison of instruments for geoelectrical soil mapping at the field scale","volume":"7","author":"Gebbers","year":"2009","journal-title":"Near Surf. Geophys."},{"key":"ref_107","unstructured":"Priori, S., Martini, E., and Costantini, E.A.C. (2010, January 1\u20136). Three proximal sensors for mapping skeletal soils in vineyards. Proceedings of the 19th World Congress of Soil Science, Soil Solutions for a Changing World 121, Brisbane, Australia."},{"key":"ref_108","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1007\/s00271-010-0253-1","article-title":"Using EM and VERIS technology to assess land suitability for orchard and vineyard development","volume":"29","author":"Fulton","year":"2011","journal-title":"Irrig. Sci."},{"key":"ref_109","doi-asserted-by":"crossref","unstructured":"Toy, C.W., Steelman, C.M., and Endres, A.L. (2010, January 21\u201325). Comparing electromagnetic induction and ground penetrating radar techniques for estimating soil moisture content. Proceedings of the 13th International Conference on IEEE, Ground Penetrating Radar (GPR), Lecce, Italy.","DOI":"10.1109\/ICGPR.2010.5550068"},{"key":"ref_110","first-page":"237","article-title":"Comparison of different geo-electric measurement techniques to detect field variability of soil parameters Landbauforschung V\u00f6lkerode. Landbauforsch","volume":"55","author":"Lilienthal","year":"2005","journal-title":"Volkenrode"},{"key":"ref_111","unstructured":"Mankin, K.R., Ewing, K.L., Schrock, M.D., and Kluitenberg, G.J. (1997). Field Measurement and Mapping of Soil Salinity in Saline Seeps, ASAE. ASAE Paper No. 973145."},{"key":"ref_112","unstructured":"Beecher, H.G. (2005). Better Prediction of Groundwater Recharge from Rice Growing, CRC. Final Research Report."},{"key":"ref_113","unstructured":"Mahmood, H.S., Hoogmoed, W.B., and Van Henten, E.J. (2009, January 6\u20138). Combined sensor system for mapping soil properties. Proceedings of the 7th European Conference on Precision Agriculture, Precision Agriculture 2009, Wageningen, The Netherlands."},{"key":"ref_114","doi-asserted-by":"crossref","unstructured":"Thomas, C. (2011). Sensor fusion for precision agriculture. Sensor Fusion\u2014Foundation and Applications, InTech.","DOI":"10.5772\/680"},{"key":"ref_115","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/B978-0-12-394275-3.00003-1","article-title":"Sensing soil properties in the laboratory, in situ and on-line\u2014A review","volume":"114","author":"Kuang","year":"2012","journal-title":"Adv. Agron."},{"key":"ref_116","doi-asserted-by":"crossref","first-page":"628","DOI":"10.1007\/s11119-012-9280-7","article-title":"Sensor data fusion to predict multiple soil properties","volume":"13","author":"Mahmood","year":"2012","journal-title":"Precis. Agric."},{"key":"ref_117","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1111\/j.1745-6584.2008.00490.x","article-title":"Mapping Water Table Depth Using Geophysical and Environmental Variables","volume":"47","author":"Buchanan","year":"2009","journal-title":"Ground Water"},{"key":"ref_118","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.geoderma.2012.10.007","article-title":"Sensor data fusion for topsoil clay mapping","volume":"199","author":"Piikki","year":"2013","journal-title":"Geoderma"},{"key":"ref_119","doi-asserted-by":"crossref","unstructured":"Rossel, R.A.V., McBratney, A.B., and Minasny, B. (2010). Use of EM38 and Gamma Ray Spec-Trometry as Complementary Sensors for High-Resolution Soil Property Mapping. Proximal Soil Sensing, Springer.","DOI":"10.1007\/978-90-481-8859-8"},{"key":"ref_120","doi-asserted-by":"crossref","unstructured":"Rossel, R.A.V., McBratney, A.B., and Minasny, B. (2010). Comparing the Ability of Multiple Soil Sensors to Predict Soil Properties in a Scottish Potato Production System. Proximal Soil Sensing, Springer.","DOI":"10.1007\/978-90-481-8859-8"},{"key":"ref_121","unstructured":"Rodionov, A., Angst, G., Amelung, W., P\u00e4tzold, S., and Welp, G. (2013). Gamma-Ray Spectrometry and Electromagnetic Induction as Complementary Tools to map Soil Properties with a High Spatial Resolution, Leibniz-Institut f\u00fcr Agrartechnik Potsdam-Bornim e.V. (ATB)."},{"key":"ref_122","first-page":"372","article-title":"Field partition by proximal and remote sensing data fusion","volume":"144","author":"Diacono","year":"2013","journal-title":"Biosyst. Eng."},{"key":"ref_123","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1016\/j.geoderma.2012.11.009","article-title":"Resistivity mapping with GEOPHILUS ELECTRICUS\u2014Information about lateral and vertical soil heterogeneity","volume":"199","author":"Ruehlmann","year":"2013","journal-title":"Geoderma"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/19\/4293\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:27:25Z","timestamp":1760189245000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/19\/4293"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,10,3]]},"references-count":123,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2019,10]]}},"alternative-id":["s19194293"],"URL":"https:\/\/doi.org\/10.3390\/s19194293","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,10,3]]}}}