Using Soil Sensors to Assess Soil Salinity

Abstract This article is reproduced from Chapter 6 of the new book, Salinity and Sodicity: A Growing Global Challenge to Food Security, Environmental Quality and Soil Resilience , in a slightly modified form. The book is available for purchase from Wiley.com or Amazon.com . The article covers the use of electromagnetic (EM) sensors for measuring apparent electrical conductivity (EC a ). In the field, electrical conductivity (EC) can be measured by two primary approaches: physical contact and electromagnetic (EM) induction. With physical contact, a current is injected into the soil, and the detector measures the resulting voltage. An EM meter does not make direct contact but uses a coil to produce an EM field. A sensor then measures the soil‐induced changes to the original EM field. Both types of sensors measure the EC a , which is different from laboratory‐derived EC values. When using EC a sensors, it is important to remember that they are sensitive to many factors, including salinity, soil moisture, bulk density, soil texture, and temperature. The purpose of this article is to provide an overview on the use of EM sensors to provide examples on the use of these sensors in the field. Earn 1.5 CEUs in Soil & Water Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning‐Center/Courses .