Abstract
An environmental sensor (the Decagon 5TE sensor with an EM50 data logger) is a soil salinity, temperature and water content (SWC) sensor that can be used by researchers and farmers around the world. Herein, 22 sensors were tested under different conditions of soil salinity, temperature, organic matter, texture, clay content, bulk density and water content, ranging from normal to extreme. The results indicated that the main issue with this device is that its SWC determinations are only accurate within a limited soil salinity and temperature range. Conversely, the organic matter, texture, clay content and bulk density have no direct impact on the sensors' accuracy. The sensors work best when the soil salinity and temperature are 2.5 dS m(-1) and 25 degrees C, respectively. This sensor can be used appropriately after calibration when the soil salinity and temperatures are within the 1.9-4.0 dS m(-1) and 16-30 degrees C ranges, respectively. When the soil salinity and temperature values are higher or lower than these ranges, the sensors do not work accurately. More investigation is needed to study the effectiveness of the sensors under high values of soil salinity and temperature. (c) 2019 John Wiley & Sons, Ltd.