“Transmission line-type electromagnetic (EM) methods for estimating soil volumetric water content [soil moisture levels] have advanced significantly in recent years, with many sensing systems now available. EM systems make use of the dependence of soil dielectric permittivity shift). However, a standard method for characterizing and comparing make accurate EM signal property measurements that EM system measurement capability has not been established. Our objective was to evaluate the permittivity measurement ability of seven different EM sensing systems using readily available media.”