Abstract Soil moisture profile sensors (SMPSs) are designed to measure the volumetric water content of soil at multiple depths simultaneously. Their vertical installation makes them particularly suitable for frequent relocation, as required for the use during cultivation of field crops. In addition to established sensor manufacturers who have been offering SMPS for some time, an increasing number of companies are now introducing new models specifically designed for agricultural applications. Beyond practical and economic factors—such as ease of installation, durability, and costs—the measurement accuracy of SMPS is a key performance criterion, yet one that end users cannot easily assess themselves. Validating sensor accuracy requires reference methods that are impractical for most users, and soil heterogeneity further complicates data interpretation. In this study, we conducted a sandbox experiment to compare the measurement accuracy of 10 SMPSs under controlled soil moisture conditions. The SMPS readings were evaluated against time‐domain reflectometry reference measurements using three SMPS devices of each type. We found that most SMPSs performed with reasonable accuracy under very dry and very wet conditions. However, in the intermediate soil moisture range, strong variations were observed with respect to slope, offset, and spread of measurements for some SMPSs, which resulted in reduced accuracy. The high intra‐sensor variability (: 0.7–3.1 vol. %) and varying measurement accuracy (: 3.1–8.3 vol. %) highlight the importance of selecting a suitable SMPS, especially for scientific applications and precision agriculture, where accurate field data are critical for informed management decisions.
Nieberding et al. (Sun,) studied this question.