A Novel Time Domain Reflectometry (TDR) System for Water Content Estimation in Soils: Development and Application

Highlights A compact, affordable time domain reflectometry (TDR) device was designed for hydrological applications. The proposed device demonstrated reliable performance across different soil textures. Laboratory experiments validated the accuracy of the system for soil moisture estimation. The device is suitable for real-time monitoring in precision agriculture and environmental studies. The device offers a viable alternative to expensive commercial TDR systems without compromising measurement accuracy. What are the main findings? Development of a low-cost TDR. Consistent and reliable performance. What is the implication of the main finding? Possibility to build the device on one's own. It makes TDR suitable for monitoring soil water status with acceptable accuracyHighlights A compact, affordable time domain reflectometry (TDR) device was designed for hydrological applications. The proposed device demonstrated reliable performance across different soil textures. Laboratory experiments validated the accuracy of the system for soil moisture estimation. The device is suitable for real-time monitoring in precision agriculture and environmental studies. The device offers a viable alternative to expensive commercial TDR systems without compromising measurement accuracy. What are the main findings? Development of a low-cost TDR. Consistent and reliable performance. What is the implication of the main finding? Possibility to build the device on one's own. It makes TDR suitable for monitoring soil water status with acceptable accuracyHighlights A compact, affordable time domain reflectometry (TDR) device was designed for hydrological applications. The proposed device demonstrated reliable performance across different soil textures. Laboratory experiments validated the accuracy of the system for soil moisture estimation. The device is suitable for real-time monitoring in precision agriculture and environmental studies. The device offers a viable alternative to expensive commercial TDR systems without compromising measurement accuracy. What are the main findings? Development of a low-cost TDR. Consistent and reliable performance. What is the implication of the main finding? Possibility to build the device on one's own. It makes TDR suitable for monitoring soil water status with acceptable accuracyAbstract Nowadays, there is a particular need to estimate soil water content accurately over space and time scales in various applications. For example, precision agriculture, as well as the fields of geology, ecology, and hydrology, necessitate rapid, onsite water content measurements. The time domain reflectometry (TDR) technique is a geophysical method that allows, in a time-varying electric field, the determination of dielectric permittivity and electrical conductivity for a wide class of porous materials. Measuring the volumetric water content in soils is the most frequent application of TDR in soil science and soil hydrology. TDR has grown in popularity over the last 40 years because it is a practical and non-destructive technique that provides laboratory and field-scale measurements. However, a significant limitation of this technique is the relatively high cost of TDR devices, despite the availability of a range of commercial systems with varying prices. This paper aimed to design and implement a low-cost, compact TDR device tailored for classical hydrological applications. A series of laboratory experiments were carried out on soils of different textures to calibrate and validate the proposed measuring system. The results show that the device can be used to obtain predictions for monitoring soil water status with acceptable accuracy (R2 = 0.95).