Performance curve of two analog sensors for estimating soil moisture

Resumen

Objective: To evaluate the impact of two soil textures on the response of commercial soil moisture sensors, specifically the WaterScout SM100 and Vegetronix VH400, used for measuring soil water content.

Design/methodology/approach: A triplicated laboratory experiment was conducted using two common soil textures in Zacatecas (sandy and loam). The sensor response to changes in water content was measured, and the relationship was analyzed using linear regression models evaluated through the coefficient of determination (R²).

Results: The sensors exhibited a strong linear response in sandy soils (R² = 0.98 for Vegetronix and WaterScout), whereas in loam soils, the fit was slightly lower (R² = 0.98 for Vegetronix and 0.89 for WaterScout). Soil texture significantly influenced measurement accuracy.

Limitations on study/implications: The study was limited to two soil textures and did not account for other influencing factors such as salinity or temperature, which may also affect sensor performance. These findings highlight the need for localized sensor calibration to improve accuracy.

Findings/conclusions: Soil texture significantly affects the precision of moisture sensors, which may impact irrigation scheduling. We recommend developing specific guidelines for the use of these sensors in local soils to enhance irrigation efficiency.