Evaluating a New Soil Color Sensor for Quantifying Soil Moisture.

Soil moisture is a key variable controlling multiple processes in agronomy, civil engineering, hydrology, and ecology. Because soil moisture changes the refractive properties of the soil, it is in principle possible to quantify soil moisture content based on soil color. Our objective was to test the new, low-cost Nix Pro soil color sensor to determine soil moisture in field conditions. Soil color was measured on a silt loam soil and sand at multiple soil water contents. Soil color was estimated as the average of three soil color measurements in each sample. Quantification of soil color was made using the CIELab color space.