Colorimetric analysis of soils using digital cameras

Abstract

Color is an important physical property in the diagnosis of soils and the description of soil profiles. Quantitative data from spectrophotometers and colorimeters have been used in soil studies for this purpose, but Munsell color description remains the main method of soil color evaluation. Low cost digital devices (cameras) could largely replace the semi-quantitative assessment of color yielded by Munsell charts, so long as they can be colorimetrically characterised to yield accurate and reproducible data. In this study, we explore the feasibility of using a digital camera to derive colorimetrically accurate images and data of 136 soil samples, using soil chart for calibration. Accurate color characterization can be achieved (ΔE_ab* color errors of <3) for 84% of studied soil samples, highlighting the merit of this rapid and low cost approach for soil color evaluation.