Prediction of soil organic carbon content using field and laboratory measurements of soil color

The understanding, prediction, and modeling efficacy of soil organic carbon (SOC) distribution across fields and larger regions requires a large number of samples that are cosdy to analyze. The objective of this study was to evaluate soil color measurements to predict SOC for agriculture and prairie land uses. Munsell soil color book (B) and chroma meter (C) color readings were taken at the midpoint depth of each horizon (HB and HC) and predetermined depth increments (IB and IC) on 125 cores. Horizon matrix (HD) colors were determined by standard description. A chroma meter was used to determine the color of prepared samples, ground to Abbreviations: HB, Munsell color book readings by horizon; HC, chroma meter readings by horizon; IB, Munsell color book readings by depth increment; IC, chroma meter readings by depth increment; SCd, chroma meter readings on dry samples; SCm, chroma meter readings on moist samples; SOC, soil organic carbon.