COLOR AND AMORPHOUS MATERIALS IN SPODOSOLS FROM MICHIGAN

Field identification of Spodosols is often difficult because the spodic horizon definition includes chemical criteria. This study was conducted to relate the color of the E and B horizons of soils classified as Spodosols in Michigan to organic C, Al, and Fe contents. Horizon colors were compared with the amounts of C, Al, and Fe in pyrophosphate and oxalate extracts. Aquods tended to be more yellow than Orthods. Hue, value, and chroma were negatively correlated with the amorphous materials. Correlation coefficients were greatest for organic C and least for Al. Color was more highly correlated with pyrophosphate-extractable amorphous materials (r = -0.57) than oxalate-extractable materials (r = -0.49). Eluviation and illuviation of organo-metallic complexes are the primary determinants of color in Michigan Spodosols.