Korean Journal of Soil Science and FertilizerISSN:0367-6315(Print) 2288-2162(Online)한국토양비료학회

Morphological characteristics provide a variety of important information for soils. Drainage class is also deternmined by the morphological characteristics such as soil color, which indicates the redox state of the soil. Soil color is usually measured with the Munsell color chart, which may not allow perfect conformity of results between surveyers. Quantitative approach, therefore, became more important to determine drainage class. In the quantification of the drainage class, we suggetsted following three factors as key points:ⅰ) earth color (hue, value, chroma), color due to rocks, and color due to redox are important factors, ⅱ) If there is a main color and mottles (color by reduction), the amount and degree of color by redox are important, ⅲ) When there is a groundwater level, the depth and the amount of the mottles (color by oxidation) are important determinants. Furthermore, not only the drainage class but also other characteristics should be quantified to create an Korean own classification system suitable for the characteristics of Korea.

Criteria for determining the drainage class.