Characteristics of Medium‐ and Fine‐Textured Humic‐Gley Soils of Ohio

Abstract Humic‐Gley soils are an important soil group in Ohio. In some western Ohio counties they comprise 20 to 25% of the upland soils derived from calcareous till. In the lake plain area of northwestern Ohio they are the dominant soil group. These soils have developed under conditions of poor or very poor drainage. Profile descriptions and data for a number of prominent series developed from medium‐ and fine‐textured materials are used to characterize the Humic‐Gley soils. Variations in texture profile and B horizon development are shown. The horizon of maximum clay content is relatively near the surface in many profiles, and shows maximum development of strong, fine or medium, angular blocky structure and noticeable clay coatings on ped surfaces. Such horizons are considered the B 2 subhorizon even though the dark surface color extends to this depth. Reaction ranges from medium acid to neutral or mildly alkaline and remains relatively uniform or increases with depth. Base saturation is high. For 9 profiles base saturation at the surface ranges between 49 and 83% (only one profile below 69%) and increases with depth, approaching or reaching 100% in the lower part of the solum. Calcium is the predominant cation. A high‐calcium status of the parent material appears to be associated with the formation of Humic‐Gley soils. Organic matter content is high. For 53 cultivated profiles the organic matter content ranges between 9.0 and 3.2% with a medium value of 5.4%. The organic matter content of the surface layer of 5 forested profiles varies between 8.3 and 11.8%. The carbon‐nitrogen ratios vary between 10.3 and 14.0 in surface layers. The carbonnitrogen ratio decreases with depth. Both illite and montmorillonite appear to be the common clay minerals of Humic‐Gley soils.