Fragipan and Water-Table Relationships of Some Brown Podzolic and Low Humic-Gley Soils

Abstract

Ground-water levels in relation to the fragipan were studied in Paxton, Scituate, and Ridgebury soils at two field sites in southeastern New Hampshire in 1956 and 1957. The first two series are Brown Podzolic soils and the last a Low Humic-Gley soil. Horizons of Scituate and Ridgebury soils at one of the sites were sampled for laboratory determination of particle size distribution, cation-exchange data, free iron content, and organic matter. Bulk density measurements were made of selected horizons, and thin sections for microscopic studies were prepared for parts of the fragipans. All three soils have coarse textures, low cation-exchange capacity, and low base status. Free iron oxides in the upper solum are lower in the Ridgebury than in the Scituate but the former has an appreciable concentration in the upper part of the fragipan. A mechanism is proposed for this concentration of iron oxides. Ground-water levels were measured in a number of access wells. These measurements indicate that the water table (1) remains in the upper solum of Ridgebury soils during the late fall, the winter, and most of the spring, (2) remains in the upper solum of the Scituate soils for short periods and in the lower solum for long periods, and (3) seldom rises above the fragipan in Paxton soils. Some of the factors affecting observed water tables are discussed.