Morphology and Genesis of Some Grayish Claypan Soils in Oklahoma: I. Morphology, Chemical and Physical Measurements

Abstract

Grayish or grayish‐brown soils with thin silty A horizons over clayey argillic horizons occurring in the Reddish Prairies of Oklahoma are described. Four profiles, two of the established Waurika series and two of the proposed Nardin series were characterized by detail profile descriptions and by physical and chemical analyses. Particle‐size distribution, bulk density, cation exchange capacity, extractable cations, pH, and organic matter were determined by soil horizons. Attempts were made to classify the pedons studied according to the 7th Approximation to ascertain the validity of the proposed Nardin series.These soils have thin silty A2 horizons with abrupt thick argillic horizons ranging from 42 to 55% clay. Clay, fine silt, organic matter, and carbonates were lost from the A horizons and were accumulated in the Bt horizons. The soils have high base status with Ca and Mg the dominant cations. A secondary maximum of organic matter accumulation occurs in the B2t horizons.