Historical Highlights in Soil Genesis, Morphology, and Classification

Although E. W. Hilgard and G. N. Coffey pioneered, it remained for C. F. Marbut to integrate concepts in a comprehensive model of soil that found acceptance in America. Establishment of the Soil Survey by the controversial Milton Whitney created a major instrument for progress in the subject matter of Division S‐V. The Soil Survey responded to the philosophies of Marbut and survived a bitter controversy during the early years of the USDA Soil Conservation Service. Division S‐5 originated as an association of soil survey workers in 1920. The association gradually broadened its scope from primary concern with soil survey affairs to include most elements of soil science. In 1936 it merged with the Soils Section of ASA as the Soil Science Society of America, with its Division S‐V responsible for the subject matter of the original association. The approaches to soil morphology, genesis, and classification have been dominated by requirements of the soil survey. From largely qualitative concepts, the work has progressed to the quantitative approaches characterized by the Soil Survey Manual of 1951 and Soil Taxonomy of 1975. Increased awareness of geomorphic history has made age a much more important element in concepts of genesis. The quantitative limits of Soil Taxonomy have focused attention on the heterogeneity of mapping units. The greatly increased amount of data and modern data processing methods promise major opportunities for advances in soil genesis and soil interpretation.