Soil Sci. Soc. Am. J. 66:335–346 In the section of Interdisciplinary Communication and Concepts on page 343, George R. Miller was incorrectly cited as an Iowa State University pedologist. The correct name is Gerald A. Miller. In the ACKNOWLEDGMENT section on page 343, E. Arthur Bettis, II should be E. Arthur Bettis, III.
Institutional and student surveys carried out in 1992 and 2004 suggest that soil science education is experiencing a significant decline in the United States and Canada. The present article reports on the data obtained in these surveys, particularly the fact that the enrollment in MSc and PhD programs in soil science in US and Canadian universities in 2004 was approximately 40% less than that in 1992. Some of the possible causes of this drop are analyzed in detail, such as the tendency of soil science education programs to keep emphasizing the agricultural side of soil science (i.e., its connection to crop production), despite the open intention of most students to pursue careers dealing predominantly, or at least in part, with environmental issues. It is argued that measures could still be taken by soil science educators and soil scientists to revert the downward trend in enrollments. Among these are licensing soil scientists, being vigilant about oversimplifications and misrepresentations of soil processes by researchers in other disciplines, expanding the scope of soil science and actively promoting its achievements, and making sure that the public at large is aware of the intrinsic, challenging complexity of soils and that it mandates a unique pluridisciplinary approach. We believe that if some of these measures were adopted, soil science could relatively and rapidly regain its place in the pantheon of science.
In the 1870s, agricultural geologists (pioneer pedologists) in Germany, Denmark, and Russia conceived of the soil profile. In more than a century since, pedologists have generally agreed on the reasons and purpose for using symbols such as A‐B‐C for the designations, but not on the definitions themselves or the assigned significance of the designations. In this paper, we submit that two seemingly conflicting classes of profile concepts evolved in the USA from European roots. The conflict stems historically from arbitrarily defined thin and thick profile concepts, often referred to as the soil or geologic weathering profiles, respectively. The pedologic or thin profile concept is depth‐restricted when compared with the geologic thick weathering profile. The geologic profile concept was developed as a homologue of the pedologic profile and is considered to be the full or complete profile of weathering. Throughout the 20th century many variations of the concept of profile appeared, and all seem to have pedo–geo conflicts, exemplified by the myriad C horizon definitions by soil scientists. Recent concepts, such as the pedoweathering profile, have integrated the terminology used by pedologists and geologists into a functional and useful classification for all horizons of complete profiles. Full 21st century understanding of soils beyond the historic 20th century needs of agriculture, increasingly requires a knowledge of soil properties to greater depth than merely the historic solum and upper C horizon, and makes understanding subsolum properties more critical than ever before.
Pedologists and Quaternary geologists developed different viewpoints almost 70 yr ago regarding concept, designation, and application of zones of weathering, termed horizons by pedologists. A sense of exclusion separated pedologic and geologic domains. The pedologic domain was confined to the upper portion of the earth's surface exhibiting the master horizons of O or A (accumulation), E (eluvial), and B (illuvial) horizons—the solum. In contrast, the domain of Quaternary geology and its interest in soil stratigraphy was focused on a paradigm stressing the subsolum— the realm of the pedologic C horizon and below. We seek to develop a unified paradigm through the introduction of a unified pedoweathering profile (PWP) concept that requires a re-examination of the C horizon concept and the redefinition and use of master horizon D. The PWP contains a C horizon concept of more limited but more precisely defined scope than traditionally used in pedology. In the traditional sense, the interval between the solum and bedrock is designated as C whether modified or not. In the PWP, the C horizon is limited to the modified part of the traditional C that shows pedogenic connection to the overlying solum. The part that is unaltered by pedogenic processes and does not have the hardness of bedrock (R) is recognized as the D horizon. The redefined subsolum horizons are not limited to the glaciated area of the midcontinental USA where these concepts were originally formulated. They exist worldwide in glaciated areas, wetlands, and alluvial, lake, and coastal plains of the past and present. With the growing importance of soil properties at depth, the PWP concept should be useful in paleopedology, soil stratigraphy, geomorphology, sedimentology, hydrogeology, and Quaternary geology.
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