|FITZPATRICK, STEPHAN - Georgia Perimeter College|
|SCHROEDER, PAUL - University Of Georgia|
Submitted to: Geoderma
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/22/2015
Publication Date: 6/17/2015
Citation: Fitzpatrick, S.D., Schroeder, P.A., Endale, D.M. 2015. Creating deep soil core monoliths: Beyond the solum. Geoderma. 51(2):85-96.
Interpretive Summary: As growth of human population accelerates, so does the challenge to provide adequate food and fiber, balancing what we take from Earth with what we put back, so that future generations can enjoy the benefit of healthy natural resources. This requires engaging ordinary folks in understanding how natural resources work, and what their vulnerabilities are, to instill good stewardship. Soil is such one natural resource of immense importance that needs to be appreciated by the public at large for the very many services it provides to humanity. But there generally is a lack of such appreciation because teaching of the science of soil, by enlarge, is limited to academic institutions. Soil monoliths are three-dimensional soil samples removed from the upper part of the earth’s crust, and preserved intact through socking with different chemicals, that can be used as teaching tools for a wide spectrum of populations about the benefits and vulnerabilities of soils. Soil monoliths are typically four to six feet long, half a foot wide and a fraction of a foot deep. We now understand that the services soils provide reach tens of feet depth. The need to understand engineering and environmental problems has led to collections of soils samples from such depths by several mechanical means. In this paper we, therefore, expand the notion of soil monoliths preparation to include such depths. Two sets of soil samples, each approximately five inches in diameter, were collected from a USDA Agricultural Research Service research facility near Watkinsville GA, extending to 30 ft below ground, during installation of monitoring wells. The samples were processed as monoliths by two different approaches so that one set can be utilized as a mobile or static demonstration tool, while a second was made to be a more static unit. The two finished sets are on display at the Geology Department of the University of Georgia, in Athens Georgia, so that students, faculty and visitors have easy access to them. The mobile unit can easily be moved around and used as a demonstration unit during any activity that draws populations of any size to the university campus, or surrounding area or elsewhere, throughout the year.
Technical Abstract: Soil monoliths serve as useful teaching aids in the study of the Earth’s critical zone where rock, soil, water, air, and organisms interact. Typical monolith preparation has so far been confined to the 1 to 2-m depth of the solum. Critical ecosystem services provided by soils include materials from the deeper soil profile. Soil monolith preparation needs to take this new paradigm into account. Soil cores from such depths can be obtained during site investigations for studies of various engineering and environmental problems. The complexity of soil structure makes the preservation and presentation of cores into monoliths difficult. The wide range of exhibition modes ranging from permanent to mobile displays creates further challenges. We present two methods for monolith preparation suited to soil type and demonstration mode. For permanent horizontal displays, a simple process using floor wax is described. For mobile and vertical displays, a solution of acetone and polyvinylidene chloride (PVDC) at a 5:1 mass ratio can be used to create good structurally sound deep soil core monoliths. In this study soil cores were obtained during installation of monitoring wells at two sites 2.5 km apart in the Piedmont of Georgia in the southeastern United States. To reduce health and safety risk, a well-ventilated location and use of protective gear, while handling and using chemicals, is essential to the process. The finished products are in display at the Geology Department, University of Georgia, Athens, GA in the USA.