Taking a large monolith to use for teaching soil morphology

Abstract

Soil morphology is often taught in introductory soil science with the use of monoliths of soil profiles. These monoliths, normally 10 to 20 cm wide and 120 cm long, are useful, particularly for demonstrating the differences that occur in the vertical direction in soils. However, changes in the horizontal direction are not shown because of the relatively narrow width. We describe a technique for taking a large monolith, 142 cm wide by 112 cm high, that exhibits many of the changes that occur both vertically and horizontally in soils. A frame and cross braces of angle iron, and a cover board of plywood are used. A backhoe is necessary to excavate the pit and to lift the monolith and frame, which weighs about 11 before trimming. We estimate that 10 to 12 man-hours are required to take and prepare the monolith. Surveys of 93 students enrolled in introductory soil science laboratories for the spring and fall semesters of 1988 indicate their preference for the large monolith over the smaller kind. We believe that the large monolith offers several advantages and is a more effective teaching aid than the smaller type.