Development of Three-Dimensional Virtual Models to Enhance Conceptualization of Soil Morphology.

An often unspoken axiom among pedologists is that soil morphology can only be taught in the field. We assume that this is because morphological concepts are primarily visual and are learned by the seamless interaction with tangible objects. As a result, we hypothesize that the development of interactive models in virtual three-dimensional (3D) space will augment and enhance the conceptualization of soil morphology, especially if these models are based on the properties of actual field samples.  Such interactive models, therefore, potentially serve as powerful pedagogical tools that could easily be adapted to online soil science courses.  Recent applications of multistripe laser triangulation (MLT) scanners make possible the digitization of 3D irregular soil bodies.  Our objectives are to use this technology to (1) create virtual models of soil monoliths, peds, and faunal and floral traces, and (2) develop a virtual library where such models can be accessed for online education.  Virtual soil monoliths were created by digitizing existing monoliths and by scanning carefully prepared excavation walls.  Soil structure types including prismatic, columnar, subangular blocky, angular blocky, and wedge were digitized and scaled to demonstrate size-class breaks.  A host of natural and modern casts of endogenic animal and plant traces were scanned to create virtual models of biogenic structures from soils and paleosols.  Since MLT scanners automatically take and overlay photos on the point clouds they produce, all objects appear in full color and can be rotated in any direction, panned, or zoomed.  In addition, 3D digital scans can easily be measured for volume, surface area, angles, and lengths, which makes these models especially adaptable to online courses.  Methodology, workflow, and examples are presented.