Experiential Learning of Soil Science: An Example from An Agricultural Travel Course to Ghana.

Experiential learning is described as an instructional system in which conditions are created for students to think, interact, and learn from the real world. It incorporates projects that engage students to develop skills to work independently or in groups. This experiential learning approach engaged students of diverse academic disciplines in the study of soil science in Ghana. As part of their pre-departure orientation, students in agronomy and four non-agriculture-related majors were trained in the basics of soil profile description. They equally learned about concepts behind the use of the soil quality kit developed by USDA/NRCS. While in Ghana, students investigated the morphological, physical, and chemical properties of soils. They also determined selected soil quality parameters on these soils which were selected based on Soil Taxonomy’s conceptual development sequence with Entisols being the least developed and Oxisols the most weathered. They were put into small multi-cultural and multi-racial groups that mixed students with varied levels of prior knowledge and expertise in soil science. This benefitted the entire group to understand the relationships between land management, inherent soil properties, environmental factors, and their interactions on soil quality. Students observed that bulk densities are significantly lower in highly developed soils. Infiltration rates inversely increased from 6.7 on the Entisols to 68.0 in/hr on the Oxisols. All soils are generally acid but surface pH and electrical conductivity reflect current soil management rather than inherent soil properties. Nitrate levels are significantly different in three of the soil orders. All soils have high levels of microbial respiration which exceed 198 Ib CO2 –C /acre/day. Microbial respiration is in the order: Inceptisols = Entisols > Alfisols>Oxisols. No earthworms were observed in the hot, northern-most, weakly developed soils. This Experiential Learning approach was an effective way of getting students to collectively think and use soil science principles.