Soil Hydrology As an Integrative Concept in Teaching Soil Science.

The soil profile is the record of the imprints of soil-forming processes throughout the life of the soil.  Many of these processes are driven by the seasonal presence or absence of soil water as well as intensity and duration of water presence in the soil. Temperature and biological influences on soils during periods of soil water flux are important ancillary soil-forming conditions. Recognizing that water movement within landscapes often is lateral, and sometimes is vertical from below is the key to using data and morphological features from a variety of soils in a landscape to understand both pattern and processes at a landscape scale and to being able to predict the results of human management and other impacts on system functions.  Understanding water movement and the seasonal distributions of soils in landscapes requires knowledge of local stratigraphy, mineralogy, climate and vegetation.  Understanding origins and meanings of redoximorphic features, mineralogy, chemistry and rooting patterns integrates soil profiles into the whole watershed dynamic.  Thus, developing and interpreting the water flow nets and their impacts on soil morphology is a concept and exercise that allows integration of soil patterns, processes and genesis across time and space.  The concept is integrative and scale adjustable and requires independent observation, thought and inference.  Using this approach as a teaching tool equips students with a philosophy and confidence that can be applied, with study and care, in any landscape in the world.  It is a lifelong framework for learning and for application of knowledge.  Our experiences have shown that most students can learn the fundamentals of the approach in a semester of carefully organized field and classroom work.