Edward C. Runge, Soil & Crop Sciences Dept, Texas A&M Univ, 2474 TAMU, College Station, TX 77843-2474, Kristofor Brye, Univ of Arkansas, 1256 N 51st Ave, Fayetteville, AR 72704, Neil Smeck, 414 E Kottman Hall, Sch Natural Resources, Ohio State Univ, Columbus, OH 43210, Craig Rasmussen, SWES Dept, Univ of Arizona, 327 N. Sawtelle Ave, Tucson, AZ 85716, Cristine Morgan, MS 2474 TAMU, Texas A&M University - Rangeland Ecology & Management, Texas A&M University, Department of Soil & Crop Sciences, College Station, TX 77845-2474, and Charles T. Hallmark, Dept of Soil & Crop Sciences, Texas A&M Univ, College Station, TX 77843-2474.
Scientists adhere to the scientific method as a research guide, developing hypotheses that are testable. Jenny's soil forming factors model is the most widely accepted model of pedogenesis, and is a powerful tool for conveying information to undergraduate students, but is Jenny’s model suitable for testing hypotheses? Are there models that need more emphasis and might induce more curiosity and productivity from our graduates? Simonson's ordering of processes (additions, losses, translocations, transformations) improved our model set, but does not address rate of change or energy needed to produce a change. Runge and Smeck's energy model gave site-specific thought by adding renewing-upward and developing-downward vectors to the model set, but does not quantitatively predict soil change. Soil forming processes may be generalized into high energy, low frequency (HELF) events (e.g., glaciation) to low energy, high frequency (LEHF) processes (e.g., water movement). HELF events occur over geologic time, reshape the landscape, and reset soil formation. In contrast, management inputs (e.g., irrigation) result in greater biomass production by adding relatively small amounts of energy to the soil system. How will repeated LEHF inputs from water, solutes, and particulate matter affect rates and trajectory of soil formation? Will Ultisols become Alfisols or Oxisols become Inceptisols? Models presented by Jenny, Simonson, or Runge and Smeck may be able to address specific components of low and high energy events, but unable to capture the impact of both high and low energy input events on pedogenesis. Quantitative energy-bases approaches at different scales by Rasmussen and Brye may be used to predict soil properties and pedogenesis. These models represent a hybrid combination of prior models and may be the next step to provide students with a meaningful and testable approach to relevant questions in soil science.