Quantifying Processes of Pedogenesis

Our knowledge of plant and animal growth and development is far superior to that of the evolution of soil, yet soil plays a fundamental role in natural ecosystems. To understand the complexity of soil systems we need to explore processes that lead to its formation. Research in pedogenesis has been focused on formalizing soil-forming factors and processes to ultimately model soil formation in the landscape. Early models described soil formation qualitatively and were mostly limited to a description of soil evolution in the landscape. They led to the development of qualitative models of pedogenesis based on empirical observations and later to quantitative models of pedogenesis based on empirical equations or detailed differential equations derived from fundamental physics. This review highlights the main models of pedogenesis and focuses on models and rates of pedogenic processes such as the production of soil from weathering of parent materials, and vertical and lateral movements in the soil profile. It will become clear that field and laboratory work is needed to improve and validate quantitative models of pedogenesis. In order to estimate and verify model parameters, it is therefore of importance to collect real-world data.