The Role of Pedotechnology in Solving Forensic and Drought Induced Soil Problems.

One goal of soil science is to apply pedological information to understand, predict and solve practical problems. This is appropriately defined as “pedotechnology”. Pedotechnology research is becoming highly multi- and inter-disciplinary. Pedo-technologists are collaborating closely with police/detectives, wetland ecologists, agriculturists, geologists, hydrologists, engineers and microbiologists like never before to help understand, predict and solve complex soil problems for a multiplicity of practical purposes.

Through case studies, this presentation will demonstrate how advanced pedotechnology information has been critical in developing coherent soil-regolith models of soil information, from microscopic observations to the landscape scale to solve practical soil problems for a broad range of stakeholders. The following case studies will be presented, which tackle difficult problems involving highly complex issues:

1. Soil and water degradation in large aquatic environments from the River Murray and Lower Lakes region in South Australia is caused by changing climatic and anthropogenic modified environments. Recent extreme drought conditions has caused water levels to recede and expose extensive areas of sulfide-containing soils previously formed under reducing conditions in lakes and rivers. As water levels have receded, sulfide minerals have oxidised to form sulfuric acid with soil pH levels as low as 1 and the acidic pore waters have evaporated at soil surfaces precipitating new assemblages of hydrated sulfate-containing evaporite (e.g. sideronatrite) and Fe-oxyhydroxysulfate (e.g. schwertmannite) minerals.  As such, soil-regolith models have been developed, which incorporate these mineral indicators because they reflect changing soil-water processes due to the unique soil and ground water geochemistry of these landscapes (e.g. diurnal, rainfall event and seasonal variations, redox, pH and rates of availability of S and other elements such as Cu, Pb, Zn, Se and As).

2. Soil information is used to both discriminate between or match soils for critical evidence to solve a range of criminal and environmental forensic investigations.