Soil Organic Chemistry
Soil organic matter (SOM) is an important, dynamic reservoir in the global carbon cycle. It has been estimated that about 1760 x 1012 kg of carbon resides in the soil environment, over twice the amount of carbon residing in the atmosphere. Hence, SOM plays a central role in the biogeochemical cycling of carbon. For example, it is intimately involved in the regulation of atmospheric 'greenhouse' gases through processes such as atmospheric methane oxidation and long-term carbon sequestion. Despite the importance of such processes in formulating environmental policies, e.g. carbon trading, relatively little of the underlying organic chemistry leading the the formation of recalcitrant SOM is fully understood. Mechanisms such as these will only ever be understood through the use of empirical evidence and only then will we be able to accurately model and predict future changes in the environment.
The majority of carbon in the soil (~90%) exists as refractory macromolecular structures often referred to as 'humic substances'. The remaining ~10% SOM comprises low molecular weight components typically consisting of free sugars, amino acids and lipids. My research seeks to address key questions relating to the mechanisms by which these chemical components are related, how refractory organic matter is formed in the soil and the chemical effects that different abiotic and biotic environments have on these processes.
