Soil aggregation is caused by organic matter interacting with soil minerals. The interaction can be caused by physical associations (i.e. organic matter coated with soil minerals) or chemical associations (ionic or van derWaals forrces) between functional groups of organic matter with active surface sites on minerals. Microbial activity in soil degrades the organic matter and results in disintegration of the organic matter- mineral bonds. This results in changes in aggregate sizes. However, it is not known how rapidly these changes occur for various organic matter-minerals associations. The aim of this project is to determine the kinetics of the organic matter degradation and shift in aggregation over time. This project would suit a student with interest in soil chemistry. The project is co-supervised by Dr Gunnar Kirchhof (UQ-SAFS). The outcome of the project is a deeper understanding of the turnover of organic matter in soil.