Mrs. Kakali Roy1, Dr. Brian Wilson1,2, Dr. S.M.F. Rabbi3, Katherine Polain1
1University Of New England, Faculty of Science, Agriculture, Business and Law, Armidale, Australia, 2NSW Office of Environment and Heritage, PO Box U221, Armidale, Australia, 3University of Sydney, Camden, Australia
Carbon storage in the soil is believed to be an effective way to sequester atmospheric carbon and abate the impact of climate change. Water soluble carbon in the soil can be adsorbed and stabilised on the clay surfaces. The mechanisms of translocation and stabilisation in this way are complex and require detailed investigation. The sorption and stabilisation of dissolved organic carbon (DOC) is dependent on the DOC concentration, clay content and mineralogy of the soil. We undertook a batch sorption experiment using DOC extracted from a C4 plant to explore the sorption of the added DOC in three soils (i.e. Dermosol, Chromosol and Ferrosol) with contrasting mineralogy. The concentration and isotopic signature of soluble and adsorbed carbon were determined, and the maximum sorption capacity of the soils were modelled. Initial DOC concentration and soil mineralogy both had significant effects on the DOC sorption and our results have significance for the long-term storage of carbon in soils, particularly in the deeper, clay rich horizons.
Katherine is in her final year as a UNE PhD candidate, investigating the role of soil microorganisms in sub-soil nutrient cycling under rotational cotton crops. Prior to her PhD studies, Katherine worked as a secondary science teacher in both New South Wales and the Northern Territory. Her honours was completed at Charles Darwin University, where she studied the role of microorganisms in the acceleration of acid mine drainage. In addition to her PhD studies, Katherine continues to engage with students and the wider community to promote science education and research, when she is not spending time with her young family!