Key researchers involved:

• Professor Feike Dijkstra (The University of Sydney)
• Dr Claudia Keitel (The University of Sydney)
• Professor Federico Maggi (The University of Sydney)
• Professor Francesca Cotrufo (Colorado State University)

This project will examine the key role that plant roots have on forming and destroying soil carbon under drought and non-drought conditions. It will investigate management practices, including fertiliser use to store more carbon in soil via the activity of plant roots. Computer models will be used to make long-term predictions about drought effects on soil carbon. This

project will provide important information to improve soil quality and food production, thereby benefiting the livestock industry in Australia.

Key researchers involved:

• Professor Balwant Singh (The University of Sydney)
• Professor Feike Dijkstra (The University of Sydney)
• Professor Charles Warren (The University of Sydney)

This project will determine soil-plant combinations that have potential to maximise organic carbon sequestration in the soil. Mineral associated organic matter (MAOM) is the key element for the long-term preservation of soil organic matter (SOM). Crop/pasture plants supply different organic compounds in the soil through organic residues, root biomass and exudates. Microbial processing of plant organic compounds is highly variable, with labile compounds mineralised quickly and believed to stabilise SOM by forming MAOM. Our research will determine carbon use efficiency of plant organic compounds and assess the efficiency of organic compounds of plant and microbial origin to form MAOM with different soil minerals. This project will provide the first comprehensive examination of the relative roles of plant exudates in relation to soil mineralogy in determining SOM stabilisation.

Key researchers involved:

• Professor Balwant Singh (The University of Sydney)
• Professor Feike Dijkstra (The University of Sydney)
• Professor Georg Guggenberger (Gottfried Wilhelm Leibniz University of Hannover)

This project will use novel and emerging techniques to discover the composition of organic carbon and stability of organic carbon present in mineral-organic associations in representative Australian soils. Expected outcomes include new knowledge necessary for emerging global carbon cycling models and improve future climate projections.

Key researchers involved:

• Professor Feike Dijkstra (The University of Sydney)
• Professor Charles Warren (The University of Sydney)
• Associate Professor Andrew Holmes (The University of Sydney)

This project will assess the interplay between earthworms, microbes, and soil environmental conditions on decomposition and stabilisation of carbon. We combine novel stable isotope, metabolomic, and genome sequencing techniques in mesocosm experiments, and generate much needed data about the role of earthworms on soil carbon sequestration.