Declining soil health has driven CMBD team member, Kirsten Heimann, to develop sustainable methods for soil remediation.

“Many soils are degraded and becoming less fertile. This challenges agriculture to produce sufficient high-quality food to feed the growing population, which is further exacerbated by climatic instability threatening crop production,” says Flinders University researcher Dr. Kirsten Heimann.

She is working with a team to develop an organic fertiliser to replace chemicals currently used to repair badly degraded agricultural regions.

The new organic fertiliser is made from fast-growing aquatic cyanobacterial biomass. Cyanobacteria are a non-toxic form of blue-green algae. Scientists in Australia, the US and Europe are testing this new biofertiliser made from a freshwater cyanobacterium Tolypothrix, which can fix nitrogen from the atmosphere (a chemical process by which molecular nitrogen in the air is converted to compounds) without the need for the addition of chemical nitrogen fertilisation.

This form of algae can be cultivated in freshwater, and even slightly saline or industrial wastewater such as from coal-fired power stations, the research team has found. Capturing biofuel may also be used to offset production costs.

Researchers say the conversion of pond-produced cyanobacterial biomass produced on farming land would provide a major in-situ source of renewable nitrogen-rich fertiliser, also helping to reduce carbon emissions from chemical fertiliser production and transport.

The article, Biomass pre-treatments of the N2-fixing cyanobacterium Tolypothrix for co-production of methane (2021) by C Velu, OP Karthikeyan, DL Brinkman, S Cirés and K Heimann has been published in Chemosphere (Elsevier) DOI: 10.1016/j.chemosphere.2021.131246

Acknowledgements: This research received funding from the Advanced Manufacturing Cooperative Research Centre (AMCRC) and associated Universities.