Battery farming: Graphite could be super-fertiliser, say researchers

Initial research by the University of Adelaide has shown this particular type of graphitic carbon contains critical slow release macro and micronutrients essential for healthy plant growth. 

Archer Exploration currently has a number of graphite deposits on Eyre Peninsula in the northwest of South Australia and has submitted a draft mining lease proposal for the development of its first planned mine at Campoona Shaft.

However, it is another of Archer’s graphite deposits, the Sugarloaf deposit, which has been getting much attention lately because its graphite has unique physical and chemical characteristics that may make it ideal for use as a dry land soil conditioner. 

Archer Exploration managing director Gerard Anderson said the Sugarloaf graphite deposit was identified as “unusual​” at an early stage.

“This particular graphite occurs as fine matted porous accumulations, the very low crystallinity sets it apart from our other graphite deposits in the Cleve area​,’’ he said.

“Last year we entered into a research collaboration with the University of Adelaide’s school of chemical engineering for a two-year, A$200,000 [US$143,000] research programme to assess this form of graphite and identify commercial uses for it focusing on large scale uses in agriculture​.”

According to Anderson, carbon compounds such as biochar and peat are already widely used to improve soils. Soil conditioning includes improving soil structure, adding essential nutrients for plant growth, aiding the storage of nutrients and by improving moisture retention.

“The problem with current broad acre fertilisers is that a large percentage of the nutrients can be lost or become unavailable to plants under different weather situations​,” Anderson added.

Farmers can find up to 70% of fertiliser washed away after a heavy rain. Early research has shown that essential macro and micro-nutrients contained in this unique graphite are released slowly under leaching conditions and remain in the soil to provide longer-term nutrient hits to plants during the growing cycle.

“The research findings to date are highly promising and we are close to taking the next step of plant trials to determine the optimum dosage rates and whether this translates into significantly improved plant health and grain yield​,” he said.

The research comes at a critical time for dry land agriculture across the world.

“The projected medium-term impact of global warming is for drier growing conditions​,’’ Anderson said.

“No till farming was currently providing a buffer against drier conditions but more ‘forward leaps’ will be needed to sustain and increase cereal production and Sugarloaf graphite may well be one of those transforming leaps​.”

The next step will to define optimum dosage rates then to commence plant trials to quantify the impact of adding the carbon on plant health and crop yield.  If successful, field trials would be undertaken.

The Sugarloaf graphite has similarities to another form of carbon found in Russia that has been used to fertilise soils for quite some time.

Anderson said Sugarloaf has an exploration target of 40-70m tonnes of 10-12% total carbon that could be converted to a resource with further drilling. 

The research project has also tested the impact of graphene coatings on conventional fertilisers. 

These molecular coatings significantly reduced the release rates of the nutrients. The University of Adelaide recently provided a brief reference to the research in a paper on the subject in New York and it immediately gained interest from global fertiliser companies.

“We know there is international interest for the product and once we are able to quantify its impact on plant health and crop yields, we believe there will be further interest in the project​,” said Anderson.