Graphene found to boost fertiliser efficiency

Researchers have developed a fertiliser that uses a graphene-based carrier to increase overall efficiency.

The researchers, from the University of Adelaide, believe the development could also reduce environmental impacts and costs for farmers.

The fertiliser carrier—the substance containing the essential elements needed to nourish plants—was found to release nutrients more slowly when loaded onto graphene oxide sheets.

So far the graphene-based carriers have been demonstrated with zinc and copper, with further plans to use macronutrients such as nitrogen and phosphate.

The researchers, working with industry partners, also found that a graphene-based carrier allows the fertilisers to be applied in a more targeted fashion and with a greater nutrient uptake by the plants.

“Fertilisers that show slower, more controlled release and greater efficiency will have reduced impact on the environment and lower costs for farmers over conventional fertilisers, bringing significant potential benefit for both agriculture and the environment,” said Head of the University of Adelaide’s Fertiliser Technology Research Centre at the Waite campus, Professor Mike McLaughlin.

“Our research found that loading copper and zinc micronutrients onto graphene oxide sheets was an effective way to supply micronutrients to plants. It also increased the strength of the fertiliser granules for better transport and spreading ability.”

The study, called Graphene Oxide: A New Carrier for Slow Release of Plant Micronutrients, was carried out by PhD student Shervin Kabiri and has been published in the journal Applied Materials and Interfaces.

It is a collaboration between the University of Adelaide’s Fertiliser Technology Research Centre and the University’s Australian Research Council Research Hub for Graphene Enabled Industry Transformation.

In 2007 The Mosaic Company, a producer of phosphate and potash, established a partnership with the Fertiliser Technology Research Centre to develop and evaluate more efficient fertiliser product. They reached a new five-year agreement in 2015, worth $8.5m. Mosaic has an option to licence the new graphene-based technology.

Nanotechnology leader at the University’s School of Chemical Engineering and director of the University’s Australian Research Council (ARC) Research Hub for Graphene Enabled Industry Transformation Professor Dusan Losic said: “Graphene is a novel new material only discovered in 2004 and has incredible properties, including a very high surface area, strength and adaptability to bind to different nutrients.

“We started exciting research on a broad range of applications of graphene four years ago—this is the first time graphene has been developed as a carrier for fertiliser nutrients.”

While the development offers a lot of potential to improve crop-growth efficiency, McLaughlin remained cautious of the remaining challenges.

“Successful commercialisation will depend on cost of graphene or graphene oxide and the ability to scale this process up, and integrate it into the commercial fertiliser production process,” he said.