Nanotechnology may soon become an everyday part of agriculture, thanks to research carried out at the University of Adelaide.
In a paper published in the journal Applied Materials and Interfaces, a team led by Mike McLaughlin of the university’s Fertiliser Technology Research Centre report the use of graphene as a new and highly targeted delivery mechanism for plant nutrients.
Graphene was first developed in 2004. It is the world’s thinnest material, a transparent single layer of carbon atoms arranged in a hexagonal lattice. Despite its apparent flimsiness, however, it is extremely tough, more than 200 times stronger than steel. It works as a conductor, but can also form a perfect impermeable barrier.
It is also very much the flavour of the month in both nanotechnology and materials science, being used in quantum computing, sensors, biomedical research, electronics – and now, agriculture.
Graphene oxide as a vehicle for nutrient delivery
McLaughlin and his colleagues demonstrate that fertilisers can be effectively deployed by loading trace elements and micronutrients such as zinc and copper into graphene oxide sheets.
Distributing the plant essentials in graphene oxide confers much greater effectiveness and control than using existing methods. Scaled up, the method promises reduced costs to farmers by prolonging fertiliser release, and less damage to the environment by reducing total fertiliser load.
To test the suitability of, the scientists infused separate sheets with zinc and copper, and then applied them to potted wheat plants. A second set of potted samples were dosed with conventional zinc and copper salts.
The trial showed that the graphene system resulted in greater uptake of the elements.
“Our research found that loading copper and zinc micronutrients onto graphene oxide sheets was an effective way to supply micronutrients to plants,” says McLaughlin.
“It also increased the strength of the fertiliser granules for better transport and spreading ability.”
The team is now turning its attention to using the graphene system to deliver macronutrients, such as nitrogen and phosphate.
Picture - Graphene’s hexagonal molecular lattice structure made of carbon atoms