Smart farmers

Expert view

Smart fertiliser solution for Great Lake water problem

The Great Lakes are a focal point of the landscape, environment, climate and the economy of east central North America.

Lake Erie, the second smallest of the five lakes, is struggling with an algae bloom that depletes oxygen in the lake, can be toxic to aquatic life and impacts the drinking water of 11m people in Canada and the United States.

See also: Technology helps North Americans get more for grain

Agriculture is one source of the high phosphorous levels behind the bloom. And farmers are taking action – from greenhouse water recycling systems to precision agriculture tools that place nutrients more precisely, and using cover crops and erosion control measures to keep phosphorous in the ground and out of the water.

But what if the fertiliser itself was the precision agriculture tool? That’s what a Canadian research team in Ottawa is working on – developing fertiliser so smart it deploys on-demand when the crop needs nutrients.

Use of nanobiosensors

Dr Maria DeRosa, a chemistry professor at Carleton University, is working with nanobiosensors called aptamers, which are small, single-stranded nucleic acids that can bind to large or small target molecules.

Maria DeRosa

Dr Maria DeRosa

She’s been working at identifying these aptamers, which are the “keys” to finding which DNA sequences will bind to the target molecules.

Crop signals

Crops such as wheat and canola release specific chemical signals when they need nitrogen, and a partnership with Agriculture and Agri-Food Canada research scientist Carlos Monreal helped Dr DeRosa identify some of those signals.

This let her programme the coating of special biodegradable fertiliser capsules she’s developed, so they only break down and release the nutrients inside when they receive a signal from the plant.

The capsule exterior protects the fertiliser from being washed away or damaged by extreme temperatures while it waits to be released.

See also: Sophistication will give farming economic and environmental win-win

On-demand fertiliser: enormous potential

The potential of the technology, currently in development, is enormous – from reducing water pollution and protecting aquatic environments to saving farmers money and lowering greenhouse gas emissions through decreased fertiliser use and fewer passes over the fields.

There’s also the possibility of developing crop-specific fertilisers that can help meet higher food production targets in the future.