On a Canadian marsh, a wave of ocean blue shipping containers is the venue for a kind of water Olympics.

Nine international teams vying for $10 million if they can stop harmful algae blooms caused by agricultural runoff.

From a shipping container in Ontario, I'm Ann Thompson, and this is NBC on Earth.

Here in our north of Toronto, in Ontario's agricultural heartland, the soil is dark and rich. When the weather

warms, it yields a variety of vegetables, carrots, onions, and increasingly Asian favorites like

bok choy.

On a bitter cold day in March, three shipping containers hung with possibility on the yet-to-be-planted fields.

Each bright blue shipping container is divided into thirds, giving each team nine square meters to try and solve one of the world's most vexing water problems.

How to remove phosphorus.

Phosphorus helps root systems grow.

It also fuels algae blooms.

Jim King, I'm Senior Vice President of Corporate Affairs at the Scott's Miracle Growth Company.

Jim, first of all, what is the role of phosphorus in fertilizer?

So, phosphorus promotes root growth in fertilizer. So if you think about the components

of most fertilizers, it's got nitrogen, it's got potassium, it's got phosphorus, or at least

it did for lawn fertilizers historically, but not currently. But nitrogen makes your grass green

and grow tall. Potassium is essentially like a multivitamin,

and then phosphorus promotes the root growth. So, and so we know that the other thing it does

is obviously create or promote algae blooms in water. Scots took phosphorus out of its lawn

fertilizer six years ago.

We looked at our formulations and determined that an established lawn probably didn't need to have

phosphorus applied to it on a regular basis. There was enough phosphorus existing in the soil.

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