MINE, FIELD | August 4th 2008

kevindooley/flickr

Potash mining in Saskatchewan is big business. The Economist's Ottawa correspondent plummets 1,000 metres into the earth to see a mine for herself. "With each kilometre I experience small waves of panic at the thought that we are getting farther from the escape shaft" ...

The metal gates of the lift clang shut and with a gentle jolt we are on our way, down 1,000 metres to the floor of PotashCorp's mine in Allan, Saskatchewan. Potash is a form of potassium chloride used as fertilizer. Its price has soared over the last year, helping to attract new workers and investment to this prairie province thought to be in long-term decline.

Philipp Gauer, the mine's general foreman, and the two other miners in the lift, wear dusty coveralls, work boots and lighted helmets. Each carries a canteen with enough water to last their 12-hour shift. In my blue paper coverall and white helmet, I look like a Smurf.

When the gates open we enter a world that might have been coloured by a little girl: everything is pink. Canadian potash is a deep rose and whatever wasn't pink originally is turned that colour by the potash dust. The company calls it "red product", but to my eye, it's a paler shade. Maybe calling it red makes it sound more manly.

After alighting in a cavern at least 15 metres high and equally wide, we clamber into a roofless Toyota that has been modified for underground use. A 15km drive leads us through a series of tunnels about six feet high and four feet wide--the same size as the potash seam being mined.

With each kilometre I experience small waves of panic at the thought that we are getting farther from the escape shaft, and we make so many twists and turns, and cross so many other tunnels, that I have lost any sense of which way is out. So I distract myself with other thoughts, such as the strong taste of salt on my lips.

We are driving along what was once the floor of an inland sea that covered most of Saskatchewan, Alberta, Montana and North Dakota. It evaporated 300-400m years ago, leaving a uniform layer of 70% salt, 5% clay and 25% potash about 1,000 metres down.

"Potash mining is very safe," says Mr Gauer, who contrasts it with hard-rock mining, where there is a constant risk that the rock walls will burst. We stop in a lighted area and he drags his finger through the pink dust on the dashboard to illustrate their mining technique. They drill tunnels designed to collapse diagonally off the main tunnels. This "relieves" the stress on the tunnels they want to keep open. It also provides a reassuring explanation for the rubble-strewn tunnels I had seen but didn't want to think too much about.

The deep rumble of machinery announces that we have arrived at our destination. Curtains of heavy plastic shroud the work area. "Put your ear plugs in and stay close to me," Mr Gauer advises. "Don't touch the walls, because sometimes pieces fall off." He then leads the way to the source of the din, a 160-tonne boring machine that is moving almost imperceptibly forward, guided by a laser beam, chewing a hole 3.3 metres high and 5.5 metres wide in the soft rock.

The machine operator gestures to me to climb up and sit in front of the multi-coloured light panel. I touch nothing ("Journalist causes mine collapse," flashes briefly through my mind), but I savour the feeling of raw power that the noise and the size of the machine convey.

The return journey seems much faster, thanks to the wind from giant ventilation machines at our back. Near the end, he confides that his high school guidance counsellor in Esterhazy, Saskatchewan, warned him not to pursue a mining career because it was a "dying industry" and he would never get a job. He is tickled pink to have proved her wrong.

The immediate future for potash looks bright. Farmers around the world need fertilizer, and potash companies are desperately trying to increase production as the price rises. PotashCorp plans to invest about C$6.1 billion ($6 billion) over the next few years to expand its capacity at its seven mines. Customers are currently on allocation: they send in a request for what they want and are told what they will get. A storage shed at the mine capable of holding 200,000 tonnes of potash was full in 2006 and totally empty now.

As we re-enter the metal cage and prepare to ascend I start to relax. Fear is a curious thing. I visited a diamond mine in north-eastern Angola during the civil war and a chaotic uranium and cobalt mine at Shinkolobwe in the Congo more recently. Both were far more dangerous, but because they were open mines, offering a reassuring view of the sky, escaping seemed quick and easy (though of course it was neither). The return to daylight comes as welcome relief.

(This column is part of a correspondent's diary on Saskatchewan, published on Economist.com)