North American inventories of the crop nutrient potash at the mine level dipped in March as exports climbed, the world's top producer by capacity, Potash Corp, said on Friday.

Stockpiles of potassium chloride, as potash is more commonly known, slid 113,000 tonnes or 3.4 percent from February to 3.171 million tonnes, according to data posted on Potash Corporation of Saskatchewan's website.

Inventories of the crop nutrient at the mine level stood 34 percent above the previous five-year average.

Spot potash prices are hovering a little over $400 per tonne.

Potash supplies piled up last year as key global consumers China and India delayed signing new supply contracts with Canpotex, the offshore marketing company owned by Potash Corp, Agrium Inc and Mosaic Co.

Canpotex announced a six-month contract with China on Dec. 31, and a deal with India followed on Feb. 7.

Potash exports by the North American producers jumped 59 percent in March from the previous month to 1.286 million tonnes.

Domestic sales, mainly to the United States, fell 13 percent from the previous month to 668,000 tonnes.

The Western Canadian province of Saskatchewan, where Potash Corp has its headquarters, is home to nearly half of the world's estimated reserves of potash.