TORONTO (Reuters) - North American fertilizer makers weathered dismal market conditions in 2009, but stocks in the sector may gain this year as early signs point to a strong recovery in crop nutrient demand.

Shares of Potash Corp, Agrium Inc and Mosaic Co — the big three of the North American fertilizer industry — are little changed this year, despite recent data indicating tightening market conditions and stronger demand ahead of the spring planting season.

"We are in the sweet spot of owning fertilizer stocks as we head into the seasonally strong spring season," said Broadpoint AmTech analyst Edlain Rodriguez, who argues that improving global fertilizer demand will lift investor sentiment and propel stocks higher. Potash Corp, the world's largest fertilizer maker, has consistently outperformed the Standard and Poor's 500 by an average of 12 percentage points between January and April, over the last six years, notes Rodriguez. Rodriguez, who has "buy" ratings on all of the big three, believes their stocks are likely to rise about 25 percent above current levels, within a 12-month horizon.

The typically staid fertilizer sector became a Wall Street darling between 2006 and 2008, as stocks hit record highs amid the commodity price boom. But the shares crumbled as the global economic crisis crushed commodity demand and pricing.

Following a bumper North American harvest in 2009, the latest industry data indicates that inventory levels of essential crop nutrients are declining, while pricing has begun to tick higher.

North American potash inventories at the producer level have begun to trend steadily lower since October. And potash export conglomerate Canpotex, which recently signed a deal to supply China's Sinofert, is now fully committed on sales through the first quarter of 2010.