CF Industries and Agrium are the U.S.-listed nitrogen fertilizer stocks that I know the symbols for, there are others.
From Barron's via Real Time Economics:
How Corn Keeps Fertilizer Costly
Here’s a puzzle: How is it that fertilizer prices are so stubbornly high while the production cost has plunged? The answer lies in the Corn Belt — and it will boost fertilizer equities for the foreseeable future.
Anhydrous ammonia, a nitrogen-based plant food, now sells for nearly $700 a ton. That’s off from the highs of $800 late last year. But the biggest variable cost in making fertilizer, natural gas, has seen its price collapse. It’s off over half from $4.50 a million British thermal units in mid-2011. Natural gas for May delivery closed at $1.927 on the New York Mercantile Exchange Friday, down 2.7% for the week.
If that drop in input costs were passed through, farmers would be paying around $231 a ton for nitrogen fertilizer, according to an analysis of the historical relationship between gas and fertilizer prices by Kevin Dhuyvetter, a farm-management specialist at Kansas State University.
So what gives?
A combination of abnormally high corn prices and increased plantings is keeping plant-food costs elevated. Fertilizer products “have been more tied to crop prices than lower natural-gas prices,” says Jeffrey Stafford, a Morningstar analyst in Chicago. “So producers have been able to capture that wide margin.”
That wasn’t always the case. Anhydrous ammonia prices stayed steady and modest from 2000 through 2006, averaging $366 a ton (ranging from a little above $200 to over $500), according to the U.S. Department of Agriculture. That period also coincided with a period of relative calm for corn prices. Corn averaged $2.29 a bushel over the period, generally bouncing between $2 and $3....MORE