Potash Corp. of Saskatchewan, Inc. POT is a fertilizer company producing three primary plant nutrients – potash, phosphate and nitrogen.Potash Corp. has a competitive advantage stemming from its mining rights to the world's largest potash reserve. The company has a strong geographic diversification as most of the potash is sent offshore. Moreover, Potash Corp. continues to invest in expanding its operational capability in potash. However, Potash Corp. is exposed to a volatile pricing environment.Let’s have a quick look at the company’s first-quarter 2016 release.Estimate Trend & Surprise HistoryInvestors should note that the earnings estimate for Potash Corp. for the first quarter has declined by a penny over the last month. The company has missed the Zacks Consensus Estimate in all of the trailing 4 quarters with an average negative surprise of 11.60%.EarningsPotash Corp. delivered adjusted earnings of 15 cents per share for the quarter. That missed the Zacks Consensus Estimate of 16 cents.RevenuesPotash Corp. reported revenues of $1,076 million. That missed the Zacks Consensus Estimate of $1,254 million.Key Developments to NoteDue to weaker demand, the company cut production and lowered its outlook for 2016 potash sales volumes to a range of 8.3-8.8 million tons. Due to the challenging market conditions Potash Corp. lowered its full-year 2016 earnings guidance to the range of 60 cents to 80 cents per share. For the second quarter, the company expects earnings to be in the range of 15 cents to 25 cents per share.Zacks RankCurrently, Potash Corp. has a Zacks Rank #5 (Strong Sell), which reflects the headwinds faced by the company.Market ReactionPotash Corp’s shares were inactive in pre-market trading. It would be interesting to see how the market reacts to the results during the trading session today.Check back later for our full write up on Potash Corp’s earnings report!Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report POTASH SASK (POT): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research