Exhibit 12
 Potash Corporation of Saskatchewan Inc.
Ratio of Earnings to Fixed Charges
(in millions of US dollars, except ratio amounts)
(unaudited)
 Year ended December 312008
    
    2007
    
    2006
    
    2005
    
    2004Canadian GAAPNet income
    
    $
    3,495.2
    
    
    $
    1,103.6
    
    
    $
    631.8
    
    
    $
    542.9
    
    
    $
    298.6Income taxes
    
    
    1,077.1
    
    
    
    416.2
    
    
    
    158.1
    
    
    
    267.4
    
    
    
    131.7Share of earnings of equity investees
    
    
    (255.8
    )
    
    
    (76.2
    )
    
    
    (54.4
    )
    
    
    (52.1
    )
    
    
    (30.9
    )Fixed charges
    
    
    187.1
    
    
    
    187.5
    
    
    
    183.5
    
    
    
    149.1
    
    
    
    132.4Distributed income of equity investees
    
    
    89.1
    
    
    
    40.6
    
    
    
    29.9
    
    
    
    18.6
    
    
    
    8.7Interest capitalized
    
    
    (42.9
    )
    
    
    (21.8
    )
    
    
    (19.1
    )
    
    
    (5.7
    )
    
    
    (2.5
    )Total Earnings Available for Fixed Charges
    
    $
    4,549.8
    
    
    $
    1,649.9
    
    
    $
    929.8
    
    
    $
    920.2
    
    
    $
    538.0Fixed ChargesInterest expensed and capitalized
    
    $
    160.9
    
    
    $
    165.4
    
    
    $
    163.6
    
    
    $
    127.2
    
    
    $
    112.8Amortization of debt issue costs
    
    
    1.8
    
    
    
    2.3
    
    
    
    1.0
    
    
    
    2.2
    
    
    
    2.2Estimated portion of rent expense representing interest
    
    
    24.4
    
    
    
    19.8
    
    
    
    18.9
    
    
    
    19.7
    
    
    
    17.4Total Fixed Charges
    
    $
    187.1
    
    
    $
    187.5
    
    
    $
    183.5
    
    
    $
    149.1
    
    
    $
    132.4Ratio of Earnings to Fixed Charges
    
    
    24.32
    
    
    
    8.80
    
    
    
    5.07
    
    
    
    6.17
    
    
    
    4.06US GAAPNet income
    
    $
    3,395.2
    
    
    $
    1,061.5
    
    
    $
    625.8
    
    
    $
    532.7
    
    
    $
    290.5Income taxes
    
    
    1,175.8
    
    
    
    452.3
    
    
    
    174.4
    
    
    
    288.0
    
    
    
    151.9Share of earnings of equity investees
    
    
    (254.8
    )
    
    
    (74.3
    )
    
    
    (54.9
    )
    
    
    (55.8
    )
    
    
    (30.9
    )Fixed charges
    
    
    187.1
    
    
    
    187.5
    
    
    
    183.5
    
    
    
    149.1
    
    
    
    132.4Distributed income of equity investees
    
    
    89.1
    
    
    
    40.6
    
    
    
    29.9
    
    
    
    18.6
    
    
    
    8.7Interest capitalized
    
    
    (42.9
    )
    
    
    (21.8
    )
    
    
    (19.1
    )
    
    
    (5.7
    )
    
    
    (2.5
    )Total Earnings Available for Fixed Charges
    
    $
    4,549.5
    
    
    $
    1,645.8
    
    
    $
    939.6
    
    
    $
    926.9
    
    
    $
    550.1Fixed ChargesInterest expensed and capitalized
    
    $
    160.9
    
    
    $
    165.4
    
    
    $
    163.6
    
    
    $
    127.2
    
    
    $
    112.8Amortization of debt issue costs
    
    
    1.8
    
    
    
    2.3
    
    
    
    1.0
    
    
    
    2.2
    
    
    
    2.2Estimated portion of rent expense representing interest
    
    
    24.4
    
    
    
    19.8
    
    
    
    18.9
    
    
    
    19.7
    
    
    
    17.4Total Fixed Charges
    
    $
    187.1
    
    
    $
    187.5
    
    
    $
    183.5
    
    
    $
    149.1
    
    
    $
    132.4Ratio of Earnings to Fixed Charges
    
    
    24.32
    
    
    
    8.78
    
    
    
    5.12
    
    
    
    6.22
    
    
    
    4.15