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 312009
    
    2008
    
    2007
    
    2006
    
    2005Canadian GAAPNet income
    
    $
    987.8
    
    
    $
    3,495.2
    
    
    $
    1,103.6
    
    
    $
    631.8
    
    
    $
    542.9Income taxes
    
    
    83.5
    
    
    
    1,077.1
    
    
    
    416.2
    
    
    
    158.1
    
    
    
    267.4Share of earnings of equity investees
    
    
    (133.7
    )
    
    
    (255.8
    )
    
    
    (76.2
    )
    
    
    (54.4
    )
    
    
    (52.1
    )Fixed
charges
    
    
    255.9
    
    
    
    187.1
    
    
    
    187.5
    
    
    
    183.5
    
    
    
    149.1Distributed income of equity investees
    
    
    130.9
    
    
    
    89.1
    
    
    
    40.6
    
    
    
    29.9
    
    
    
    18.6Interest capitalized
    
    
    (68.2
    )
    
    
    (42.9
    )
    
    
    (21.8
    )
    
    
    (19.1
    )
    
    
    (5.7
    )Total Earnings Available for Fixed Charges
    
    $
    1,256.2
    
    
    $
    4,549.8
    
    
    $
    1,649.9
    
    
    $
    929.8
    
    
    $
    920.2Fixed
ChargesInterest expensed and capitalized
    
    $
    227.2
    
    
    $
    160.9
    
    
    $
    165.4
    
    
    $
    163.6
    
    
    $
    127.2Amortization of debt issue costs
    
    
    3.0
    
    
    
    1.8
    
    
    
    2.3
    
    
    
    1.0
    
    
    
    2.2Estimated portion of rent expense
representing interest
    
    
    25.7
    
    
    
    24.4
    
    
    
    19.8
    
    
    
    18.9
    
    
    
    19.7Total Fixed Charges
    
    $
    255.9
    
    
    $
    187.1
    
    
    $
    187.5
    
    
    $
    183.5
    
    
    $
    149.1Ratio of Earnings to Fixed Charges
    
    
    4.91
    
    
    
    24.32
    
    
    
    8.80
    
    
    
    5.07
    
    
    
    6.17US GAAPNet income
    
    $
    996.1
    
    
    $
    3,395.2
    
    
    $
    1,061.5
    
    
    $
    625.8
    
    
    $
    532.7Income taxes
    
    
    56.1
    
    
    
    1,175.8
    
    
    
    452.3
    
    
    
    174.4
    
    
    
    288.0Share of earnings of equity investees
    
    
    (132.5
    )
    
    
    (254.8
    )
    
    
    (74.3
    )
    
    
    (54.9
    )
    
    
    (55.8
    )Fixed
charges
    
    
    255.9
    
    
    
    187.1
    
    
    
    187.5
    
    
    
    183.5
    
    
    
    149.1Distributed income of equity investees
    
    
    130.9
    
    
    
    89.1
    
    
    
    40.6
    
    
    
    29.9
    
    
    
    18.6Interest capitalized
    
    
    (68.2
    )
    
    
    (42.9
    )
    
    
    (21.8
    )
    
    
    (19.1
    )
    
    
    (5.7
    )Total Earnings Available for Fixed Charges
    
    $
    1,238.3
    
    
    $
    4,549.5
    
    
    $
    1,645.8
    
    
    $
    939.6
    
    
    $
    926.9Fixed
ChargesInterest expensed and capitalized
    
    $
    227.2
    
    
    $
    160.9
    
    
    $
    165.4
    
    
    $
    163.6
    
    
    $
    127.2Amortization of debt issue costs
    
    
    3.0
    
    
    
    1.8
    
    
    
    2.3
    
    
    
    1.0
    
    
    
    2.2Estimated portion of rent expense
representing interest
    
    
    25.7
    
    
    
    24.4
    
    
    
    19.8
    
    
    
    18.9
    
    
    
    19.7Total Fixed Charges
    
    $
    255.9
    
    
    $
    187.1
    
    
    $
    187.5
    
    
    $
    183.5
    
    
    $
    149.1Ratio of Earnings to Fixed Charges
    
    
    4.84
    
    
    
    24.32
    
    
    
    8.78
    
    
    
    5.12
    
    
    
    6.22