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Exhibit 31(a)

CERTIFICATION

I, William J. Doyle, certify that:



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|1. | I have reviewed this annual report on
    Form 10-K of Potash Corporation of Saskatchewan Inc.;                                                                                                                                                                                                                                             
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|2. | Based on my knowledge, this annual report does
    not contain any untrue statement of a material fact or omit to
    state a material fact necessary to make the statements made, in
    light of the circumstances under which such statements were
    made, not misleading with respect to the period covered by this
    annual report;
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|3. | Based on my knowledge, the financial statements,
    and other financial information included in this annual report,
    fairly present in all material respects the financial condition,
    results of operations and cash flows of the registrant as of,
    and for, the periods presented in this annual report;                       
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|4. | The registrants other certifying officer
    and I are responsible for establishing and maintaining
    disclosure controls and procedures (as defined in Exchange Act
    Rules 13a-15(e) and 15d-15(e)) for the registrant and
    we have:                                                                                              



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| | (a) | designed such disclosure controls and procedures,
    or caused such disclosure controls and procedures to be designed
    under our supervision, to ensure that material information
    relating to the registrant, including its consolidated
    subsidiaries, is made known to us by others within those
    entities, particularly during the period in which this annual
    report is being prepared;  
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| | (b) | evaluated the effectiveness of the
    registrants disclosure controls and procedures and
    presented in this report our conclusions about the effectiveness
    of the disclosure controls and procedures, as of the end of the
    period covered by this report based on such evaluation; and                                                                                                            
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| | (c) | disclosed in this report any change in the
    registrants internal control over financial reporting that
    occurred during the registrants most recent fiscal quarter
    (the registrants fourth fiscal quarter in the case of an
    annual report) that has materially affected, or is reasonably
    likely to materially affect, the registrants internal
    control over financial reporting; and



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|5. | The registrants other certifying officer
    and I have disclosed, based on our most recent evaluation of
    internal control over financial reporting, to the
    registrants auditors and the audit committee of the
    registrants board of directors (or persons performing the
    equivalent functions):



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| | (a) | all significant deficiencies and material
    weaknesses in the design or operation of internal control over
    financial reporting which are reasonably likely to adversely
    affect the registrants ability to record, process,
    summarize and report financial information; and
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| | (b) | any fraud, whether or not material, that involves
    management or other employees who have a significant role in the
    registrants internal control over financial reporting.                                                                                                       

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|Date: March 11, 2004 |  | By: |  | /s/ WILLIAM J. DOYLE                     
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|                     |  |     |  | William J. Doyle                         
|                     |  |     |  | President and Chief Executive
    Officer