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Exhibit 21

SUBSIDIARIES OF
POTASH CORPORATION OF SASKATCHEWAN INC.

|                                         |  |                               |  | 
|---------------------------------------- |  | ----------------------------- |  | 
|                                         |  | Jurisdiction of Incorporation
|Name of Entity                           |  | or Formation                 
|                                         |  |                              
|175360 Canada Inc.                       |  | Canada                       
|609430 Saskatchewan Ltd.                 |  | Saskatchewan                 
|628550 Saskatchewan Ltd.                 |  | Saskatchewan                 
|AA Sulfuric Corp.                        |  | Louisiana                    
|AC Industries                            |  | Delaware                     
|Augusta Service Company Inc.             |  | Delaware                     
|Canpotex Bulk Terminals Ltd.             |  | Canada                       
|Chilkap Resources Ltd.                   |  | Yukon                        
|El Boldo Limitada                        |  | Chile                        
|El Roble Limitada                        |  | Chile                        
|Houston Ammonia Terminal, L.P.           |  | Delaware                     
|Inversiones PCS Chile Limitada           |  | Chile                        
|Inversiones
RAC Chile Limitada           |  | Chile                        
|Minera Saskatchewan Limitada             |  | Chile                        
|PCS (Barbados) Shipping Ltd.             |  | Barbados                     
|PCS Administration (USA), Inc.           |  | Delaware                     
|PCS Barbados Holdings SRL                |  | Barbados                     
|PCS Cassidy Lake Company                 |  | Ontario                      
|PCS Cassidy Lake Limited                 |  | Canada                       
|PCS Chile I LLC                          |  | Delaware                     
|PCS Chile II LLC                         |  | Delaware                     
|PCS Fosfatos do Brasil Ltda.             |  | Brazil                       
|PCS Hungary Holding Limited              |  | Hungary                      
|PCS Industrial Products Inc.             |  | Delaware                     
|PCS Joint Venture, LP                    |  | Florida                      
|PCS Jordan LLC                           |  | Delaware                     
|PCS L.P. Inc.                            |  | Delaware                     
|PCS Nitrogen Amm Term Corp I             |  | Texas                        
|PCS Nitrogen Amm Term Corp II            |  | Delaware                     
|PCS Nitrogen Delaware LLC                |  | Delaware                     
|PCS Nitrogen Fertilizer, L.P.            |  | Delaware                     
|PCS Nitrogen Fertilizer Limited          |  | Trinidad                     
|PCS Nitrogen Fertilizer Operations, Inc. |  | Delaware                     
|PCS Nitrogen, Inc.                       |  | Delaware                     
|PCS Nitrogen LCD Corporation             |  | Delaware                     
|PCS Nitrogen Limited                     |  | Trinidad                     
|PCS Nitrogen Ohio, L.P.                  |  | Delaware                     
|PCS Nitrogen Payroll Corporation         |  | Delaware                     
|PCS Nitrogen Trinidad Corporation        |  | Delaware                     
|PCS Nitrogen Trinidad Limited            |  | Trinidad                     





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##### 



|                                                     |  |                               |  | 
|---------------------------------------------------- |  | ----------------------------- |  | 
|                                                     |  | Jurisdiction of Incorporation
|Name of Entity                                       |  | or Formation                 
|                                                     |  |                              
|PCS Phosphate Company, Inc.                          |  | Delaware                     
|PCS Purified Phosphates                              |  | Virginia                     
|PCS Sales (Canada) Inc.                              |  | Saskatchewan                 
|PCS Sales (Indiana), Inc.                            |  | Indiana                      
|PCS Sales (Iowa), Inc.                               |  | Iowa                         
|PCS Sales (USA), Inc.                                |  | Delaware                     
|PCS USA LLC                                          |  | Delaware                     
|Phosphate Holding Company, Inc.                      |  | Delaware                     
|Potash Corporation of Saskatchewan (Florida) Inc.    |  | Florida                      
|Potash Corporation of Saskatchewan Transport Limited |  | Saskatchewan                 
|Potash Holding Company, Inc.                         |  | Delaware                     
|RAC
Investments Ltd.                                 |  | Cayman                       
|Texasgulf Aircraft Inc.                              |  | Delaware                     
|Tg Corporation                                       |  | Delaware                     
|White Springs Agricultural Chemicals, Inc.           |  | Delaware