Exhibit 10.1.6
AMENDMENT NO. 4 TO THE
TERRA INDUSTRIES INC.
SUPPLEMENTAL DEFERRED
COMPENSATION PLAN
     WHEREAS, Terra Industries Inc. (the “Company”) maintains the Terra
Industries Inc. Supplemental Deferred Compensation Plan as amended effective as
of July 26, 2000 (the “Plan”); and
     WHEREAS, in light of the restrictions imposed on deferred compensation
plans by the American Jobs Creation Act of 2004, it is now considered desirable
to provide for the discontinuance of active participation in the Plan and the
cessation of Participant deferrals under the Plan;
     NOW, THEREFORE, BE IT RESOLVED that, pursuant to the power reserved to the
Company by Section 12.04 of the Plan, the Plan be and it hereby is amended by
adding the following amendment, effective as of December 31, 2004:

  1.   Discontinuance of Active Participation. Effective as of January 1, 2005,
each Participant in the Plan as of that date will continue as a Participant in
the Plan, subject to the terms and conditions of the Plan, as modified by this
Amendment No. 4. However, notwithstanding any provision of the Plan to the
contrary, employees of the Company who were not Participants in the Plan on
December 31, 2004 shall not be eligible to become Participants after that date.

  2.   Discontinuance of Participant Deferrals. Effective for plan years
beginning after December 31, 2004, no additional Participant deferrals will be
made to the Plan. However, Participants’ account balances under the Plan shall
continue to be credited with interest and earnings in accordance with
Section 5.02 of the Plan.

  3.   Vesting of Employer Matching Contributions. Any Employer Matching
Contributions credited to a Participant on or before December 31, 2004, shall
continue to vest in accordance with Section 5.04 of the Plan.

  4.   Trust Agreement. This Amendment No. 4 shall not affect the terms and
conditions of the Trust Agreement under Terra Industries Inc. Deferred
Compensation Plan(s) with The Security National Bank of Sioux City, Iowa, made
effective as of January 1, 1995.

 

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     IN WITNESS WHEREOF, the Company has caused this Amendment No. 4 to be
executed by its duly authorized officer as of the 24th day of December, 2004

            TERRA INDUSTRIES INC.
      /s/ Francis G. Meyer       By Francis G. Meyer
Its Senior Vice President