POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that I, Francis G. Meyer, hereby constitute
and appoint John W. Huey and Debra J. Bliven, and each of them, my true and
lawful attorneys-in-fact and agents, with full power of substitution and
resubstitution for me and in my name, place and stead, to sign any reports on
Form 3 (Initial Statement of Beneficial Ownership of Securities), Form 4
(Statement of Changes in Beneficial Ownership of Securities) and Form 5 (Annual
Statement of Beneficial Ownership of Securities) relating to transactions by me
in Common Shares or other securities of Terra Nitrogen GP Inc. and all
amendments thereto, and to file the same, with the Securities and Exchange
Commission and the appropriate securities exchange, granting unto said
attorneys-in-fact and agents, and each of them, or their substitutes, full power
and authority to do and perform each and every act and thing requisite or
necessary to be done in and about the premises, as fully to all intents and
purposes as I might or could do in person, hereby ratifying and confirming all
that said attorneys-in-fact and agents, and each of them, or their substitutes,
may lawfully do or cause to be done by virtue hereof. This Power of Attorney
shall be effective until such time as I deliver a written revocation thereof to
the above-named attorneys-in-fact and agents.

Dated: March 3, 2009

/s/ Francis G. Meyer
 Francis G. Meyer