<Page>
Exhibit 3.i(u)
CERTIFICATE OF INCORPORATION
OF
KALIUM CARLSBAD CHEMICAL COMPANY
FIRST: The name of the Corporation is Kalium Carlsbad Chemical
Company.
SECOND: The address of the Corporation's registered office in the
State of Delaware is 1013 Centre Road, Wilmington, 19805, County of New
Castle. The name of the Corporation's registered agent at such address is
Corporation Service Company.
THIRD: The purpose of the Corporation is to engage in any lawful
act of activity for which corporations may be organized under the General
Corporation Law of Delaware.
FOURTH: The total number of shares of all classes of capital stock
which the Corporation shall have the authority to issue is 1,000 shares of
common stock with a par value of $1.00 per share.
FIFTH: The names and mailing address of the incorporators are
Robert J. Lewis and Betty Ann Thornson, both c/o Sidley & Austin, One First
National Plaza, Chicago, Illinois 60603.
SIXTH: In furtherance and not in limitation of the powers
conferred by statute, the Board of Directors is expressly authorized to make,
alter or repeal the Bylaws of the Corporation, subject to any specific
limitation on such power contained in any Bylaws adopted by the stockholders.
Elections of directors need not be by written ballot unless the Bylaws of the
Corporation so provide.
SEVENTH: A director of the Corporation shall not be personally
liable to the Corporation or its stockholders for monetary damages for breach
of fiduciary duty as a director, except for liability (i) for any breach of
the director's duty of loyalty to the Corporation or its stockholders, (ii)
for acts or omissions not in good faith or which involve intentional
misconduct or a knowing violation of law, (iii) under Section 174 of the
General Corporation Law of Delaware, or (iv) for any transaction from which
the director derived an improper personal benefit. If the General Corporation
Law of Delaware is amended to authorize corporate action further eliminating
or limiting the personal liability of directors, then the liability of a
director of the Corporation shall be eliminated or limited to the fullest
extent permitted by the General Corporation Law of Delaware, as so amended.
Any repeal or modification of this Article Seventh by the stockholders of
the Corporation shall not adversely affect any right or protection of a
director of the Corporation existing at the time of such repeal or
modification.
<Page>
EIGHTH: Each person who is or was a director or officer of the
Corporation, and each person who serves or served at the request of the
Corporation as a director or officer of another enterprise, shall be
indemnified by the Corporation in accordance with, and to the fullest extent
authorized by, the General Corporation Law of Delaware as it may be in effect
from time to time.
NINTH: The corporation reserves the right to amend, alter, change
or repeal any provision contained in this Certificate of Incorporation, in
the manner now or hereafter prescribed by statute, and all rights conferred
upon the stockholders herein are granted subject to this reservation.
THE UNDERSIGNED, being the incorporators named above, have executed
this Certificate of Incorporation of Kalium Carlsbad Chemical Company on
June 14, 1996.
/s/ Robert J. Lewis /s/ Betty Ann Thornson
- --------------------------------- -----------------------------------
Robert J. Lewis Betty Ann Thornson
<Page>
CERTIFICATE OF AMENDMENT
TO
CERTIFICATE OF INCORPORATION
OF
KALIUM CARLSBAD CHEMICAL COMPANY
Kalium Carlsbad Chemical Company, a corporation organized and
existing under and by virtue of the General Corporation Law of the State of
Delaware, DOES HEREBY CERTIFY:
1. That the Incorporators of said corporation, by written consent, adopted
a resolution adopting the following amendment to the Certificate of
Incorporation:
RESOLVED, that the Certificate of Incorporation is hereby amended
by striking out Article One thereof and by substituting in lieu of said
Article the following new Article:
ARTICLE ONE
The name of the corporation (hereinafter called the
corporation) is IMC Kalium Carlsbad Potash Company.
2. That the corporation has not received any payment for any of its stock.
3. That the aforesaid amendment was duly adopted in accordance with the
applicable provisions of Section 241 of the General Corporation Law of the
State of Delaware.
IN WITNESS WHEREOF, the undersigned corporation has caused this
Certificate of Amendment to be signed by Robert J. Lewis and Betty Ann
Thornson, being all the Incorporators as of the 19th day of June, 1996.
KALIUM CARLSBAD CHEMICAL COMPANY
By: /s/ Robert J. Lewis By: /s/ Betty Ann Thornson
---------------------------------- ---------------------------------
Robert J. Lewis Betty Ann Thornson
Incorporator Incorporator
<Page>
CERTIFICATE OF AMENDMENT
OF
CERTIFICATE OF INCORPORATION
OF IMC KALIUM CARLSBAD POTASH COMPANY
The undersigned officer, Rose Marie Williams, Secretary, of IMC
Kalium Carlsbad Potash Company, a corporation organized and existing under
the General Corporation Law of the State of Delaware (the "Company"), does
hereby certify that:
1. Article One of the Certificate of Incorporation of the Company is hereby
amended in its entirety as follows:
"ARTICLE ONE
The name of the corporation is IMC Potash Carlsbad Inc."
2. This Certificate of Amendment was duly adopted by sole director and the
sole stockholder of the Company according to the provisions of Sections
141(f), 228 and 242 of the General Corporation Law of the State of
Delaware.
IN WITNESS WHEREOF, I have hereunto subscribed my name this 23 day of
JUNE, 2000.
IMC KALIUM CARLSBAD POTASH COMPANY
[SEAL] By: /s/ Rose Marie Williams
---------------------------------
Rose Marie Williams
Secretary
<Page>
STATE OF DELAWARE
SECRETARY OF STATE
DIVISION OF CORPORATIONS
FILED 04:00 PM 06/29/2001
010317564 - 2634147
CERTIFICATE OF AMENDMENT
TO
CERTIFICATE OF INCORPORATION
OF
IMC POTASH CARLSBAD INC.
*****
Adopted in accordance with the provisions
of Section 242 of the General Corporation Law
of the State of Delaware
*****
Rose Marie Williams, being the duly elected Secretary of IMC Potash
Carlsbad Inc., a corporation duly organized and existing under and by virtue
of the General Corporation Law of the State of Delaware (the "Company"), does
hereby certify as follows:
FIRST: That effective June 30, 2001, the Certificate of
Incorporation of the Company be, and hereby is, amended by deleting Article
FOURTH in its entirety and substituting in lieu thereof a new Article FOURTH
to read as set forth in EXHIBIT A attached hereto.
SECOND: That the sole director of the Company approved the amendment
by written consent pursuant to the provisions of Sections 141(f) and 242 of
the General Corporation Law of the State of Delaware and directed that such
amendment be submitted to the sole stockholder of the Company for its
consideration, approval and adoption thereof.
THIRD: That the sole stockholder of the Company approved the
amendment by written consent in accordance with Sections 228 and 242 of the
General Corporation Law of the State of Delaware.
*****
<Page>
IN WITNESS WHEREOF, I have hereunto subscribed my name this 29th day
of June, 2001.
IMC POTASH CARLSBAD INC.,
a Delaware corporation
By: /s/ Rose Marie Williams
---------------------------------
Rose Marie Williams
Secretary
<Page>
EXHIBIT A
FOURTH:
A. AUTHORIZED SHARES. The total number of shares of capital stock
which the Corporation has authority to issue is Two Thousand (2,000) shares
of common stock with a par value of $1.00 per share (the "COMMON STOCK")
B. STOCK SPLIT. Immediately upon the filing of the Certificate
of Amendment to the Certificate of Incorporation with the Secretary of State
of the State of Delaware (the "EFFECTIVE TIME"), each share of Common Stock
outstanding at the Effective Time shall be, without further action by the
Corporation or any of the holders thereof, changed and converted into a
number of shares of Common Stock equal to that number determined by
multiplying each outstanding share of Common Stock by 1.802. Each certificate
then outstanding representing shares of Common Stock shall automatically
represent from and after the Effective Time that number of shares of Common
Stock equal to the number of shares shown on the face of the certificate
multiplied by 1.802.
C. TRANSFER RESTRICTIONS. The following provisions shall apply
with respect to the Common Stock authorized, issued, and outstanding from
time to time. The Corporation shall not issue shares of Common Stock unless
(i) IMC Canada Ltd., a company incorporated in Canada ("IMC CANADA"), shall
simultaneously issue Common Shares without par value ("IMC CANADA COMMON
SHARES") in equal number and (ii) IMC Global Netherlands B.V., a company
incorporated in The Netherlands ("IMC NETHERLANDS"), shall simultaneously
issue shares with a par value of ten Euro (EUR 10) per share ("IMC
NETHERLANDS COMMON SHARES") in equal number, and each such share of Common
Stock, IMC Canada Common Share and IMC Netherlands Common Share shall be
registered in the name of the same person or persons and issued to such
person or persons subject to the condition that such Common Stock, IMC Canada
Common Shares and IMC Netherlands Common Shares shall only be transferable,
repurchasable, or redeemable and otherwise dealt with together. The
Corporation will not take any action which will result in an increase or
decrease in the numbers of shares of Common Stock issued and outstanding
(including, but not limited to, through purchase, exchange, reclassification,
reorganization, consolidation, merger, split, reverse split, or dividend)
unless in connection therewith there is a commensurate increase or decrease,
as applicable, in the number of IMC Canada Common Shares and IMC Netherlands
Common Shares issued and outstanding such that each issued and outstanding
share of Common Stock continues to have an associated issued and outstanding
IMC Canada Common Share and IMC Netherlands Common Share. The Common Stock
shall not be transferable (including transfers to or by the Corporation), and
shall not be transferred on the books of the Corporation, unless in
connection therewith there is a transfer is made by the same transferor to
the same transferee of an equal number of IMC Canada Common Shares and IMC
Netherlands Common Shares. Each certificate representing shares of Common
Stock shall contain a legend in form and substance approved by the board of
<Page>
directors of the Corporation with respect to the transfer restrictions set
forth in this Article Fourth.