FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Popowich James L.   2. Issuer Name and Ticker or Trading Symbol MOSAIC CO [MOS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O THE MOSAIC COMPANY, 3033 CAMPUS DRIVE, SUITE E490 3. Date of Earliest Transaction (Month/Day/Year) 10/04/2015 (Street) PLYMOUTH, MN 55441 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 10/04/2015   M   1,687 (1) A $ 0 11,577 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Units

$ 0 (2)

10/04/2015

M

2,813

(3)

(4)

Common Stock

2,813

$ 0

0

D

Restricted Stock Units

$ 0 (2)

(5)

(4)

Common Stock

1,997

1,997

D

Restricted Stock Units

$ 0 (2)

(6)

(4)

Common Stock

3,144

3,144

D

Restricted Stock Units

$ 0 (2)

(7)

(8)

Common Stock

3,402

3,402

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Popowich James L. C/O THE MOSAIC COMPANY 3033 CAMPUS DRIVE, SUITE E490 PLYMOUTH, MN 55441	X

Signatures

/s/ Mark J. Isaacson, Attorney-in-Fact for James L. Popowich		10/06/2015
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The reporting person, pursuant to the terms of the Restricted Stock Unit Agreement under which the award of restricted stock units was made, elected to receive 40% of the restricted stock units in the form of cash with the balance paid in the form of shares of common stock at the time the award was paid.
(2)	One-for-One
(3)	The restricted stock units vested on October 4, 2013. Vested shares were delivered to the reporting person on October 4, 2015.
(4)	Not applicable.
(5)	The restricted stock units vested on May 15, 2014. Vested shares will be delivered to the reporting person on October 3, 2016.
(6)	The restricted stock units vested on May 14, 2015. Vested shares will be delivered to the reporting person on May 15, 2017.
(7)	The restricted stock units will vest on the date of the issuer's 2016 Annual Meeting of Stockholders. Vested shares will be delivered to the reporting person on May 14, 2018.
(8)	Not Applicable

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