ANNUAL MEETING OF STOCKHOLDERS

Mosaic shareholders are invited to attend our 2010 Annual Meeting of Stockholders which will be held on Thursday, October 7, 2010, at 10 a.m. EDT. The meeting will be at The Palmetto Club at Fishhawk Ranch, 17004 Dorman Road, Lithia, Florida 33547.

SAFE HARBOR

Certain statements in the Annual Report that are neither reported financial results nor other historical information are forward-looking statements. Such forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results and Mosaic's plans and objectives to differ materially from those expressed in the forward-looking statements.

SHAREHOLDER RETURN INFORMATION

The following performance graph compares the cumulative total return on our common stock for a period beginning May 31, 2005, with the cumulative total return of the Standard & Poor's 500 Stock Index, and a peer group of companies selected by us.

Our 2010 peer group is comprised of Agrium Inc., CF Industries Holdings, Inc. and Potash Corporation of Saskatchewan Inc. Our stock price performance differs from that of our peer group during some periods due to differences in the market segments in which we compete or in the level of our participation in such segments compared to other members of the peer group. In accordance with Standard & Poor's policies, companies with less than a majority of their stock publicly traded are not included in the S&P 500 Index, and accordingly, we are not included in the S&P 500 Index on account of our controlling stockholder. The comparisons set forth below assume an initial investment of $100 and reinvestment of dividends or distributions.

STOCK PERFORMANCE

Comparison of Cumulative Total Return Among The Mosaic Company, S&P 500 Index and Peer Group Index.

CORPORATE HEADQUARTERS

3033 Campus Drive
Suite E490
Plymouth, MN 55441
763.577.2700
800.918.8270

TRANSFER AGENT

American Stock Transfer & Trust Company
59 Maiden Lane
New York, NY 10038
877.777.0800

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

KPMG LLP 90
South Seventh Street
Minneapolis, MN 55402

MEDIA CONTACT

Rob Litt
Manager — Public Affairs
763.577.6187
media@mosaicco.com

INVESTOR CONTACT

Christine Battist
Director — Investor Relations
763.577.2828

investor@mosaicco.com
Mosaic's 10-K Report, filed in July 2010 with the Securities and Exchange Commission, is available to shareholders and interested parties without charge by contacting Christine Battist.

WEBSITE

www.mosaicco.com