UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.           2          ) *

Adecoagro SA

(Name of Issuer)

Common Shares

(Title of Class of Securities)

L00849106

(CUSIP Number)

December 31, 2018

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

x    Rule 13d-1 (b)

¨     Rule 13d-1(c)

¨     Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the ACT but shall be subject to all other provisions of the Act (however, see the Notes).

Adecoagro SA

13-15 Avenue de la Liberté  

L-1931 Luxembourg 

R.C.S. Luxembourg B 153 681

Common Shares

L00849106

This statement is filed by Brandes Investment Partners, L.P., an investment adviser registered under the Investment Advisers Act of 1940, its control persons and its holding company. (See, also, Exhibit A.)

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class securities, check the following ¨.

                                                                                        N/A

                                                                                       See Exhibit A

                                                                                        N/A

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

EXHIBIT A

Identification and Classification of Members of the Group

Pursuant to Rule 13d-1(b)(ii)(J) and Rule 13d-1(k)(1) under the Securities and Exchange Act of 1934, the members of the group making this joint filing are identified and classified as follows:

EXHIBIT B

Joint Filing Agreement Pursuant to Rule 13d-1

This agreement is made pursuant to Rule 13d-1(b)(ii)(J) and Rule 13d-1(k)(1) under the Securities and Exchange Act of 1934 (the “Act”) by and among the parties listed below, each referred to herein as a “Joint Filer.” The Joint Filers agree that a statement of beneficial ownership as required by Sections 13(g) or 13(d) of the Act and the Rules thereunder may be filed on each of their behalf on Schedule 13G or Schedule 13D, as appropriate, and that said joint filing may thereafter be amended by further joint filings. The Joint Filers state that they each satisfy the requirements for making a joint filing under Rule 13d-1.

EXHIBIT C

Power of Attorney for Schedules 13D, 13G and Form 13F

I, Glenn Carlson, as member of Co-GP of LLC., which is a General Partner of Brandes Worldwide Holdings, L.P., and which is also the limited partner of Brandes Investment Partners, L.P., hereby appoint Ian N. Rose as attorney-in-fact and agent, in all capacities, to execute, on my behalf and on behalf of of Co-GP LLC., Brandes Investment Partners, L.P., and Brandes Worldwide Holdings, L.P., to file with the appropriate issuers, exchanges and regulatory authorities, any and all Schedules 13D, 13G and Form 13F and documents relating thereto required to be filed under the Securities and Exchange Act of 1934, including exhibits, attachments and amendments thereto and request for confidential treatment of information contained therein in connection with my being a “control person” (as contemplated for purposes of Schedule 13D, 13G and Form 13F) of Brandes Investment Partners, L.P., its subsidiaries and affiliates. I hereby grant to said attorneys-in-fact full authority to do every act necessary to be done in order to effectuate the same as fully, to all intents and purposes, as I could if personally present, thereby ratifying all that said attorneys-in-fact and agents may lawfully do or cause to be done by virtue hereof.

I hereby execute this Power of Attorney as of this 6th day of February 2019.

EXHIBIT D

Disclaimer of Beneficial Ownership

Co-GP, LLC, Brandes Worldwide Holdings, L.P., Glenn Carlson, and Jeff Busby disclaim beneficial interest as to the shares referenced above, except for an amount equal to substantially less than one percent of the shares reported on this Schedule 13D. None of these entities or individuals holds the above-referenced shares for its/his own account except on a de minimis basis.