As filed with the Securities and Exchange Commission on July 30, 2025

Registration No. 333-284972

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

AMENDMENT NO. 1 to

FORM S-4

REGISTRATION STATEMENT

UNDER THE SECURITIES ACT OF 1933

Arcadia Biosciences, Inc.

(Exact name of Registrant as specified in its charter)

5950 Sherry Lane, Suite 215

Dallas, TX 75225

(214) 974-8921

(Address including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

Thomas J. Schaefer

Chief Executive Officer

5950 Sherry Lane, Suite 215

Dallas, TX 75225

(214) 974-8921

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after the effectiveness of this registration statement and the satisfaction or waiver of all other conditions under the Exchange Agreement described herein.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box:  ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13(e)-4(i) (Cross-Border Issuer Tender Offer) ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) ☐

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this proxy statement/prospectus is not complete and may be changed. Arcadia may not sell its securities pursuant to the proposed transaction until the Registration Statement filed with the Securities and Exchange Commission is effective. This proxy statement/prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state or other jurisdiction where the offer or sale is not permitted.

PRELIMINARY PROXY STATEMENT/PROSPECTUS

SUBJECT TO COMPLETION, DATED JULY 30, 2025

On behalf of the board of directors of Arcadia Biosciences, Inc., a Delaware corporation (“Arcadia”), we are pleased to enclose the accompanying proxy statement/prospectus relating to the proposed business combination of Arcadia and Roosevelt Resources LP, a Texas limited partnership (“Roosevelt” or the “Partnership”). We are requesting that you take certain actions as an Arcadia stockholder, as described in greater detail below.

Pursuant to the Securities Exchange Agreement, dated as of December 4, 2024 (as amended by a First Amendment to the Exchange Agreement, dated as of April 25, 2025 (the "First Amendment") (the agreement, as amended by the First Amendment and as it may be amended from time to time, referred to as the "Exchange Agreement"), by and among Arcadia, Roosevelt, and Elliott Roosevelt, Jr. and David A. Roosevelt, in their capacities as representatives of the limited partners of the Partnership (the “LP Representatives”), Arcadia will issue shares of its common stock (sometimes referred to as “Arcadia common stock,” “Common Stock” or “common stock”) to the limited partners of Roosevelt in exchange for all of the limited partnership interests of Roosevelt and to the sole member of the general partner of Roosevelt (together with the limited partners, referred to collectively as the “Limited Partners”) in exchange for all of the equity interests in Roosevelt (such exchange, contributions and issuances referred to as the “Exchange”). As a result of the Exchange, Roosevelt will become a wholly owned subsidiary of Arcadia.

On the terms and subject to the conditions set forth in the Exchange Agreement, upon the closing (the “Closing”) of the transactions contemplated by the Exchange Agreement (sometimes referred to as the “Transactions”) and consummation of the Exchange (the “Effective Time”), Arcadia will issue a number of shares of Common Stock (the shares to be issued referred to as the “Exchange Shares”) to the Limited Partners equal to 12,303,360 shares or such other number such that the number of shares issued to the Limited Partners of Roosevelt equals 90.0% of the number of shares of Common Stock that are outstanding at and immediately after the Closing giving effect to the number of shares issuable to the Limited Partners of Roosevelt (and not giving effect to any other shares of Common Stock that may be issuable to any other persons in connection with or immediately after the Closing), and subject to the requirement in the Exchange Agreement that in no event will the number of Exchange Shares be less than the number required so that the number of shares issued to the Limited Partners is, immediately after the Closing, at least eighty percent (80%) of the total number of the outstanding shares of Arcadia’s common stock. The Exchange Agreement does not provide for an adjustment to the total number of shares of common stock that the Limited Partners will be entitled to receive in light of changes in the market price of Arcadia common stock.

Based on (i) the number of shares of Arcadia common stock outstanding on March 31, 2025, (ii) an assumed 12,303,360 shares issuable to the Limited Partners, and (iii) the closing price of the common stock as reflected in the NASDAQ Stock Market LLC’s (“Nasdaq”) Nasdaq Official Closing Price, or NOCP, data and Nasdaq's historical quotes data of $2.81 and $2.697, respectively, on December 4, 2024, the last trading day before public announcement of the proposed transaction, the Exchange Shares represent total aggregate consideration of approximately $33,182,162 and $34,572,442, respectively, as of such date. We expect that after the Closing, we will be a “controlled company” under applicable Nasdaq rules because more than 50% of the voting power for the election of directors will be beneficially held by one stockholder, Elliott Roosevelt, Jr., who is expected to be deemed to beneficially own approximately 60% of the outstanding shares of common stock immediately after the Closing. At the Closing or shortly thereafter, Arcadia expects to change its corporate name to “Roosevelt Resources, Inc.,” and expects that the common stock of the combined company will be listed on the Nasdaq Capital Market under a new trading symbol.

We expect and intend the Exchange will qualify as an exchange under Section 351 of the Internal Revenue Code of 1986, as amended (the “Code”). Provided that the Exchange qualifies as an exchange under Section 351 of the Code, then subject to the limitations and qualifications described in “Material U.S. Federal Income Tax Consequences of the Exchange,” no gain or loss should be recognized by the U.S. holders of Arcadia common stock or the U.S. holders of Partner Interests of the Partnership.

Arcadia will hold a special meeting of stockholders (the “Meeting”) in order to seek the stockholder approvals necessary to complete the Exchange and related matters contemplated by the Exchange Agreement. At the Meeting, Arcadia will ask its stockholders to: (1) approve the issuance of Arcadia common stock pursuant to the Exchange and the Exchange Agreement, pursuant to Nasdaq Listing Rules 5635(a) and 5635(d) (which we refer to as the “share issuance proposal”); (2) approve an amendment to Arcadia’s amended and restated certificate of incorporation to effect a reverse stock split of Arcadia common stock, if the board of directors of Arcadia (the “Board”) determines in its discretion to effect a reverse stock split, at a ratio to be determined by the Board and, if the Board determines to effect a reverse stock split in connection with obtaining Nasdaq approval of the continued listing of the Arcadia common stock after the Effective Time, anticipated to be before the Effective Time of the Exchange, but in all events before [•], 2025 (the “reverse split proposal”); (3) approve, on a non-binding basis, the compensation that may become payable to certain named executive officers that is based on or otherwise relates to the proposed Exchange transaction (sometimes referred to as the “exchange-related compensation proposal”); (4) approve and adopt the 2025 Long Term Incentive Plan (the “LTIP proposal”); and (5) approve the adjournment of the Meeting, if necessary, if there are not sufficient votes to approve the above proposals at the time of the Meeting. It is a closing condition to Arcadia's and Roosevelt's obligations to complete the Exchange that the Arcadia common stock, including the Exchange Shares upon issuance, shall be or have been approved for listing on the Nasdaq Capital Market, and the closing of the Exchange is contingent on Nasdaq approval by Nasdaq of the Company's listing application in connection with the transactions contemplated by the Exchange Agreement.

The Meeting will be held on [•], 2025, at [•] Central time. The Meeting will be held in a virtual format only from Arcadia’s offices at 5950 Sherry Lane, Suite 215, Dallas, TX 75225. Information about the Meeting and the Exchange is contained in this proxy statement/prospectus. In particular, see “Risk Factors” beginning on page 25. We urge you to read this proxy statement/prospectus carefully and in its entirety.

Your vote is very important regardless of the number of shares of Arcadia common stock that you own. The Exchange cannot be completed without the approval of the share issuance proposal and certain of the other proposals described in the proxy statement/prospectus by the Arcadia stockholders. Whether or not you plan to attend the Meeting, please vote as soon as possible to make sure that your shares are represented at the Meeting.

The Arcadia board of directors recommends that holders of Arcadia common stock vote “FOR” each of the proposals described herein to be considered at the Meeting of Arcadia stockholders.

Thomas J. Schaefer

Chief Executive Officer

Arcadia Biosciences, Inc.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this proxy statement/prospectus. Any representation to the contrary is a criminal offense.

This proxy statement/prospectus is dated [•], 2025, and is first being mailed to Arcadia stockholders on or about [•], 2025.

Notice of Special Meeting of Stockholders

To Arcadia Stockholders:

On December 4, 2024, Arcadia Biosciences, Inc. (“Arcadia” or the “Company”), Roosevelt Resources LP (“Roosevelt” or the “Partnership”) and Elliott Roosevelt, Jr. and David A. Roosevelt, in their capacities as representatives of the limited partners of the Partnership (the “LP Representatives”) entered into a Securities Exchange Agreement (as amended by a First Amendment to Exchange Agreement dated as of April 25, 2025 (the "First Amendment") (the agreement as amended by the First Amendment, as it may be amended from time to time, referred to as the "Exchange Agreement").

Pursuant to the Exchange Agreement, subject to the terms of the Exchange Agreement, at the closing of the transactions contemplated by the Exchange Agreement, Arcadia will issue shares of its common stock (sometimes referred to as “Arcadia common stock,” “Common Stock” or “common stock”) to the limited partners of the Partnership in exchange for all of the limited partnership interests of Roosevelt and to the sole member (the “GP Member” and together with the limited partners, referred to collectively as the “Limited Partners”) of the general partner of Roosevelt in exchange for its membership interest (sometimes referred to as the “GP Interest” and together with the limited partnership interests of the Limited Partners, sometimes referred to as the “Partner Interests”) in the limited liability company that is the general partner of the Partnership (the “General Partner”) (such exchange, contributions and issuances referred to as the “Exchange”). As a result of the Exchange, the Partnership will become a wholly owned subsidiary of Arcadia. A copy of the Exchange Agreement (including the First Amendment) is attached as Annex A to the accompanying proxy statement/prospectus.

NOTICE IS HEREBY GIVEN that a special meeting of Arcadia stockholders (which we refer to as the “Meeting,” including any adjournments or postponements thereof) will be held on [•], 2025, virtually via conference call at [•], Central time.

At the Meeting you will be asked to vote on the following matters:

The Board has fixed the close of business on [•], 2025, as the record date for the Meeting. Only holders of record of Arcadia common stock as of the close of business on the record date for the Meeting are entitled to notice of, and to vote at, the Meeting or any adjournment or postponement thereof.

Your vote is very important regardless of the number of shares of Arcadia common stock that you own. The Exchange cannot be completed without the approval of the share issuance proposal by Arcadia stockholders, and other closing conditions of the Exchange will not be satisfied if the reverse split proposal and the LTIP proposal are not approved by Arcadia stockholders.

Arcadia’s board of directors recommends that holders of common stock vote “FOR” each of the proposals to be considered at the Meeting.

Whether or not you plan to attend the Meeting, please vote as soon as possible by either completing, signing, dating and returning the accompanying proxy card in the enclosed postage-paid envelope or voting using the telephone or Internet voting procedures described on your proxy card. If your shares are held in the name of a bank, broker or other nominee, please follow the instructions on the voting instruction card furnished by such bank, broker or other nominee.

By Order of the Board of Directors

TABLE OF CONTENTS

CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus contains forward-looking statements within the meaning of the safe harbor provided by Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, about Arcadia and Roosevelt. Forward-looking statements are all statements other than statements of historical facts. The words “anticipate,” “believe,” “ensure,” “expect,” “if,” “intend,” “estimate,” “probable,” “project,” “forecasts,” “predict,” “outlook,” “aim,” “will,” “could,” “should,” “would,” “potential,” “may,” “might,” “anticipate,” “likely” “plan,” “positioned,” “strategy,” and similar expressions or other words of similar meaning, and the negatives thereof, are intended to identify forward-looking statements. Forward-looking statements include any statements regarding the expected timetable for completing the proposed transaction, the results, effects, and benefits of the proposed transaction, future opportunities for the combined company, future financial performance and condition, guidance. Any other statements regarding Arcadia’s or Roosevelt’s future expectations, beliefs, plans, objectives, financial condition, assumptions or future events or performance that are not historical facts are forward-looking statements. Forward-looking statements involve a wide variety of risks and uncertainties that could cause actual results to differ materially, and reported results should not be considered as an indication of future performance. These risks and uncertainties relating to Arcadia include, but are not limited to, the risks set forth in filings that Arcadia makes with the Securities and Exchange Commission (“SEC”) from time to time, including in Arcadia’s Annual Report on Form 10-K for the year ended December 31, 2024 and other filings that Arcadia has made with the SEC since that date. Specific forward-looking statements also include statements regarding Roosevelt’s technology, Roosevelt’s anticipated development and production plans, and the ability of Roosevelt to grow production. The risks and uncertainties relating to Roosevelt include, without limitation, statements with respect to Roosevelt’s strategy and prospects, resource potential, expected future expenditures, production, financial position, business strategy, revenues, costs, capital expenditures and debt levels. Forward-looking statements are based on current expectations and assumptions and analyses made by Roosevelt and its management in light of their experience and perception of historical trends, current conditions and expected future developments, as well as other factors appropriate under the circumstances. However, whether actual results and developments will conform to expectations is subject to a number of material risks and uncertainties, including but not limited to: declines in oil, natural gas liquids or natural gas prices; the level of success in development and production activities; adverse weather conditions that may negatively impact development or production activities; the timing of development expenditures; inaccuracies of reserve estimates or assumptions underlying them; revisions to reserve estimates as a result of changes in commodity prices; risks related to level of indebtedness and periodic redeterminations of the borrowing base and interest rates under Roosevelt’s credit facility; Roosevelt’s ability to generate sufficient cash flows from operations to meet the internally funded portions of its capital expenditures budget; the effects of future regulatory or legislative actions; cost and availability of transportation and storage capacity as a result of oversupply, government regulation or other factors; and possible changes in taxation and environmental regulation. The combined company will have other risks and uncertainties as set forth below.

In addition, these forward-looking statements involve significant risks and uncertainties that could cause actual results to differ materially from those anticipated, including, but not limited to, the possibility that stockholders of Arcadia may not approve the issuance of new shares of Arcadia common stock in the transaction or other proposals that are closing conditions under the Exchange Agreement or that the stockholders of Arcadia or the Limited Partners of Roosevelt may not approve other proposals relating to the Exchange Agreement; the risk that one or more conditions to the Closing of the proposed transaction may not be satisfied, that either party may terminate the Exchange Agreement or that the Closing of the proposed transaction might be delayed or not occur at all; potential adverse reactions or changes to business or employee relationships, including those resulting from the announcement or completion of the transaction; the diversion of management time on transaction-related issues; the ultimate timing, outcome and results of integrating the operations of Arcadia and Roosevelt; the effects of the business combination of Arcadia and Roosevelt, including the combined company’s future financial condition, results of operations, strategy and plans; changes in capital markets and the ability of the combined company to finance operations in the manner expected; the risks of oil and gas activities; and the fact that operating costs and business disruption may be greater than expected following the public announcement or consummation of the proposed transaction. Statements regarding business outlook, including changes in revenue, pricing, capital expenditures, cash flow generation, strategies for our operations, oil and natural gas market conditions, legal, economic and regulatory conditions, and environmental matters reflect only our expectations regarding these matters.

Any information contained in hyperlinks in this proxy statement/prospectus is not deemed to be incorporated by reference into this proxy statement/prospectus unless this proxy statement/prospectus specifically states that such material is incorporated by reference herein.

Moreover, actual results could differ materially from those contained in any forward-looking statement as a result of various additional factors, including, without limitation:

The foregoing risks should not be construed as exhaustive and should be read in conjunction with statements that are included herein and elsewhere. Arcadia can give no assurance that the conditions to the closing of the Exchange will be satisfied. For further discussion of the factors that may cause Arcadia, Roosevelt or the combined company’s actual results, performance or achievements to differ materially from any future results, performance or achievements expressed or implied in such forward-looking statements, or for a discussion of risks associated with the ability of Arcadia and Roosevelt to complete the Exchange and the effect of the Exchange on the business of Arcadia, Roosevelt and the combined company, see the section titled “Risk Factors” in this proxy statement/prospectus.

Additional factors that could cause actual results to differ materially from those expressed in the forward-looking statements are discussed in reports filed with the SEC by Arcadia. See section titled “Where You Can Find More Information” of this proxy statement/prospectus.

If any of these risks or uncertainties materialize or any of these assumptions prove incorrect, the results of operations of Arcadia, Roosevelt or the combined company could differ materially from the results contemplated by forward-looking statements made in this proxy statement/prospectus.

All forward-looking statements in this proxy statement/prospectus speak only as of the date of this proxy statement/prospectus. Arcadia and Roosevelt do not undertake any obligation to update any forward-looking statement to reflect events or circumstances after the date on which any statement is made, the occurrence of unanticipated events or any new information that becomes available in the future, except as required by applicable securities laws. As forward-looking statements involve significant risks and uncertainties, caution should be exercised against placing undue reliance on such statements.

Solely for convenience, the trademarks, service marks and trade names referred to in this proxy statement/prospectus may appear without the ®, TM, or SM symbols, but such references do not constitute a waiver of any rights that might be associated with the respective trademarks, service marks, or trade names.

QUESTIONS AND ANSWERS ABOUT THE EXCHANGE AND MEETING

The following are some questions that you may have about the Exchange and the Meeting, and brief answers to those questions. We urge you to read carefully the remainder of this proxy statement/prospectus because the information in this section does not provide all of the information that might be important to you with respect to the Exchange and the Meeting. For your convenience, a Glossary of Oil and Gas Terms has been included and appears under the heading, “Roosevelt Business,” beginning on page 140.