Tessenderlo Kerley v. Sacramento Ag Products: Fertilizer Patent Dismissed Without Prejudice
Tessenderlo Kerley, Inc. filed suit against Sacramento Ag Products, LLC in the Eastern District of California, asserting US8545591B2 covering potassium sulfite-based liquid fertilizer technology against competing products. After 126 days, both parties stipulated to dismiss all claims without prejudice, each bearing their own legal costs.
Potassium sulfite fertilizer dispute ends early without merits ruling
Tessenderlo Kerley, Inc., a specialty agricultural chemistry company, filed this infringement action on October 25, 2024 in the Eastern District of California against Sacramento Ag Products, LLC. The suit centred on US8545591B2, a patent covering low-salt, seed-safe liquid fertilizer formulations based on potassium sulfite and potassium bisulfite chemistry — the technology underlying Tessenderlo Kerley’s K-ROW 23® product line. Sacramento Ag Products’ Grow-K 238 liquid fertilizer was identified as the accused product.
The case was closed on February 28, 2025, when both parties jointly stipulated to dismissal under Federal Rule of Civil Procedure 41(a)(1)(A)(ii). The dismissal was entered without prejudice as to all claims, causes of action, and parties, with each side bearing its own attorney fees and costs. A without-prejudice dismissal means no judgment was entered on the merits and Tessenderlo Kerley retains the right to refile the same claims against Sacramento Ag Products in the future.
The 126-day lifespan of this case — from filing to closure — suggests the parties reached resolution very early in the litigation lifecycle, likely before significant discovery or claim construction proceedings. The cost-neutral fee arrangement and without-prejudice nature of the dismissal are consistent with a negotiated commercial resolution, though the public record does not disclose the specific terms of any agreement between the parties. What drove the resolution — whether licensing, product redesign, or commercial negotiation — remains unknown from the available court record.
Filing to Case Dismissed in 126 days
126 days — resolved well before the district court average of 2–3 years for patent trials
Stipulated dismissal without prejudice: what the ruling means for both parties
Rule 41(a)(1)(A)(ii) stipulated dismissal explained
A dismissal under FRCP 41(a)(1)(A)(ii) is a joint stipulation signed by all parties — not a court-ordered dismissal. Because it is entered without prejudice, no judgment is recorded on the merits. The patent claims are legally untested and unresolved. Tessenderlo Kerley could theoretically refile the same infringement claims; however, any future refiling could trigger ‘two-dismissal rule’ scrutiny if a prior dismissal in another forum exists.
No merits judgment enteredWithout prejudice — enforceability of US8545591B2 is preserved
A without-prejudice dismissal leaves the patent’s validity and enforceability wholly intact. The public record specifies ‘dismissed without prejudice’ explicitly, meaning Tessenderlo Kerley retains full enforcement rights. The patent has not been found invalid, unenforceable, or non-infringed. For competitors in the potassium sulfite fertilizer space, this outcome should not be read as a signal that the patent is weak or easily designed around.
Patent validity unaffectedSacramento Ag Products escapes judgment — but risk persists
Sacramento Ag Products obtained a cost-neutral exit with no adverse judgment. However, without prejudice means this is not a clean resolution — the infringement question over Grow-K 238 remains legally open. If Sacramento Ag Products continues selling the accused product without a licence or design-around, it remains exposed to potential refiling. The short case duration suggests the commercial dispute may have been resolved outside the court record.
Litigation risk not extinguishedEarly resolution signals possible licensing or supply arrangement
Stipulated dismissal within 126 days — before any substantive briefing would typically conclude — is consistent with parties reaching a commercial resolution such as a licensing agreement, distribution arrangement, or product reformulation commitment. The even cost allocation further suggests a negotiated outcome rather than capitulation by either side. Companies in the liquid fertilizer sector should monitor whether Grow-K 238 remains on the market and whether any product changes follow.
Possible commercial settlementFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Tessenderlo Kerley, Inc. | Company | Agricultural specialty chemistry company — holder of US8545591B2Search in Eureka ↗ |
| Defendant | Sacramento Ag Products, LLC | Company | Sacramento-based agricultural products distributor, maker of Grow-K 238 liquid fertilizerSearch in Eureka ↗ |
| Plaintiff counsel | Adam Baechler , PHV | Attorney | Counsel for Tessenderlo Kerley, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Jonathan J. Boustani | Attorney | Counsel for Tessenderlo Kerley, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Lyric Menges | Attorney | Counsel for Tessenderlo Kerley, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Roya Rahmanpour | Attorney | Counsel for Tessenderlo Kerley, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Barnes & Thornburg, LLP | Law Firm | Representing Tessenderlo Kerley, Inc.Search in Eureka ↗ |
| Defendant counsel | Matthew Christian Holohan | Attorney | Counsel for Sacramento Ag Products, LLCSearch in Eureka ↗ |
| Defendant law firm | Quarles & Brady LLP | Law Firm | Representing Sacramento Ag Products, LLCSearch in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | California Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulation’s explicit ‘without prejudice as to all claims, causes of action, and parties’ language is broad and deliberate — it forecloses any argument that certain claims or parties were resolved with finality. The cost allocation (‘each party bearing that party’s own attorney’s fees and costs’) is consistent with a negotiated commercial resolution rather than a concession. No merits finding was made on infringement, validity, or enforceability of US8545591B2. Both parties retain their full legal positions as of the filing date.
US8545591B2 — potassium sulfite liquid fertilizer formulations
US8545591B2 protects compositions and methods relating to liquid fertilizer formulations that deliver potassium and sulfur via potassium sulfite and potassium bisulfite chemistry. The ‘low salt index’ and ‘seed safe’ characteristics are key commercial differentiators — allowing in-furrow application without the seedling burn risk associated with higher-salt potassium sources such as potassium chloride. The application, filed under number US13/440939, covers a technically distinct approach to soluble potassium delivery in agronomic settings.
For the agricultural inputs sector, this patent represents a meaningful barrier in the growing market for premium liquid fertilizers targeting precision application and seed safety. Potassium sulfite-based fertilizers occupy a niche between standard MOP (muriate of potash) and more expensive specialty grades, making them commercially attractive to crop nutrition programmes. Any company seeking to develop, import, or distribute a low-salt liquid potassium-sulfur fertilizer product in the US market should assess this patent’s claim scope before commercialisation, particularly given its active enforcement history.
Should you run an FTO analysis against US8545591B2?
Any agricultural input company developing or distributing a liquid fertilizer that combines potassium sulfite or potassium bisulfite with seed-safe or low-salt positioning should treat US8545591B2 as a priority FTO target. The dismissal without prejudice in this case confirms the patent remains enforceable and the claim scope has not been judicially narrowed. Distributors, formulators, and importers of competing potassium-sulfur liquid fertilizers — especially those marketing in-furrow or starter fertilizer applications — face direct exposure.
PatSnap Eureka’s FTO Search Agent allows R&D and legal teams to map US8545591B2’s independent and dependent claims against your specific formulation parameters, rapidly identifying overlap risk. Eureka can also surface continuation applications, related family members, and prosecution history that may affect claim interpretation — giving your team a defensible freedom-to-operate position before product launch or distribution agreements are signed.
Run a freedom-to-operate analysis on US8545591B2 to assess your product’s exposure
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What this case signals for the agricultural fertilizer IP landscape
A swift, cost-neutral dismissal in a specialty fertilizer patent case carries quiet but important signals for the sector.
Without-prejudice exits preserve future enforcement leverage
Tessenderlo Kerley’s decision to dismiss without prejudice — rather than settle with prejudice — keeps US8545591B2 in active enforcement position. Competitors offering potassium sulfite-based liquid fertilizers should treat this outcome as a continuation of risk, not a resolution of it. The patent clock has not been stopped.
Speed of resolution suggests patent disputes can resolve commercially without costly discovery
At 126 days, this case closed before typical claim construction proceedings would begin. Patent holders in the agricultural chemistry sector may find that early filing combined with targeted enforcement can drive rapid commercial outcomes — potentially including licensing — without requiring full litigation expenditure.
Tessenderlo v Sacramento — key questions answered
Dismissal without prejudice means no judgment was entered on the merits of the infringement claims. US8545591B2 remains valid and enforceable, and Tessenderlo Kerley retains the right to refile the same claims against Sacramento Ag Products. The patent’s validity was not challenged or adjudicated in this proceeding.
Tessenderlo Kerley asserted US8545591B2, a patent covering low-salt, seed-safe liquid fertilizer formulations based on potassium sulfite and potassium bisulfite chemistry. The accused product was Sacramento Ag Products’ Grow-K 238 fertilizer. Tessenderlo Kerley’s own K-ROW 23® product embodies the same technology.
The case closed via joint stipulation under FRCP 41(a)(1)(A)(ii) before substantive litigation milestones such as claim construction. The 126-day duration is consistent with parties reaching a commercial resolution — potentially a licensing agreement or supply arrangement — early enough to avoid costly discovery. The specific terms driving resolution are not disclosed in the public court record.
The dismissal is without prejudice and makes no determination on infringement. Whether Sacramento Ag Products can continue selling Grow-K 238 depends on any private agreements reached between the parties and whether the product’s formulation falls within the claims of US8545591B2. The court made no finding either way, and the underlying patent risk remains legally unresolved.
A cost-neutral fee arrangement — where no party is awarded attorney fees — is typical in negotiated commercial resolutions and Rule 41 stipulated dismissals. It suggests neither party achieved a sufficiently dominant outcome to justify fee-shifting under 35 U.S.C. § 285 (exceptional case standard). This arrangement is consistent with a balanced commercial negotiation rather than a clear win for either side.
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