Mexico sets definitive countervailing duty on ammonium sulfate from China

The Ministry of Economy imposed a definitive anti-dumping duty of 0.1488 dollars per kilogram on imports of ammonium sulfate originating in the People’s Republic of China, regardless of the country of export, after establishing dumping and material injury to the domestic production industry. The measure was published in the Official Journal of the Federation (DOF) of Friday, August 14, 2026, within the Final Resolution of case file AD 30-24, signed on June 25, 2026, by Secretary Marcelo Luis Ebrard Casaubon, and will enter into force the day after its publication.

The resolution, issued by the International Trade Practices Unit pursuant to the Foreign Trade Act and the WTO Anti-Dumping Agreement, concludes a two-year proceeding. The investigation covered the period from July 1, 2023, to June 30, 2024, with an injury analysis period from July 1, 2021, to June 30, 2024. The product concerned is ammonium sulfate, a nitrogenous fertilizer with the formula (NH4)2SO4 —21% nitrogen and 24% sulfur—, classified under tariff item 3102.21.01 of the TIGIE, used in crops such as maize, wheat, rice, sorghum, potato, and forage.

From the petition to the final resolution

• October 8, 2024: Agrogen, S.A. de C.V. submits the request for investigation.
• February 20, 2025: the Initiation Resolution is published in the DOF.
• November 24, 2025: the Preliminary Resolution sets a provisional duty of 0.1807 dollars per kilogram.
• August 14, 2026: the Final Resolution confirms the unfair practice and imposes the definitive duty.

The petitioner, which produced 56% of the national ammonium sulfate during the investigation period, received support from Metalúrgica Met-Mex Peñoles and Fefermex. The exporter Fujian Shenyuan New Materials Co. Ltd. and the importers FERGO, FERNO, Isquisa, NPK Soluciones, PROFERNO, and PRONAMEX appeared in the proceeding.

Dumping and Established Injury

The Secretariat determined a price discrimination margin of 0.1849 dollars per kilogram, calculated on the basis of the best information available, considering that the exporter did not provide reliable documentary evidence. During the period analyzed, the Chinese imports:

• grew by 973%, from 3% to 46% of apparent domestic consumption (74% of total imports during the investigation period);
• entered the market with price undercutting relative to the domestic price that went from 12% to 46%;
• coincided with declines of 50% in production and POMI, 58% in domestic sales, 38% in employment, and 65% in wages of the domestic industry.

Final Duty and Scope

Under the lesser-duty rule —Articles 9.1 of the Anti-Dumping Agreement and 62 of the Foreign Trade Act—, the duty was set below the dumping margin, at the level that places Chinese prices at the non-injurious price for the domestic industry:

• it will apply throughout the national territory, with collection by the Ministry of Finance and Public Credit;
• it covers imports entering under tariff item 3102.21.01 or any other;
• importers will be exempt if they prove that the origin of the goods is not China (Article 66 of the Foreign Trade Act);
• the resolution will be communicated to ANAM and SAT for customs enforcement.

Ammonium sulfate remains exempt from the payment of tariff until December 31, 2026, by virtue of the basic basket decrees published on December 31, 2024 and 2025, and can be imported without tariff or duty from 22 countries.

Impact for agriculture and importers

The importing companies had requested not to impose duties or to apply a 3% duty, warning of possible inflationary effects on the basic basket —between 2% and 4%— and risks to agricultural supply. The Secretariat responded that the measure corrects an unfair practice without restricting trade, that alternative supply sources exist, and that no risk of shortage exists.

The duty, in force since August 15, 2026, will increase by 148.8 dollars the cost of each ton of Chinese ammonium sulfate entering the country, with a direct effect on fertilizer importers and the cost of farm inputs. For domestic producers, it restores conditions of fair competition against a good that, according to the case file, was sold below cost; for farmers, the final price will depend on the availability of alternative origins and on public supply programs.

Source: Official Journal of the Federation, Publication No. 221/2026, Friday, August 14, 2026, pp. 308-349 (official reference: Final Resolution of the administrative antidumping investigation proceeding on imports of ammonium sulfate originating in the People’s Republic of China, regardless of the country of shipment, case file AD 30-24).