Act on the Quality Control of Fertilizer (Act No. 127 of 1950)

Japan's fertilizer legislation was promulgated on 1 May 1950 as Act No. 127, originally titled the Fertilizer Control Act and known informally in English as the Fertilizer Regulation Act. It remains the basic instrument governing fertilizers in Japan; the title in current use is the Act on the Quality Control of Fertilizer, reflecting a revision cycle undertaken by MAFF from 2019 to 2021.

Article 1 states the purpose: by regulating the production of fertilizers, to secure the quality, fair trade and safe use of fertilizers, and thereby contribute to maintaining and increasing agricultural productivity as well as to protecting public health. Article 2 defines a fertilizer as a substance applied to the ground to supply nutrients to plants or to bring about a chemical change in the soil to help plants grow, or a substance applied to a plant to feed it.

The Act divides fertilizers into two classes. 'Special-purpose fertilizer' means rice bran, compost and other fertilizers designated by the Minister, while 'general-purpose fertilizer' means any fertilizer other than a special-purpose fertilizer. The distinction matters because the heaviest regulatory obligations — official specifications and brand registration — attach to general-purpose fertilizers, with the central government taking registration for most categories and prefectural governors taking it for the residual category.

Official specifications are the technical core. Article 3 requires the Minister to establish specifications for minimum and maximum amounts of main components, the maximum amount of plant-harmful components that may be contained, and other necessary particulars, differentiated by type of general-purpose fertilizer. Before establishing, changing or repealing the official specifications, the Minister must issue public notice at least 30 days in advance. That notice requirement gives the industry a defined window to prepare, and makes the specifications a matter of public record rather than administrative practice.

Registration operates by brand. A person intending to produce a general-purpose fertilizer in the course of trade must have it registered — by the Minister for the categories enumerated in the Act, or by the prefectural governor where the place of business is located, as the case may be. Registration is not required where no official specification has been established, or for designated blended fertilizers, a category introduced to accommodate blends made exclusively from already-registered inputs.

The concept of 'guaranteed content of ingredients' carries the commercial weight. It means the minimum content of main components, expressed as a percentage, guaranteed by the producer, importer or seller. A guarantee in this sense is a floor that the product must meet, not an average or a target — which is why Japanese registration dossiers are built around the analytical methods capable of demonstrating compliance with the guaranteed figure.