ISO 22862 Fertilizers and soil conditioners — Compound fertilizer — General requirements

ISO 22862:2021 sets out general requirements for compound fertilizers. Published on 8 November 2021, it represents the international standardisation of the product category that accounts for the largest share of manufactured fertilizer sold worldwide.

Compound fertilizers are produced by chemical reaction or granulation rather than by dry blending, which gives each granule the same nutrient ratio. That is the defining property of the category and the reason it behaves differently from bulk blends in both storage and the field: every granule carries the declared formulation, so the product cannot segregate on the way to the soil.

The standard addresses product characterisation, nutrient content and declaration, and the physical and chemical parameters that matter in commerce — moisture content, granule size and size distribution, crushing strength, and the caking behaviour that determines whether a bagged product can still be poured after a season in a warehouse.

It reached publication considerably later than the standards covering urea, water-soluble fertilizers and controlled-release products, which reflects the difficulty of the subject rather than its importance. Compound fertilizer spans an enormous range of formulations and production routes, and agreeing general requirements across that variety takes longer than specifying a single chemical product.