Overview
ISO 7851:2022 - Fertilizers, soil conditioners and beneficial substances - Classification establishes an internationally consistent system for classifying fertilizers, soil conditioners and beneficial substances. The standard organizes products primarily by nutrient content (e.g., N, P, K, secondary nutrients, micronutrients) and supplements this with auxiliary classification criteria such as product type, acidity/alkalinity, solubility and fertilizer efficiency. Annex A provides the classification scheme for nutrient-based categories.
Key topics and technical requirements
- Main classification (nutrient content)
- Inorganic fertilizers: straight N, P or K fertilizers; NP, NK, PK binaries; NPK ternaries; secondary nutrient (Ca, Mg, S) and micronutrient fertilizers.
- Organic fertilizers: organic nitrogenous, synthetic nitrogenous, NP/NK/PK/NPK organic variants.
- Organo‑mineral (semi‑organic) fertilizers: blends or combinations of organic and inorganic nutrient sources.
- Fertilizers with added beneficial substances: products containing plant biostimulants or beneficial nutrients.
- Fertilizing product blends: mixtures of two or more fertilizing products where individual components remain identifiable.
- Auxiliary classification principles
- Acidity/alkalinity: chemical (aqueous solution) and physiological effects on medium pH (acidic, neutral, alkaline).
- Product types: solids (powdered, granular - including size metrics such as SGN, D50, UI), liquids and other physical forms.
- Other auxiliary criteria: fertilizer efficiency and solubility categories (used to inform application and storage).
- Soil conditioners and beneficial substances
- Inorganic soil conditioners (including Ca, Mg, S types), organic and synthetic organic conditioners, and conditioners with added fertilizers/beneficials.
- Beneficial substances: includes plant biostimulants and beneficial nutrients (see Clause 6).
Applications
ISO 7851:2022 is used to:
- Standardize product classification for labelling, product datasheets and technical catalogs.
- Support regulatory compliance, harmonized market descriptions and trade documentation.
- Guide product development and R&D by clarifying categories (organic, inorganic, organo‑mineral).
- Assist procurement, quality control and laboratory testing by defining product types and relevant physical descriptors (e.g., granule size, solubility).
- Facilitate interoperability for databases, supply‑chain management and comparative analyses across regions.
Who will use this standard
- Fertilizer and soil‑conditioner manufacturers, formulators and R&D teams
- Regulators, certification bodies and standards organizations
- Agronomists, extension services and agricultural consultants
- Laboratories, QA/QC teams and product registrars
- Traders, procurement specialists and supply‑chain managers
Related standards
- ISO 8157 - Fertilizers and soil conditioners: Vocabulary (normative reference used by ISO 7851).
- Developed by ISO/TC 134 (Fertilizers, soil conditioners and beneficial substances).
Keywords: ISO 7851:2022, fertilizer classification, soil conditioner standard, plant biostimulant classification, NPK fertilizers, organo‑mineral fertilizers, micronutrient fertilizers, fertilizer labelling, Annex A.