GB/T 21633-2008

This standard specifies the requirements for compound fertilizers, test methods, inspection rules, labeling, packaging, transportation, and storage.
This standard applies to fertilizers made by dry mixing methods and labeled with at least two of the three nutrients (nitrogen, phosphorus, and potassium), including those with various names. It also applies to slow-release, controlled-release, and compound fertilizers with an organic matter content not exceeding 20%. Additionally, it applies to compound fertilizers or complex fertilizers made by dry mixing nitrogen and/or phosphorus and/or potassium fertilizer particles.
This standard does not apply to products that are only dry mixed with organic particles and/or biological agents and/or trace elements on the basis of compound fertilizers or complex fertilizers.