FprEN 18251

Soil improvers and growing media - Determination of phosphonate content FprEN 18251

Publication date:   Oct 16, 2025

Scope

This document specifies a method for the extraction and determination of phosphonates (P-PO3) in growing media and soil improvers using ion chromatography and conductivity detection (IC-CD).
This document is applicable to the fertilizing product blends where a blend is a mix of two or more fertilizing products belonging to the categories of fertilizers, liming material, soil improvers, growing media, inhibitors and plant biostimulants, and where soil improvers and/or growing media are the components with the highest percentage in the blend by mass or volume, or in the case of products in liquid form by dry mass. If the soil improvers and/or growing media are not the components with the highest percentage in the blend, the document relevant to the component with the highest percentage in the blend applies. In case a blend is composed of fertilizing products mixed in equal quantities, the user of the document decides which standard to apply. 
NOTE 1 A soil improver consists of a single bulky (volume-building) component or a mix of bulky (volume-building) components (for example peat, wood fibres, coconut coir, compost, expanded perlite).
NOTE 2 This method has been validated in an interlaboratory study with specific products that were present on the market during the study (as included in Annex A, being biowaste compost (dry spiked), liquid digestate (spiked) and growing media blend (peat, green compost, wood fibre, liming material and inorganic fertilizer (NPK + micro elements), dry spiked).

Related legislation

Legislation related to this standard