This standard BS EN 15957:2011 Fertilizers. Extraction of phosphorus which is soluble in neutral ammonium citrate is classified in these ICS categories:
65.080 Fertilizers
This document specifies a method for the extraction of phosphorus soluble in neutral ammonium citrate. The method is applicable to all fertilizers in respect of which solubility in neutral ammonium citrate is laid down in Regulation (EC) 2003/2003, Annex I (see [2]).