prEN 17771

This document specifies a method for the determination of the total nitrogen content and the content of ammoniacal, nitric, ureic and organic nitrogen in organic and organo-mineral fertilizers.
This document is applicable to fertilizing product blends, where the blend is a mix of at least two of the following components: fertilizers, liming materials, soil improvers, biostimulants and where the following category organic fertilizers, organo-mineral fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If the organic fertilizer or the organo-mineral fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply.
This document is applicable to products that at least contain a total nitrogen content of 1 % by mass. In case of fertilizing product blends, it is unattainable to ascertain the origin of the measured nitrogen with respect to the specific component.
NOTE  Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.