FprEN 13654-1

Soil improvers and growing media - Determination of nitrogen - Part 1: Modified Kjeldahl method

Publication date:   Oct 23, 2025

Scope

This document specifies a method for the determination of nitrogen in soil improvers and growing media. The Kjeldahl method determines ammonium-N, nitrate-N, nitrite-N and organic N content of soil improvers and growing media. Nitrogen in N-N-linkages, N-O-linkages and some heterocyclics (especially pyridine) is only partially determined [6], [7], [8].
NOTE 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 composted bark (20 mm to 40 mm, biowaste compost (Rottegrad 3), green compost (Rottegrad 5, 0 mm to 15 mm), solid digestate, liquid digestate, soil improver (pellets, sieved 4 mm, growing media blend 1 (white peat, green compost, wood fibre, lime, inorganic fertilizer (NPK + micro elements)), growing media blend 2 (white peat, black peat, expanded perlite, lime, organic fertilizer) and growing media blend 3 (white peat, black peat, clay, inorganic fertilizer (NPK + micro elements))).

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