prEN 17757

Inorganic fertilizers - Determination of specific nutrients

This document specifies references to methods for the determination of the content of the following specific nutrients in inorganic fertilizers:
—   the total nitrogen content;
—   the ammoniacal nitrogen content;
—   the nitric nitrogen content;
—   the urea nitrogen content;
—   the content of nitrogen from isobutylidenediurea (IBDU) and crotonylidenediurea (CDU);
—   the cyanamide nitrogen content;
—   the methylene-urea nitrogen content (and urea formaldehyde, if applicable);
—   the total phosphorus content;
—   the water-soluble phosphorus content;
—   the neutral ammonium citrate soluble phosphorus content;
—   the formic acid soluble phosphorus content;
—   the total potassium content;
—   the water-soluble potassium content;
—   the total magnesium content;
—   the water-soluble magnesium content;
—   the total calcium content;
—   the water-soluble calcium content;
—   the total sulfur content;
—   the water-soluble sulfur content;
—   the total sodium content;
—   the water-soluble sodium content.
This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant biostimulants, and where the following category: inorganic fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If inorganic 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. 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.

Anorganische Düngemittel - Bestimmung spezifischer Nährstoffe

Dieses Dokument legt Verweisungen auf Verfahren zur Bestimmung der folgenden spezifischen, in anorganischen Düngemitteln enthaltenen Nährstoffe fest:
   Gesamtgehalt an Stickstoff;
   Gehalt an Ammoniumstickstoff;
   Gehalt an Nitratstickstoff;
   Gehalt an Harnstoffstickstoff;
   Gehalt an Stickstoff aus Isobutylidendiharnstoff (IBDU, en: isobutylidenediurea) und Crotonylidendiharnstoff (CDU, en: crotonylidenediurea);
   Gehalt an Cyanamidstickstoff;
   Gehalt an Stickstoff aus Methylenharnstoff (und Formaldehydharnstoff, sofern zutreffend);
   Gesamtgehalt an Phosphor;
   Gehalt an wasserlöslichem Phosphor;
   Gehalt an in neutralem Ammoniumcitrat löslichem Phosphor;
   Gehalt an in Ameisensäure löslichem Phosphor;
   Gesamtgehalt an Kalium;
   Gehalt an wasserlöslichem Kalium;
   Gesamtgehalt an Magnesium;
   Gehalt an wasserlöslichem Magnesium;
   Gesamtgehalt an Calcium;
   Gehalt an wasserlöslichem Calcium;
   Gesamtgehalt an Schwefel;
   Gehalt an wasserlöslichem Schwefel;
   Gesamtgehalt an Natrium;
   Gehalt an wasserlöslichem Natrium.
Dieses Dokument ist anwendbar auf Düngeproduktmischungen, bei denen eine Mischung aus mindestens zwei der folgenden Komponenten besteht: Düngemittel, Kalkdünger, Bodenverbesserungsmittel, Kultursubstrate, Hemmstoffe und Pflanzen-Biostimulanzien, und wenn die Kategorie „anorganische Düngemittel“ den höchsten Prozentsatz in der Mischung bezüglich Masse oder Volumen, oder im Falle von flüssigen Formen bezüglich Trockenmasse ausmacht. Wenn das anorganische Düngemittel nicht den höchsten Prozentsatz in der Mischung ausmacht, gilt die Europäische Norm für den höchsten Prozentsatz der Mischung. Im Falle, dass die Düngeproduktmischung aus Komponenten gleicher Menge besteht, entscheidet der Anwender, welche Norm angewendet wird. Variationen in analytischen Verfahren für Düngeproduktmischungen können zu unterschiedlichen Ergebnissen führen, da einige Komponenten oder Matrixwechselwirkungen das Ergebnis beeinflussen können. Validierungen haben gezeigt, dass die entwickelten Standardverfahren robust und zuverlässig über unterschiedliche Produktzusammensetzungen hinweg sind. Jedoch sind mögliche Interferenzen und unerwartete Ergebnisse bei der Analyse von Düngeproduktmischungen möglich.

Engrais inorganiques - Détermination des éléments nutritifs spécifiques

Le présent document spécifie les références aux méthodes de détermination de la teneur en éléments nutritifs spécifiques suivants dans les engrais inorganiques :
—   la teneur en azote total ;
—   la teneur en azote ammoniacal ;
—   la teneur en azote nitrique ;
—   la teneur en azote uréique ;
—   la teneur en azote de l’isobutylidène diurée (IBDU) et de la crotonylidène diurée (CDU) ;
—   la teneur en azote cyanamidé ;
—   la teneur en azote de la méthylène-urée (et de l’urée-formaldéhyde, le cas échéant) ;
—   la teneur en phosphore total ;
—   la teneur en phosphore soluble dans l’eau ;
—   la teneur en phosphore soluble dans le citrate d’ammonium neutre ;
—   la teneur en phosphore soluble dans l’acide formique ;
—   la teneur en potassium total ;
—   la teneur en potassium soluble dans l’eau ;
—   la teneur en magnésium total ;
—   la teneur en magnésium soluble dans l’eau ;
—   la teneur en calcium total ;
—   la teneur en calcium soluble dans l’eau ;
—   la teneur en soufre total ;
—   la teneur en soufre soluble dans l’eau ;
—   la teneur en sodium total ;
—   la teneur en sodium soluble dans l’eau.
Le présent document est applicable aux mélanges de fertilisants constitués d’au moins deux des composants suivants : engrais, amendements minéraux basiques, amendements du sol, supports de culture, inhibiteurs, biostimulants des végétaux, et dans lesquels la catégorie « engrais inorganiques » représente le pourcentage le plus élevé du mélange en masse ou en volume, ou dans le cas d’un liquide, en masse sèche. Si l’engrais inorganique ne représente pas le pourcentage le plus élevé du mélange, la Norme européenne relative au pourcentage le plus élevé du mélange s’applique. Dans le cas où le mélange de fertilisants est constitué de composants en quantités égales, l’utilisateur décide quelle norme appliquer. Les variations dans les méthodes d’analyse des mélanges de fertilisants peuvent conduire à des résultats différents, car certaines interactions de composants ou de la matrice peuvent affecter le résultat. Les procédures de validation ont montré que les méthodes normalisées développées sont robustes et fiables pour diverses compositions de produits, mais que des interférences éventuelles et des résultats inattendus lors de l’analyse des mélanges de fertilisants sont possibles.

Anorganska gnojila - Določanje specifičnih hranil

General Information

• Status: Not Published
• Publication Date: 28-Feb-2028
• ICS: 65.080 - Fertilizers
• Technical Committee: CEN/TC 260 - Fertilizers and liming materials
• Drafting Committee: CEN/TC 260/WG 7 - Chemical analysis
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 12-Feb-2026
• Due Date: 13-Oct-2026
• Completion Date: 12-Feb-2026
• Directive: Not Harmonized2019/1009 - Regulation (EU) 2019/1009 of the European Parliament and of the Council of 5 June 2019 laying down rules on the making available on the market of EU fertilising products and amending Regulations (EC) No 1069/2009 and (EC) No 1107/2009 and repealing Regulation (EC) No 2003/2003 (Text with EEA relevance)
• Mandate: M/564 - Fertilising products in support of Regulation (EU) 2019/1009
• Mandate: M/564 AMD 1 - amending Implementing Decision C(2020) 612 as regards certain harmonised standards and standardisation deliverables, deadlines for their adoption and the duration of the validity of the standardisation request
• Mandate: M/564 AMD 2 - Commission Implementing decision amending Implementing Decision C(2020)612 as regards harmonised standards, the deadlines for the adoption of those standards and the duration of the validity of the standardisation request to the European Committee for Standardisation as regards the EU fertilising products in support of Regulation (EU) 2019/1009 of the European Parliament and of the Council
• Ref Project: oSIST prEN 17757:2026 - Inorganic fertilizers - Determination of specific nutrients

Relations

• Revises: CEN/TS 17757:2022 - Inorganic fertilizers - Determination of specific nutrients
• Effective Date: 03-Jul-2024

Overview

prEN 17757: Inorganic fertilizers - Determination of specific nutrients is a European draft standard developed by CEN/TC 260. This document defines the reference methods used to determine the content of key nutrients in inorganic fertilizers, supporting compliance with EU regulations, particularly Regulation (EU) 2019/1009. The standard covers a comprehensive range of nutrient forms, including various types of nitrogen, phosphorus, potassium, magnesium, calcium, sulfur, and sodium.

The adoption and implementation of prEN 17757 is critical for manufacturers, laboratories, regulatory bodies, and other stakeholders involved in the production, blending, and quality assessment of inorganic fertilizers. The standard ensures reliable, harmonized analytical methods across diverse products and facilitates trade and regulatory compliance in the European market.

Key Topics

Nutrient Determinations Covered

• Nitrogen:
  • Total nitrogen
  • Ammoniacal nitrogen
  • Nitric nitrogen
  • Urea nitrogen
  • Nitrogen from IBDU (isobutylidenediurea) / CDU (crotonylidenediurea)
  • Cyanamide nitrogen
  • Methylene-urea and urea formaldehyde nitrogen
• Phosphorus:
  • Total phosphorus
  • Water-soluble phosphorus
  • Neutral ammonium citrate soluble phosphorus
  • Formic acid soluble phosphorus
• Potassium:
  • Total potassium
  • Water-soluble potassium
• Magnesium:
  • Total and water-soluble magnesium
• Calcium:
  • Total and water-soluble calcium
• Sulfur:
  • Total and water-soluble sulfur
• Sodium:
  • Total and water-soluble sodium

Applicability

• Fertilizer blends where inorganic fertilizer is the predominant component by mass or volume
• Other fertilizing products containing fertilizers, liming materials, soil improvers, growing media, inhibitors, or plant biostimulants
• Guidance when components are present in equal quantity, allowing user discretion on standard selection

Sampling and Sample Preparation

• Outlines the necessity for representative samples and reliable preparation according to referenced EN standards

Analytical Robustness

• Validation procedures confirm methods are reliable across varied blend compositions, though chemical or matrix interactions may occasionally impact results

Applications

prEN 17757 serves multiple practical purposes for the fertilizer industry and regulatory bodies:

• Regulatory Compliance: Enables manufacturers and importers to demonstrate conformity with EU fertilizer regulations, particularly for labeling and market access.
• Quality Assurance: Provides laboratories with standardized procedures for nutrient determination, improving consistency and reliability of results.
• Product Certification: Supports third-party assessment and certification schemes by offering clear methodological references.
• Fertilizer Blending: Offers guidance for analyzing blended products, ensuring that nutrient declarations are accurate even in complex mixes.
• Trade Facilitation: Harmonizes testing approaches across EU and EFTA member states, simplifying cross-border movement of fertilizing products.
• Environmental Protection: Assists in the assessment of fertilizer composition, ultimately contributing to sustainable agriculture and responsible nutrient management.

Related Standards

prEN 17757 references a wide array of other harmonized standards for sampling, preparation, and nutrient analysis in fertilizers, such as:

• Sampling and Preparation: EN 1482 series
• Nitrogen, Phosphorus, Potassium Analysis: EN 15475, EN 15476, EN 15477, EN 15919, EN 15958, EN 15959, prEN 15956, prEN 18316
• Elemental Analysis (Mg, Ca, Na, S): EN 16196, EN 16197, EN 16198, EN 16199, EN 15749, prEN 15960, prEN 15961
• Vocabulary: prEN 12944-1 and prEN 12944-2

Users are encouraged to consult these supporting documents for detailed procedures and definitions in fertilizer analysis and to ensure compliance with current European Union regulatory requirements.

Keywords: inorganic fertilizers, nutrient determination, European standard, fertilizer analysis, regulatory compliance, CEN, nitrogen, phosphorus, potassium, sampling, quality assurance.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2026
Anorganska gnojila - Določanje specifičnih hranil
Inorganic fertilizers - Determination of specific nutrients
Anorganische Düngemittel - Bestimmung spezifischer Nährstoffe
Engrais inorganiques - Détermination des éléments nutritifs spécifiques
Ta slovenski standard je istoveten z: prEN 17757
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2026
ICS 65.080 Will supersede CEN/TS 17757:2022
English Version
Inorganic fertilizers - Determination of specific nutrients
Engrais inorganiques - Détermination des éléments Anorganische Düngemittel - Bestimmung spezifischer
nutritifs spécifiques Nährstoffe
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 260.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17757:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 7
4 Sampling and sample preparation . 7
4.1 Sampling . 7
4.2 Sample preparation . 7
5 Methods for extraction and determination of specific nutrients . 7
5.1 Total nitrogen content . 7
5.2 Ammoniacal nitrogen . 8
5.3 Nitric nitrogen . 8
5.4 Urea nitrogen content . 8
5.5 Content of nitrogen from IBDU and CDU . 8
5.6 Cyanamide nitrogen content . 8
5.7 Methylene-urea and urea formaldehyde nitrogen content . 8
5.8 Phosphorus content . 8
5.9 Potassium content . 8
5.10 Magnesium content . 9
5.11 Calcium content . 9
5.12 Sulfur content . 9
5.13 Sodium content . 9
Annex ZA (informative) Relationship of this European Standard and the essential
requirements of Regulation (EU) 2019/1009 making available on the market of EU
fertilising products aimed to be covered . 10
Bibliography . 16

European foreword
This document (prEN 17757:2026) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This document is currently submitted to CEN Enquiry.
This document will supersede CEN/TS 17757:2022.
CEN/TS 17757:2022:
a) the CEN Technical Specification has been adopted as a European Standard including the addition of
Annex ZA;
b) Scope (Clause 1) updated:
c) Normative references (Clause 2) updated;
d) Bibliography updated;
e) determination of formic acid soluble phosphorus content (5.8) and total potassium content (5.9)
added.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this
document.
Introduction
Regulation (EU) 2019/1009 [1] lays down the rules on the making available on the market of EU
fertilizing products and the specific safety and quality requirements for the defined product function
categories (PFCs). Inorganic fertilizers have been classified into PFC 1(C).
The specific safety and quality requirements in relation to the following specific nutrients are defined in
this document as well as normative references of the test methods to be used in order to measure the
compliance with the related requirement in the Regulation (EU) 2019/1009 [1].

1 Scope
This document specifies references to methods for the determination of the content of the following
specific nutrients in inorganic fertilizers:
— the total nitrogen content;
— the ammoniacal nitrogen content;
— the nitric nitrogen content;
— the urea nitrogen content;
— the content of nitrogen from isobutylidenediurea (IBDU) and crotonylidenediurea (CDU);
— the cyanamide nitrogen content;
— the methylene-urea nitrogen content (and urea formaldehyde, if applicable);
— the total phosphorus content;
— the water-soluble phosphorus content;
— the neutral ammonium citrate soluble phosphorus content;
— the formic acid soluble phosphorus content;
— the total potassium content;
— the water-soluble potassium content;
— the total magnesium content;
— the water-soluble magnesium content;
— the total calcium content;
— the water-soluble calcium content;
— the total sulfur content;
— the water-soluble sulfur content;
— the total sodium content;
— the water-soluble sodium content.
This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the
following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant
biostimulants, and where the following category: inorganic fertilizers is the highest % in the blend by
mass or volume, or in the case of liquid form by dry mass. If inorganic 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. 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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1482-2:2024, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part
2: General sample preparation provisions
prEN 12944-1:2026, Fertilizers, liming materials and inhibitors — Vocabulary — Part 1: General terms
prEN 12944-2:2026, Fertilizers, liming materials and inhibitors — Vocabulary — Part 2: Terms relating to
fertilizers
prEN 15475:2026, Inorganic fertilizers — Titrimetric determination of ammoniacal nitrogen
EN 15476:2009, Fertilizers — Determination of nitric and ammoniacal nitrogen according to Devarda
EN 15477:2009, Fertilizers — Determination of the water-soluble potassium content
prEN 15478:2026, Inorganic fertilizers — Determination of total nitrogen in urea, methylene-urea and
urea formaldehyde
EN 15560:2023, Inorganic fertilizers — Determination of total nitrogen in calcium cyanamide nitrate free
EN 15561:2023, Inorganic fertilizers — Determination of total nitrogen in calcium cyanamide containing
nitrates
EN 15562:2023, Inorganic fertilizers — Determination of cyanamide nitrogen
EN 15604:2009, Fertilizers — Determination of different forms of nitrogen in the same sample, containing
nitrogen as nitric, ammoniacal, urea and cyanamide nitrogen
EN 15749:2022, Fertilizers — Determination of sulfates content using three different methods
EN 15750:2009, Fertilizers — Determination of total nitrogen in fertilizers containing nitrogen only as
nitric, ammoniacal and urea nitrogen by two different methods
EN 15919:2011, Fertilizers — Extraction of phosphorus soluble in 2 % formic acid
prEN 15925:2026, Inorganic fertilizers — Extraction of total sulfur present in various forms
EN 15926:2011, Fertilizers — Extraction of water soluble sulfur where the sulfur is in various forms
prEN 15956:2025, Inorganic fertilizers — Extraction of phosphorus soluble in mineral acids
prEN 15957:2026, Inorganic fertilizers — Extraction of phosphorus which is soluble in neutral ammonium
citrate
EN 15958:2011, Fertilizers — Extraction of water soluble phosphorus
EN 15959:2023, Inorganic fertilizers — Determination of extracted phosphorus P O
2 5
prEN 15960:2025, Inorganic fertilizers — Extraction of total calcium, total magnesium, total sodium and
total sulfur in the forms of sulfates
prEN 15961:2025, Inorganic fertilizers — Extraction of water-soluble calcium, magnesium, sodium and
sulfur in the form of sulfates
EN 16196:2012, Fertilizers — Manganimetric determination of extracted calcium following precipitation
in the form of oxalate
EN 16197:2012, Fertilizers — Determination of magnesium by atomic absorption spectrometry
EN 16198:2012, Fertilizers — Determination of magnesium by complexometry
EN 16199:2012, Fertilizers — Determination of the sodium extracted by flame-emission spectrometry
EN 17864:2023, Inorganic fertilizers — Determination of nitrogen content in IBDU (isobutylidenediurea)
and CDU (crotonylidenediurea)
prEN 18316
...