oSIST prEN 17729:2026

Soil improvers - Methods for the determination of the dry matter, quantity, copper, zinc, chloride, nitrogen, P2O5 and K2O content

This document provides an overview of relevant methods for the determination of specific parameters in solid soil improvers, including:
— dry matter content;
— quantity;
— copper and zinc content;
— chloride content;
— nitrogen content;
— P2O5 (phosphorus pentoxide) and K2O (potassium oxide) content.
This document is applicable to the fertilizing product blends where a blend is a mix of two or more fertilising 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 European Standard relevant to the component with the highest percentage in the blend applies. In case a blend is composed of fertilising products mixed in equal quantities, the user of the standard decides which standard to apply.
NOTE 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).

Bodenverbesserungsmittel - Bestimmung spezifischer Parameter

Amendements du sol - Vue d'ensemble des méthodes pour la détermination de la matière sèche, de la quantité, du cuivre, du zinc, des chlorures, de l'azote, et de la teneure en P2O5 et K2O

Izboljševalci tal in rastni substrati - Metode za določanje suhe snovi, količine, bakra, cinka, klorida, dušika, P2O5 in K2O

General Information

• Status: Not Published
• Public Enquiry End Date: 01-Feb-2026
• ICS: 65.080 - Fertilizers
• Technical Committee: KAT - Soil quality
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 06-Nov-2025
• Due Date: 26-Mar-2026
• Directive: 2003/2003 - Regulation (EC) N° 2003/2003 of the European Parlament and of the council of 13 October 2003 relating to fertilisers
• Directive: 2019/1009 - 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
• 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
• Mandate: M/XXX - COMMISSION IMPLEMENTING DECISION of XXX on a standardisation request to the European Committee for Standardization, to the European Committee for Electrotechnical Standardization and to the European Telecommunications Standards Institute as regards certain measuring instruments in support of Directive 2014/32/EU of the European Parliament and of the Council
• Ref Project: prEN 17729 - Soil improvers - Methods for the determination of the dry matter, quantity, copper, zinc, chloride, nitrogen, P2O5 and K2O content

Relations

• Revises: SIST-TS CEN/TS 17729:2022 - Soil improvers - Determination of specific parameters
• Effective Date: 01-Jan-2026

Overview

oSIST prEN 17729:2026 is a European standard developed by CEN/TC 223 that outlines methods for determining key parameters in soil improvers. The standard addresses procedures to measure dry matter content, quantity, copper, zinc, chloride, nitrogen, phosphorus pentoxide (P2O5), and potassium oxide (K2O) levels in solid soil improvers. It applies not only to single soil improvers but also to complex fertilizing product blends where soil improvers and/or growing media constitute the highest mass or volume proportion.

This standard supports compliance with Regulation (EU) 2019/1009 concerning the safety, quality, and market availability of EU fertilizing products. The scope ensures uniform testing and analysis methods to enhance the reliability of soil improver products used in agriculture and horticulture.

Key Topics

• Dry Matter Content
  Accurate quantification of dry matter is essential to assess the moisture level of soil improvers and grow media. The standard specifies sample preparation and testing protocols to ensure consistent moisture content determination.

• Quantity Determination
  The standard covers methods for measuring the quantity of soil improvers based on particle size-materials up to 60 mm and those exceeding 60 mm-using standardized volumetric or mass-based approaches.

• Trace Metals: Copper and Zinc Content
  Important micronutrients like copper and zinc must be monitored to avoid toxicity or deficiency. Methods for evaluating these trace metals ensure soil improvers meet safety and quality requirements.

• Chloride Content
  Chloride levels affect soil chemistry and plant health. This standard provides testing procedures to analyze chloride content accurately.

• Nitrogen Content
  Nitrogen is a vital nutrient for plant growth. oSIST prEN 17729:2026 includes two laboratory methods-the modified Kjeldahl method and the Dumas method-to determine nitrogen content in soil improvers.

• Phosphorus Pentoxide (P2O5) and Potassium Oxide (K2O) Content
  These elements are crucial macronutrients influencing soil fertility. The standard specifies determination through aqua regia soluble extraction to ensure precise measurement.

• Applicability to Fertilizing Product Blends
  The standard clarifies its use with blended fertilizing products incorporating multiple categories such as fertilizers, liming materials, inhibitors, or plant biostimulants, prioritizing the dominant component as soil improver or growing media.

Applications

oSIST prEN 17729:2026 is widely applicable in quality control laboratories, research institutions, and manufacturing facilities involved in the production, certification, and regulation of soil improvers and growing media. Its practical applications include:

• Agricultural Input Quality Assurance
  Ensuring soil improvers used in crop production meet defined quality parameters to optimize soil health and plant nutrition.

• Regulatory Compliance
  Facilitating conformity assessments for fertilizing products under EU legislation, supporting market authorization and trade.

• Product Development and Innovation
  Assisting manufacturers in developing new soil improver formulations through reliable assessment of chemical and physical properties.

• Environmental Safety Monitoring
  Controlling heavy metal content such as copper and zinc to prevent environmental contamination and safeguard ecosystem health.

Related Standards

oSIST prEN 17729:2026 references and complements several related European standards to provide a comprehensive approach to soil improver analysis:

• prEN 17732:2025 - Terminology for Soil Improvers and Growing Media
• EN 12579:2024 - Sampling Methods for Soil Improvers and Growing Media
• prEN 13040-1:2025 - Sample Preparation and Dry Matter Determination
• prEN 13654 series (Part 1 & 2): 2025 - Nitrogen Determination by Modified Kjeldahl and Dumas Methods
• prEN 18259:2025 - Determination of Aqua Regia Soluble Elements including P2O5, K2O, Copper, Zinc
• prEN 18252:2025 - Chloride Content Determination
• EN 12580:2022 & EN 15238:2022 - Quantity Determination for Particle Sizes Up to and Greater Than 60 mm

These interlinked standards work together to ensure consistent terminology, sampling procedures, and precise analytical techniques for soil improvers and related fertilizing products.

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Keywords: oSIST prEN 17729:2026, soil improvers, dry matter content, copper content, zinc content, chloride determination, nitrogen measurement, phosphorus pentoxide, potassium oxide, EU fertilizing products, CEN standards, fertilizer blends, soil amendment testing, sampling methods, fertilizer quality control.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2026
Izboljševalci tal in rastni substrati - Metode za določanje suhe snovi, količine,
bakra, cinka, klorida, dušika, P2O5 in K2O
Soil improvers - Methods for the determination of the dry matter, quantity, copper, zinc,
chloride, nitrogen, P2O5 and K2O content
Bodenverbesserungsmittel - Bestimmung spezifischer Parameter
Amendements du sol - Vue d'ensemble des méthodes pour la détermination de la
matière sèche, de la quantité, du cuivre, du zinc, des chlorures, de l'azote, et de la
teneure en P2O5 et K2O
Ta slovenski standard je istoveten z: prEN 17729
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
December 2025
ICS Will supersede CEN/TS 17729:2022
English Version
Soil improvers - Methods for the determination of the dry
matter, quantity, copper, zinc, chloride, nitrogen, P2O5 and
K2O content
Amendements du sol - Vue d'ensemble des méthodes Bodenverbesserungsmittel - Bestimmung spezifischer
pour la détermination de la matière sèche, de la Parameter
quantité, du cuivre, du zinc, des chlorures, de l'azote, et
de la teneure en P2O5 et K2O
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 223.
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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17729:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Sampling and sample preparation . 6
4.1 Sampling . 6
4.2 Sample preparation for chemical and physical tests . 6
5 Determination . 6
5.1 Determination of the dry matter content . 6
5.2 Determination of the nitrogen content . 6
5.2.1 Modified Kjeldahl method . 6
5.2.2 Dumas method . 6
5.3 Determination of the aqua regia soluble P O and K O content . 6
2 5 2
5.4 Determination of the copper and zinc content . 6
5.5 Determination of quantity . 7
5.5.1 Determination of quantity for materials up a particle size up to 60 mm . 7
5.5.2 Determination of quantity (indicated by volume or mass) for materials up a particle
size greater than 60 mm . 7
5.6 Determination of the chloride content . 7
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 . 8
Bibliography . 9

European foreword
This document (prEN 17729:2025) has been prepared by Technical Committee CEN/TC 223 “Soil
improvers and growing media”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN enquiry.
This document will supersede CEN/TS 17729:2022.
This document includes the following significant technical changes with respect to CEN/TS 17729:2022:
— The title has been revised;
— The quantity requirements have been added to the Introduction;
— An applicability statement has been included in the Scope;
— Clause 2, Normative references, has been updated;
— Annex ZA has been 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
Different product functions warrant different product safety, quality and quantity requirements adapted
to their different intended uses. EU fertilizing products have therefore been divided into different product
function categories (PFCs), which are subject to specific safety, quality and quantity requirements, as
specified in the Regulation (EU) 2019/1009 [1].
Soil improvers have been classified as PFC 3. The specific safety, quality and quantity requirements in
relation to specific parameters are specified in this document, as well as normative references of the test
methods to be used to assess the compliance with the related requirement.
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