kSIST FprEN 17731:2026
(Main)Growing media - Methods for the determination of the electrical conductivity, pH, dry matter content, quantity, total copper and zinc content, water soluble chloride content, and CaCl2/DTPA extractable nitrogen, P2O5 and K2O content
- Abstract
This document specifies references to methods to be used for the determination of specific parameters in growing media, but does not contain the methods themselves. The specific parameters in this document are:
— electrical conductivity;
— pH;
— dry matter content;
— quantity;
— total copper and zinc content;
— water soluble chloride content;
— nitrogen, P2O5 and K2O content extractable by CaCl2/DTPA
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 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 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 growing medium 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).
- Status
- Not Published
- Public Enquiry End Date
- 19-Apr-2026
- Technical Committee
- KAT - Soil quality
- Current Stage
- 5020 - Formal vote (FV) (Adopted Project)
- Start Date
- 02-Nov-2026
- Due Date
- 21-Dec-2026
- Mandate
- M/XXX - M/XXX
kSIST FprEN 17731:2026 is a draft European Standard from CEN for growing media. It specifies which test methods to use for electrical conductivity, pH, dry matter, quantity, total copper and zinc, water soluble chloride, and CaCl2/DTPA extractable nitrogen, P2O5 and K2O. It is written for laboratories, manufacturers, and other users who need to assess growing media and certain fertilising product blends against the relevant requirements.
What does kSIST FprEN 17731:2026 specify?
kSIST FprEN 17731:2026 specifies references to methods for determining selected parameters in growing media, but it does not include the analytical methods themselves. Its structure is simple: Clause 1 covers scope, Clause 2 lists normative references, Clause 3 gives terms and definitions, Clause 4 covers sampling and sample preparation, and Clause 5 sets out the determination routes for each parameter. Annex ZA links the standard to Regulation (EU) 2019/1009.
The standard applies to fertilising product blends when growing media are the main component by mass, volume, or dry mass for liquids. When another component is dominant, the standard for that dominant component applies instead. For equal blends, the user decides which standard to apply.
| Annex | What it covers |
|---|---|
| Annex ZA | Relationship between this European Standard and Regulation (EU) 2019/1009, including the conformity mapping |
What are the key requirements of kSIST FprEN 17731:2026?
kSIST FprEN 17731:2026 requires users to follow the linked test standards for sampling, preparation, and each determination. In practice, the document is a route map: it tells you which method to use for each measurement so results are comparable and fit for compliance checking.
Sampling and sample preparation
Clause 4 requires sampling for quality and quantity control to follow EN 12579:2024. It also requires sample preparation for chemical and physical tests to follow prEN 13040-1:2025, Clauses 6 to 10. That matters because the test result depends on how the sample is taken and prepared before any measurement starts.
Determination of chemical and physical parameters
Clause 5 assigns a specific reference method to each parameter:
- electrical conductivity - prEN 13038:2025
- chloride content - prEN 18252:2025
- pH - prEN 13037:2025
- dry matter - prEN 13040-1:2025
- CaCl2/DTPA extractable nitrogen, P2O5 and K2O - prEN 13651:2025
- aqua regia soluble copper and zinc - prEN 13650:2025 for extraction, then prEN 18259:2025 for determination
This structure matters because the document separates extraction from measurement where needed, especially for metals and nutrients.
Quantity depends on product form and particle size
Clause 5 also splits quantity determination into four cases:
- plugs - prEN 18250:2025
- pre-shaped growing media other than plugs - FprEN 15761:2025
- growing media other than pre-shaped materials with particle size not greater than 60 mm - EN 12580:2022
- growing media other than pre-shaped materials with particle size greater than 60 mm - EN 15238:2022
That means the user must identify the product form before testing, otherwise the wrong quantity method could be used.
Link to EU fertilising products
Annex ZA maps the clauses to the essential requirements of Regulation (EU) 2019/1009 for PFC 4 growing media. Where the standard is cited in the Official Journal of the European Union, compliance with the relevant normative clauses supports presumption of conformity within the scope of the standard. In practice, this is the bridge between laboratory testing and regulatory conformity assessment.
What terms does kSIST FprEN 17731:2026 define?
The terms and definitions in prEN 17732:2025 apply to this document. Key terms used here include:
- Growing media - a single bulky component or a mix of bulky components, such as peat, wood fibres, coconut coir, compost, or expanded perlite.
- Fertilising product blend - a mix of two or more fertilising products belonging to the named categories in the scope.
- PFC 4 - the product function category for growing media under Regulation (EU) 2019/1009.
- Quantity - the amount of material, measured by the method chosen for the product form and particle size.
- Dry matter - the material remaining after preparation and drying-related measurement.
- CaCl2/DTPA - the extraction route used here for nutrient determination.
- Aqua regia soluble elements - elements released by aqua regia digestion before elemental measurement.
Who uses kSIST FprEN 17731:2026?
kSIST FprEN 17731:2026 is used by testing laboratories, growing media producers, fertiliser and soil improver suppliers, and quality managers who need a consistent way to measure composition and quantity. It is also relevant for conformity assessment, product release, and documentation under the EU fertilising products framework.
Buyers and technical specifiers use it to understand which test method supports a declared value or compliance claim. Regulators and market surveillance bodies can also use it when checking whether results were generated with the correct method.
What changed in kSIST FprEN 17731:2026 from the previous edition?
kSIST FprEN 17731:2026 will supersede CEN/TS 17731:2022. The stated changes are:
- the title has been revised
- quantity requirements have been added in the Introduction
- an applicability statement has been added in the Scope
- Clause 2, Normative references, has been updated
- Annex ZA has been added
Which standards are used with kSIST FprEN 17731:2026?
kSIST FprEN 17731:2026 relies on several companion standards for the actual test work:
- EN 12579:2024 - sampling
- EN 12580:2022 - quantity for materials with particle size up to 60 mm
- prEN 13037:2025 - pH
- prEN 13038:2025 - electrical conductivity
- prEN 13040-1:2025 - sample preparation and dry matter
- prEN 13650:2025 - aqua regia digestion
- prEN 13651:2025 - CaCl2/DTPA extraction
- EN 15238:2022 - quantity for materials with particle size greater than 60 mm
- FprEN 15761:2025 - quantity for pre-shaped growing media other than plugs
- prEN 17732:2025 - terms and definitions
- prEN 18250:2025 - quantity for plugs
- prEN 18252:2025 - chloride content
- prEN 18259:2025 - aqua regia soluble elements
What does the kSIST FprEN 17731:2026 document contain?
kSIST FprEN 17731:2026 contains the scope, normative references, terms and definitions, sampling and sample preparation rules, and a clause-by-clause list of the reference methods to use for each parameter. It also contains Annex ZA, which shows how the standard relates to Regulation (EU) 2019/1009.
The document’s practical content is the method-selection framework, not the measurement procedures themselves. Clause 5 points users to the correct sampling, digestion, extraction, and measurement standards for each parameter and product form. Annex ZA provides the conformity mapping used for EU fertilising products.
Relations
- Effective Date
- 20-Nov-2024
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Frequently Asked Questions
kSIST FprEN 17731:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Growing media - Methods for the determination of the electrical conductivity, pH, dry matter content, quantity, total copper and zinc content, water soluble chloride content, and CaCl2/DTPA extractable nitrogen, P2O5 and K2O content". This standard covers: This document specifies references to methods to be used for the determination of specific parameters in growing media, but does not contain the methods themselves. The specific parameters in this document are: — electrical conductivity; — pH; — dry matter content; — quantity; — total copper and zinc content; — water soluble chloride content; — nitrogen, P2O5 and K2O content extractable by CaCl2/DTPA 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 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 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 growing medium 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).
This document specifies references to methods to be used for the determination of specific parameters in growing media, but does not contain the methods themselves. The specific parameters in this document are: — electrical conductivity; — pH; — dry matter content; — quantity; — total copper and zinc content; — water soluble chloride content; — nitrogen, P2O5 and K2O content extractable by CaCl2/DTPA 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 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 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 growing medium 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).
kSIST FprEN 17731:2026 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
kSIST FprEN 17731:2026 has the following relationships with other standards: It is inter standard links to SIST-TS CEN/TS 17731:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
kSIST FprEN 17731:2026 is associated with the following European legislation: EU Directives/Regulations: 2003/2003, 2019/1009; Standardization Mandates: M/564, M/564 AMD 1, M/564 AMD 2, M/XXX. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
kSIST FprEN 17731:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 17731:2026
01-april-2026
Rastni substrati - Metode za določanje električne prevodnosti, pH, suhe snovi,
količine, celotnega bakra in cinka, klorida, topnega v vodi, ter dušika, P2O5 in
K2O, dobljenih z ekstrakcijo s CaCl2/DTPA
Growing media - Methods for the determination of the electrical conductivity, pH, dry
matter, quantity, total copper and zinc content, water soluble chloride content, and
CaCl2/DTPA extractable nitrogen, P2O5 and K2O content
Bodenverbesserungsmittel - Bestimmung spezifischer Parameter
Supports de culture - Vue d'ensemble des méthodes pour la détermination de la
conductivité électrique, du pH, de la matière sèche, de la quantité, de la teneur total en
cuivre et en zinc, de la teneur en chlorures solubles dans l'eau, de l'azote
extractable/CaCl2/DTAPA, et de la teneur en P2O5 et K2O
Ta slovenski standard je istoveten z: prEN 17731
ICS:
65.080 Gnojila Fertilizers
oSIST prEN 17731:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 17731:2026
oSIST prEN 17731:2026
DRAFT
EUROPEAN STANDARD
prEN 17731
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2026
ICS 65.080 Will supersede CEN/TS 17731:2022
English Version
Growing media - Methods for the determination of the
electrical conductivity, pH, dry matter, quantity, total
copper and zinc content, water soluble chloride content,
and CaCl2/DTPA extractable nitrogen, P2O5 and K2O
content
Supports de culture - Méthodes pour la détermination Kultursubstrate - Verfahren zur Bestimmung der
de la conductivité électrique, du pH, de la matière elektrischen Leitfähigkeit, des pH-Werts, der
sèche, de la quantité, de la teneur totale en cuivre et en Trockensubstanz, der Menge, des Gesamtkupfer- und -
zinc, de la teneur en chlorure soluble dans l'eau et de la zinkgehalts, des Gehalts an wasserlöslichem Chlorid
teneur en azote, en P2O5 et en K2O extractibles par und des Gehalts an mit CaCl2/DTPA extrahierbarem
CaCl2/DTPA Stickstoff, P2O5 und 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17731:2026 E
worldwide for CEN national Members.
oSIST prEN 17731:2026
prEN 17731:2026 (E)
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 . 6
5 Determination . 6
5.1 Determination of the electrical conductivity . 6
5.2 Determination of the chloride content . 6
5.3 Determination of pH . 6
5.4 Determination of dry matter . 6
5.5 Determination of the nitrogen, P O and K O content extractable by CaCl /DTPA . 6
2 5 2 2
5.6 Determination of the aqua regia soluble copper and zinc content . 7
5.7 Determination of quantity . 7
Bibliography . 10
oSIST prEN 17731:2026
prEN 17731:2026 (E)
European foreword
This document (prEN 17731:2026) 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 17731:2022.
prEN 17731:2026 includes the following significant technical changes with respect to
CEN/TS 17731:2022:
— The title has been revised;
— The quantity requirements have been added in 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.
oSIST prEN 17731:2026
prEN 17731:2026 (E)
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].
Growing media have been classified as PFC 4. 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.
oSIST prEN 17731:2026
prEN 17731:2026 (E)
1 Scope
This document refers to methods to be used for the determination of specific parameters in growing
media, but does not contain the methods themselves. The specific parameters in this document include:
— electrical conductivity;
— chloride;
— pH;
— dry matter;
— nitrogen, P O (phosphorus pentoxide) and K O (potassium oxide) content extractable by
2 5 2
CaCl /DTPA;
— copper and zinc content;
— quantity.
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 im
...