kSIST FprEN 13039:2026
(Main)Soil improvers and growing media - Determination of organic matter content and ash
- Abstract
This document specifies a routine method for determining the organic matter and the ash content of soil improvers and growing media.
NOTE 1 The loss on ignition (LOI) is often used as an estimate for the content of organic matter in the sample. Inorganic substances or decomposition products (e.g. H2O, CO2, SO2, O2) are released or absorbed and some inorganic substances are volatile under the reaction conditions. Thus, a conversion to the organic carbon content is not possible.
NOTE 2 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 bark (Pinus pinaster, 20 mm to 40 mm fraction), green compost (Rottegrad 5,0 mm to 15 mm), liquid digestate, mineral wool, soil improver (pellets, sieved 4 mm) and growing media blend (white peat, black peat, expanded perlite, lime, organic fertilizer)).
- Status
- Not Published
- Public Enquiry End Date
- 01-Dec-2025
- Technical Committee
- KAT - Soil quality
- Current Stage
- 5020 - Formal vote (FV) (Adopted Project)
- Start Date
- 13-Oct-2026
- Due Date
- 01-Dec-2026
- Mandate
- M/XXX - M/XXX
kSIST FprEN 13039:2026 is a SIST standard for determining the organic matter content and ash content of soil improvers and growing media. It specifies a routine loss on ignition (LOI) method for laboratories, product control and conformity testing, and it is based on the CEN draft European Standard prEN 13039.
What does kSIST FprEN 13039:2026 specify?
kSIST FprEN 13039:2026 specifies a routine method for measuring organic matter and ash in soil improvers and growing media. The method is based on drying and controlled ignition, so it is suitable when a practical mass-based result is needed for routine laboratory work.
The scope note explains that LOI is often used as an estimate of organic matter, but it is not a direct measure of organic carbon. That matters in practice because some inorganic substances can be lost or changed during heating, so the result should be reported as LOI-based organic matter, not converted to carbon content.
The document is organized into:
- Clause 1 - Scope
- Clause 2 - Normative references
- Clause 3 - Terms and definitions
- Clause 4 - Principle
- Clause 5 - Apparatus
- Clause 6 - Sampling
- Clause 7 - Procedure
- Clause 8 - Calculation and expression of results
- Clause 9 - Test report
- Clause 10 - Validation of the method
- Annex A - Performance characteristics of the method
- Bibliography
Annex A gives the validation materials and performance data for several product types used in the interlaboratory study.
What are the key requirements of kSIST FprEN 13039:2026?
kSIST FprEN 13039:2026 requires a dried test portion to be heated in a defined way, and the mass loss and residue are then used to calculate organic matter and ash. In practice, the method depends on controlled temperature, representative sampling and careful weighing.
Principle and temperatures
Clause 4 sets the core sequence: dry the test portion at 105 °C ± 2 °C, then ash it at 550 °C ± 25 °C. Organic matter is taken as the loss in mass on ignition, while ash is the remaining residue. For users, this means the oven and furnace settings must be controlled closely if results are to be comparable.
Apparatus and weighing
Clause 5 requires a drying oven, a muffle furnace, a shallow basin, a desiccator and an analytical balance with 0,01 g scale interval. The basin must suit a 5 g test portion and be free from volatile contamination. In practice, the equipment choice affects both mass stability and repeatability.
Sampling and sample preparation
Clause 6 points users to EN 12579:2024 for sampling, and Clause 7 requires sample preparation in accordance with prEN 13040-1:2025. The laboratory should receive a representative sample that has not been damaged in transport or storage. This is important because the result reflects the sample received, not the whole batch unless sampling was done correctly.
Procedure and safety
Clause 7 requires drying the test portion for at least 4 h at 105 °C ± 2 °C, then ignition in stages up to 550 °C ± 25 °C, with repeat ashing if the mass change is still above 0,01 g. The safety note warns about sharps and dusty samples. For routine work, this means the operator must watch both sample handling and constant mass behavior.
Calculation and reporting
Clause 8 gives formulae for organic matter and ash as percentages by mass of the dried sample. Clause 9 requires a full sample identification, the standard reference, results to one decimal place, unusual observations, and any non-standard or optional operation. That makes the report usable for audits, customer records and later comparison.
Method validation
Clause 10 states that the method was validated in accordance with ISO 5725-2 and that performance characteristics were determined by interlaboratory study. Annex A gives the repeatability and reproducibility data. This matters when users need to judge whether the method is suitable for product control or specification checks.
What terms does kSIST FprEN 13039:2026 define?
- Organic matter - the carbon fraction of a sample that is free from water and inorganic substances.
- Ash - the residual mineral matter left after controlled burning destroys the organic material.
- Loss on ignition (LOI) - the mass loss after ignition; the standard uses it as an estimate of organic matter.
- Test portion - the prepared part of the sample that is weighed, dried and ignited.
- Repeatability - the spread of results under the same measurement conditions, as used in the validation data.
- Reproducibility - the spread of results between laboratories, also reported in Annex A.
Who uses kSIST FprEN 13039:2026?
kSIST FprEN 13039:2026 is used by testing laboratories, soil improver and growing media producers, and quality managers who need routine data on organic matter and ash. Buyers and regulators can also use it when checking product declarations or comparing lots. The validation materials include bark, green compost, liquid digestate, mineral wool, a pelleted soil improver and a peat-based blend, so the method is aimed at a broad range of market products.
What changed in kSIST FprEN 13039:2026 from the previous edition?
kSIST FprEN 13039:2026 replaces EN 13039:2011. The stated technical changes are an adapted scope and an expanded drying temperature range.
Which standards are used with kSIST FprEN 13039:2026?
- CEN/TS 17732:2022 - provides the terminology used in the document.
- EN 12579:2024 - provides the sampling method for soil improvers and growing media.
- prEN 13040-1:2025 - provides the sample preparation step before the determination.
- ISO 5725-2 - provides the statistical basis used for method validation and the performance data in Annex A.
What does the kSIST FprEN 13039:2026 document contain?
The document contains the measurement principle, apparatus list, sampling instruction, step-by-step drying and ignition procedure, calculation formulae and test report items. It also includes validation information and performance characteristics in Annex A, with tables for the materials tested and the repeatability and reproducibility results. The bibliography points users to the statistical method, the EU fertilising products regulation and the published interlaboratory study report.
Relations
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
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Frequently Asked Questions
kSIST FprEN 13039:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Soil improvers and growing media - Determination of organic matter content and ash". This standard covers: This document specifies a routine method for determining the organic matter and the ash content of soil improvers and growing media. NOTE 1 The loss on ignition (LOI) is often used as an estimate for the content of organic matter in the sample. Inorganic substances or decomposition products (e.g. H2O, CO2, SO2, O2) are released or absorbed and some inorganic substances are volatile under the reaction conditions. Thus, a conversion to the organic carbon content is not possible. NOTE 2 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 bark (Pinus pinaster, 20 mm to 40 mm fraction), green compost (Rottegrad 5,0 mm to 15 mm), liquid digestate, mineral wool, soil improver (pellets, sieved 4 mm) and growing media blend (white peat, black peat, expanded perlite, lime, organic fertilizer)).
This document specifies a routine method for determining the organic matter and the ash content of soil improvers and growing media. NOTE 1 The loss on ignition (LOI) is often used as an estimate for the content of organic matter in the sample. Inorganic substances or decomposition products (e.g. H2O, CO2, SO2, O2) are released or absorbed and some inorganic substances are volatile under the reaction conditions. Thus, a conversion to the organic carbon content is not possible. NOTE 2 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 bark (Pinus pinaster, 20 mm to 40 mm fraction), green compost (Rottegrad 5,0 mm to 15 mm), liquid digestate, mineral wool, soil improver (pellets, sieved 4 mm) and growing media blend (white peat, black peat, expanded perlite, lime, organic fertilizer)).
kSIST FprEN 13039:2026 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 13039:2026 has the following relationships with other standards: It is inter standard links to SIST EN ISO 13161:2021, SIST-TP CEN ISO/TR 22930-1:2021, SIST EN ISO 22125-2:2020, SIST-TP CEN ISO/TR 22930-2:2021, SIST EN ISO 23548:2025, SIST EN ISO 11665-6:2020, SIST EN ISO 18589-1:2021, SIST EN ISO 13165-3:2025, SIST EN ISO 20044:2024, SIST EN ISO 18589-5:2021, SIST EN ISO 13160:2021, SIST EN ISO 19581:2025, SIST EN ISO 11665-5:2020, SIST EN ISO 13165-2:2023, SIST EN ISO 13162:2021. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
kSIST FprEN 13039:2026 is associated with the following European legislation: EU Directives/Regulations: 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 13039:2026 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 13039:2025
01-november-2025
Izboljševalci tal in rastni substrati - Določanje organske snovi in pepela
Soil improvers and growing media - Determination of organic matter content and ash
Bodenverbesserungsmittel und Kultursubstrate - Bestimmung des Gehaltes an
organischer Substanz und Asche
Amendements du sol et supports de culture - Détermination de la teneur en matière
organique et des cendres
Ta slovenski standard je istoveten z: prEN 13039
ICS:
65.080 Gnojila Fertilizers
oSIST prEN 13039:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 13039:2025
oSIST prEN 13039:2025
DRAFT
EUROPEAN STANDARD
prEN 13039
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2025
ICS 65.080 Will supersede EN 13039:2011
English Version
Soil improvers and growing media - Determination of
organic matter content and ash
Amendements du sol et supports de culture - Bodenverbesserungsmittel und Kultursubstrate -
Détermination de la teneur en matière organique et Bestimmung des Gehaltes an organischer Substanz und
des cendres Asche
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 13039:2025 E
worldwide for CEN national Members.
oSIST prEN 13039:2025
prEN 13039:2025 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Apparatus . 5
6 Sampling . 5
7 Procedure . 5
7.1 Safety . 5
7.2 Test sample . 5
7.3 Determination . 5
8 Calculation and expression of results . 6
9 Test report . 6
10 Validation of the method . 6
10.1 Validation in accordance with ISO 5725-2. 6
10.2 Performance characteristics. 6
Annex A (informative) Performance characteristics of the method . 7
Bibliography . 10
oSIST prEN 13039:2025
prEN 13039:2025 (E)
European foreword
This document (prEN 13039:2025) 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 EN 13039:2011.
prEN 13039:2025 includes the following significant technical changes with respect to EN 13039:2011:
— the scope has been adapted.
— the temperature range for the drying has been expanded.
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.
oSIST prEN 13039:2025
prEN 13039:2025 (E)
1 Scope
This document specifies a routine method for determining the organic matter and the ash content of soil
improvers and growing media.
NOTE The loss on ignition (LOI) is often used as an estimate for the content of organic matter in the sample.
Inorganic substances or decomposition products (e.g. H O, CO , SO , O ) are released or absorbed and some
2 2 2 2
inorganic substances are volatile under the reaction conditions. Thus, a conversion to the organic carbon content is
not 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.
CEN/TS 17732:2022, Soil improvers and growing media – Terminology
EN 12579:2024, Soil improvers and growing media - Sampling
prEN 13040-1:2025, Soil improvers and growing media — Sample preparation — Part 1: Sample
preparation for chemical and physical tests, determination of dry matter content, moisture content and
laboratory bulk density
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CEN/TS 17732:2022 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
organic matter
carbon fraction of a sample which is free from water and inorganic substances
3.2
ash
residual mineral matter remaining after the destruction of organic matter/material by controlled burning
4 Principle
The test portion is dried at 105 °C ± 2 °C, then ashed at 550 °C ± 25 °C. The ash is determined as the
residue on ignition. The organic matter is taken to be the loss of mass on ignition. Both are expressed as
a percentage by mass of the dried sample.
NOTE 1 Loss on ignition (LOI) is an empirical parameter, thus in principle there is no interference connected to
the determination. However, for some purposes the determination of LO
...