oSIST prEN 13651:2025

SLOVENSKI STANDARD
01-december-2025
Izboljševalci tal in rastni substrati - Ekstrakcija hranil, topnih v kalcijevem
kloridu/DTPA (CAT)
Soil improvers and growing media - Extraction of calcium chloride/DTPA (CAT) soluble
nutrients
Bodenverbesserungsmittel und Kultursubstrate - Extraktion von in Calciumchlorid/DTPA
(CAT) löslichen Nährstoffen
Amendements du sol et supports de culture - Extraction des éléments nutritifs solubles
dans le chlorure de calcium/DTPA (CAT)
Ta slovenski standard je istoveten z: prEN 13651
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
October 2025
ICS 65.080 Will supersede EN 13651:2001
English Version
Soil improvers and growing media - Extraction of calcium
chloride/DTPA (CAT) soluble nutrients
Amendements du sol et supports de culture - Bodenverbesserungsmittel und Kultursubstrate -
Extraction des éléments nutritifs solubles dans le Extraktion von in Calciumchlorid/DTPA (CAT)
chlorure de calcium/DTPA (CAT) löslichen Nährstoffen
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 13651:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents . 4
5.1 General. 4
5.2 Reagents . 4
6 Apparatus . 5
6.1 General. 5
6.2 Apparatus . 5
7 Sampling . 5
8 Test sample . 5
9 Procedure . 6
9.1 Safety . 6
9.2 Extraction of material in solid form . 6
9.2.1 Test samples passing through a 20 mm sieve . 6
9.2.2 Test samples passing through a 40 mm sieve (≤20 % or 20-40 % retained on the sieve) . 6
9.2.3 Test samples passing through a 40 mm sieve (>40 % retained on the sieve) . 6
9.3 Extraction of material in pre shaped form . 6
9.4 Filtration . 6
10 Determination of the extracted nutrients and elements . 6
11 Expression of results . 7
12 Test report . 7
13 Validation of the method . 7
13.1 Validation in accordance with ISO 5725-2. 7
13.2 Performance characteristics. 7
Annex A (informative) Examples of methods of analysis used for the determination of nutrients
and elements . 8
Annex B (informative) Performance characteristics of the method . 9
Bibliography . 26

European foreword
This document (prEN 13651:2025) 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 13651:2001.
— The title has been changed;
— The principle (Clause 4) has been completed;
— The procedure (Clause 8) has been updated with new types of test samples;
— The expression of results (Clause 10) has been completed inserting conversion factors and a
calculation on a dry matter basis;
— Methods of analysis (Annex A) have been updated.
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.
1 Scope
This document specifies an extraction method for the routine determination of calcium chloride/DTPA
(CAT-method) extractable nutrients and elements in organic soil improver, inorganic soil improver,
growing medium, compost and digestate.
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 apply.
4 Principle
A sample is extracted with calcium chloride/DTPA at 22 °C ± 3 °C in an extraction volume ratio of 1 to 5.
The extracted nutrients and elements are determined by various methods as appropriate (see Annex A).
If soluble calcium is to be determined, a barium chloride/DTPA solution with the same molar
concentration may be used.
5 Reagents
5.1 General
All reagents used shall be of recognized analytical quality and water with a specific conductivity not
higher than 0,2 mS/m at 25 °C, free from the elements to be determined.
5.2 Reagents
5.2.1 Dihydrated calcium chloride, CaCl ·2H O.
2 2
5.2.2 Diethylenetriaminepentaacetic acid (DTPA), C H N O .
14 23 3 10
5.2.3 Hydrochloric acid, c(HCl) = 1:1 vol/vol.
5.2.4 Concentrated extracting solution CaCl /DTPA, (CAT), dissolve 14,7 g CaCl ·2H O (5.2.1) and
2 2 2
7,88 g DTPA (5.2.2) in 800 ml hot water (temperature approximately 80 °C) with stirring on a magnetic
stirrer in a 1 000 ml beaker. At 75 °C ± 10 °C the reagents will dissolve within 2 h. Allow to cool to ambient
temperature. Transfer the solution to a 1 000 ml flask and dilute to the mark with water. The solution is
stable at room temperature for several weeks. Any precipitation that occurs will disappear with warming
and stirring.
5.2.5 Extracting solution CaCl /DTPA, (CAT), dilute the concentrated extracting solution (5.2.4) with
water in the proportions one part concentrated solution with nine parts water. The final concentration
of the extracting solution should be 0,01 mol/l CaCl and 0,002 mol/l DTPA. The pH of the extracting
solution should be adjusted if necessary to be between 2,6 and 2,65 by using HCl (5.2.3).
5.2.6 Nitric acid, c(HNO ) = 15 mol/l: ⍴ ≈ 1,42 g/ml; not less than 65 % mass/volume.
5.2.7 Nitric acid, c(HNO ) = 0,5 mol/l, dilute 35 ml nitric acid (5.2.6) to one litre with water.
6 Apparatus
6.1 General
NOTE It has been found convenient to carefully clean the equipment (e.g. using nitric acid) and keep separate
sets of glassware for the determination of Boron, in order to reduce the possibility of within-laboratory
contamination.
All glass apparatus and plastic vessels used in the procedure should be subject to an appropriate
preparation procedure in order to keep the risk of contamination as low as possible. It is recommended
that all vessels (glass and plastic) are cleansed by carefully immersing in warm nitric acid (5.2.7) for a
minimum of 6 h and then rinsed in water.
Rubber stoppers, which may contain traces of metals shall not be used. It is recommended to use plastic
or any other stopper free of all substances to be analysed.
Borosilicate glassware shall not be used if boron is to be determined.
6.2 Apparatus
The apparatus consists of the usual laboratory apparatus, and in particular the following:
6.2.1 Plastic bottles or containers, sufficiently large (500 ml to 2 000 ml) with screw cap to
accommodate the volume of the sample, extractant and at least 10 % air volume.
6.2.2 Shaking or mixing machine, capable of holding the plastic bottles or containers (6.2.1) and
maintaining the sample in suspension without damaging the structure of the sample. The use of a
horizontal table shaker is recommended.
6.2.3 Filter paper, cellulose-based ashless types, with a medium pore size of approximately 8 µm and
diameter of 150 mm.
6.2.4 Analytical balance with an accuracy of 10 mg.
7 Sampling
Sampling is not part of the method specified in this document. EN 12579:2024 shall be followed dealing
with soil improvers and growing media. It is important that the laboratory receives a sample that is
representative of the product under consideration. The sample should not have been damaged or
changed during transport or storage.
8 Test sample
Prepare the laboratory sample in accordance with prEN 13040-1:2025, Clause 9, and determine the
laboratory bulk density of the sample in accordance with prEN 13040-1:2025, Annex A.
9 Procedure
9.1 Safety
SAFETY PRECAUTIONS — Care should be taken when handling substances of caustic nature or samples
that may contain sharps or is of a dusty nature.
9.2 Extraction of material in solid form
9.2.1 Test samples passing through a 20 mm sieve
Take a weight equivalent to 60 ml of the sample volume (prEN 13040-1:2025, Clause 9.2.5) to the nearest
1 g and transfer to the container (6.2.1). Add 300 ml of extracting solution (5.2.5), secure the cap and
shake
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