🌱 Sampling of soil improvers and growing media — bulk, packaged and liquid material, samples for chemical, physical and microbiological testing, PN-EN 12579

Physicochemistry PN-EN 12579

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN 12579:2024-09 (English version), in full (our translation): “This document specifies methods for sampling soil improvers and growing media for the subsequent determination of their quality and quantity. The document specifies the principles to be taken into account when taking a sample and ensuring an adequate quantity of material for testing. This document applies to materials in solid form (including pre-shaped growing media) and in liquid form. The document is intended for use by manufacturers, buyers and enforcement agencies in verifying claims made for these materials. It is not intended that the document should be required for the purpose of manufacturing control. The requirements of this document can differ from the national legal requirements for the declaration of the material concerned”. The Polish title of the 2024 edition uses the term “ulepszacze gleby” (soil improvers) for the same materials that the 2013 edition called “środki poprawiające glebę”. We read the text in the sample of SIST EN 12579:2024 (the text of EN 12579:2024 without changes): European foreword, introduction, Clauses 1–5 and 6.1–6.2.2 (up to the number of final samples); we do not have 6.3–10 (number and distribution of sampling points, volume of samples, incremental samples, samples for microbiological testing, final sample, liquid materials, packing, labelling, sampling report, dispatch) or Annexes A–F — we know only their titles from the table of contents.

ACCORDING TO THE TEXT OF EN 12579:2024 (foreword, introduction, Clauses 1–6.2.2, table of contents). The standard was prepared by CEN/TC 223 “Soil improvers and growing media”, under a standardization request of the European Commission; it supersedes EN 12579:2013. Technical changes from the 2013 edition: requirements for liquid materials added to the scope and the sampling procedure; requirements for sampling for microbiological testing added; Annexes B (informative — examples of apparatus for sampling liquids), C (informative — methods of mixing liquids), D (informative — schematic overview of the procedure), E (normative — procedure for bulk material, steps 1–6) and F (normative — procedure for packaged material, steps 1–6) added; normative Annex A gives the required final sample size. Introduction: the materials are difficult to sample because of their variety and inhomogeneity, and when packed they may be compressed — this has to be counteracted before sampling; sampling should be undertaken by a suitably competent person. Scope (1): methods of sampling for the subsequent determination of quality and quantity; material in solid form (including pre-shaped growing media) and liquid form; for manufacturers, buyers and enforcement agencies verifying claims; not necessarily intended for manufacturing control; its requirements can differ from national legal requirements for declaration. References (2): prEN 13040-1 (under preparation — sample preparation, dry matter, moisture content, bulk density), CEN/TS 17732 (terminology), EN 12580 (determination of a quantity), EN 15238 (quantity for particle size greater than 60 mm), prEN 15761 (under preparation — pre-shaped growing media). Terms (3): batch, consignment, sampled portion (from which one representative combined sample is taken, and for microbiological testing — segment samples), sampling point, incremental sample, combined sample, final sample (only for chemical and physical testing, after reduction where necessary), segment and segment sample (microbiological testing), laboratory sample, bulk material, package (up to about 100 l in a sack, a compressed block or bale, also a big bale of about 4 m³), solid form and liquid form (suspension or solution). Requirements (4): every final sample shall be representative of the whole sampled portion; apparatus clean, dry, of a material that does not contaminate the sample, adapted to the batch size, aggregate state and particle size. For microbiological testing: apparatus unused or sterilized, a separate set for each segment sample (new, unopened plastic bags need no sterilization); no contact with skin or liquids when sampling for human pathogens; segment samples of at least 1 l or 200 g (at the moisture content as received), delivered to the laboratory as quickly as possible and not later than 72 h, kept at 5 °C ± 3 °C and never frozen; the number of samples to be tested follows the relevant regulation or quality assurance standard. Liquids: those containing free ammonia should not be sampled manually; solutions, slurries and suspensions may be sampled manually after homogenization (Annex C); internal dimension of the apparatus in the region of 50 mm, but at least three times the largest particle. The moisture content of solid material is determined according to prEN 13040-1; excessively wet material that cannot be broken down into a flowable state is not suitable for the determination of quantity and cannot give a representative result. Apparatus (5): shovel, scoop or other apparatus preserving the characteristics of the material (sterilizable for microbiology), drills with a diameter of at least three times the largest particle; in a large batch of bulk material the material may be released by a wheel loader; apparatus for sample division; manual apparatus for liquids (a weighted bottle opened at a specific depth or filled gradually while lowered); sample valves on the storage vessel, on the loading line and on an external circulation line; sample containers (e.g. plastic buckets, tubs, barrels); air- and water-tight packing containers; sterilizing device. Procedure for solid materials (6): scheme in Annex D; equal representative samples of one sampled portion can only be obtained by dividing the combined sample — but samples for microbiological testing or bulk density shall not be divided; bulk material is sampled, whenever possible, from a moving stream over its whole width. Constraints (6.2.1): a consignment that appears to be from different batches or of different materials — sample separately; a sampled portion of not more than 5 000 m³ (bulk) or 10 000 packages of the same material from the same consignment; damaged or adversely affected packages should not be selected. For quantity determination of packages, each incremental sample is a final sample: the individual package if it exceeds 30 l (particles up to 60 mm) or 70 l (particles over 60 mm), or enough packages to give at least 30 l or 70 l. Number of final samples (6.2.2): except for quantity determination and microbiological testing, and unless otherwise agreed by the parties, at least four — for the supplier, for the buyer (receiver or enforcement officer), for the testing laboratory and for an independent tester in case of dispute.

STATUS (PKN catalogue cards as of 02.10.2026). The card of PN-EN 12579:2024-09 (English version, published 23-09-2024, 40 pages, price group R) has no “Withdrawn” header: Food, Agriculture and Forestry Sector, KT 90 Soil Cultivation and Horticulture, ICS 65.080, “Introduces: EN 12579:2024 [IDT]”, “Replaces: PN-EN 12579:2013-12 – English version”. The PKN search engine (query “PN-EN 12579”, 02.10.2026) does not show a Polish-language version of the 2024 edition; it shows the 2001 (Polish version), 2013-12 and 2024-09 editions. The card of PN-EN 12579:2013-12 (16 pages) has the “Withdrawn” header: withdrawal date 23-09-2024, “Replaced by: PN-EN 12579:2024-09 – English version”; its scope covered only materials in solid form and excluded fibrous materials. What changed for the result: according to the foreword of EN 12579:2024, liquid materials and samples for microbiological testing were added, together with normative step-by-step procedures for bulk and packaged material (Annexes E and F) — a laboratory sampling according to the 2013 edition has no requirements in it for liquids or for microbiological samples (temperature, time, sterility).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 02.10.2026). The number 12579 appears in 8 records of 8 laboratories: AB 006, AB 213, AB 313, AB 418, AB 680, AB 1095, AB 1150, AB 1365. In the current scopes on the PCA website (read 02.10.2026, issues from 19.12.2025 to 09.09.2026) six laboratories cite the 2024-09 edition (AB 006, AB 213, AB 418, AB 1095, AB 1150, AB 1365), AB 313 — the replaced 2013-12 edition, and AB 680 writes “PN-ISO 12579:2013” (as in the PCA document; we know of no ISO standard with this number, presumably the PN-EN 12579:2013 edition is meant). The “Laboratories” tab (“PN-EN 12579”) shows 7 laboratories — without AB 680, whose entry begins with “PN-ISO” — checked with a query of the tab on the labcoda.pl production server on 02.10.2026.

WHAT THE LABORATORIES TEST (PCA entries). In all eight scopes this is the activity “Sampling for tests”, broken down in the methodology description into chemical and physical tests, in several scopes also microbiological, biological and parasitological ones. Object: “Plant cultivation aids” (most), “Soil improvers” (AB 1150), “Organic fertilizers” (AB 006); AB 1095 describes sampling as tests performed in the field (“Ł, M” in the marking column).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. During sampling: the sampled portion must not exceed 5 000 m³ in bulk or 10 000 packages — one sample from a larger quantity does not represent it within the meaning of the standard; material that does not appear to be one batch is not combined into one sample. During division: samples for microbiological testing and for bulk density are not divided — the final sample for bulk density has to be taken separately. In microbiology: a sample stored without cooling or frozen, delivered after 72 h, gives microbial counts not representative of the material (composts and digestates can ferment). With liquids: an inhomogeneous liquid sampled through a narrow tube or without homogenization can be tested without error, and the result will still not describe the tank. With packages: material compressed in the package has to be loosened before sampling (introduction of the standard), otherwise volume and density will be distorted.

WHAT WE DO NOT GIVE. We do not have 6.3–10 or Annexes A–F: the number and distribution of sampling points, the volumes of incremental and final samples (Annex A), the steps of the procedures for bulk and packaged material, the methods of mixing liquids, the content of the sampling report and the dispatch requirements — so we give none of these numbers.

Method principle

From the sampled portion (not more than 5 000 m³ in bulk or 10 000 packages of one batch), incremental samples are taken with clean, dry apparatus, combined into a combined sample and divided into representative final samples (at least four: supplier, buyer, laboratory, referee); samples for microbiological testing and bulk density are not divided — they are taken aseptically as segment samples (at least 1 l or 200 g), cooled to 5 °C ± 3 °C and delivered within 72 h.

Applications

• Soil improvers and growing media (composts, substrates, digestates) — sampling for chemical, physical and microbiological testing; 8 laboratories in PCA scopes
• Verification of the manufacturer’s claims by the buyer or an enforcement agency (scope of the standard)
• Determination of the quantity of packaged material (EN 12580, EN 15238) — incremental samples as final samples

Key parameters

Standard

Standard number

PN-EN 12579:2024-09 (wersja angielska; EN 12579:2024 IDT)

Title (PL)

Ulepszacze gleby i podłoża uprawowe — Pobieranie próbek

Title (EN)

Soil improvers and growing media — Sampling

Step-by-step procedure

1. Sampled portion

   Establish whether the consignment is one batch of one material; sampled portion of not more than 5 000 m³ in bulk or 10 000 packages; do not select damaged packages. PN-EN 12579:2024-09 current (PKN cards as of 02.10.2026).

2. Apparatus

   Clean, dry, of a material that does not contaminate the sample; for microbiology unused or sterilized, a separate set for each segment sample.

3. Taking incremental samples

   Bulk material, whenever possible, from a moving stream over its whole width; number and distribution of points and volumes according to 6.3 and Annexes E and F (we do not have these clauses). Liquids — after homogenization, with apparatus of about 50 mm diameter.

4. Combined sample and final samples

   Combine the incremental samples and divide into at least four representative final samples; do not divide samples for microbiological testing or bulk density. Size of the final sample according to Annex A.

5. Samples for microbiology

   At least 1 l or 200 g; cool to 5 °C ± 3 °C, do not freeze; deliver to the laboratory not later than 72 h; observe the regulations on bio-hazardous samples.

6. Packing, labelling, report

   According to Clauses 8–10 (we do not have their content); the moisture content of solid material is determined according to prEN 13040-1.

Required equipment and apparatus

Health and safety (OHS)

• Liquids containing free ammonia — the standard recommends that they are not sampled manually (4.3)
• When sampling for human pathogens — no contact of the sample with skin or liquids; transport according to the regulations on bio-hazardous materials (4.2)
• Composts and digestates can ferment in the container — keep them cooled and tightly closed

Frequently asked questions