Foreword

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This document was prepared by Technical Committee ISO/TC 134, Fertilizers, soil conditioners and beneficial substances.

This fourth edition cancels and replaces the third edition (ISO 3944:1992) of which it constitutes a minor revision. The changes are as follows:

the normative reference to ISO 8358 in Clause 6 was changed to ISO 14820-2.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

The bulk densities (loose and tapped) of a fertilizer provide information relative to the required size of packaging materials, store-houses, stock-rooms, etc. Generally, the bulk density (tapped) is up to 10 % greater than the bulk density (loose), and sometimes it can exceed this value. Both bulk densities depend on the actual density, surface form and particle size of the fertilizers.

The bulk density (loose) can be used to calculate the maximum volume of a given mass of fertilizer which can be expected in practice. The actual volume occupied by a given mass of fertilizer will normally be within the range calculated from the bulk density (loose) and the bulk density (tapped).

1 Scope

This document specifies a method for the determination of the bulk density (loose) of solid fertilizers, except powder fertilizers.

The method is applicable to dry fertilizers only.

The method is not suitable for materials which contain a large proportion of particles exceeding 5 mm in diameter.

2 Normative references

3 Terms and definitions

4 Principle

5 Apparatus

5.1

5.2

5.3

6 Preparation of test sample

7 Procedure

8 Expression of results

8.1 Method of calculation

8.2 Repeatability

9 Test report

ISO 3944:2026

Fertilizers. Determination of bulk density (loose)

Current

Published:

20 Feb 2026