ASTM D5715-23

Standard Practice for Estimating the Degree of Humification of Peat and Other Organic Soils (Visual/Manual Method)

SIGNIFICANCE AND USE
4.1 The purpose of this practice is to standardize the routine description of peat and other organic soils for various uses (such as, peatland inventories and resource evaluations). This practice should be used to supplement other field information, such as, site location, surface morphology, surface vegetation, water table, moisture content, fiber content, wood content, and visually identifiable plant types and parts.
Note 1: This standard is a visual/manual method and is not meant to replace the more precise method of laboratory classification of peat (see Classification D4427). It should also be noted, this practice is independent of the determination of whether an articluar deposit contains peat that is defined in Classification D4427 on the basis of laboratory determination of ash content (see Test Method D2974).
SCOPE
1.1 This practice covers the visual determination of the degree of humification of peat and other highly organic soils by visually evaluating the color of the water expelled upon compression. This practice is not used for the determination of the degree of organic decomposition of organic matter in mineral soils.  
1.2 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved though the ASTM consensus process.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jan-2023
• ICS: 13.080.40 - Hydrological properties of soils
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.22 - Media for Plant Growth

Relations

• Refers: ASTM D2974-20e1 - Standard Test Methods for Determining the Water (Moisture) Content, Ash Content, and Organic Material of Peat and Other Organic Soils
• Effective Date: 15-Jan-2020
• Refers: ASTM D2974-20 - Standard Test Methods for Determining the Water (Moisture) Content, Ash Content, and Organic Material of Peat and Other Organic Soils
• Effective Date: 15-Jan-2020
• Refers: ASTM D4427-13(2017) - Standard Classification of Peat Samples by Laboratory Testing
• Effective Date: 01-May-2017
• Refers: ASTM D2974-14 - Standard Test Methods for Moisture, Ash, and Organic Matter of Peat and Other Organic Soils
• Effective Date: 01-Nov-2014
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM D4427-13 - Standard Classification of Peat Samples by Laboratory Testing
• Effective Date: 01-Jul-2013
• Refers: ASTM D2944-13 - Standard Practice of Sampling Processed Peat Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM D2974-13 - Standard Test Methods for Moisture, Ash, and Organic Matter of Peat and Other Organic Soils
• Effective Date: 01-Jun-2013
• Refers: ASTM D653-11 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Sep-2011
• Refers: ASTM D653-09 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Jan-2009
• Refers: ASTM D653-08a - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Dec-2008
• Refers: ASTM D653-08 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Nov-2008
• Refers: ASTM D2944-71(2008) - Standard Test Method of Sampling Processed Peat Materials
• Effective Date: 01-Jan-2008
• Refers: ASTM D653-07f - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 15-Dec-2007
• Refers: ASTM D653-07e - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Nov-2007

Overview

ASTM D5715-23 is an international standard that provides a visual and manual method for estimating the degree of humification in peat and other organic soils. This practice focuses on the routine field description of peat for various uses, such as peatland inventory, geotechnical investigations, and natural resource evaluation. The standard guides users in categorizing peat and organic soils by visually evaluating the color and consistency of water expelled during sample compression, as well as the proportions of intact plant material and amorphous matter.

This ASTM standard is intended for use alongside other field observations, including site location, surface morphology, water table data, moisture content, fiber content, and visible plant types. It supplements, but does not replace, laboratory classification methods.

Key Topics

• Degree of Humification: This practice introduces ten categories (H1 to H10), with H1 being the least decomposed and H10 the most decomposed peat. This classification is based on the visual composition of the material.

• Sample Collection: Proper field sampling techniques are essential to maintain the sample's original condition. Methods can include piston coring, grab sampling by hand, or block sampling.

• Visual Assessment: Peat samples are manually compressed to expel water and amorphous matter. Observations focus on:

  • Color of expelled water
  • Amount and consistency of material released
  • Intactness and recognizability of plant parts
  • Visual indications of decomposition

• Reporting: Users must document the determined classification, physical observations, and other relevant field data, such as sample site, technician ID, and sampling time.

• Supplement to Laboratory Methods: While useful for routine field assessments, the ASTM D5715-23 practice is not as precise as laboratory-based classifications, such as those described in ASTM D4427 or by measuring ash content per ASTM D2974.

Applications

The ASTM D5715-23 standard practice is valuable in multiple practical scenarios:

• Peatland Inventory and Resource Evaluation: Provides a consistent approach for describing the humification status of organic soils, supporting land management and resource assessment initiatives.

• Environmental and Geotechnical Assessments: Supports field teams in rapid characterization of organic deposits, guiding decisions related to construction feasibility, environmental protection, and restoration.

• Agriculture and Horticulture: Helps assess the suitability of peat for use in soil amendments or as a growth medium, based on decomposition stage and organic content.

• Academic and Research Purposes: Allows researchers to compare and document peat properties systematically during ecological, hydrological, or carbon cycle studies.

Related Standards

Several ASTM standards are referenced to ensure compatibility and comprehensive data collection:

• ASTM D653: Terminology relating to soil, rock, and fluids-provides essential definitions for consistent communication.
• ASTM D2944: Practice for sampling processed peat materials for horticultural purposes.
• ASTM D2974: Methods for determining water content, ash content, and organic material in peat and organic soils.
• ASTM D4427: Laboratory classification of peat samples for more detailed and precise categorization.

Practical Value

By following ASTM D5715-23, organizations and professionals:

• Benefit from a standardized, field-ready procedure for the visual assessment of peat humification.
• Gain actionable insights quickly without the need for laboratory analysis.
• Achieve better consistency in reporting and evaluating organic soils across diverse projects.

Keywords: peat, organic soils, humification, soil classification, visual assessment, ASTM D5715-23, field method, resource evaluation, environmental soils, decomposition, geotechnical.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5715 − 23
Standard Practice for
Estimating the Degree of Humification of Peat and Other
Organic Soils (Visual/Manual Method)
This standard is issued under the fixed designation D5715; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* D653 Terminology Relating to Soil, Rock, and Contained
Fluids
1.1 This practice covers the visual determination of the
D2944 Practice of Sampling Processed Peat Materials for
degree of humification of peat and other highly organic soils by
Horticultural Purposes
visually evaluating the color of the water expelled upon
D2974 Test Methods for Determining the Water (Moisture)
compression. This practice is not used for the determination of
Content, Ash Content, and Organic Material of Peat and
the degree of organic decomposition of organic matter in
Other Organic Soils
mineral soils.
D4427 Classification of Peat Samples by Laboratory Testing
1.2 This practice offers a set of instructions for performing
one or more specific operations. This document cannot replace
3. Terminology
education or experience and should be used in conjunction
3.1 Definitions:
with professional judgment. Not all aspects of this practice may
3.1.1 For definitions of common technical terms used in this
be applicable in all circumstances. This ASTM standard is not
standard, refer to Terminology D653.
intended to represent or replace the standard of care by which
3.1.2 organic soils, n—soil with a high content of carbon-
the adequacy of a given professional service must be judged,
based compounds that are very compressible and have poor
nor should this document be applied without consideration of
load sustaining properties.
a project’s many unique aspects. The word “Standard” in the
3.1.3 peat, n—a naturally-occurring highly organic sub-
title of this document means only that the document has been
stance derived primarily from plant materials that is distin-
approved though the ASTM consensus process.
guished from other organic soil materials by its lower ash
1.3 This standard does not purport to address all of the
content (less than 25 % ash by dry mass—see Practice D2974)
safety concerns, if any, associated with its use. It is the
and from other phytogenic material of higher rank (that is,
responsibility of the user of this standard to establish appro-
lignite coal) by its lower calorific value on a water saturated
priate safety, health, and environmental practices and deter-
basis.
mine the applicability of regulatory limitations prior to use.
3.2 Definitions of Terms Specific to This Standard:
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard- 3.2.1 degree of humification, H, n—is the present visual
composition of peat and highly organic soils belonging in one
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- of ten categories with H1 being the least decomposed and H10
being the most decomposed.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Significance and Use
2. Referenced Documents
4.1 The purpose of this practice is to standardize the routine
2.1 ASTM Standards: description of peat and other organic soils for various uses
(such as, peatland inventories and resource evaluations). This
practice should be used to supplement other field information,
This test method is under the jurisdiction of ASTM Committee D18 on Soil and
such as, site location, surface morphology, surface vegetation,
Rock and is the direct responsibility of Subcommittee D18.22 on Media for Plant
water table, moisture content, fiber content, wood content, and
Growth.
Current edition approved Feb. 1, 2023. Published February 2023. Originally visually identifiable plant types and parts.
approved in 1995. Last previous edition approved in 2014 as D5715 – 14. DOI:
NOTE 1—This standard is a visual/manual method and is not meant to
10.1520/D57150-23.
replace the more precise method of laboratory classification of peat (see
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Classification D4427). It should also be noted, this practice is independent
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on of the determination of whether an articluar deposit contains peat that is
the ASTM website. defined in Classification D4427 on the basis of laboratory determination of
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5715 − 23
ash content (see Test Method D2974).
7.2.5 H5—Moderately decomposed peat that, when
squeezed, releases very turbid water containing a small amount
5. Sample
of amorphous granular peat through the fingers. The residue
5.1 The sample used for this practice can be collected using
remaining in hand is strongly pasty in consistency and the
piston coring devices or simply as a grab sample (that is, by tissues of the original source plants are difficult to recognize.
hand) or a block sample by any of a number of means as long
7.2.6 H6—Moderately decomposed peat that, when
as it still retains its original in-situ composition (that is,
squeezed, releases through the fingers about one-third of the
moisture as well as solid components).
peat. The residue
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D5715 − 14 D5715 − 23
Standard Practice for
Estimating the Degree of Humification of Peat and Other
Organic Soils (Visual/Manual Method)
This standard is issued under the fixed designation D5715; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This practice covers the visual determination of the degree of humification of peat and other highly organic soils. soils by
visually evaluating the color of the water expelled upon compression. This practice is not used for the determination of the degree
of organic decomposition of organic matter in mineral soils.
1.2 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace
education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be
applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the
adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s
many unique aspects. The word “Standard” in the title of this document means only that the document has been approved though
the ASTM consensus process.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D2944 Practice of Sampling Processed Peat Materials for Horticultural Purposes
D2974 Test Methods for Determining the Water (Moisture) Content, Ash Content, and Organic Material of Peat and Other
Organic Soils
D4427 Classification of Peat Samples by Laboratory Testing
3. Terminology
3.1 Definitions:
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.22 on Soil as a Medium Media
for Plant Growth.
Current edition approved Nov. 1, 2014Feb. 1, 2023. Published November 2014February 2023. Originally approved in 1995. Last previous edition approved in 20062014
as D5715 – 00D5715 – 14.(2006). DOI: 10.1520/D57150-14.10.1520/D57150-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5715 − 23
3.1.1 For definitions of common technical terms in this practice, refer to Terminology D653.
3.1 Definitions of Terms Specific to This Standard:Definitions:
3.2.1 degree of humification—as defined by this practice, degree of humification refers to any one of ten categories (indicated by
the letter “H”), with H1 being the least decomposed and H10 being the most decomposed. This terminology actually refers to the
present visual composition of the peat and highly organic soils.
3.1.1 For definitions of common technical terms used in this standard, refer to Terminology D653.
3.1.2 organic soils—soils, n—soil with a high content of carbon-based compounds. In general, organic soils compounds that are
very compressible and have poor load sustaining properties.
3.1.3 peat—peat, n—a naturally-occurring highly organic substance derived primarily from plant materials. Peatmaterials that is
distinguished from other organic soil materials by its lower ash content (less than 25 % ash by dry mass-seemass—see Practice
D2974) and from other phytogenic material of higher rank (that is, lignite coal) by its lower calorific value on a water saturated
basis.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 degree of humification, H, n—is the present visual composition of peat and highly organic soils belonging in one of ten
categories with H1 being the least decomposed and H10 being the most decomposed.
4. Significance and Use
4.1 The purpose of this practice is to standardize the routine description of peat and other organic soils for various uses (such as,
peatland inventories and resource evaluations). This practice should be used to supplement other field information, such as, site
location, surface morphology, surface vegetation, water table, moisture content, fiber content, wood content, and visually
identifiable plant types and parts.
NOTE 1—This standard is a visual/manual method and is not meant to replace the more precise method of laboratory classification of peat (see
Classification D4427). It should also be noted, this practice is independent of the determination of whether a particluaran articluar deposit contains peat
that is defined in Classification D4427 on the basis of laboratory determination of ash content (see Test Method D2974).
5. Sample
5.1 The sample used for this practice can be collected using piston coring devices or simply as a grab sample (that is, by hand)
or a block sample by any of a number of means as long as it still retains its original in-situ composition (that is, moisture as well
as solid components).
NOTE 2—In practice, the sample is collected using a field reconnaissance peat sampler; but it may be collected by a more sophisticated piston sampler.
5.2 Samples shouldshall be shipped and stored in containers and maintained in an environment which preve
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