Soil Profile Description
Otto Spaargaren
ISRIC – World Soil
Information
Wageningen
The Netherlands
Why soil profile descriptions ?

In surveys: as typical example of soil
mapping unit or of one of its components

For research: as baseline record to
illustrate the environmental setting and
relationships between the soil attributes

For land resource development: as
base for building geo-referenced land
information systems
Guidelines

FAO Guidelines for
Soil Profile Description.
3rd Edition.
1990 – English
1993 – French
Purpose of the FAO Guidelines

To enhance standardization and
uniformity of soil profile descriptions, in
order to facilitate cross-references and
comparison between soil descriptions

To contribute, through the objective
description and recording of soil
properties, both to the understanding of
the land of which the soil forms part, and
to the reliable transfer of technology
Sources for the FAO
Guidelines

USDA Soil Survey Manual

Revised Legend of the Soil Map of the
World

Keys to Soil Taxonomy

Australian Soil and Land Survey Field
Handbook
Content of the FAO Guidelines

General information about the soil, both
administratively and environmentally

Description of the individual soil horizons

Linkage to computerized information
systems, in particular the FAO-ISRIC Soil
Database (SDB)
General Information Section







Registration and location
Soil classification
Landform and topography
Land use and vegetation
Parent material
Surface characteristics
Soil-water relationships
General information (1) :
Registration and location









Profile number
Soil profile description status
Date of description
Author(s)
Soil unit
Location
Elevation
Map sheet number and grid reference
Coordinates
General information (2) :
Soil classification

Soil taxonomic classification
–
–
–
–

WRB reference group name
FAO Legend (1974) and Revised Legend
(1988) Soil Map of the World
Soil Taxonomy (1999)
National
Soil climate
General information (3) :
Landform and topography







Topography
Landform
Land element
Position
Slope
Micro-topography
Soil-landscape sequential relationships
General information (4) :
Land use and vegetation

Land use

Human influence

Vegetation
General information (5) :
Parent material

Parent material
–
–

Unconsolidated material
Rock type
Effective soil depth
General information (6) :
Surface characteristics

Rock outcrops

Surface coarse fragments

Erosion

Surface sealing

Surface cracks

Other surface characteristics
General information (7) :
Soil-water relationships

Drainage class

Internal drainage

External drainage

Flooding

Groundwater

Moisture conditions of the soil
Soil horizon description









Horizon designation and dimensions
Soil colour
Primary constituents
Organization of the constituents
Voids (porosity)
Concentrations
Biological activity
Soil reaction
Samples
Soil horizon description (1) :
Designation and dimensions

Horizon symbol – H, O, A, E, B, C and
R master horizon nomenclature, and the
subordinate characteristics within master
horizons and layers

Horizon boundary – depth, distinctness
and topography
Soil horizon description (2) :
Master horizon designation (1)
Organic horizons:
H or O
H = wet
O = dry
Soil horizon description (3) :
Master horizon designation (2)
Mineral horizons:
A (organic matter)
E (eluviation)
B (illuviation)
C (parent material,
unconsolidated)
Soil horizon description (4) :
Master horizon designation (3)
Mineral horizons:
R (parent rock)
Soil horizon description (5) :
Subordinate characteristics of master
horizons (1):
c
f
g
h
j
k
m
Concretions or nodules
Frozen soil
Gleying evidenced by mottling
Accumulation of organic matter
Jarosite mottling
Accumulation of carbonates
Cementation or induration
Soil horizon description (6) :
Subordinate characteristics of master
horizons (2):
n
o
p
q
r
s
t
Accumulation of sodium
Residual accumulation of sesquioxides
Ploughing or other disturbance
Accumulation of silica
Strong reduction
Illuvial accumulation of sesquioxides
Accumulation of silicate clay
Soil horizon description (7) :
Subordinate characteristics of master
horizons (3):
v
w
x
y
z
Occurrence of plinthite
Development of colour or structure
Fragipan character
Accumulation of gypsum
Accumulation of salts more soluble than
gypsum
Soil horizon description (8) :
Soil colour

Matrix colour – hue, value and chroma,
both dry and moist, according to the
Munsell Soil Color Charts, or the Revised
Standard Soil Color Charts

Mottling – abundance, size, contrast,
boundary and colour (dry and moist)
Soil horizon description (9) :
Primary constituents

Texture of the fine earth fraction –
sand, loamy sand, sandy loam, loam, silt
loam, silt, silty clay loam, silty clay, clay
loam, sandy clay loam, sandy clay, clay

Rock fragments – gravel, stones,
boulders
Soil horizon description (10) :
Organization of soil constituents

Soil structure – grade, size and type
–

Types: single grain, massive, granular,
prismatic, columnar, angular blocky,
subangular blocky, platy, rock structure,
stratified structure
Consistence – dry, moist and wet
Soil horizon description (11) :
Voids (porosity)
Voids include all space in the soil. They are
described in terms of
–
–
–
–
–
Type
Size
Abundance
Continuity
Orientation
Soil horizon description (12) :
Concentrations

Cutanic features – clay, humus,
pressure faces, slickensides, iron
coatings

Cementation and compaction –
continuity, structure, nature, degree

Mineral nodules – abundance, kind,
size, shape, hardness, nature, colour
Soil horizon description (13) :
Biological activity

Roots – abundance and size

Biological features – abundance and
kind
Soil horizon description (14) :
Soil reaction

Presence of carbonates – noncalcareous, slightly calcareous,
moderately calcareous, strongly
calcareous and extremely calcareous
(tested with 10% HCl)

Field pH – Hellige test, field pH meter,
NaF test for volcanic soils
Soil horizon description (15) :
Samples
Basically, there are two methods of
collecting soil samples:
–
Sampling in equal proportions over the whole
horizon (recommended method)
–
Sampling in equal proportions within a depth
of 20cm, either from the centre of the
horizon, or at balanced intervals if the
horizon exceeds 50cm thickness
Linkages (1) :
FAO-ISRIC Soil Database (SDB)

Permits storage and retrieval of large
amounts of field and analytical data

Provides a flexible coding system to
accommodate local needs

Can be linked to geographical
information systems (GIS), automated
land evaluation packages, or statistical
programs
Linkages (2) :
FAO-ISRIC Soil Database (SDB)
The following data sets can be stored in
the SDB:

Field descriptions: coded information
on site and profile characteristics

Standard soil analytical results:
chemical analyses, soluble salts

Soil physical analytical results:
infiltration and water retention data
New developments
In 2002, a new “Field Book
for Describing and Sampling
Soils” (Version 2.0) was
issued by the National Soil
Survey Center of the
USDA’s Natural Resources
Conservation Service
New developments
In 2003, a “Students Guide for Soil
Description, Soil Classification and Site
Evaluation” was prepared by R. Jahn, H.P. Blume and V.B. Asio, for workshops
and international seminars in Poland and
The Philippines
New developments
In 2003, FAO and CSIC issued “The Multilingual
Soil Profile Database” (SDBm Plus), an
upgraded and expanded
Windows version of the
SDBm software, which
had replaced the DOSbased version of SDB
The USDA Field Book

Very comprehensive, with numerous
useful diagrams and illustrations

Introduces new descriptive elements,
such as “redoximorphic features”, “soil
crusts”, and “odor”

Provides little linkage to the FAO
Guidelines (e.g. no comparison between
particle size classes of USDA and FAO)
The Student Guide

Builds strongly on the 1990 Guidelines,
with elements of the “Kartieranleitung”
(Germany, 1994), SOTER (1995), WRB
(1998), and Soil Taxonomy (1999)

Links observation to interpretation

Biased towards soil conditions in
temperate regions
SDBm Plus (1)

Re-designed and re-written as Windows
application

Multilingual (English, French, Spanish,
German)

Detailed soil profile characterization
SDBm Plus (2)

Possibility of monitoring the temporal
variability of analytical, physical and
hydraulic soil properties

Metadata facility for describing analytical
methods and procedures used

Linkage between database and land
evaluation/geographical information
systems (LES/GIS)
Conclusions (1)

There is a need to update the 1990 FAO
Guidelines for Soil Profile Description, in
order to accommodate new knowledge
and needs for recording soil properties

The new USDA Field Book and the
Student Guide provide good practical
material to be incorporated in a 4th
Edition of the Guidelines, enhancing the
interpretative value
Conclusions (2)

Special attention should be paid to the
consequences of changes with respect to
the older versions of the Guidelines (see,
for example, the change in textural
boundaries in 1990)

Care should be taken that presented
methods are valid worldwide, or that
users are cautioned for the limited
validity of methods given
Afterthought
“In view of the high costs of soil survey,
soil profile descriptions should be made
as detailed and comprehensive as
possible, so that they can serve multiple
purposes.”