1. Soil Profile Description
Otto Spaargaren
ISRIC – World Soil Information
Wageningen
The Netherlands

2. 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

3. Guidelines FAO Guidelines for Soil Profile Description. 3rd Edition.
1990 – English
1993 – French

4. 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

5. 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

6. 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)

7. General Information Section
Registration and location
Soil classification
Landform and topography
Land use and vegetation
Parent material
Surface characteristics
Soil-water relationships

8. 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

9. 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

10. General information (3) : Landform and topography
Land element
Position
Slope
Micro-topography
Soil-landscape sequential relationships

11. General information (4) : Land use and vegetation
Human influence
Vegetation

12. General information (5) : Parent material
Unconsolidated material
Rock type
Effective soil depth

13. General information (6) : Surface characteristics
Rock outcrops
Surface coarse fragments
Erosion
Surface sealing
Surface cracks
Other surface characteristics

14. General information (7) : Soil-water relationships
Drainage class
Internal drainage
External drainage
Flooding
Groundwater
Moisture conditions of the soil

15. Soil horizon description
Horizon designation and dimensions
Soil colour
Primary constituents
Organization of the constituents
Voids (porosity)
Concentrations
Biological activity
Soil reaction
Samples

16. 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

17. Soil horizon description (2) :
Master horizon designation (1)
Organic horizons:
H or O
H = wet
O = dry

18. Soil horizon description (3) :
Master horizon designation (2)
Mineral horizons:
A (organic matter)
E (eluviation)
B (illuviation)
C (parent material, unconsolidated)

19. Soil horizon description (4) :
Master horizon designation (3)
Mineral horizons:
R (parent rock)

20. Soil horizon description (5) :
Subordinate characteristics of master horizons (1):
c Concretions or nodules
f Frozen soil
g Gleying evidenced by mottling
h Accumulation of organic matter
j Jarosite mottling
k Accumulation of carbonates
m Cementation or induration

21. Soil horizon description (6) :
Subordinate characteristics of master horizons (2):
n Accumulation of sodium
o Residual accumulation of sesquioxides
p Ploughing or other disturbance
q Accumulation of silica
r Strong reduction
s Illuvial accumulation of sesquioxides
t Accumulation of silicate clay

22. Soil horizon description (7) :
Subordinate characteristics of master horizons (3):
v Occurrence of plinthite
w Development of colour or structure
x Fragipan character
y Accumulation of gypsum
z Accumulation of salts more soluble than gypsum

23. 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)

24. 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

25. 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

26. Soil horizon description (11) : Voids (porosity)
Voids include all space in the soil. They are described in terms of
Type
Size
Abundance
Continuity
Orientation

27. 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

28. Soil horizon description (13) : Biological activity
Roots – abundance and size
Biological features – abundance and kind

29. Soil horizon description (14) : Soil reaction
Presence of carbonates – non-calcareous, 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

30. 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

31. 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

32. 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

33. 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

34. 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

35. 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 DOS-
based version of SDB

36. 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)

37. 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

38. SDBm Plus (1) Re-designed and re-written as Windows application
Multilingual (English, French, Spanish, German)
Detailed soil profile characterization

39. 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)

40. 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

41. 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

42. 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.”