3. Table of contents
01.
03.
04.
Introduction to Soil
Taxonomy
The 12 Soil Orders
Application and
Importance of Soil
Taxonomy
02. Hierarchy in Soil
Taxonomy
05. Challenges and
Solutions
5. •Soil Taxonomy is a system for classifying soils based on their
properties and behaviors.
•Emphasizes consistent terminology for soil scientists and land
managers worldwide.
•Importance: Helps in understanding soil characteristics,
managing land, agriculture, and environmental sustainability.
•Historical Background and Development
•Developed by the USDA (United States Department of
Agriculture) in the 1960s.
•Evolved to meet the needs of different regions and types of soils
globally, offering a systematic approach.
6. Principles of Soil Classification:
• Based on observable and measurable soil properties (e.g., color, texture,
structure).
• Soils are classified hierarchically into Orders, Suborders, Great Groups,
Subgroups, Families, and Series.
• Focuses on soil formation processes (pedogenesis) and properties that affect
soil behavior.
Importance:
• Agriculture: Determines soil suitability for different crops, guiding farming practices.
• Environmental Impact: Supports the study of ecosystem functions, biodiversity, and
water quality.
• Sustainable Development: Essential for managing soils responsibly in the face of
climate change and population growth.
8. Divides each Order by
factors like moisture,
temperature, or specific
properties.
Further divides by
horizon characteristics
(e.g., soil color, mineral
content).
SixHierarchical Levels
Broadest level, based on
dominant soil-forming
processes (12 Orders).
Distinguishes typical and
transitional properties
within Great Groups.
Differentiates soils by
particle size, mineral
composition,
temperature.
Family
Orders Suborder Great Group
Most specific level, naming
soils based on geographic
origins with unique,
consistent profiles.
Subgroup Series
Soil Taxonomy organizes soils into six hierarchical levels to refine classification from broad
to specific characteristics.
12. 1. Alfisols
•Characteristics: High fertility, clay-rich subsoil, often found in
temperate, deciduous forests.
•Environment: Typically form in areas with moderate to high rainfall.
•Use: Good for agriculture, supporting crops like corn and wheat.
2. Andisols
•Characteristics: Derived from volcanic ash, rich in minerals, highly
porous, and excellent for water retention.
•Environment: Volcanic regions such as the Pacific Northwest,
Japan, and parts of South America.
•Use: Very productive for crops like coffee, due to high nutrient
content.
13. 3. Aridisols
4. Entisols
•Characteristics: Dry soils with limited organic matter, often showing
salt or calcium deposits.
•Environment: Desert and arid regions with sparse vegetation, such
as the southwestern USA.
•Use: Low agricultural productivity without irrigation; used mainly for
grazing.
•Characteristics: Young soils with minimal horizon development, often found
in areas with rapid erosion or deposition.
•Environment: Floodplains, dunes, and steep slopes.
•Use: Typically used for grazing or forestry due to limited nutrient
development.
14. 5. Gelisols
6. Histosols
•Characteristics: Soils with permafrost within 2 meters of the
surface, often rich in organic matter.
•Environment: Arctic and subarctic regions like Alaska, Siberia,
and northern Canada.
•Use: Limited use due to cold temperatures and permafrost,
supporting only limited vegetation.
•Characteristics: High organic matter content, typically formed in
waterlogged conditions.
•Environment: Wetlands, bogs, and marshes, such as the Everglades in
Florida.
•Use: Drained for agriculture in some regions; supports unique ecosystems.
15. 7.
Inceptisols
8. Mollisols
•Characteristics: Young soils with more development than Entisols but limited
horizon formation.
•Environment: Widely distributed in various climates, including mountainous
areas.
•Use: Often used for agriculture and forestry due to relatively moderate fertility.
•Characteristics: Thick, dark, organic-rich top layer; highly fertile.
•Environment: Grassland regions, such as the prairies in North America and
the pampas in South America.
•Use: Highly productive soils, widely used for growing crops like wheat, corn,
and soybeans.
16. 9. Oxisols
10. Spodosols
•Characteristics: Highly weathered, nutrient-poor, typically red or yellow
due to iron and aluminum oxides.
•Environment: Tropical regions, such as the Amazon Basin, Africa, and
Southeast Asia.
•Use: Limited agricultural use without significant fertilization; prone to
nutrient depletion.
•Characteristics: Acidic soils with a bleached upper layer (E horizon) and
dark, organic-rich subsoil.
•Environment: Found under coniferous forests in cool, moist climates like
the northeastern USA and parts of Scandinavia.
•Use: Suitable for forestry; agriculture is limited due to acidity.
17. 11. Ultisols
12. Vertisols
•Characteristics: Weathered, nutrient-poor, clay-rich soils, generally acidic.
•Environment: Humid subtropical and tropical regions, such as the
southeastern USA.
•Use: Used for agriculture with fertilization; good for forestry.
•Characteristics: Clay-rich soils that expand and contract with moisture
changes, creating deep cracks.
•Environment: Found in areas with seasonal wet and dry climates, such
as parts of Texas and India.
•Use: Challenging for construction; agricultural use includes crops like
cotton and sorghum.
19. Agriculture &
Land
Management
Crop selection and
yield
Environmental
Studies
Studying ecosystems,
water quality and
carbon storage.
Global
Relevance
Climate change impact
Research and
Education
Soil study and
training
Future
Perspectives
Technology like
remote sensing
Applicatio
ns
21. Challenges Solutions
Complex Classification Use simplified guides and digital tools
Regional Soil Variation Apply region-specific criteria and research
Resource-Intensive Fieldwork Leverage remote sensing and satellite data
Climate Change Impacts
Update taxonomy with adaptive
classifications
Limited Awareness
Expand educational programs and
outreach
Data Consistency Issues Standardize global data collection methods
22. Thanks!
➮ (FAO) – World Reference Base for
Soil Resources
United States Department of
➮
Agriculture (USDA) Soil Taxonomy
Handbook
References:
