Soil Formation
Pedogenesis · Horizons · Weathering
MICRO-REALM 01
Pedogenesis
- THE PROCESS OF SOIL FORMATION
- COMBINES WEATHERING & ORGANIC ADDITION
- A DYNAMIC, ONGOING EVOLUTION
MICRO-REALM 02
Parent Material
- PASSIVE FORMATION FACTOR
- UNDERLYING BEDROCK OR DRIFT
- DICTATES MINERAL COMPOSITION & TEXTURE
MICRO-REALM 03
Climate (Active)
- MOST IMPORTANT ACTIVE FACTOR
- TEMPERATURE & PRECIPITATION
- CONTROLS RATE OF WEATHERING & BIOLOGY
MICRO-REALM 04
Topography
- STEEP SLOPES = EROSION (THIN SOIL)
- FLAT VALLEYS = ACCUMULATION (DEEP SOIL)
- AFFECTS DRAINAGE & SUN EXPOSURE
MICRO-REALM 05
Vegetation & Biota
- ROOTS BREAK DOWN ROCKS (MECHANICAL)
- ORGANIC ACIDS DISSOLVE MINERALS
- ADDS HUMUS TO THE TOPSOIL
MICRO-REALM 06
Time Factor
- SOIL MATURITY DEPENDS ON DURATION
- YOUNG SOILS = WEAK PROFILE
- TAKES CENTURIES TO FORM 1CM OF TOPSOIL
MICRO-REALM 07
Physical Weathering
- MECHANICAL BREAKDOWN OF ROCK
- EXFOLIATION (THERMAL EXPANSION)
- FROST WEDGING IN COLD REGIONS
MICRO-REALM 08
Chemical Weathering
- ALTERATION OF MINERAL STRUCTURE
- OXIDATION (RUSTING OF IRON)
- HYDRATION, CARBONATION, SOLUTION
MICRO-REALM 09
Soil Profile
- VERTICAL SECTION OF THE SOIL
- FROM SURFACE DOWN TO BEDROCK
- REVEALS THE HISTORY OF PEDOGENESIS
MICRO-REALM 10
Soil Horizons
- A HORIZON: LEACHING ZONE (ELUVIATION)
- B HORIZON: ACCUMULATION ZONE (ILLUVIATION)
- DEFINES SOIL CLASSIFICATION
MICRO-REALM 11
Humus Formation
- DECOMPOSITION OF ORGANIC MATTER
- DARK, AMORPHOUS SUBSTANCE
- IMPROVES SOIL STRUCTURE & FERTILITY
MICRO-REALM 12
Rock-Soil Nexus
- DIRECT INHERITANCE OF PROPERTIES
- BASALT LAVA → BLACK COTTON SOIL
- GRANITE/GNEISS → RED/YELLOW SOIL