Soil Flashcards
What is the study of soil?
pedology
Derivatives of pedology
Pedon (soil) and Logos (reason)
Russian soil scientist
Dokuchaev
How do soils form?
They develop over identical bedrock exposed to various climates
Who introduced the idea that climate plays a major role in soil formation to the US?
Marbut
5 Categories of Soil Influence
- Parent material
- Climate since accumulation
- Plant and animal life
- Land relief
- Time other factors have interacted
What climatic forces act on the parent material?
Precipitation, temperature, humidity, wind
What is immature soil?
Lacks well-developed layers
What is a profile?
Vertical column of soil
What are horizons in a profile?
Soil layers
What is the O Horizon?
Dominated by Organic material such as leaves, lichens, etc.
How deep is the O Horizon?
0-2 inches
What is the A Horizon?
AKA the surface layer in a soil survey, Accumulation of organic matter and minerals
In which horizon does most root activity occur in plants?
A Horizon
How deep is the A Horizon?
2-10 inches
How deep is the B Horizon?
10-30 inches
How deep is the C Horizon?
30-48 inches
What makes up the E Horizon?
Sand and silt-sized particles
What is lost in the E Horizon?
Silicate clay, iron, aluminum
Which horizon is referred to as subsoil?
B Horizon
What horizon is known as the “zone of accumulation?”
B Horizon
What is leaching?
Water moves nutrients from the A Horizon to the B Horizon
Which horizon is referred to as the “zone of leaching?”
A Horizon
Why are some minerals drawn upwards from lower soil layers?
High evaporation rates and plant absorption
What is the fragipan layer?
Dense, nearly impermeable subsurface layer
What is claypan?
Fragipan layering caused by extreme soil compactness