Chapter 12- Soil Flashcards
A complex,plant-supporting system made up of disintegrated rock, remains of wastes of organisms, water, gases, nutrients, and microorganisms
Soil
The base geological material in a particular location.
Parent material
The continuous mass of solid rock that makes up earths crust.
Bed rock
Describes the physical and chemical processes that break down rocks and minerals into smaller particles. Often the first process in soil formation
Weathering
What are the six soil horizons and their names
- O Horizon: litter later
- A Horizon: topsoil
- E Horizon: leaching layer
- B Horizon: subsoil
- C Horizon: weathered/parent material
- R Horizon: parent material
What is in the soil horizons
O: mostly organic matter
A: organic matter mixed with minerals
E: minerals and organic matter leach down to B
B: minerals and organic matter accumulate
C: weathered parent material only slightly altered or not at all by soil formation
R: parent material
Which Horizon has the most plant nutrients available?
A horizon (topsoil)
What happens to particle size in organic matter as you move down to the horizons?
As one moves downward through soil a profile, the particle size increases and concentrate of organic matter decreases.
What happens to minerals in soil?
Minerals are transported downward as a result of leaching.
What is leaching?
The process where solid particles suspended or dissolved in a liquid are transported to another location.
A cross-section of all the soil horizons in a specific soil, from surface to bedrock.
Soil profile
Particles less than 0.002 millimeters in diameter
Clay
Particles ranging from 0.002 to 0.05 millimeters in diameter
Silt
A mix between clay, for silt, and sand and is the best for agriculture.
Loam
Particles with diameter of 0.05 or greater
Sand
What are some factors that influence soil formation?
Climate, organisms, landforms, parent material, and time
What are the two main types of weathering?
Physical and chemical wheathering
The drop-off of eroded material at a new location.
Deposition
The state/process of rotting/decay
Decomposition
The organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms
Humus