Soil Flashcards
Most of our food and fiber is obtained from…
cropland.
agriculture
practice of raising crops and livestock for human use and consumption
cropland
land use to raise crops for human use
rangeland
land use for grazing livestock
soil
complex mixture of inorganic material, decaying organic material, air, water, nutrients and living organisms
Soil is derived from _____ and shaped by microorganisms.
rock
It takes _____ years to develop 1 inch of topsoil
200-1000
Topsoil is formed from…
parent material.
parent material
base geologic material in particular location
Examples of parent material include…
(1) hardened lava or volcanic ash
(2) sediment deposited by glaciers or flowing water
(3) wind-blown dunes
(4) bedrock
Parent material is broken down into smaller particle by…
weathering.
humus
partially-decomposed organic matter
productive for plant life
Weathering and accumulation of organic matter influenced by…
(1) climate
(2) organisms
(3) topography
(4) parent material
(5) time
soil profile
entire cross-section of soil
leaching
process in which minerals dissolved/suspended in water are transported downward
Ordering of soil layers is…
O Horizon: Organic
A Horizon: Topsoil
E Horizon: Eluviated (leaching layer)
B Horizon: Subsoil
C Horizon: Weathered parent material
R Horizon: Rock (parent material)
o horizon
contain organic matter deposited by organisms
a horizon (topsoil)
mixture of inorganic mineral components with humus from above (o horizon)
What is the most nutritive part of soil for plants?
topsoil (a horizon)
e horizon (eluviated)
most heavily leeched, losing minerals like iron, aluminum, and silicate clay
b horizon (subsoil)
contains minerals leeched from above (e horizon)
c horizon (weathered parent material)
partially weathered parent material