Tags & Description
What are the 4 ways to classify soil?
color, texture, structure, pH
wind and rain
Two main causes of physical weathering
humus
partially decomposed organic matter; dark, spongy material made up of complex organic compounds
crop rotation
alternating crops grown in a field
sand
largest soil particle
clay
smallest soil particle
silt
a soil particle that is larger than clay and smaller than sand
How do plants help to protect soil from erosion?
slowing wind and water roots hold soil in place and absorb water
shelterbelt
rows of trees or other tall plants
deposition
the drop off of eroded material at a new location
tilling
turning over of soil before planting
overgrazing
causes the compaction of soil, greater soil exposure, nonnative plants invading exposed areas, and increased wind and water erosion
1930s
In what decade did the Dust Bowl occur?
yield
the amount of crop produced in a given area
monoculture
growing a single crop over a large area
weathering, decomposition, deposition
What are the processes through which soil is formed?
38%
Approximately what percentage of land is used for agriculture?
human activity
What is the cause of most erosion?
loam
soil with a relatively even mixture of clay, silt, and sand
parent material
the base geological material in a particular location
soil degradation
the deterioration of the soil characteristics needed for plant growth or other ecosystem services
desertification
the loss of more than 105 of productivity due to erosion, soil compaction, forest removal, overgrazing, drought, and other processes
sustainable ranching
occurs when the grazing animals' populations stay within an ecosystem's carrying capacity
contour farming
plowing sideways across a hillside, perpendicular to the hill's slope
terracing
creating a series of steps, like a staircase
salinization
the build up of salts in the upper layers of soil
broad spectrum
A pesticide that kills a variety of organisms is described as being what?
the Green Revolution
involved developed countries creating strains of corn, rice, and wheat with larger seed heads and disease resistance; very high crops yields; use of irrigation and machinery; these crops and techniques were then shared with developing nations
Name negative impacts of agriculture that got worse with the Green Revolution.
erosion, salinization, eutrophication, pollution
Bacillus thuringiensis
a type of bacteria in the soil that kills the larvae of many pests
intercropping
planting of different crops in mixed arrangements
Agent Orange
the name of the pesticide used during the Vietnam War to thin out the jungle
What does IPM stand for?
integrated pest management
What does IPM involve?
gaining extensive knowledge of the pest combining several different techniques using chemical pesticides as a last resort and in the smallest quantities needed
pollinators
insects, bats, honeybees, and hummingbirds are all what kind of organism?
increased fossil fuels use of machinery irrigation improvements use of synthetic fertilizers use of chemical pesticides
List 5 changes to agriculture that occurred between the arrival of the Industrial Revolution and the mid-1900's.
Explain how irrigation can lead to increased salinization of crop land.
Use of lots of water means water goes into the lower layers of soil. The water in the lower layers picks up dissolved salts. When water evaporates from the surface, it pulls water up through the layers of soil, bringing dissolved salts up with it. The salts get left behind at the surface.