Soil Flashcards
What is soil?
A complex plant-supporting system of weathered rock, organic matter, gases, water, nutrients, and microorganisms
Soil is a renewable resource and its own ecosystem.
What is the composition of soil?
1/2 parent material, 1/2 water and gas
Parent material is the base geological material from which soil is formed.
What are the types of weathering?
- Physical: No chemical change
- Chemical: Alters parent material
- Biological: Organisms break down parent material
What is humus?
A dark, spongy, crumbly mass formed by partial decomposition and accumulation
Humus is essential for soil fertility.
What is peat?
Partially decayed, compressed organic matter in cool temperatures and surface water saturation
Peat formation slows decay.
What is a soil profile?
The cross-section of soil as a whole, showing different horizons.
What does the ‘A’ horizon represent in the OABCR horizons?
Topsoil; contains inorganic minerals, organic matter, and humus.
What does leaching refer to in soil science?
The process where dissolved particles move down through the horizons.
What color indicates high organic matter in soil?
Black or dark brown.
What is the largest terrestrial carbon sink?
Soils.
What causes soil degradation?
- Deforestation
- Agriculture
- Livestock
- Chemical contaminations
What is desertification?
When previously productive land becomes desert, losing over 10% productivity.
What was a consequence of the Dust Bowl?
- Dust storms
- Lost new seeds
- Lung problems
- More grasshoppers
- Bad tasting meat
What are some methods for erosion control?
- Crop rotation
- Intercropping
- Agroforestry
- Contour farming
- Terracing
- Shelterbelts
- No-till
What types of agriculture exist?
- Traditional
- Subsistence
- Industrialized
- Polyculture
- Monoculture
What are the two types of fertilizers?
- Inorganic: mined and synthetic
- Organic: manure, organic matter, compost
What are the impacts of irrigation?
- Uses too much freshwater
- Waterlogging
- Salinization
- Degradation of soil
What are the two generations of pesticides?
- 1st generation: Metals and organic material
- 2nd generation: Synthetic inorganic compounds
What was the outcome of the case study Johnson v. Monsanto?
Dewayne Johnson won in court against Monsanto after being diagnosed with terminal cancer from exposure to Roundup.
What is biological control in pest management?
Battling weeds and pests with their natural predators
Examples include using cactus moths.
What is the role of Rainbow Community Gardens?
A small local urban farm that serves as a gathering place and has plots for new immigrants.
Fill in the blank: Soil formation starts when parent material is exposed to the __________, __________, and __________.
hydrosphere, atmosphere, biosphere
True or False: Soil can be damaged but is not a renewable resource.
False
What is the significance of dark grey soil color?
Indicates waterlogged clay.
What are the consequences of over-fertilization?
- Algal blooms
- Nitrates contaminate groundwater
What does the ‘B’ horizon represent in the OABCR horizons?
Subsoil, “hardpan” (hard mineral-rich layers); minerals leach down
What does the ‘C’ horizon represent in the OABCR horizons?
fragmented, only slightly altered parent material
What does the ‘R’ horizon represent in the OABCR horizons?
unaltered parent material (bedrock)
Colour meaning of black
High organic matter content
Colour meaning of Yellow
Rich In clay
Colour meaning of white
Calcium carbonate
What type of soil may have a permafrost?
Arctic soil
What location used to be referred to as the fertile Crescent?
The Middle East
What are the negative impacts of monoculture?
Less biodiversity, More Susceptible to disease, Narrowing human diet and gut biome
