T5 (Soil) Definitions Flashcards
A Soil Profile
A vertical section through a soil, and is divided into horizons (distinguishable layers).
Weathering
The decomposition and disintegration of rocks in situ.
Soil Structure
The shape and arrangement of individual soil particles.
A loam
A well-balanced soil with significant proportions of sand, silt and clay. (ideal soil for cultivation w/ balance between water-holding ability and freely draining, aerated conditions)
Agribusiness
When food production is not to satisfy the community’s needs but is to ensure profitable return for capital investment.
Commercial Farming
Farming for profit - often of a single crop.
Subsistence Farming
Produces only enough to feed the farmer and his/her family, with none to sell for profit.
Intensive Farms
Generally take up a small area of land but aim to have very high output (through large inputs of capital and labour) per unit area of land.
Extensive Farms
Large in comparison to the money and labour put into them (e.g. the cattle ranches of central Australia, where only a few workers are responsible for thousands of acres of land).
Organic Farming
An ecocentric approach to farming by achieving an ecological balance.
Buffer Zones
Areas of land containing native vegetation that are adjacent to or surround agricultural land.
Deforestation
The removal of some or all of a cover of trees.
Soil exhaustion
When a soil becomes depleted of a particular mineral.
Fertile Soil
Non-renewable resource due to rate of use compared to length of time to replenish.
Soils
Open systems in steady-state equilibrium.
Leaching
Downward movement of soluble material.
Calcification
The accumulation of calcium salts in a body tissue (or soil).
Salinization
Increasing salt content in soil.
Chemical Weathering
The erosion or disintegration of rocks caused by chemical reactions.
Biological Weathering
Process in which plants and animals chemically alter rocks and physically break rocks through their growth and movement. (disintegration and decomposition)
Macronutrients
Needed in large quantities - Oxygen, carbon, hydrogen, nitrogen
Micronutrients
trace elements such as magnesium, phosphorus needed in small doses
Decomposition
Changes leaf litter into humus
Mineralization
The decomposition or oxidation of the chemical compounds in organic matter releasing the nutrients contained in those compounds into soluble inorganic forms that may be plant-accessible.
Physical Weathering
Happens when rocks disintegrate (break up) because they are under stress.
Under-nourishment
Not enough energy in food intake
Malnutrition
Food intake lacks nutrients
Monoculture
Single crop farm
Polyculture
Multiple crops farm
Shifting Cultivation / slash-and-burn agriculture
New land cleared by cutting down small areas of forest trees and setting fire to them
Upslope Ploughing
Creates little channels which promote surface runoff which will result in gullying.
Overcultivation
If soil is fragile, excessive growing of crops will weaken its structure and the soil can be washed or blown away.
Overgrazing
Animals strip land of vegetation and expose soil to wind and rain.
Terracing
Stabilises slopes and reduces flow of water surface
Contour Banks
Small stone walls used to trap flowing water and the soil it is carrying
Gully dams
fill gullies w/ branches and stones to trap water and soil, infilling gully
Contour Ploughing
slows flow of water across surface
Strip Cropping
Growing 2 crops in same area - taller crop acts as windbreak
Afforestation
Replanting trees
Windbreaks / shelterbelts
trees / bushes slow wind down
