Soils Flashcards
Why is soil a living system?
The micro organisms living inside the soil.
Define soil:
A natural system consisting if four components.
Air, water, organic matter and mineral matter.
5 major independent soil forming factors
Topography Time Climate Parent material Organisms
Mechanical weathering:
Physical disintegration
Water freezing
Chemical weathering:
Change the chemical make up
Acid rain, oxidation
Humus:
Dark colored organic material. Contains decomposed pieces of plant and animal wastes and residues. Materials synthesised by micro organisms
6 major horizons
O A E B C R
O horizon contains:
Organic litter from dead plants and animals
A horizon contains
Mineral material-rich in humus
E horizon contains:
Leaching occurs
B horizon contains:
Accumulation of materials that washed down from above horizons
C horizon contains:
Parent material- partially weathered bedrock
R horizon contains:
Bedrock with little evidence of weathering
Soil profile:
Sectional view of the various horizons
Soil texture:
Proportions of sand, silt and clay in a particulate
Soil structure:
Arrangement of grouping of soil particulates into aggregates
Hygroscopic water:
Water in soil which exists as a microscopic level around clay.
Hydric soils:
Formed under conditions of saturation long enough to develop anaerobic conditions.
Flooding
Pounding
Mollisols:
Most productive
Crop and rangeland
Spodosols:
Sandy deposits
Great Lakes
New England
Alfisols:
Humid climates
Deciduous forests
Ultisols:
Forested subtropical
Less fertile
Oxisols:
Warm, wet climate
Tropical rainforests
Gelisols:
Young soils- little profile development
Permafrost, Alaska, tundra
Do all soils have all horizons?
No.
Macro nutrients
Large quantities required
Micro nutrients
Small amounts required.
Iron, zinc
Macro and micro nutrients are the building blocks for?
Chlorophyll
Permeability:
Ease that water and air pass through a layer of soil.
Factors that impact water holding capacity:
Type of soil surface
Climate (temp, humidity, velocity)
Soils deficient in clay are?
Structureless
soils too rich in clay form?
Compacted later
Micro pore space is most useful? True or false
true
Alifisol:
Forest soils
pH: 6-7
Entisol:
New soils
Histols:
Organic soils
Swamps and bogs
Inceptisols:
Moderately developed
Coniferous forests (BWCA)
A on R or C
Mollisols:
Prairie soils
Spodosols:
Forest soil: infertile. Sandy
Aridsol:
Desert soil
Ultisol:
Forest leached soil
Oldest soil
Appalachian mountains
Oxisols:
Rainforest not in us
Soil profiles depend on 2 soil forming factors :
Climate and organisms
6 measures of system being sustainable:
Conservation Economically viable Environmentally friendly Resource conserving Socially responsible Yields of high quality
Erosion:
Wind
Water
