Definitions Flashcards
Basic composition (5)
Inorganic matter, decayed organic matter, living organisms, water, air.
Basic structure
Loose, porous material. Never solid like rock.
Soil texture is
The proportion of sand silt and clay in a sample.
Clays can determine nutrient availability by
The transformation of soil structure and contaminants.
Soil texture influences
Soil fertility
Water holding capacity
Susceptibility to erosion
Humus is
The remains of once living matter. A dark coloured material where the structure of organic material is lost through decomp and chemical transformation.
Organic matter is greatest in
Cool moist regions and lowest in warm dry areas.
Soil solution is
An aqueous solution of ions dissolved in gases that are in contact with the soil.
Clays have a high net
Negative electrical charge
Isomorphous substitution is when
Ions of a similar shape and size are swapped between the soil solution and clay sheets.
Particle density is the
Mass by volume of different particles.
Bulk density is the
Mass of a specific volume of dry soil, including pore space and solids.
Bulk density will always be
Lower than particle density.
The formation of all soils can be attributed to five factors
Patent material Topography Climate Biota Time
The four soil forming processes
Addition of material
Loss of components
Transformation
Translocation
The three components that compose a soil texture are
Sand silt and clay
Water holding capacity of clay silt and sand
Clay - high
Silt - moderate
Sand - low
Drainage rate of clay silt and sand
Clay - slow unless cracked
Silt - moderate
Sand - fast
Inherent fertility of clay silt and sand
Clay - high
Silt - moderate
Sand - low
Ease of pollutant leaching of clay silt and sand
Clay - low unless cracked
Silt - moderate
Sand - high
Ease of compaction of clay silt and sand
Clay - high
Silt - moderate
Sand - low
Water erosion susceptibility of clay silt and sand
Clay - moderate
Silt - high
Sand - low
Wind erosion vulnerability of clay silt and sand
Clay - low
Silt - high
Sand - moderate
