What are the three phases of soil? (states of matt
1. Solid phase (organic matter)
2. Liquid phase (solution)
3. Gaseous phase (O2/CO2)
Why study soils?
1. Food production (99.7%)
5. Nutrient cycling (N, P, C, S)
6. Filter/water storage - filter potential pollutants
7. Key role in the environment
What are the factors that make up soil formation?
1. Climate - rain, wind, temperature, radiation
2. Topography - relief, slope, characteristics
3. Organisms - flora, fauna, humans
4. Parent material - geology
What is soil classification?
Naming system - describe and identifies soil orders
What is soil degradation?
What is the difference between minerals and rocks?
Minerals are aggregates of rocks - they make it up.
Name characteristics of minerals.
-Specific chemical composition - formula
-A regular atomic arrangement - crystalline
What is the difference between a primary and a sec
Primary minerals: From parent material. E.g. quartz, feldspar
Secondary minerals: From components of primary minerals. E.g. Fe (iron) and Al (aluminium) oxides.
What is a silicon tetrahedron? (SiO4)4-
-Silicon fits neatly into the hole made when 4 oxygen atoms (positively charged) arrange themselves as a tetrahedron.
-Building block of all silicates
-Tetrahedron's positive charge (Si++++) can combine with the negative charge (metals).
What are the silicates?
1. Fe (iron)
2. Mg (magnesium)
3. Al (aluminium)
4. K (potassium)
5. Na (sodium)
6. Ca (calcium)
What group belongs in the single chain structures?
What group belongs in the double chain structures?
Amphibole group. (perfect cleavage)
What group belongs in sheet structures (planar)? (
-Tetrahedrons linked by 3 oxygens with perfect cleavage.
What group belongs in three dimensional (3D)?
-Tetrahedron linked by 4 oxygens.
Name other soil minerals besides silicates.
Al and Fe oxides.
-Hematite (Fe2O3), red in colour.
Name a different type of soil organic matter.
-Living component - bacteria, organisms, humus matter, residues.