Trace Evidence (Soil)
DaiJah, Tia, Summer, Rihanean
Features of the soil profile and the soil horizons are often described in the field in terms of the soil's physical properties. Horizons are defined based on difference in the physical properties.
- Soil Texture
- Soil Structure
- Soil Consistence/Soil Strength
- Soil Color
- Soil Permeability
- Soil Temperature
- Salinity (EC)
- Cation exchange capacity (CEC)
- Organic matter
- C:N ratio (Carbon to Nitrogen)
- Soil pH is probably the most commonly measured soil chemical property and is also one of the more informative. Like the temperature of the human body, soil pH implies certain characteristics that might be associated with a soil. Since pH (the negative log of the hydrogen ion activity in solution) is an inverse, or negative, function, soil pH decreases as hydrogen ion, or acidity, increases in soil solution. Soil pH increases as acidity decreases.
- Soils are composed of solid, liquid, and gas; soluble and insoluble; and organic as well as inorganic substances. There are ions and compounds, salts, acids, bases, minerals, and rock fragments. There are also colloids which are very active chemically. They are very fine soil particles, including humus, fine silicate clays, and oxides and hydroxides of iron and aluminum. Colloids carry electrochemical charges, both positive and negative, and these charges develop by substitution in the lattice structure and dissociation of active groups.
Test, Labs, and Analyzing
Soil is most common in the world. It's mixed with different-sized mineral grains. The proportions of sand, silt, clay and organic matter determine a soils properties. Pg272
Soils composition is different from place to place and is controlled by factors; climate, parent material, living organisms, topography and time. A sample taken a few meters deep is different from a sample up above.
Work Cited Section.....
Physical Properties: http://broome.soil.ncsu.edu/ssc012/Lecture/topic8.htm
Chemical Properties: http://soils.tfrec.wsu.edu/mg/chemical.htm