Calculations
Taxonomy and Development
Mineralogy
Physical Properties
Hydrologic Properties
100

What is the equation for VWC?

VWC= water volume (cm3)/ total volume of sample (cm3

100

The finest level soil taxonomic group is ___________.

series

100

Sands and silts are __________ minerals.

primary

100

What are the four physical properties of soil?

Texture, color, pores/voids, and structure

100

Do soils with lots of pore space have high or low bulk density? 

Low bulk density

200

What is the equation for bulk density? 

Bulk Density= mass/volume

200

Organic matter comprises about what percentage of the soil?

5%

200

The most abundant nonsilicates are __________.

oxides

200

30% clay, 60% silt, and 10% sand; what soil texture is this?

Silty clay loam

200

Do soils with high organic matter have high or low bulk density? 

Low bulk density

300

What is the VWC of 400 cm3 of soil where the field water weight is 213 g and the oven dry weight is 133 g?

VMC= 20 %

300

What process leads to the development of the E horizon?

eluviation

300

Name a specific 2:1 clay mineral.

Montmorillonite

300

From high to low, categorize each soil texture to its susceptibility to wind erosion.

Silt, sand, clay

300

What is capillary water? 

Water held above the saturated zone

400

What is the wet bulk density of a 300 cm3 soil core that weighs 433 g (field wet weight)?

BDwet= 1.433 g/cm3

400

List the four pedogenic processes.

additions, losses, translocation, transformation

400

Before substitution, a typical tetrahedron is composed of what two elements?

oxygen and silicon

400

Which grade of soil structure describes “aggregates that separate when soil is disturbed”?

Strong

400

What are 3 hydrologic soil properties? Hint: multiple right answers

Smaller pore size

More porosity

Lower bulk density 

Greater water-holding capacity 

Gleying

Mottling

More unavailable water for plants


500

Core samples were obtained by hand auger with a diameter of 6.35 cm and analyzed by 2 cm depth increments. Calculate bulk density and VWC. See Screen. 

See Screen

500

Spodosols come from the Greek spodos which means ___________.

wood ash

500

List the three categories of true 2:1 silicate clays.

smectites, micas, vermiculites

500

Which soil structure is this describing? Indistinct aggregates, blocky with rounded corners, 10 to < 20mm

Weak medium subangular blocky

500

What are the 3 forces governing soil water potential? And what is the equation?

1. Gravimetric Potential 

2. Matric Potential 

3. Osmotic (solute) Potential 

soil water potential= gravimetric potential + matric potential + osmotic potential