ENVS 200 Exam 1

What is Soil

100

Soil Composition

45% Sand, Silt, Clay

25% Water

25% Air

5% Organic Matter

200

Soil, A Soil, The Soil

• The Material. Mixture of minerals, gases, water, organic matter, & organisms capable of supporting plant life
• An Individual Natural Body. Organized, 3D, Region/Biome Specific, Distinct Properties
• All Soils. Everywhere. Composed of the material, roots, ground-dwelling animals, & rocks. Called the Pedosphere

300

What is the full taxonomy (order, suborder, etc.) for a loamy-skeletal, mixed, mesic Udic Haplustalf (name: Casto)

Order: Alfisol

Suborder: ustalf

Great group: Haplustalf

Subgroup: Udic Haplustalf

Family:  loamy-skeletal, mixed, mesic Udic Haplustalf

Series: Casto

400

4 Soil Formation Processes

1. Addition

2. Losses

3. Transformation

4. Translocation

500

5 Soil Formation Factors

Climate, Organisms, Relief/ Topography, Parent Materials, Time (CL.O.R.P.T.)

Definitions

100

Ecosystem

A community of organisms & their physical environment functioning together as a system

200

Macropore

Space between soil particles measuring >80um in diameter

300

Epipedon, Endopedon

Surface Horizon (O, A)

Subsurface Horizon (B, C, E)

400

Define Hue, Value & Chroma

Hue- Color family (ie. red, blue, green)

Value- Lightness/ darkness of a color

Chroma- Color intensity/ saturation

500

6 Ecosystem Services

• Medium for plant growth
• Recycling system for nutrients and organic wastes
• Modifier of the atmosphere
• Habitat for soil organisms
• Engineering medium
• System for water supply and purification

Soil Formation

100

Order of Horizons (Full Names, Top to Bottom)

Organic Layer (O), Topsoil (A), Zone of Eluviation (E), Zone of Accumulation (B), Parent Material (C), Bedrock (R)

200

Define conservation tillage

Tillage leaving at least 30% of plant residues on soil surface

300

Define parent materials

Organic or geographic precursors to soil

400

Name and define 4 types of transported parent materials 

Alluvial, lacustrine, marine, glacial till, glacial outwash, colluvial, eolian

500

6 weathering reactions

• Hydration, Hydrolysis, Dissolution, 
• Acid-base reactions, Complexation, Redox

Soil Physics

100

Define bioturbation

The mixing of of soil by organisms (worms, moles, etc.)

200

Porosity increases as...

-Soil particle size increases

-Soil particle surface area decreases

-Bulk density decreases

-Aggregation increases

300

What is the formula for bulk density?

Db= M/V

bulk density is dry soil mass over soil volume

400

A  of soil container weighs 6.5 g. The dry soil weight is with the container is 190g. The volume of the container is  110 cm^3. What is the bulk density?

1.66 g/cm^3

500

Name 3 shapes of peds

Spheroidal 

Plate-like

Block-like

Prism-like (columnar or prismatic)

Other

100

Name the 3 types of rocks

Igneous, Metamorphic, Sedimentary

200

Munsell soil color format

Hue, Value, Chroma

300

What soil is found in tropical rainforests, is extremely weathered, and low in organic matter?

Oxisol

400

Explain how Stoke's law is applied in soil science

-How fast particles fall through a liquid (water) based on mass

-helps determine soil texture

-observed in the jar test

500

Name all temperature regimes in increasing temperature order

Hypergelic, Pergelic, Subgelic, Cryic, Frigid, Mesic, Thermic, Hyperthermic