Soils Test 1

Many soil materials were transported before soil formation began. What mode of transportation is associated with LOESS parent materials?

Wind

This is the likely dominant type of weathering in the Arctic.

Physical

The parent material for soils formed in organic materials is called:

cumulose

Soil fertility and soil productivity are two terms for the same concept.

False

If a late spring rainstorm drops 2.5 inches of rain on a gently sloped landscape in 2 hours ... Which soil textural types will have the greatest amount of surface runoff?

Fine

If a late spring rainstorm drops 2.5 inches of rain on a gently sloped landscape in 2 hours... Which soil textural types would likely retain the most water 3 days after the storm?

Fine

According to the "official" definition of soil...

Formed in place, includes all materials less than 2 mm in diameter, unconsolidated materials, naturally occurring, occupies top two meters of the lithosphere,

O horizon

Found often in undisturbed forests or wetlands, consists of organic materials in various stages of decomposition

Identify the five over-arching general functions in the list of soil functions below.

Habitat for soil organisms, landscaping and engineering medium, recycler of raw materials, medium for plant growth, regulator of water supplies

Put the hierarchy of the soil taxonomy in the correct order from the broadest (1) to the most specific (6).

Order, suborder, great group, sub group, family, series

What are soil chemical properties?

Organic matter and acidity

Five factors work in concert to produce a soil profile. What are they?

Organisms (Vegetation and biota), Parent material, Relief (topography), Climate, Time

What are the four biotic factors of soil?

Plant roots, insects, decomposers, organic residues and humus

Which of the following soil properties will have the greatest influence on the ability of the soil to provide a suitable habitat for these organisms?

Porosity (aeration), soil water content, organic matter type and composition, textural type

What are soil functions?

Purifies and stores water (provides it to plants, home to organisms, recycles dead organisms (disposal of waste products), Produces food and fibers, provides nutrients to plants The soil acts as the Earth's recycler, filter, purifier, and storehouse. The soil ecosystem recycles dead organisms into the building blocks of new life, it transforms toxic substances into simple compounds, it renders pathogenic organisms harmless, and it purifies and stores water as it passes through.

List common parent materials and where the come from/how they form.

Residual= Formed in place (in bedrock) Loess= Wind-blown silt and clay Marine= Moved by or deposited in oceans Glacial= Transported by rivers of moving ice Alluvial= Moved by streams Colluvial= Moved by gravity Cumulose=Sedentary organic materials Eolian=wind blown materials

Identify five of the listed soil properties that directly affect water intake and storage in soils.

Soil compaction (density), organic matter content, aeration and infiltration, texture and aggregation, surface cover

Which of the following statements regarding soil productivity and soil fertility is most accurate?

Soil fertility is one thing that affects soil productivity.

The ability of a soil to function, to sustain biological productivity, to maintain environmental quality, and to promote plant and animal health is ____________.

Soil quality

How many soil ORDERS are there in the USDA-NRCS soil classification system?

12

What is an ecosystem?

A body of relationships that connect a community of living things with their environment and each other.

Which of the following is the expected sequence of horizons in an undisturbed soil profile?

A,B,C

Surface litter

Accumulation of recently dead organisms

What is a benefit of humus to soil health?

Aggregate stabilizer, soil binder, improves water retention and infiltration, promotes porosity and structure,

According to the course notes, which of the following relationship of rainfall and temperature to weathering is TRUE?

As annual rainfall and temperature increase, chemical weathering dominates over physical weathering.

Subsoil is expected to be ...

B and C horizons

The change of organic carbon into CO2 is an example of _____________ weathering.

Biological

The growth of lichens on rocks is an example of ______________ weathering.

Biological

For the monolith of the Hastings soil series, the structure of the first subsoil layer (B horizon) is best described as:

Blocky

The effects of biota on soil formation are closely related to, and hard to distinguish from, the effects of ___________.

Climate

Potential Soil or Environmental Related Limitations for Intensive Food or Fiber Production: Environmental

Climate Factor, Too cold, Too hot, Too dry, Too wet, short growing season

If a late spring rainstorm drops 2.5 inches of rain on a gently sloped landscape in 2 hours ... Which soil textural types will allow the most rapid rate of water infiltration?

Coarse

If a late spring rainstorm drops 2.5 inches of rain on a gently sloped landscape in 2 hours ... Which soil textural types will have the most rapid rate of drainage (internal)?

Coarse

Bedrock (Horizon R)

Consolidated, rocky material, solid rock parent material, not effected by soil forming processes

For the monolith of the Fillmore soil series, the first subsoil layer (B horizon) was also described as:

Cracked due to clay shrinking

From the list below, select two items that are directly impacted by TOPOGRAPHY during soil formation.

Depth to water table and erosion of soil material

"Major effects of climate on soil formation are ... "

Due to the amount and distribution of rainfall, due to increased chemical reaction rates at higher temperatures, sometimes hard to distinguish from those of vegetation, reflected in the soil organic matter content, weathering of parent material and decomposition of organic matter

Which horizon is severely leached and has lost significant amount of clay, iron, aluminum, and salts?

E horizon

Subsoil (B Horizon)

Layer of clay accumulation, with other elements accumulating that have moved down from above. Receives materials such as lime, clay and salts which have been leached from materials above it.

Topsoil (A horizon)

Layer of greatest biological activity and organic matter accumulation. Contains more organic material than any other horizon besides the O horizon

Soil horizons are ...

Layers in a soil profile

The presence of an E horizon in a soil profile signifies:

Leached nutrients: coniferous forest ecosystem, typically leached due to decomposition of acidic vegetation and or frequent saturation with water

Potential Soil or Environmental Related Limitations for Intensive Food or Fiber Production: Chemical

Low Organic Matter%, Low Natural Fertility%, Acidic (Low pH), Alkaline (High pH), Excess Salts (Salinity), Contamination

Parent Material (C Horizon)

Mainly un-weathered, loose material. Unconsolidated.

What are the biological properties of soil?

Microbial activity/biomass, plant vigor, soil respiration (CO2), earthworm counts

What are the four abiotic factors of soil?

Minerals, air, water, clay

What are the four components of the soil ecosystem?

Minerals, water, air, living organisms (life)

What are chemical properties of soil?

Nitrate nitrogen, salinity-soluble salts (EC), acidity and alkalinity (pH), organic matter content

What element is most influential in controlling the rate of organic matter decomposition.

Nitrogen

Which horizon is found more often in forest soil than under grasslands?

O horizon

A soil is located near a river on a gentle slope. It has formed in loess parent material and has been in native woodlands vegetation for a very long time. The climate is temperate and the moisture regime is udic. The probable sequence of horizons in the soil profile will be:

O-A-E-B-C

From the list below, select three items which are directly impacted by PARENT MATERIAL during soil formation.

Soil textural type (e.g. coarse or fine texture), soil nutrient content (e.g. calcium content), ease of mineral weathering by physical or chemical means

Select four of the following soil properties that will be of greatest interest to an engineer designing a roadway or building foundation?

Structure and aggregation, soil density (compaction), textural class (% of sand, silt, and clay), soil depth

Organic Layer (O-horizon)

Surface accumulation of recently dead organisms and organic materials, may be slightly decomposed.

What are physical properties of soils?

Texture and aggregation, topsoil depth, surface cover, soil compaction (density), aeration and infiltration

Why study soil soil classification and taxonomy?

The value of this information is to enable you to work on a location whose soils you are not familiar with. Being able to interpret soil names can provide you with a great deal of information about a soil without ever seeing it.

Why do green or grassy plant residues usually decompose faster than woody residues?

They generally contain more protein, and thus more nitrogen than woody-type residues.

Soils found in a depression areas are often more developed (older) than surrounding soils because of differences in ...

Topography

What are the 4 processes in which soils form?

Transformations, Additions, Translocations, and Losses

From the list below, select four items that are directly impacted by CLIMATE during soil formation.

Type of native vegetation, Type and rate of chemical weathering of soil parent materials, Amount of material translocated within a soil profile

A Soil Profile is a ...

Vertical cross section of all soil horizons

Potential Soil or Environmental Related Limitations for Intensive Food or Fiber Production: Physical

Very fine Texture, Very Coarse Texture, Shallow rooting zone, Eroded condition, Compacted/Crusted, Steep Slopes (>8%), Poor Drainage, Wetland

Which of the essentials for life do plants receive from the soil?

Water and nutrients

The means by which rocks and minerals are changed by physical and chemical processes into other soil components describes which of the following terms?

Weathering

Biota directly influences soil formation by affecting the:

amount of organic matter and porosity

What are the soil moisture regimes?

aridic= dry more than 50% of the year, irrigation required for crops udic= ustic= aquic= xeric= in

What or whose activity is responsible for the formation of organic matter in soil?

fungi, bacteria, invertebrates, decomposers

The B horizon is characterized as a ...

horizon that has the most accumulated clay

The A horizon is characterized as a ...

horizon that is mainly mineral but also has organic matter

Topsoil is expected to have ...

the most biological activity, O and A horizons, most disturbance, highest organic matter content

The C horizon is characterized as a/an ...

unformed soil layer in loose parent material, unaffected by soil forming processes

Name the 5 soil forming factors

vegetation/biota, topography, time, climate, parent materials

A soil is located on a stabilized sand dune. The soil profile consists of a thin, light brown A horizon over a thick C horizon. What is the age of this soil?

very young