Soils Exam 1

Question 0

Soil spatial variable

Answer 0

Large to micro scale concerning climatic vegetation to aggregates

Question 1

Gelisols

Answer 1

Very cold climate
Permafrost
Slow soil formation
High organic content due to slow decomposition

Question 2

Spodosols

Answer 2

Acid soils with thin subsurface
Form in coarse textured parent materials
Form under coniferous vegetation

Question 3

Alfisols

Answer 3

Moderately leached forest souls
Temperate humid and subhumid regions
Very productive
Found in upper Midwest of USA

Question 4

Weathering involves both

Answer 4

Destruction and synthesis

Question 5

4 processes of soil formation

Answer 5

Transformation

Question 6

Organic parent material

Answer 6

Forms where plant growth exceeds rate of decomposition

Question 7

Aridisols

Answer 7

Light color low organic matter
High salts and minerals
Deserts

Question 8

Glaciel till parent material

Answer 8

Material deposited directly by Glaciel ice

Question 9

E horizon

Answer 9

Bleached almost white color, often sandy. Elucidation of clay. Fe, Al

Question 10

6 functions of soil

Answer 10

Support plant growth
Control fate of water
Recycling system
Modify atmosphere
Habitat for organisms
Engineering medium

Question 11

C horizon

Answer 11

Un consolidated material

Question 12

Mollisols

Answer 12

Dark, soft and if grasslands
Thick and dark
Crumb like structure
Important for agriculture

Question 13

Alluvial parent material

Answer 13

Sediments deposited by streams and rivers and deposited into floodplains, deltas, etc

Question 14

Biochemical reactions double fur every ___ degree Celsius increase in temperature

Answer 14

10

Question 15

Degree of weathering is related to ________ rather than total precipitation?

Answer 15

Effective

Question 16

Soil interface consists of:

Answer 16

45% solids

5% organic matter

Question 17

O horizon

Answer 17

Organic materials above mineral soil

Question 18

Andisols

Answer 18

Volcanic ash
Highly organic
High water and naturally fertile
Covers significant land in PAC NW

Question 19

Eolian parent material

Answer 19

Silt sized material and smaller carried by wind. Volcanic ash

Question 20

Lacustrine parent materials

Answer 20

Materials deposited when glacial out wash turns into lake. Stratified

Question 21

A horizon

Answer 21

Topmost mineral horizon containing enough organic material to blacken. Coarse texture

Question 22

Histosols

Answer 22

Mainly organic
20-30% organic matter
Mostly found in pears and mucks

Question 23

Vertisols

Answer 23

Clay rich
Sink and swell
Bad for engineering, mixing, tilling.
Dark color doesn’t indicate high OM

Question 24

Glacial out wash

Answer 24

Coarse sands and gravel deposited by glacial out wash

Question 25

Oxisols

Answer 25

Highly weathered in humid tropical Rain forests Well structured High clay content rich in Fe and Al oxide minerals

Question 26

Colluvial parent material

Answer 26

Angular Rick fragments transported downhill by gravity

Question 27

Marine parent material

Answer 27

Sediments carried by rivers or streams into marine environments

Question 28

B horizon

Answer 28

Accumulating clays. Parent material no longer visible

Question 29

5 master soil horizons:

Answer 29

``` O A E B C ```

Question 30

Ultisols

Answer 30

Strongly leached acidic forests Humid temperate and tropical regions Intensive weathering Many yellow red clays from Fe oxides

Question 31

Entisols

Answer 31

``` Very recent Entering a horizon Great diversity Steep Ricky settings Fly vial and alluvial can be productive ```

Question 32

Residual patent material

Answer 32

Develops from underlying Rick and is not transported

Question 33

Inceptisols

Answer 33

More developed than entisols Being invented into souks Fertile inPac. NW infertile in pa

Question 34

Soil color factors

Answer 34

Organic matter, water, presence and oxidation state of iron and manganese

Question 35

Is silt cohesive?

Answer 35

No

Question 36

Physical processes of soil aggregates

Answer 36

Wetting drying, freezing thawing

Question 37

Field capacity:

Answer 37

Only water held against gravity renaming | -10 to -30 kPa

Question 38

Per meant wilting point:

Answer 38

When plant roots can no longer extract water | Around - 1500 kPa

Question 39

Soil texture

Answer 39

Different sized particles

Question 40

Sand size?

Answer 40

2 - .05 mm

Question 41

Silt size?

Answer 41

.05 - .002 mm

Question 42

3 types of water movement in soil:

Answer 42

Saturated flow : gravity Unsaturated flow: matric Vapor flow

Question 43

Clay size?

Answer 43

.002 >

Question 44

Forces that affect potential energy of soil water:

Answer 44

Gravity Matric Osmotic

Question 45

______ - many primary soil particles held in a single cluster

Answer 45

Aggregate

Question 46

2 types of soil density?

Answer 46

Particle density - mass of solids/volume of solids Bulk density - mass of solids/ volume of soil

Question 47

Chart used for soil color

Answer 47

Munsell color chart

Question 48

10YR 5/6 | What does this describe?

Answer 48

Hue Value Chroma

Question 49

Soil properties

Answer 49

Color, texture, structure, density, porosity, compaction

Question 50

Soil texture influences:

Answer 50

Bulk density, water holding capacity, cation(gas) exchange, aeration, erodability, drivability, strength

Question 51

Biological processes of soil aggregates

Answer 51

Burrowing organisms, plant root extension, root, fungal, and bacterial secretions

Question 52

Percentage if earth's freshwater in soils?

Answer 52

33%

Question 53

Volumetric water content

Answer 53

Volume of water present per unit volume of dry soil

Question 54

Gravimetric water content

Answer 54

Mass of water present per unit mass of dry soil

Question 55

Tortuosity

Answer 55

Soil pores are not smooth like glass capillaries and move slower through tortuous paths

Question 56

As water potential gradient increases, so dues_____

Answer 56

The rate if flow