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Flashcards in Soils Exam 1 Deck (57)
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0
Q

Soil spatial variable

A

Large to micro scale concerning climatic vegetation to aggregates

1
Q

Gelisols

A

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

2
Q

Spodosols

A

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

3
Q

Alfisols

A

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

4
Q

Weathering involves both

A

Destruction and synthesis

5
Q

4 processes of soil formation

A

Transformation

6
Q

Organic parent material

A

Forms where plant growth exceeds rate of decomposition

7
Q

Aridisols

A

Light color low organic matter
High salts and minerals
Deserts

8
Q

Glaciel till parent material

A

Material deposited directly by Glaciel ice

9
Q

E horizon

A

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

10
Q

6 functions of soil

A
Support plant growth
Control fate of water
Recycling system
Modify atmosphere
Habitat for organisms
Engineering medium
11
Q

C horizon

A

Un consolidated material

12
Q

Mollisols

A

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

13
Q

Alluvial parent material

A

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

14
Q

Biochemical reactions double fur every ___ degree Celsius increase in temperature

A

10

15
Q

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

A

Effective

16
Q

Soil interface consists of:

A

45% solids

5% organic matter

17
Q

O horizon

A

Organic materials above mineral soil

18
Q

Andisols

A

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

19
Q

Eolian parent material

A

Silt sized material and smaller carried by wind. Volcanic ash

20
Q

Lacustrine parent materials

A

Materials deposited when glacial out wash turns into lake. Stratified

21
Q

A horizon

A

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

22
Q

Histosols

A

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

23
Q

Vertisols

A

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

24
Q

Glacial out wash

A

Coarse sands and gravel deposited by glacial out wash

25
Q

Oxisols

A

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

26
Q

Colluvial parent material

A

Angular Rick fragments transported downhill by gravity

27
Q

Marine parent material

A

Sediments carried by rivers or streams into marine environments

28
Q

B horizon

A

Accumulating clays. Parent material no longer visible

29
Q

5 master soil horizons:

A
O
A
E
B
C
30
Q

Ultisols

A

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

31
Q

Entisols

A
Very recent
Entering a horizon
Great diversity
Steep Ricky settings
Fly vial and alluvial can be productive
32
Q

Residual patent material

A

Develops from underlying Rick and is not transported

33
Q

Inceptisols

A

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

34
Q

Soil color factors

A

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

35
Q

Is silt cohesive?

A

No

36
Q

Physical processes of soil aggregates

A

Wetting drying, freezing thawing

37
Q

Field capacity:

A

Only water held against gravity renaming

-10 to -30 kPa

38
Q

Per meant wilting point:

A

When plant roots can no longer extract water

Around - 1500 kPa

39
Q

Soil texture

A

Different sized particles

40
Q

Sand size?

A

2 - .05 mm

41
Q

Silt size?

A

.05 - .002 mm

42
Q

3 types of water movement in soil:

A

Saturated flow : gravity
Unsaturated flow: matric
Vapor flow

43
Q

Clay size?

A

.002 >

44
Q

Forces that affect potential energy of soil water:

A

Gravity
Matric
Osmotic

45
Q

______ - many primary soil particles held in a single cluster

A

Aggregate

46
Q

2 types of soil density?

A

Particle density - mass of solids/volume of solids

Bulk density - mass of solids/ volume of soil

47
Q

Chart used for soil color

A

Munsell color chart

48
Q

10YR 5/6

What does this describe?

A

Hue
Value
Chroma

49
Q

Soil properties

A

Color, texture, structure, density, porosity, compaction

50
Q

Soil texture influences:

A

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

51
Q

Biological processes of soil aggregates

A

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

52
Q

Percentage if earth’s freshwater in soils?

A

33%

53
Q

Volumetric water content

A

Volume of water present per unit volume of dry soil

54
Q

Gravimetric water content

A

Mass of water present per unit mass of dry soil

55
Q

Tortuosity

A

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

56
Q

As water potential gradient increases, so dues_____

A

The rate if flow