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Flashcards in Soils Exam 1 Deck (57):
0

Gelisols

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

1

Soil spatial variable

Large to micro scale concerning climatic vegetation to aggregates

2

Spodosols

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

3

Alfisols

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

4

Weathering involves both

Destruction and synthesis

5

4 processes of soil formation

Transformation

6

Organic parent material

Forms where plant growth exceeds rate of decomposition

7

Aridisols

Light color low organic matter
High salts and minerals
Deserts

8

Glaciel till parent material

Material deposited directly by Glaciel ice

9

E horizon

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

10

6 functions of soil

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

11

C horizon

Un consolidated material

12

Mollisols

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

13

Alluvial parent material

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

14

Biochemical reactions double fur every ___ degree Celsius increase in temperature

10

15

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

Effective

16

Soil interface consists of:

45% solids
5% organic matter

17

O horizon

Organic materials above mineral soil

18

Andisols

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

19

Eolian parent material

Silt sized material and smaller carried by wind. Volcanic ash

20

Lacustrine parent materials

Materials deposited when glacial out wash turns into lake. Stratified

21

A horizon

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

22

Histosols

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

23

Vertisols

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

24

Glacial out wash

Coarse sands and gravel deposited by glacial out wash

25

Oxisols

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

26

Colluvial parent material

Angular Rick fragments transported downhill by gravity

27

Marine parent material

Sediments carried by rivers or streams into marine environments

28

B horizon

Accumulating clays. Parent material no longer visible

29

5 master soil horizons:

O
A
E
B
C

30

Ultisols

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

31

Entisols

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

32

Residual patent material

Develops from underlying Rick and is not transported

33

Inceptisols

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

34

Soil color factors

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

35

Is silt cohesive?

No

36

Physical processes of soil aggregates

Wetting drying, freezing thawing

37

Field capacity:

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

38

Per meant wilting point:

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

39

Soil texture

Different sized particles

40

Sand size?

2 - .05 mm

41

Silt size?

.05 - .002 mm

42

3 types of water movement in soil:

Saturated flow : gravity
Unsaturated flow: matric
Vapor flow

43

Clay size?

.002 >

44

Forces that affect potential energy of soil water:

Gravity
Matric
Osmotic

45

______ - many primary soil particles held in a single cluster

Aggregate

46

2 types of soil density?

Particle density - mass of solids/volume of solids

Bulk density - mass of solids/ volume of soil

47

Chart used for soil color

Munsell color chart

48

10YR 5/6
What does this describe?

Hue
Value
Chroma

49

Soil properties

Color, texture, structure, density, porosity, compaction

50

Soil texture influences:

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

51

Biological processes of soil aggregates

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

52

Percentage if earth's freshwater in soils?

33%

53

Volumetric water content

Volume of water present per unit volume of dry soil

54

Gravimetric water content

Mass of water present per unit mass of dry soil

55

Tortuosity

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

56

As water potential gradient increases, so dues_____

The rate if flow