Soil and Its Uses

1
Third hour exam
Friday April 12
11 pm here
100 points
(of 500 for semester)
29 questions
57 bubbles
If University-approved conflict
Sign up with Karin Nelson
by Wednesdays lecture
2
Soil
EEE 105
Ch. 14
http//www.life.uiuc.edu/animalbiology/105/
Name eee105
Password prAIRie
3
Soil
Ch. 14
4
Land
Portion of the world not covered by water.
Soil
Mixture of minerals, organic material, living
organisms, air, and water
5
Soil Formation
Soil
Parent Material
Ancient rock layers with recent deposits from
lava or glacial flows
Weathering
Fragmentation or chemical change of the parent
material
6
Soil Formation
Soil
Weathering
Mechanical
temperature changes abrasion
7
Soil Formation
Soil
Weathering
Mechanical
temperature changes abrasion
Chemical
8
Soil
Glaciation
Wisconsin glaciation
18,000 years ago
9
Soil
Glaciation
soil deposition
10
Soil
Glaciation
soil deposition
moraines
11
Soil
Glaciation
soil deposition
moraines
Moraines formed of till
12
Soil
Glaciation
soil deposition
moraines
loess
wind blown dust
13
Soil Formation
Soil
Weathering
Mechanical
Chemical
Biological
humus
dead organic material
root hairs exchange nutrients
aerates
, hydrates soil
14
Soil Formation
Soil
Weathering
Mechanical
Chemical
Biological
humus
dead organic material
root hairs exchange nutrients
aerates
, hydrates soil
composting
15
Soil Formation
Soil
Weathering
Mechanical
Chemical
Biological
humus
dead organic material
soil flora fauna
earthworms
16
Soil Formation
Soil
earthworms
Charles Darwins last book
The Formation of Vegetable Mould by the Action of
Earthworms
17
Soil Properties
Soil

• Texture - Determined by the size of soil
  particles.
• Too many large particles leads to extreme
  leaching.
• Too many small particles leads to poor drainage.

18
Soil Properties
Soil

• Texture

2 - 64 mm
gravel
0.05 - 2mm
sand
silt
0.002 - 0.05 mm
loess
clay
lt 0.002 mm
Soil types characterized by
sand, silt, clay
19
Soil

• Soil Profile - A series of horizontal layers of
  different chemical composition, particle size,
  and amount of organic matter.
• Horizon - Each recognizable layer of the profile.

20
Soil

• A Horizon - (Topsoil) Uppermost layer - contains
  most of the soil nutrients and organic matter.
• B Horizon - (Subsoil) Underneath topsoil.
  Contains less organic matter and fewer organisms,
  but accumulates nutrients leached from topsoil.
• C Horizon - Weathered parent material - very
  little organic material.

21
Grassland Soils
A Horizon
topsoil leaching
most root growth
22
Forest Soils
Topsoil thin
topsoil leachate
forms a subsoil
that supports
substantial root growth
23
(No Transcript)
24
Soil

• Mixtures ?
• Over 15,000 separate soil types have been
  classified in North America.

25
Soil

Morrow Plots
26
Soil

• Erosion - Wearing away and transportation of soil
  by wind and water.

Worldwide removes 25.4 Billion tons/yr
Poor agricultural practices increase erosion
and lead to the transport of associated
fertilizers and pesticides
Made worse by deforestation
and desertification
27
Desertification
28
Desertification
29
Soil
1985
1976
Tombouctou, Mali
30
Desertification
31
Desertification

• Climate change
• Deforestation
• Overgrazing

32
Desertification

• The U.S.Inter-Mountain West

33
Desertification

• The U.S.Inter-Mountain West

34
Salinization
35
H2O
Calcium
Sodium
36
Salinization
37
Soil

• Erosion - Wearing away and transportation of soil
  by wind and water.

Worldwide removes 25.4 Billion tons/yr
Poor agricultural practices increase erosion
and lead to the transport of associated
fertilizers
and pesticides
Made worse by deforestation and desertification
38
Soil

• Erosion

Most current agricultural areas lose topsoil
faster than it can be replenished
Wind erosion
Water erosion
39
Soil

• Erosion - Wearing away and transportation of soil
  by wind and water.

40
Soil

• Erosion

41
Soil

• Erosion

Sustainable farming
Illinois Erosion Sediment Control Law
called T by 2000
T tolerable soil loss
3-5 tons/acre/year
42
Soil

• Erosion

Sustainable farming
Conservation tillage
43
Soil

• Erosion

Sustainable farming
Conservation tillage
Hedgerows
44
Soil

• Erosion

Sustainable farming
Conservation tillage
Hedgerows
Perimeter wetlands
45
Soil

• Erosion

Great Plains have had four serious bouts of wind
erosion since late 1800s.