By: William H. Livingston, School of Forest Resources, University of Maine
Samantha Langley-Turnbaugh, Dept. Env. Sci. & Policy, University of Southern Maine

Readings& Web Sites:

Pages 26-30, 415-435 in Kricher, J.C. 1998. A Field Guide to Eastern Forests, North America. Houghton Mifflin Co., NY. 488 p.

Pages 3-50, 99-104, 153-154, 162 in Harpstead, M.I., T.J. Sauer, and W.F. Bennett. 1997. Soil Science Simplified, 3rd Ed. Iowa State Univ. Press, Ames. 210 p.

I.Introduction

II.What is soil?

A.Surface layer of the earth

B.Natural materials

C.Supports plant life

Used in large amounts / Used in small amounts
From air and water / From soil / From soil
Carbon (C) / Nitrogen (N) / Manganese (Mn)
Hydrogen (H) / Phosphorus (P) / Boron (B)
Oxygen (O) / Potassium (K) / Molybdenum (Mo)
Calcium (Ca) / Copper (Cu)
Magnesium (Mg) / Zinc (Zn)
Sulfur (S) / Chlorine (Cl)
Iron (Fe)

III.What Makes Soil?

A.Interaction of abiotic and biotic factors in the environment.

B.Because environment differs from location to location, soils differ from location to location

C.Particle size

1.Sand (0.05mm to 2mm)
2.Clay (<0.002 mm)
3.Silt (0.002 to 0.05 mm)
4.Loam - mixture of all three

D.Parent Material

1.Materials underlying soil
2.Five categories
a)Minerals and rocks
b)Glacial deposits
c)Wind blown deposits (silt)
d)Water-body deposits (silt/clay)
e)Organic deposits (mucky organic)

E.Climate

1.Factors that affect break-down of mineral components
2.Affect which life forms can live in area.
3.Water dissolves and carries minerals to lower layers in soils - soil development

F.Living organisms

1.Vegetation
2.Bacteria and fungi
3.Animals

G.Topography - the lay of the land

1.Hilly - variable water dynamics
2.Flat - uniform soils

H.Time

1.All factors interact over time

2.Soil develops

3.Soil "age" actually refers to soil development - dependent on all factors

IV.Characterizing Soils

A.Soil Profile - layers or "horizons"

1.Organic horizon develops on top

2.Most have 3 mineral horizons"

B.Major Soil Types

1.Primitive/immature

2.Volcanic

3.Desert

4.Grassland

5.Organic

6.Southern forest

7.Northern conifer

8.Northern hardwood

V.Maine's Forest Soils

A.Typical characteristics of "Spodosols"

1.Cool, humid climate

2.Coniferous vegetation (acidic foliage)

3. Well developed O horizons

4.Narrow A horizon (cold)

5.E horizon between A and B horizon

6.B horizon

7.Parent material from granite

8.Drainage determines how well trees can grow

a)Poor drainage in many areas
b)Good drainage associated with;

VI.Nitrogen fixation

A.Fourth most needed nutrient

B.Special bacteria are needed to convert gaseous N to water soluble N

1.A little in soil.

VII.Conclusion

A.Soils and climate determine which plants will be present

B.Soil characteristics determined by multiple factors (parent material, climate, topography, vegetation, time)

C.Maine's soils favor growth of forests.

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Terms

Soil

Organic

Inorganic

Minerals

Anchorage

Nutrients

Parent material

Sand

Clay

Silt

Loam

Glacial deposits

Topography

Soil profile

Soil age

0 horizon

A horizon

B horizon

C horizon

E horizon

Primitive/immature soil

Volcanic soil

Desert soil

Grassland soil

Organic soil

Sourthern forest soil

Northern conifer soil

Northern hardwood soil

Spodosols

Leaching

Organic acids

Granite

Poor drainage

Good drainage

Nitrogen fixation

N-fixing bacteria

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