Soils Unit
Name: __________________________________
Students will know and understand
Students will learn concepts by doing
1. Soil formation factors, including climate and parent
· Depict the process of soil formation by drawing a comic
material, influence soil types and uses.
2. Soil texture and structure influence soil properties and
usability.
3. Soil is a natural filter and can collect nutrients and other
materials from water.
4. The development, use, and management of soil as a
natural resource are directly related to soil properties.
strip.
· Determine soil texture by feel and ribbon testing.
· Describe and sketch the differences in soil structure types.
· Compare the permeability and filtration capacity of
different soil types.
· Calculate slope of an area of land.
· Classify land according to appropriate use based on slope,
erosion factors, drainage, and workability.
What is soil? What is dirt?
Essential Questions:-22 points
Directions: These will be answered throughout our lesson.
1.
What is soil?
2.
Why is soil considered a natural resource?
3.
How is soil formed?
4.
How is soil texture influenced by the soil formation process?
5.
How can I determine soil texture?
6.
What soil characteristics determine soil structure?
7.
How does soil serve as a natural filter?
8.
How does soil type influence the filtering ability of soil?
9.
How does slope contribute to soil properties and characteristics?
10. How is land classified?
11. Why is there a need for Class I and Class II soils?
35 Key Terms—70 points--Directions: When assigned simply work together and place the word next to the definitions below. I will only
assign about 10-15 words at a time, but over a short period of time.
Aggregate
Bedrock
Clay
Climate
Erosion
Filtration
Formation
Gravel
Ground cover
Horizon
Infiltration
Internal drainage
Irrigation
Land
Loam
Mineral
Organic matter
Organism
Parent material
Ped
Permeability
Porosity
Rock
Sand
Silt
Slope
Soil
Soil profile
Soil structure
Soil texture
Taxonomy
Topography
Topsoil
Valley
Weathering
Definitions
1.
The surface layer of soil, containing relatively high percentages of decomposed and partially decomposed
organic matter.
2.
Any igneous, sedimentary, or metamorphic rock that is represented as a unit in geological mapping.
3.
Soil that consists of less than 52 percent sand, 28 to 50 percent silt, and 7 to 27 percent clay, resulting in
a soil texture ideal for gardening.
4.
Refers to the extent of voids or openings in the soil that exist between soil particles and soil peds or clods.
These pores hold water and air for absorption by plant roots. A porosity of 50% is excellent for plant
growth.
5.
An elongated depression between uplands, hills, or mountains
6.
Mineral matter of variable composition, consolidated or unconsolidated, assembled in masses or
considerable quantities in nature.
7.
The arrangement of primary soil particles into compound particles or aggregates that are separated from
adjoining aggregates. Size, shape, and distinctness are used to describe soil structure. Farmers often
describe soil structure with words, such as crumbly or cloddy.
8.
The group of processes whereby earth or rock material is worn away, loosened, or dissolved and removed
from any part of the earth’s surface.
9.
A natural part of the Earth’s surface characterized by any single factor or combination of topography,
climate, soil, rocks, vegetation; the natural landscape.
10. The artificial application of water to soil for the purpose of increasing plant production.
11. A size term denoting particles, regardless of mineral composition, with diameter less than two microns.
12. The capacity of soil or rock for transmitting a fluid. Degree of permeability depends upon the size and
shape of the pores, the size, and shape of their interconnections, and the extent of the latter.
13. Atmospheric action on rock surfaces producing decomposition, disintegration, or alteration of rock.
14. A vertical section of a soil. The section, or face of an exposure made by a cut, may exhibit with depth a
succession of separate layers although these may not be separated by sharp lines of demarcation
15. Unweathered hard rock that lies directly beneath the soil layers or beneath superficial geological deposits,
such as glacial drift.
16. In soil science, a group of textural classes in which the particles are finer than gravel but coarser than
silt, ranging in size from 2.00 to 0.5 millimeters in diameter. It is the textural class of any soil that
contains 85 percent or more of sand and not more than 10 percent of clay.
17. The many soil particles held together in a small mass
18. The process by which water on the ground surface enters the soil.
19. Any vegetation that grows close to the ground, producing protection for the soil.
20. Inorganic compound that occurs naturally in the Earth and has a distinctive structure.
21. The relative proportion in a soil of the various size groups of individual soil grains.
22. Slope of the land and the position on the landscape, such as the top of a hill, a hillside, or the foot of a
slope.
23. The relative degree of downward movement of water in a soil. Also called permeability.
24. A unit of soil structure such as an aggregate, crumb, prism, block, or granule, formed by natural
processes (in contrast with a clod, which is formed artificially by compression of a wet clay soil).
25. The percolation of rainwater through the soil.
26. A textural class of soils that contains 80 percent or more of silt and less than 12 percent clay
27. The mineral and organic surface of the earth capable of supporting upland plants. It has been (and is
being) formed by the active factors of climate and biosphere exerting their influence on passive parent
material and topography over neutral time.
28. Accumulation of water-worn pebbles larger than two millimeters in diameter.
29. A layer of soil, approximately parallel to the surface, having distinct characteristics produced by soilforming processes.
30. Any living individual whether plant or animal.
31. The change in elevation for a given horizontal distance of the surface of the Earth, often expressed as a
percentage.
32. The science of classification of organisms and other objects and their arrangement into systematic groups,
such as species, genus, family, and order.
33. The horizon of weathered rock or partially weathered soil material from which the soil is formed.
34. Matter found in, or produced by, living animals and plants, which contains carbon, hydrogen, oxygen,
and often nitrogen and sulfur.
35. The sum total of all atmospheric or meteorological influences, principally temperature, moisture, wind,
pressure, and evaporation, which combine to characterize a region and give it individuality by
influencing the natures of its land forms, soils, vegetation, and land use.
Soils Day 1:
Actively listen and engage in the power point presentation on the formation of Soils. Record your notes
on the handout below.
List five key processes that interact to form soil AND describe each one
1.
2.
3.
4.
5.
6. What is the opposite of soil formation AND what two forms does it come in? (Bonus questions-What
are loess, alluvial and colluvial soils and what do they all have in common?)
7. What are some likely contributing factors to soil erosion?
Soils Day 2:
Lab1-Mechanical and Chemical Weathering.
Methods:
A.
Question being Investigated:
______________________________________________________________________________________
______________________________________________________________________________________
B.
Methods
1.
Obtain about 10 g each of presoaked samples of marble, granite, and basalt; 3 small capped vials;
tweezers; forceps; beaker; and a hand lens
2.
Fill beaker with about 200 mL H2O
3.
Dab dry the rock samples and mass. Record this mass. Inspect each sample noting texture, edges, color
and general appearance. Record.
4.
Place the samples in their separate vials and add just enough H2O to cover. Cap and shake continuously
for 3 minutes. Repeat step 3.
5.
Repeat steps 3 and 4 three more times (up to 12 minutes)
Record your data here (25 points)
Rock type
Initial mass (g)
Mass -3 min
Mass-6 min
Mass-9 min
Mass-12 min
Granite
Basalt
Marble
Lab 1 continued…Create a line graph with 3 lines showing change in mass over time. Your x axis will
have 5 points beginning with initial mass. Use a ruler. No free hand. Scale, labels, legend (key), graph
title, neatness and accuracy ALL count. You’re expected to use the ENTIRE space below. (50 points)
Soils Day 3-Soil texture notes and Power Point
1. What is soil texture?
2. Why is it important?
3. What are the 4 main components of most soils?
4. Define humus.
5. How does humus influence soil nutrient levels and soil moisture?
6. Based on Slide 16--Create a table that compares the three particles that make up texture for
these 8 properties: First with your group predict. Then we’ll discuss. Use the terms, poor, low,
medium, high, good (the words “slow” & “fast” will be used only once)
Property/Behavior
Sand
Silt
Clay
Water holding
Aeration
OM decomposition
Water erosion pot.
Compact-ability
Sealing (ponds)
Nutrient supplying
Pollutant leaching
Soils Lab 2: Texture by Feel Analysis of Soil
Purpose: determine the texture of your three unknown soil samples. See handout. Record your samples
below:
Sample
Length of Ribbon (cm)
Soil Texture
A
B
C
Soils Assessment:
Purpose--Soil is a naturally occurring resource that forms under a wide range of conditions. Soil types
vary greatly based upon the conditions and location of formation. The parent materials, typically rocks
and minerals, also influence the soil type. The kinds of soil present in a location depend on parent
materials, climate, organisms, topography, and time.
Observations on Earth, visits to the Moon by humans, and robotic missions to Mars demonstrate that all
these planetary bodies have soil on their surfaces. This evidence suggests that soil formation may be a
normal part of planetary development.
On Earth, the thin-layer of life sustaining soil supports buildings, catches and stores much of the water
that circulates, and provides a means to produce food, fiber, and forest products. With all of its abilities
to provide humans with a valuable natural resource, soil is very vulnerable and fragile. As such, it can
be destroyed very easily and cannot be replaced once it is destroyed. The formation of soil on Earth
occurs over a long period of time in many climatic and geographic areas. Soil forming factors influence
the type of soil and the rate that it is made.
Materials:
Computer with Internet access (optional)  Reference text books  Colored pencils  Project 2.1.1 Comic
Template  Pencil 
For this project, you will develop a comic strip that depicts parent materials weathering to form soil. Use
your notes from the presentation, The Formation of Soils, as your primary source of information and the
computer and reference texts as additional sources. The comic strip must include each of the five factors
of soil formation. Your comic strip must be at least 15 frames and identify a minimum of four stages of
soil development. Additional parameters for the project are below. Parameters  Depict five factors of
soil formation  Consist of 15 frames  Include captions  Show parent material/soil in four stages of
development
See Comic strip handout—50 points—Once assigned you have exactly 2 class periods to complete!
Next Up
Soil Bulk Density and Compaction
BMP powerpoint-notes
pH
Horizons
Fertilizers
Filtration
Slope
Surveys
Site Index
Web activities (nrcs soil site?)