E. T. A LOCAL WAY OF LEARNING
Title: SOIL STUDIES
Author: Jane Ducey
Eulalie Rivera Elementary School
Grade Level: 5-8
1. The Sun 1. Social Studies
2. Ecosystems 2. Science
3. Carrying Capacity 3. Language Arts
4. Clean Water
6. Natural Resources
Student shall examine with a hand lens soil samples from a variety of places on
the campus; student shall make soil from rock pieces and organic matter, using
vinegar, a comparable weak acid, as a substitute for carbonic acid which occurs
naturally; student shall compost organic matter, in order to better understand
soil as a valuable and limited natural resource.
How do soils form? Weathering of the parent rock, by forces of nature such as
wind and water, is the very slow process by which soils are formed. Wind blows
small pieces of rock (sand) against larger ones and wears away the larger rock.
Soils also are formed as rocks are rolled along by streams. The rocks have been
rubbed together until the rough particles are knocked off. Changes in the
temperature of rocks cause expansion and contraction and break off small parts
of rock. Plants taking root and growing help break down the parent material by
the action of root growth.
When plants die and decompose, they add organic matter. Carbon dioxide is one
important end product in the decay of organic material. CO2 combines with the
water in the soil to form a weak acid whose dissolving effect is several times
that of pure water in breaking down rock.
Rock particles become soil when living micro-organisms, air, moisture, and
organic matter (decomposed plant and animal materials) are added. The many
different types of soil in the world are the result of different combinations
of the five major factors of soil formation: They are time, topography, parent
rock, climate and living organisms, including plants. Each kind of soil is made
up of different quantities of minerals and organic materials that determine its
physical and chemical properties. In turn this determines how the soil will
respond to different uses and treatment.
Check area size used
3 inch square
6 inch square
12 inch square
CLASSIFY ITEMS TALLY NUMBER FOUND HERE (/~iL) TOTAL
Pieces of limestone or sandstone Vinegar
Flame or hot plate Fallen leaves
Small jar with tight lid Plastic bag
From the activities suggested below select all or several as time permits in
order to insure student understanding of soil as a natural resource.
1. Making soil is a slow process. Using two pieces of sandstone or limestone,
rub them together. Note how long it takes to rub off fine particles.
2. Heat a small piece of limestone and drop it quickly into a pan of ice water.
What happens to the limestone when it contracts after expansion?
3. Fill a small glass jar to the brim with water, cap it tightly, and place it
in a plastic bag and put it in the freezer. Note what happens to the jar.
4. Put a few pieces of limestone in a pan with vinegar and heat it on a hot
plate. Note the bubbles that form on the piece of stone (CO2). How long does it
take for the limestone to break up?
5. Find a piece of decayed branch in the forest and put it in a container in
the classroom. Note the dust that continues to come from the log or branch
over a period of time. What is causing this to happen? Dig into the wood
where you find small holes. Can you find any animals responsible for the
6. In a hedge row or forest area where there is leaf litter dig up a square
foot of soil, about four inches deep. Examine it handful at a time. Record
and classify--animal, vegetable or mineral. Use the attached worksheet for
7. Make a compost pile or bin. Put leaves, grass clippings, fruit skins and
any other plant discarded material. Turn it over with a tool and see what
animal life is busy in the compost. It will be usable in a few weeks.
Use a soil testing kit or contact the Agricultural Extension Service and ask to
have the soil in your yard tested.
U.S. Department of Agriculture
Soil Conservation Service