Download Soils Part One: What`s in soil

Soils Part One: What’s in soil?
Students will discuss:
 The four components of soil
 Relative amounts of soil components, including air and water
Materials
 small plastic bag of loose, crushed, soil for each pair of students
 newspaper
 hand lenses
 tissue paper or thin paper towel ( cheap school brown paper towels do not work)
 overhead projector
 water
 2-cup containers: plastic or paper cups, soup cans or beakers.
 1 cup measuring cups
Procedure
 Pass out one bagged soil sample to each pair of students and have them pour it onto
newspaper
 Instruct the students to investigate their soil samples with the provided hand lenses,
writing down what they find
 Before asking the students to share what they found, realte to them the four components
of soil: AIR, MOISTURE, MINERAL MATTER(small stones, sand etc.) and ORGANIC
MATTER(formerly living things like plant and animal matter)
 Invite students to relate what they found, and into which category they believe it fits
 Tell the students that they will be doing an experiment regarding the amount of moisture
contained in soil.
 Place on a lit overhead a dry and wet paper towel, these will be our “controls”- a basis for
comparison
 Next, place several of the soil samples on paper towels and let sit for several minutes
 Dump of the soil from each paper towel, and place each onto a lit overhead projector
 Ask the students to rank the soil samples by moisture content. Is there a relationship
between soil components and moisture content? (There should be-the higher the soil’s
organic matter, the higher its moisture)
 Have students divide into pairs again to investigate soil air content
 Provide each pair with 1 cup of dry soil in a 2 cup measuring cup.
 Have each group slowly pour 1 cup of water into the soil sample. (Notice the air bubbles
rising to the surface?)
 Have the students pour off the water that remains on top of the mud mixture, and subtract
its approximate amount from 1 cup. This number is the relative amount of air found in
this soil sample
 What are the four components of soil? (Organic matter. Mineral matter, air, water)
o Which are the most variable, why? (water and air, precipitation forces out air,
replaces it with water
o Why do worms move to the surface when it rains? ( to breathe)