Title: Soil Contamination
Subject:
Science
Grade: 2, 4, 5, 6, 7, 10
Topics(s)/ Concept(s):
experimental design, experiment, variables, investigation
Objectives: The purpose of this experiment is to have students manipulate a single variable in an
investigation.
Time to Complete: 45 minutes active time, 4 weeks observation
Materials: Egg Cartons, Potting Soil, 1 teaspoon of grass seed, Epson Salts, Used Coffee grounds, water
Activity: see “Procedure” below
Assessment: formative assessment through discussion with student during activity (do they understand what
a variable is? Can they collect and record data?)
Extended Activity: see “Taking It Further” below
Cross-Curricular/Related Lessons:
see “Taking It Further” below
Standards: Investigation and Experimentation (Grades 2-8): Scientific progress is made by asking
meaningful questions and conducting careful investigations. Investigation & Experimentation - Grades 9 To 12
Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for
understanding this concept and addressing the content in the other four strands, students should develop their
own questions and perform investigations. Students will: D. Formulate explanations by using logic and
evidence.
Dehesa Charter School
Experiment of the Month
Soil Contamination
Will altering the soil a plant is grown in affect the growth of that plant?
Introduction: Discuss how the environment may affect how living things develop. Include plants and humans
in this discussion. Explain that outside influences or contaminants may have a dramatic impact on how people
and plants develop. Children and plants that are undernourished may not develop properly. The purpose of this
experiment is to have students manipulate a single variable for multiple subjects in an investigation. This
experiment is most appropriate for grades 3-10.
Materials: Egg Cartons, Potting Soil, 1 teaspoon of grass seed, Epson Salts, Used Coffee grounds, water
**note on seeds: you may choose to use grass seed from a local nursery. Alternatively, you can use wheat
berries (available at health food stores) that have been soaked for 8-12 hours.
Procedure:
1. Most plants need specific chemicals that are absorbed through their root systems. Think about what
happens if plants got everything they needed from the soil. What do you think would happen if plants
were in soil that was polluted (contained a contaminant)?
Parents: This would be a good time to discuss pollution, water run off et cetera. Ask your
children to brainstorm possible sources of contamination. (Improperly disposed paint cans, Oil
and Gas spills, Poison to get rid of unwanted animals, Weed Killer et cetera)
The single variable for this experiment will be the “Additive” for each plant. This can be
expanded for older students by testing several different amounts of additive (i.e. ¼ tsp, ½ tsp, 1
tsp of Epsom Salt, and so on ).
2. Cut the egg cartons so that they form individual "pots" for the seeds.
3. Place a minimal amount of potting soil in each of the pots.
4. Sprinkle approximately ¼ of a teaspoon of seed into each pot. The specific amount of seed and soil in
each pot is not critical what is most important is that each pot has the same amount of soil and seed.
5. Mark the pots "1, 2 and 3".
6. Pot 1 is the "control" pot. This pot will get seeds, soil, water and sunlight.
7. Pot 2 is the "coffee pot". Sprinkle the soil of pot 2 with used coffee grounds.
8. Pot 3 is the "salt pot". Mix water and Epsom salt and water the plant with it.
9. You may want to set up 3-5 pots each with treatment 1,2, 3 so you can replicate your data.
10. Place the plants in the windowsill. Record when you see the first seeds germinate. Measure your grass
sprouts with a ruler. Record all of your data and observations. Set a time for working with the plants
every day. Explain the importance of each plant getting the same amount of sunlight and water each day.
Everything for each plant should be the same, with the exception of the methods used as outside
influences per this experiment.
11. Tend to the plants as planned. At the end of each week, compare the experimental plants with the control
plant to see the impact of environmental influences on the plants. Discuss which plants are doing the
best. Which are doing the worst? Why?
Taking it Further:
1. Investigate different types of soils. (Sand, potting soil and dirt from your back yard)
2. Try different varieties of grass. Are some grasses able to grow despite soil contamination?
3. Research Drought Tolerant grasses. Repeat the experiment, but give each subject a different amount of
water. Try to determine the least amount of water you can use to get the grass to grow.
Data Sheet
Record your observations of each. Use quantitative measurements (numbers) to describe the growth of
each subject.
List the dates
that you
measure in
this column
You should
measure at
least three
times a week.
Control
Date of
Germination________
Coffee Grounds
Date of
Germination_________
Epsom Salt
Date of
Germination__________
In this column list the height of each plant from the soil to the tip of the tallest grass blade.
Data Sheet
Qualitative Observation.
On this sheet make notes about what you observed. Observations might include grass color, density, blade
thickness et cetera. You may also want to include photographs you took of this experiment.
Control
__________________________________________________________________________________________
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Coffee Grounds
__________________________________________________________________________________________
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Epsom Salt
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
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