A Dirty Job
Ages 4 and up (two 60 minute sessions)
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Objectives:
- To show the water holding capacities of different garden soils and learn the affects those capacities can have on plant growth.
- To gain some understanding of soils and how it maintains plant life.
- Can be used with section 5.2 to learn about toads.
Materials:
- Source of Heavy Clay soil (clay can be bought in a craft store and used if clay soil isn’t available)
- Three, gallon size, zip lock bags filled with different soils: One with sandy loam, one with sand and one with clay
- Dry grass clippings
- 5 gallon bucket
- 3 Clear plastic cups or soda bottles
- Sticks and stuff for decorating
- Water
- Paper towels
- Several plastic dish pans; one for every two children
Set up:
Dig up clay from the ground and place it in a 5 gallon bucket. Add water to smooth it out and mix it up. Remove any debris and life forms like rocks, sticks and worms.
Find two other kinds of soil, preferably sandy loam and sand. Put some of each in the zip lock bags. Put holes in the bottom of the plastic containers.
Part One:
Encourage the children to explore the differences in the soils. Talk about water holding capacities of different soils. Put the three different kinds of soil in the clear paper cups and put them side by side on paper towels. Talk to the children about how fast or slow water goes through soil. Talk about how water mixes or dissolves nutrients in soil. Explain how that nutrient rich water is taken up by plants. Use the stop watch to time a few cups of water draining through the different soils in the plastic cups. If you couldn’t get a stop watch, or for more excitement, have the children count and record what number they got to before the water came out the bottom each cup. Talk about which kind of soil might be best or bad for plants and why.
Part Two:
Introduce the idea of using the clay soil to create adobe and introduce what adobe means and what it is used for. Make toad houses or other garden art out of the adobe by passing out dish pans to groups of two, dividing the clay up among the children and encourage them to get their hands dirty. Amend the clay with the grass clippings to provide added strength. A ratio of 2:1 clay to clippings works well. Divide the amended clay up evenly among the children. Have fun creating and constructing. Place the creations in the sunshine to dry. When they are completely dry, have your little gardeners choose a special place for their masterpieces to reside for the summer.
Questions:
What is dirt made of?
How do plants get the nutrients from soil?
Why does water move so fast through sand?
What does transpiration mean?
Where do the nutrients in the soil come from?
