Objectives
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Students will describe: why a certain ratio of organic matter in the soil can
help determine a soil layers' permeability; why local farmers do or do not want
soil permeability
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Standards Addressed
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Minnesota Grad Standards: Middle Level: Earth & Space Systems: Structure of the Earth System: Soils |
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Each group needs:
1) a measuring cup,
2) potting soil,
3) clean sandbox sand,
4)
3 same-size cans with the lids/ends removed,
5) cheesecloth,
6) scissors,
7)
masking tape,
8) water,
9) 3 clear jars,
10) clock with second hand
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Time Requirement
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Prep: student can collect materials 3, 4 & 9 - teacher: 30 minutes
Activity: One 50-minute class period |
Procedure/ Outline
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1. This activity is used as a demo or quick activity during a soils discussion (Assemble materials for each group before so disposal is fast and easy.)
2. Discuss soil permeability and its ability to hold water based on permeability and the ratio of organic materials in the soil.
3. Using needed supplies, cover each jar opening with cheesecloth and secure, cover one end of each can and secure the cheesecloth (use double later of cheesecloth on each can.)
4. Cheesecloth-end down, fill the first can 1/2 full with potting soil; the second 1/2 full with sand, and the third 1/4 full with potting soil and 1/4 with sand (combined before filling can). Pack the soils tightly and place each can over a jar.
5. Add 1/2 cup water to each can and a) see which can drips water first; b) see how much water drains into each jar during a specified time frame.
6. Explain the results and why a greater ratio of organic soil holds water better. (Is this MORE or LESS permeable? Why or Why not?)
7. Discuss area farmer's needs for soil permeability - what do we need and why? (goes both ways - good discussion topic!)
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Modifications /Adaptions/ Extensions
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How can different types of soil be used to filter water? (This makes a fun
contest, you can use the same materials and other simple absorbent items, add
materials to the water for increased turbidity). Measure rates of permeability
and volumes of water collected in certain time frames (Math 1) |
Assessment
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The results of this activity or a simple set-up of the activity can be used as a
question base for a quiz or lab test
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Other Comments
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Messy, but fun and easy to demonstrate permeability |
