Lesson 4 Why Are Soils and Rocks Important?

STUDENT SKILLS: predicting, observing, inferring, communicating, comparing, measuring

Lesson 4: Why Are Soils and Rocks Important?

Activity 4A:

What Type of Soils Grow Plants the Best? SUMMARY: Students will make predictions and observe which soils are best for growing plants.

KIT MATERIALS: Pictures of plants Sand, clay, humus Small paper cups Bean seeds Rulers Plastic spoons Spray bottle

TEACHER TO PROVIDE: Copies of MySci™ Journal pages Water

ENGAGE Ask the students what grows in soil. Show the students the pictures of various plants and ask where they think each of the plants grow. Ask the students if they think all of the plants grow in the same place. A similarity all the plants share is that they all grow in soil. Ask the students what would happen to a plant if it does not have the best soil in which to grow. Show the picture of the unhealthy plant and discuss with students.

NOTE TO TEACHER: You may want to include several control groups (i.e. equal parts of all three soil components, all clay, all sand, all humus, etc.).

EXPLORE Divide the class into groups of four. Tell the students that they will need to use what they have learned to decide which type of soil mixture is best for plants to grow. Have the students decide what type of mixture they would like to try. They can use all sand, all clay, all humus or a mixture of each. They need to write down their mixture in their MySci™ Journal. Give each group a small paper cup, a tablespoon, and a pencil. When each group has filled their cups with the amounts of sand, clay, or humus they choose, tell them write what their mixture is on the outside of their cup (for example, 3 tablespoons sand, 1 tablespoon clay). They should stir the contents of each cup with the pencil so that the soil mixtures are wellmixed. Distribute some bean seeds to each of the groups. Have the students use the pencil to poke two holes in the soil mixture in their cup. Into each hole they are to drop two bean seeds and push some soil over them. When all the seeds have been planted in each cup, use the spray

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Lesson 4: Why Are Soils and Rocks Important?

bottle to place water into each cup. Every day examine the cups to see if the plants have broken through the surface. Once they do, use a ruler to measure their growth. Hold the ruler next to the seedling and have the students record the data in their MySci™ Journals.

EXPLAIN When the activity has begun to show some results, ask the children to interpret their charts by responding to questions like, “Did the seeds in each of the cups sprout at the same time?” “In which of the cups did the seed seem to grow the best?” “Did every group’s plants do the same thing?” (To determine the answer to this question, it might be helpful to cut the charts in horizontal strips and put all the #1’s together and all the #2”s, etc. In this way students could concentrate on one at a time.) Ask the students to consider a desert. How would they describe the soil of a desert? What kinds of plants live in the desert? Compared to a forest, do deserts have many kinds of plants? Why might that be, based on what they’ve seen in this activity? Beside the fact that sand does not absorb water very well, it also doesn’t contain many of the nutrients that contribute to healthy plant growth. Clay does not absorb water well either but it also does not allow it to drain through and may actually cause it to stand or pool—a condition that does not support plant growth. Too much water can be as bad for a plant as too little. Humus on the other hand contains many nutrients and absorbs water.

ELABORATE Use some of the soil samples from around the school or encourage students to bring some from home. Ask them to predict which soils will be better for the growth of plants and then, proceed as in the activity above. Since humus is the most nutrient rich part of soil, their choices should favor the samples that are darker in color and smell earthier. Teach the students the poem, “Little Brown Seeds.” Little Brown Seeds By Author Unknown Little brown seeds so small and round Are sleeping quietly underground. Down came the raindrops Sprinkle, sprinkle, sprinkle. Out comes the rainbow Twinkle, twinkle, twinkle. Little Brown seeds way down below Up through the earth they grow, grow, grow. Little green leaves come one by one They hold up their heads and look at the sun. TM

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Lesson 4: Why Are Soils and Rocks Important?

Print out copies of the poem on the page 45 for the students to have. Cut the pages into strips and have the students put the strips into sequential order. You can have the students read the poem aloud and put actions to the words.

EVALUATE Have students compare their plant results with other groups. Decide which soil mixtures worked the best. Discuss with the students why they think they got the results they did. Have them record their results in their MySci™ Journal.

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Lesson 4: Why Are Soils and Rocks Important?

Little brown seeds so small and round Are sleeping quietly under ground.

They hold up their heads And look at the sun.

Little green leaves come One by one.

Down come the raindrops Sprinkle, sprinkle, sprinkle.

Out comes the rainbow, Twinkle, twinkle, twinkle.

Little Brown seeds way down below Up through the earth they grow, grow, grow.

Little green leaves come one by one They hold up their heads and look at the sun.

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Lesson 4: Why Are Soils and Rocks Important?

Activity 4B:

How Are Rocks Used? SUMMARY: Students will recognize some building stones and describe how they are used.

KIT MATERIALS: Pictures of rocks and minerals Big book: Rocks

TEACHER TO PROVIDE: Copies of MySci™ Journal pages Copies of MySci™ Activity Sheet 4B

ENGAGE Distribute paper and pencils to the students. Take the students outside on the school grounds. Explain to them that they will write down all the places they see rocks being used. Remind them that they are not going on a rock hunt to gather rocks, but are looking for creative ways people use rocks. When they return from their walk, have the students draw the places they saw rocks being used in their MySci™ Journal.

EXPLORE Show students the different type of rocks and minerals from the pictures. Have them return to their seats to draw a picture in their MySci™ Journal of what they think one of the rocks could be used for.

EXPLAIN Ask the students if they can name a way that people use rocks. Ask them if anyone lives in a brick or stone house. See if they remember from their walk what other type of things are made from rocks. (e.g. buildings, roads, sidewalks, statues, etc.) Explain that people use rocks for a variety of different things such as jewelry, glass, lawn decorations, etc.

ELABORATE Read the Rock big book to the students and discuss. Pay close attention to pages 12–17 which explain how rocks are used. NOTE TO TEACHER: The big book can serve as a review of the Earth unit.

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Lesson 4: Why Are Soils and Rocks Important?

EVALUATE Have students complete MySci™ Activity Sheet 4B.

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Activity Sheet 4B Name

Soils are used for

Rocks and minerals are used for

Date

MySci™ Journal Drawing Page Name

Date

MySci™ Journal Graph Page Name

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MySci™ Journal Writing and Drawing Page Name

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MySci™ Journal Writing Page Name

Date