4.C.1.SoilsareFiltersLesson

7/29/2019 4.C.1.SoilsareFiltersLesson

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Ka Hana Imi Naauao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 1

Objectives: 1) To understand what soil is and why it is important; and 2) to learn basic conceptsin chemistry and physics through experimentation.

Time:10-20

20-45

5-10

15-25

5Total

55+ min

Procedures:1. INTRO LECTURE & POWERPOINT: Explain what soil is and how soils form

(link to rock cycle). Ask students why soil is important (e.g, nutrients toplants, physically & chemically filters our drinking water). Show differenttypes of soil (e.g. clay, sand, topsoil, etc.). Preview vocabulary. View theSoils PowerPoint, Part 1. (See Teachers Notes sections A & B). AnotherSoil PowerPoint you may prefer is an automatic download to your desktop(no webpage will open) at:

www.windward.hawaii.edu/PACES/summerfiles/pwrpnt/Soil.ppt

2. COLLECT & PROFILE SOILS: Read the 1st paragraph of the handout aloudwith the students (see Teachers Notes, section C), then collect soil samplesnearby (or you may use the samples you collected yourself above). Then dothe simple analysis of soil conditions described in the handout, brieflyfollowing up in a later lesson once all materials have settled.

3. DEMO/LAB OR POWERPOINT: SPONGES Use a sponge to illustrate keysoil concepts related to agriculture, water, the environment, and engineering.Students can follow along with the demo using their own sponges, water and

basins. (See Teachers Notes section D &/or the Soil PowerPoint, Part 2.)

4. ACTIVITY #1: LAB & TALKING POINTS Soil is a Filter (by Dr. Dirt.Students will discover that soils physically and chemically filter impurities outof water and the role of soil in having good drinking water. See TeachersNotes section E and students Soil is a Filter handout.

5. SUMMARIZE KEY POINTS. End with the importance of soil in filteringHawaiis drinking water. Preview next lesson: Is Hawaiis drinking watersafe?

Materials: For teacher:Soil samples (sand, topsoil); sponges; colander, sieve &/or screen; coffeefilters; clear large containers for soil collection & analysis

For students:3oz and 5oz paper cups for each group; toothpicks; grape Kool-Ade; Safety:n/a

LESSON: SOILS ARE FILTERS

UNIT 4: Kilohonua & Kalawai (Geology & Hydrology)

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Assessment/Performance Indicators: Informal assessment:Active participation in lecture and

activities.

Formal assessment:none

Points:10 pts for full participation9=B8=C7=D

Exceeds Expectations: Student is able to explain

how soil is linked to rockcycle

Student is able toillustrate key soilconcepts related toagriculture, water, theenvironment, and

engineering Student can articulate

importance of soil infiltering Hawaiis drinkingwater

Meets Expectations: Student can explain at

least two ways soil isimportant

Student candemonstrate how soilis a filter

Student can explainkey points of lesson

Needs Improvement: Student can identify

one way soil isimportant

Student can identifysoil as a filter

Student turns inassignments, but workis not complete

Learning Styles:

Left Brain Right Brain Auditory Visual Kinesthetic/Tactile Spatial

Enrichment/Extension:

Make Edible Soil Profiles: www.chymist.com/earth%20science.pdf(fun but may be messy)

This website has many other soil and science activities to try:www.funsci.com/fun3_en/exper1/exper1.htm

Other Ohia Project Lessons: http://www.mgf-hawaii.com; click on water lessons or go directlyto: http://www.mgf-hawaii.org/PDF/water/Hold_It.pdf

Keywords: agriculture, biochemical cycles, chemical filter, ecosystems, engineering,environment, humus, nutrients, organic matter, rocks, soil sedimentation test, soils

References

Information about soil water from sponges: www.wtamu.edu/%7Ecrobinson/sponge/index.htmlSoil as a filter by Dr. Dirt: www.wtamu.edu/%7Ecrobinson/DrDirt/filter.html Moanalua Gardens Foundation, Cultural and Environmental Education in Hawaii Informationfor two activities: Soil is a Physical Filter (Ohia Project) and water lessons http://www.mgf-hawaii.com EARTH SCIENCE by David A. Katz. Information of the Earths layers

www.chymist.com/earth%20science.pdf


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Teachers Notes for: Unit 4, Lesson Geology & Hydrology

A) Vocabulary Nutrient nourishing substance Compound combination of chemicals

Leachate - a solution or product obtained by leaching or percolation Cation (say KAT-eye-on) positively charged ion Anion (say AN-eye-on) a negatively charged ion

B) Discussion Questions What types of rocks and/or soil do you see at home? Where do you see something different in Hawaii? Where do you see more greenery and what does that tell you? How is a rock like a sponge as a filter? How are rocks in Hawaii different from other places in the word? Similar?

C) Collect & Profile Soil SamplesGet permission to do this at school in the agriculture yard, a garden, the edge ofa field or at a nearby stream or beach. Youll need shovels and buckets.

D) Sponge Demo Discuss images below using sponges in class (alsoavailable in PowerPoint at end of Hawaiian Soils). Retrieved & adapted 5/08/08from: www.wtamu.edu/%7Ecrobinson/sponge/index.html

A household sponge can be used to demonstrate several characteristics of the relationsof soil and water.

"Dry" Soils Infiltration and Runoff Wetting and Saturation

Water Holding Capacity Percolation and Drainage Engineering and BearingCapacity


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COLLECT & PROFILE SOIL SAMPLES

The ground is modified and enriched by theplants growing on it. Making a section of soil(figure 4), you can observe different layers:

a layer rich in organic matter, the humus (O) a layer rich in roots and living organisms (A) a layer less rich in life, but still used by roots

(B), and an inert soil (C).1 - With a shovel, dig a hole of at least 40 cm(15inches) deep in a meadow. Describe thelayers of soil which you see, perhaps take somepictures. 2 - Do the same in other kinds of soil,for example in a wood, or near a river. Makecomparisons and try to explain the differences

you observe.

ANALYSIS OF THE SOIL COMPOSITIONThe soil is composed of many different sizedparticles. With this simple experiment you canseparate the main components of the soil andevaluate their proportions.1 - Go into a field an collect a sample of soil. Putit in a jar of water. Stir it well and let it settle.Observe and describe the different layers ofmaterials.2 - In water, particles settle more quickly thebigger they are. It is possible to use this propertyto determine the amount of each component ofthe soil. Put 3 parts water and 1 part of soil in thecontainer (try 1 cup soil and three cups of waterin a quart jar); shake the container for 5 minutesand let the material set. With reference to thefigure 1, after 40 seconds measure the thicknessof sediment. Call this A; after 30 minutesmeasure again and call this B; after 24 hoursmeasure C. Now, by subtraction, you candetermine the thickness of the main layers: C-B =

layer of clay, B-A = layer of silt, A = layer ofgravel and sand. Using a sieve with 2 mm holes(less than 1/8 inches), you can separate thegravel from the sand and determine their ratio.On the basis of these data, calculate the content(%) of each component of the soil sample.

Retrieved & adapted 5/23/08 from:

www.funsci.com/fun3_en/exper1/exper1_04.gif

Repeat the same experiment with soilcollected in other places (i.e: meadow,

woods, stream bank) or anyplace the soilis different (i.e: muddy, sandy). Describethe composition of each soil and try toexplain the differences. You can alsoevaluate the composition of the soil for apotted plant, and correct it. E.g, if waterdoesn't drain well, would more sandhelp? If it needs to hold water longerwould clay or organic matter be helpful?


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Activity #1 - Soil is a Filter (by Dr. Dirt)Retrieved & adapted 5/08/08 from:http://www.wtamu.edu/%7Ecrobinson/DrDirt/filter.html

This series of film clips demonstrates the process and results with two soils: a sandand a clay loam. A clay loam is a fine-textured soil. This example also has about 2%

soil organic matter, which makes the soil dark. Brief film clips are available inQuicktime (QT) or RealPlayer (RP) formats. If neither is available on your computer,click the name above to download them.

Materials and Preparation: 3 oz and 5 oz solo cups (Put 3-5 holes in bottom of 5 oz cup. A toothpick works

well.). The 5 oz cup fits inside 3 oz cup, then put the toothpick inside, betweenthe cups.

grape Kool-ade other colors, e.g., green, red, orange, yellow food coloring "floaties" clean sand

fine topsoilNote: The results are more dramatic if the sand has been sieved to remove thesmaller particles. If you do not have soil sieves, you can use a colander or aspaghetti strainer if the holes are small. Another material that makes a good sieve isscreening. A fine screen attached to a small frame makes an excellent sieve.

Introduction: Ask students What is a filter? (Show a coffee filter or a tea bag to aid discussion.)Can soil be a filter?Do all soils work the same?

Hypothesis: Briefly explain Have students make hypothesis and complete table in Soil is a Filter handout.What will happen to the dirty water "floaties"?What color will come out the bottom?

Methods:We will use two soils, a sand by itself, and a sand with topsoil on top. (The sandkeeps the topsoil in the cup.) Sand has large, rough particles. Topsoil is a mixtureof particle sizes.

SAND:A. Take a 5 oz cup with holes in the bottom and fill it half full of sand.B. Put it inside the 3 oz cup. Put a toothpick between the cups so that air can escape

from the bottom cup.C. Pour some of the dirty water into the top cup

Ask Students What happens to the things floating in the water?

A. Pour out the water in the bottom cup.B. Pour some of the grape Kool-aid into the top cup.


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Name: Class:Lab: Soil is a Filter

1.HYPOTHESIS Dirty water Grape Kool-adeSand Hypothesis (guess)

Topsoil Hypothesis (guess)

2.EXPERIMENT Dirty water Grape Kool-adeSand Observations

Topsoil Observations

3.CONCLUSIONS

Physics

Chemistry

Applications ofthis knowledgeto your lifeApplication ofthis knowledgeto thecommunity


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Talking Points Activity: Soil is a Filter

Cut out the following information on small paper slips and distribute among the class, askingeach to state what their paper says and, if they can, how it relates to this lab.

1. Physics (how things work) is the reason the water flows faster through the sand thanthrough the clay loam.

2. Chemistry (how things are made) is the reason the leachates are different colors.

3. The clay particles have a negative charge.

4. The organic matter has both negative and positive charges.

5. The organic dyes in grape drink have opposite charges: Blue is positive, red is negative.

6. Since opposites attract, the blue dye is attracted to the clay particles, while the red dyeis allowed to pass through the soil.

7. Nitrates (and other soil chemical compounds) are anions (have negative charges), andso move through the soil with water.

8. Other compounds, like ammonium and potassium, are cations (have positive charges),and so tend to be held in the soil.

9. Blue and red make purple.

10. The smallest soil particles (clays) have a negative charge.

11. Opposite charges attract and like charges repel.

12. In all cases the red dye passes through the soil, so it must have a like charge as the soil(negative).

13. The blue dye is retained in three of the soils, so it must have an opposite charge(positive).

14. In this case, the soil with the purple leachate had very good structure, and the Kool-ade

probably went through the pores and did not mix much with the soil.

4.C.1.SoilsareFiltersLesson

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