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THE DIRT ON WORMS!
by Karen Byers

GRADE: 4

TIME ALLOTMENT: 3 one hour lessons and 1 two week investigation

SUBJECT MATTER: Life Science, Ecology, Earthworms

OVERVIEW
An ecosystem consists of a community of interacting organisms and the physical environment in which they live. It is the combination and interaction of plants, animals, minerals, and people. Bill Moyers Reports Earth on Edge presents several different ecosystems that are in danger because man has interfered with the balance of organisms. The Grassland Ecosystem is one of 6 large ecosystems on which life on Earth most heavily depends. We’ll view the segment about the Great Plains grasslands and one man’s effort to help it return to a more balanced state. We’ll make a connection from the large picture to a smaller, more familiar one. We’ll examine earthworms. Worms are a crucial part of the soil ecosystem, playing an important role in bringing plant material into the soil, building soil structure, and making plant essential minerals available. Students will observe the behavior of worms in the classroom. Through a number of hands-on activities the students will make predictions, observe, collect and record data. Guest lecturers will help them with worm anatomy and physiology and with soil and water conservation. We’ll seek more information to our questions by investigating several soil and worm websites. Finally, the students will write a letter to The President which will defend earthworms by explaining their value to the United States.

LEARNING OBJECTIVES

Students will be able to:

• Identify human and non-human factors that might change an ecosystem
• Recognize the importance of the interrelationships among plants, animals, minerals, and people in an ecosystem.
• Appreciate the life of earthworms and gain a better understanding about other living things with which we share this Earth.
• Ask questions, make predictions and find answers through the video, discussions, hand-on activities and the Internet.
• Make observations, collect and record data. Identify some careers that are interested in earthworms.
• Communicate their understandings of the importance of a balanced ecosystem of soil and earthworms by writing a letter defending worms.

MEDIA COMPONENTS

Video
Bill Moyers Reports Earth on Edge.

Books
A kid’s handbook for keeping the earth healthy and green I can save the earth, Anita Holmes, Julian Messner, NY 1993.

Worms are a Class Act Educational Guide in association with The-Can-O- Worms stacking worm bins. Viscor Distribution Inc., 12165 Cherrywood Drive, Maple Ridge, BC V2X0B7

Canada Critters, AIMS Life Science Activities for Grades K-6. by Maureen Allen, Debby Deal, Gale Kahn, Suzanne Scheidt, Vincent Sipkovich

Riddles: What is a worm’s favorite punishment? Being grounded. Why couldn’t Batman go fishing? Because Robin ate all the worms. What kind of exercise is good for robins before breakfast? Worm-ups. What did the fish say to the bait? Squirm worm.

WEB SITES

The companion website for Bill Moyers Reports Earth on Edge.
http://www.pbs.org/earthonedge/science/index.html

How much soil is there? This site uses an apple as a tool for seeing what percentage of the Earth is covered by soil.
http://ltpwww.gsfc.nasa.gov/globe
/app_soil/hmsoil.htm

A Soil Science Education Program from NASA
http://ltpwww.gsfc.nasa.gov/globe/index.htm

This site has a movie of the birth of a baby worm and a brief description of the worm’s anatomy and physiology.
http://yucky.kids.discovery.com/noflash
/worm/pg000102.html

This site looks at the benefits of having worms in our environment. There is a link to instructions about how to build a worm bin.
http://yucky.kids.discovery.com/noflash
/worm/pg000104.html

This site uses an interview with a worm to teach some important facts. http://yucky.kids.discovery.com/noflash
/worm/pg000216.html

The Pacific Dust Express. A website that looks at the 2001 dust cloud composed of soil from China as it drifts around the world. http://science.nasa.gov/headlines/y2001
/ast17may_1.htm?list14558

A Dust Bowl Site with photos and a brief description. http://www.usd.edu/anth/epa/dust.html

A companion site for the PBS show, “The American Experience: Surviving the Dust Bowl.” http://www.pbs.org/wgbh/pages/amex/dustbowl

A Science Inquiry Lesson about worms with answers to many questions you might ask. http://www.exploratorium.edu/IFI/resources
/lifescienceinquiry/doesawormhave.html

This NOVA site for teachers has the instructions for making a worm bin. http://www.pbs.org/wgbh/
nova/teachersguide/odyssey/odyssey_sp3.html

MATERIALS

• large US map
• “What Am I” sheet, (1 per student)
• Worm observation question sheet (1 per student)
• Diagram of a worm (1 per student)
• Student Science Journals
• Large chart for class questions and ideas
• Earthworms Spray bottle to keep worms moist
• Moist paper towels
• Pencils
• Magnifying lenses
• 4 glass jars (quart size)
• Labels
• Sand or gravel (about 4 cups)
• Coffee grounds (1-2 cups)
• Brown sugar (1-2 cups)
• 5 sheets of black construction paper
• Potting soil
• Chopped vegetables, (about 3 cups of cucumbers, carrots, etc)
• Fruit scraps (about 2 cups)
• Grass clippings (about 3 cups)
• Dry Leaves (about 50)

STANDARDS

From the National Science Education Standards, Content Standards: K-4 http://www.nap.edu/readingroom
/books/nses/html/6c.html

• Content Standard A, Science as Inquiry. As a result of activities in grades K-4, all students should develop: Abilities necessary to do scientific inquiry Understanding about scientific inquiry.
  
  
• Content Standard C: Life Science. As a result of activities in grades K-4, all students should develop understanding of: The characteristics of organisms Life cycles of organisms Organisms and environments.
  
  
• Content Standard E, Science and Technology. As a result of activities in grades K-4, all students should develop: Understanding about science and technology.
  
  
• Content Standard F: Science in Personal and Social Perspectives. As a result of activities in grades K-4, all students should develop understanding of: Types of resources Changes in environments.

PREP FOR TEACHER

• Preview the video; know where your pause points are located.
• Obtain the worms. Earthworms, also called nightcrawlers, may be dug up from a garden, field, or compost pile. You also can purchase them in a pet or bait shop.
• Do the activities ahead of time so you can anticipate any problems or questions that may arise.
• Copy the worksheets.
• Assemble all materials.
• Bookmark the lesson websites.
• Invite the guest speaker.
• Display a US map.
• Preview the websites. http://www.exploratorium.edu/IFI/resources
  /lifescienceinquiry/doesawormhave.html for answers to some questions that you might want to know.

PREVIEWING ACTIVITIES

Introduce the video. The students will see a part of America that is very important to us all. It is the Great Plains. Most of our food and much of the world’s food is grown there.

As the earth’s population grows, more food will be needed. Will we be able to meet the need? There might be a big problem that will make growing more food difficult.

We’ll discover the problem and hear one man’s solution.

EXTENSIONS

Science:
There are many follow up ideas for science lessons: Food chains, food webs, producers, consumers, decomposers, habitats, ecosystems, renewable and non-renewable resources, anatomy and physiology of the worm.

Math:
If one worm makes 6 inches of topsoil every 20 years, how deep will the soil be in 80 years if it isn’t eroded, blown, or scraped away?

Social Studies:
Study and look at pictures of “The Dust Bowl” era.

Language Arts: Make “W” tongue twisters. Use only “W” words. For example: Witty Wanda weaves words, or Waldo worm whispers weather.

Creative Writing:
Worm autobiography

Art: Draw a picture of what worms do under the surface of the soil.

PE: Stage a Worm Olympics which uses some worm behaviors such as; long stretch, rapid retraction, compost shifting, burrow, soil mixing, burrow, wriggle, react to light.) Make up your own events)

Community Connections: Assemble and maintain a worm bin for the school or a community garden.

VIEWING ACTIVITIES

Define these words as they appear in the video: prairie, herbicide, pesticide, fertilizer, mulch, erosion, subsidy, and yield per acre.

The FOCUS FOR MEDIA INTERACTIONS will be the discussions and clarifications during the pauses. The title of the show is “Bill Moyers Report Earth on Edge.”

START at the introduction and play until you see Africa on a map and hear, “We begin at home.” PAUSE. Discuss how the activities of man affect the earth. Explain that they will see one man-made dilemma; The US is losing valuable topsoil.

PLAY through the early history of the plains then PAUSE. Review that the Great Plains was the best farmland in the world when the pioneers arrived. Review some of the crops shown: grains, sorghum, soybeans, milo, corn. PLAY through the scenes about the Dust Bowl. PAUSE when Moyers says, ”In fact the land didn’t ever completely recover.” Discuss the causes of the Dust Bowl. (massive plowing of the native plants)

PLAY until Moyers says, “This is the quiet unseen crisis of the land here.” PAUSE and review the facts. Every acre loses 7 tons of soil a year. Since the first pioneers settled there, the area has lost 1/3 of its topsoil and ˝ of its nutrients. Make a prediction, “Can anything be done to stop and maybe even reverse this decline?” Ask the students to listen for the changes the farmer has made to stop the problem.

PLAY until after they hear about the excessive use of chemicals. PAUSE. Ask what they heard. No-till farming was defined. It saves time and energy. It creates clods that help control weeds. The stalks act as mulch. Ask how advertising affects farmers? Does it make them want to the products mentioned?

PLAY through the discussion about subsidies. PAUSE and explain subsidies. PLAY through the discussion about water quality. PAUSE. Look at the map again. Point out the river drainage system of the mid-west and discuss the affects of all the soil and chemicals to the water and the Gulf of Mexico. PLAY until the end of the segment on the Great Plains. STOP. Summarize.

Discuss the benefits of prairie grass. It breaks the wind. It stops dust. It helps to clean water. It provides cover, nesting and food for wildlife. They saw a few simple changes made by one farmer that could help to solve the problem.. Do they think those changes could make a difference? How would that happen?

Emphasize that it will take everyone working toward the goal to make it happen. Finally, they saw that when you lose one item in an ecosystem, you disturb the diversity balance, and may lose many other members of the community. Ask if this problem affect the students? Are we members of the earth’s ecosystems?

POST VIEWING ACTIVITIES

CULMINATING ACTIVITY
Introduce the animal. “Read aloud from the What Am I sheet” before you tell them that the next lesson is about earthworms. Tell them to listen carefully. They might be able to figure out what they’ll be doing next in their exploration of the interdependence of Earth’s systems.

Step 1. Set up 5 worm jars. (10 min) Divide the class so each group has one jar. We will set up 2 demonstration jars and 3 jars for regular worms. All 5 jars will be set up exactly the same. (Why?) (We’re changing only one variable.)

Set up: Rinse the jars well. Do not use soap. (Why?). Put into each jar: 10 cm of dry potting soil, and 2-3 cm of chopped vegetable and fruit scraps. Evenly mix both together. Add ˝ cup of grass clippings and top with 10 leaves. Gently place 3 worms into one of the jars. No worms will be in the other demo jar. Label them. In the other 3 jars add: a thin layer composed of a mixture of coffee grounds and brown sugar and put 10 leaves.

Place 4 worms into each of the jars and label. These jars are reserve worms. Spray with water until the jars are moist. Worms need to stay moist because they breathe through their skin. Our lungs must also stay moist for us to breathe. Worms have special glands that secrete mucous to keep their body moist. Make a sleeve for black construction paper that loosely fits around the jars. We will be observing the 2 demo jars for 2 weeks.

In your journal write the date, the time, the title of this investigation, the materials used and the procedure for making the jars. (Model this on the board.) When this is done each student will write a prediction about what will happen in the 2 jars or what they will look like in 2 weeks. This is their hypothesis. Daily they will record the date, the time and their observations. At the end of two weeks they will write a conclusion. Worm observations. (20-30 min) For this section you may collect your own worms or use the reserve worms.

Step 2. Divide the class into groups of 3 or 4. Each group will gather all materials except the worms. (hand lenses, paper towels, spray bottles, pencil, worm observation question sheet) We will make some predictions, observe some physical attributes of the worms, and record our thoughts and observations in our journals. Read the worm question sheet. Make your predictions in your journal before you get your worm. Rinse 2 worms per group in water that has been standing a few hours and place them on the wet paper towels. Treat your worms with care and respect. We will not be cutting open any worms. Observe your worm so you can record results and make conclusions about your predictions in your journal. Complete the rest of the sheet by writing your responses in your journal. Clean up.

Step 3. Invite a zoologist who can prepare a dissection and explain the internal anatomy and physiology of earthworms.

Step 4. As a whole class exercise, visit these websites and point out what the students can find there.

a. This site uses an apple as a tool for seeing what percentage of the Earth is covered with soil. http://ltpwww.gsfc.nasa.gov/globe /app_soil/hmsoil.htm

b. This site has photos of the Dust Bowl. http://www.usd.edu/anth/epa/dust.html

c. This site has a movie of the birth of a baby worm and a brief description of the worm’s anatomy and physiology. http://yucky.kids.discovery.com/noflash/worm/pg000102.html

d. An interview with a worm can be found at: http://yucky.kids.discovery.com/noflash/worm/pg000216.html.

Make one copy for every 2 students. Have each take a role and read the interview together. You may decide to look at other websites or allow your students time for independent exploration of the sites. The website about the China dust cloud is quite a current story.

For additional lesson plans and ideas relating to this topic and many others try TeacherSource at PBS Online! You will find activities, lesson plans, teacher guides and links to other great educational web sites! Search the database by keyword, grade level or subject area! Mathline and Scienceline are also great resources for teachers seeking teaching tips, lesson plans, assessment methods, professional development, and much more!