Dredging for Decomposers
Grade Levels: 1st – 3rd
Description:
Students will experience the process of decomposition, from understanding that only organic
objects decompose to collecting organisms that live in the compost bins at GBBG. The soil
components silt, sand, and clay will also be discussed and viewed.
Objectives:
Upon completion of this lesson, students will be able to
• Explain the process of decomposition
• List several organisms that live in the soil and aid in decomposition
• Compare items that can decompose to items that can’t decompose
• Identify that soil of made of different components: silt, sand, and clay
1 2600 Larsen Road • Green Bay, WI 54303 • 920‐490‐9457 • www.gbbg.org
Dredging for Decomposers Pre‐Visit Activities Please use the following materials as an aid to help prepare your students for their visit to Green
Bay Botanical Garden. The vocabulary list consists of terms that may be used during your visit
and the activities listed below are designed to familiarize your students with the topics that will
be covered during their visit. They are listed as options – it is not necessary to complete them all
or do them in any particular order. Please feel free to modify the vocabulary definition or
activities in any way to better suit your students. Keep in mind, their experience will be
enhanced if they are familiar with the concepts before their visit, or if the learning that took
place in the Garden is reviewed and reinforced back in the classroom.
Vocabulary
Biodegradable: the ability of an object to be broken down by microscopic organisms into simple
compounds such as carbon dioxide and water
Carnivore: animals that eat only other animals, or meat
Clay: a type of very fine-grained soil or rock, so small it’s hard to see just one grain; the main
component in heavy, sticky, and wet soil
Compost: the result of decomposition; a nutrient-rich humus, or soil, that is excellent for
improving soil quality and plant growth
Decay/Decompose: to rot; to break down into basic elements like carbon dioxide and water
Decomposer: an organism that feeds on dead organic matter, helping to break it down
Decomposition: the process by which bacteria, fungi, and other organisms break organic wastes
into nutrients that can be used by plants and animals
Humus: organic material made of decayed plant matter that provides nutrients for plants
Larva: the second stage of an insect lifecycle, though it looks like a worm the larva of an insect
actually has 6 true legs
Organic: made from or consisting of living organisms
Predator: an animal that hunts down and eats other animals as food
Sand: a type of fine grained soil or rock, usually quartz fragments; the soil typically found on
beaches and deserts
Silt: a type of fine grained soil typically found at the bottom of lakes or rivers
2 2600 Larsen Road • Green Bay, WI 54303 • 920‐490‐9457 • www.gbbg.org
Dredging for Decomposers Pre‐Visit Activities Activity 1:
Discuss with children what happens to our trash. Create a situation for them: A man is walking
down the street when he decides he would like a snack. He goes into a store and buys a bag of
potato chips. He continues walking as he eats his chips and soon he’s eaten the whole bag. Now
that the bag is empty, what does he do with it? Ask children to come up with a variety of
answers. If they say he would throw the bag away, ask them to be very specific about where.
Discuss with them what happens to the bags, bottles and wrappers that people throw on the
street. How does garbage get into the school yard? Discuss with students about recycling
objects that can be recycled, reusing items that can be reused, and throwing garbage into trash
cans. Take students on a trash clean-up walk around the school grounds.
Activity 2:
Create birdfeeders from items that would otherwise be thrown away. Collect empty milk cartons
and other supplies for each student, or have the class collect their own. Have an example feeder
to show the students, then help them create their own. They can decorate it however they wish.
Fill the feeders with seeds and hang them in the school yard and watch them for birds. They
have put trash to a good use!
3 2600 Larsen Road • Green Bay, WI 54303 • 920‐490‐9457 • www.gbbg.org
Dredging for Decomposers Pre‐Visit Activities Activity 3:
Go on a soil scavenger hunt! Give each student or group of students a collecting container and
shovel or spoon and show them where they can dig in the soil around your school yard. (If soil
is unavailable at school, bring in a small sample of soil from home for students to observe.) Ask
students to dig slowly and carefully and collect different things they find in the soil. After 15-20
minutes, bring the groups back together and ask students to share their findings. (Their findings
will likely include rocks, worms and other creatures, dead plant material, garbage, and manmade objects.) Ask questions like: What is it? Where did it come from? Does it help plants?
How? Conclude that soil is made of many different things, it is not just one substance. After
your discussion be sure to return items to the appropriate place.
Activity 4:
Observe worms to get to know them better. Collect or purchase enough worms for each pair of
student to have one worm. Discuss with students the proper way to treat their worm, then give
them a worm and a damp paper towel to place their worm on. Create a list of questions to have
students answer while observing their worm: Describe your worm (use color, texture, smell).
Which end is the head, how can you tell? How fast does the worm move? Can it move
backwards? Why would it do that? Is it sensitive to touch? How can you tell? Does it prefer
light or dark? What does your worm do when it meets another worm? If you collected other
decomposing insects in Pre-Activity 3, you can also observe the other insects you’ve found.
Compare the students’ observations of these animals.
4 2600 Larsen Road • Green Bay, WI 54303 • 920‐490‐9457 • www.gbbg.org
Dredging for Decomposers Post‐Visit Activities Activity 1:
Raise composting creatures in your classroom. Worms and pill bugs are easy to find and care
for. Find a large, clear plastic or glass container with a lid to turn into their home. Fill the
container with loose, damp soil. You can even mix in strips of shredded paper. The soil should
be kept damp but not wet. Pill bugs and worms can be collected from the soil in your school
yard, or red worms can be purchased from a bait shop. They like to eat your leftover food, so put
some apple cores, lettuce, potato slices, etc. into the container and cover them with a bit of soil.
If you put the food close to the sides of the container, you may be able to watch them eat. Poke
several small holes into the cover and put it on tight. The worms and pill bugs will prefer their
container to be kept dark, so lay a cloth or box over it when you are not observing them. Try
experiments to see how quickly it takes your new friends to eat their food, or test out different
vegetables and fruits to see what they like the best.
Activity 2:
Create mini-landfills in your classroom to discover what happens to our trash. Use clear jars
filled with soil as the landfills. Select several different materials that we may throw away: an
apple core, a scrap of paper, a soda can, a piece of a plastic or styrofoam container, etc. Fill each
jar about halfway with soil. Place one piece of trash into each jar, cover it with soil, and keep the
soil damp. Put a label on the jar to show what item was buried. Leave the lid off and place the
jar away from people and out of direct sunlight, but remember to stir it occasionally and keep the
soil damp. Have students predict what they think will happen to each item. Observe and record
what changes occur in the jars over a 2-3 week period. Discuss what happened to each item:
Which items were stating to decompose? Did some items not change at all? What comparisons
can be made between the mini-landfills and a real landfill?
Activity 3:
Build recycled paper pots to plant seeds in to take home. Have students shred several
newspapers into small pieces (about the size of a business card) and soak them in a bucket of
water over night. Blend the paper/water mixture several minutes by hand until the pulp has the
consistency of oatmeal. Take a handful of the mixture and drop it into a plastic cup. Have
students shape the mixture by pressing it against the bottom and sides of the cup. Be sure to
periodically drain the water out of the cup. Use a pencil to make a drainage hole in the bottom of
the paper pulp. Let the pulp dry for a few days in a warm place like the window sill. Then pop
the paper pot out of the plastic cup, fill it with soil, and plant seeds! The cups can be planted
right into the ground when the plant is ready to plant outside. The pots will decompose in the
soil.
Activity 4:
Visit a nearby woods or field. Look for natural items that are decomposing (dead plants, logs,
etc.) and see if you can find any decomposers that are helping with the process (fungi, insects,
worms, etc.). Investigate what you find carefully, and discuss what you see, smell, and feel.
Talk about why decomposition is such an important process in nature.
5 2600 Larsen Road • Green Bay, WI 54303 • 920‐490‐9457 • www.gbbg.org
Dredging for Decomposers Resources
Teacher Resources:
Appelhof, Mary. 1982. Worms Eat My Garbage. Kalamazoo, MI: Flower Press.
Applehof, Mary; Fenton, Mary Frances; Harris, Barbara Loss. 1993. Worms Eat Our Garbage:
Classroom Activities for a Better Environment. Kalamazoo, MI: Flower Press.
Kalman, Bobbie and Schaub, Janine. 1992. Squirmy Wormy Composters. New York: Crabtree
Publishing Company.*
Lavies, Bianca. 1993. Compost Critters. New York: Dutton Children’s Books.*
Pascoe, Elaine. 1997. Earthworms. Woodbridge, CT: Blackbirch Press, Inc.*
Student Books:
Cronin, Doreen. 2003. Diary of a Worm. HarperCollins Publishers.*
Glaser, Linda. 1996. Compost! Growing Gardens From Your Garbage. Brookfield, CT: The
Millbrook Press.*
Glaser, Linda. 1992. Wonderful Worms. Brookfield, CT: The Millbrook Press.*
Hunter, Anne. 1999. What’s Under the Log?. New York: Houghton Mifflin Company.*
Pfeffer, Wendy. 1997. A Log’s Life. NewYork: Simon & Schuster Books for Young
Readers.*
Tresselt, Alvin. 1972. The Dead Tree. New York: Parents’ Magazine Press.*
* Books available for checkout in Green Bay Botanical Garden’s Children’s Library
6 2600 Larsen Road • Green Bay, WI 54303 • 920‐490‐9457 • www.gbbg.org