Oregon Agriculture in the Classroom Logo
Lesson Overview
  • 50 Minutes
  • 1, 4, 5, 9
  • K - 5th Grade
  • State Standards:
    NGSS: 4-LS1-1, 4-LS1-2, 5-LS2-1, K-LS1-1

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Materials List
  • Recycled styrofoam cooler (Styrofoam coolers are used to ship medicine that needs to stay cold. Many doctors, dentists, and veterinarians receive several coolers each month. The coolers are often thrown away after the shipment is received. Consider asking a local medical office to save one for your classroom.)
  • Drill with a large bit
  • Shredded paper
  • 2-3 full pages of paper
  • Soil
  • Spray bottle filled with water
  • Vegetable scraps
  • Red wiggler worms
  • 2 jars
  • 2 jar lids with holes
  • Dark soil
  • Light sandy soil
  • Vegetable scraps
  • Dark paper, 2 pieces
  • Tape
  • Red wiggler worms
  • Tray
  • Newspaper
  • Measuring tape
  • Flashlight
  • Chenille stem
  • Items to act as barriers (ex., pencil, clothespin, block of wood, crumbled paper, pile of soil, etc.)
  • Paper towels
  • Wax paper
  • Seeds

Vermicomposting

Categories: Agriculture , Science

The class will create a worm bin which will serve as a basis for investigations about ecosystems, life and nutrient cycles, and decomposition.

INSTRUCTIONS

  • Interest Approach – Engagement

    1. Ask the students what the word recycling means. Make a list of items they have recycled before.
    2. Ask the students if food can be recycled. Tell them to imagine they are in the cafeteria at their school. Have them try to think of ways they can use the leftover food being thrown away to make something else. (This question will probably bring interesting responses.)
    3. Ask the students what happens to leaves in the forest during the winter. (They fall to the ground.) Ask them why the leaves that fall from the trees every year don’t just pile up higher and higher. (They break down/decompose and become part of the soil.) Explain that food can be recycled in the same way plants are recycled in the environment. Tell them that they will recycle their leftovers into a special soil that will help give plants the nutrients they need. The secret is worms.
    4. Tell the students that they are going to build a worm bin to serve as a home for worms that will be kept in the classroom to observe and study.
    5. Show them the worms that will be added to the bin, and allow them to find a worm and look at it closely. Tell the group that these red wiggler worms are especially suited for composting food scraps inside an indoor bin.

    Procedures

    Activity 1: Setting up a Vermicomposting Bin

    1. Prior to class, drill ventilation holes in the cooler lid. Have a vacuum cleaner handy—this can be messy!
    2. Ask the students what kind of environment they think worms need to be comfortable and healthy. (They will probably say worms need soil to live in.) Explain that the worms you have are a special kind that don’t burrow deep into the soil. Red wiggler worms prefer to live near the surface of the soil where they have lots of organic matter to eat. They need protection from the sunlight but don’t like to be deep in heavy soil. Explain to the students that they will be making them a home out of newspaper strips.
    3. Have the students rip newspaper into inch-wide strips to use as bedding for the worms.
    4. As the students are ripping the newspaper, discuss the importance of moisture, air, and temperature in the worm bin.
    5. Fill the cooler about half full with shredded paper. Wet the shredded paper until it is uniformly damp but not dripping. It should feel like a well wrung-out towel. Explain to the students that worms breathe through their moist skin. If they dry out, they can’t breathe. However, if the bin gets too wet there may not be enough oxygen for the worms.
    6. Mix the soil with the shredded paper. A couple of scoops with a trowel is plenty. The soil should be moist, but not muddy. Explain to the students that worms don’t have teeth. The hard mineral particles in the soil will help break down food in the worm’s gut. Soil also contains microorganisms that will help jump-start the composting process.
    7. Add the red wiggler worms on top, and watch as they burrow down to get away from the light.
    8. Add vegetable scraps as food for the worms. Begin with one cup or less. It will take the worms some time to acclimate to their new home and develop an appetite. Feed the worms as needed. Worms can survive on paper alone but will readily devour many other foods. Discuss with the students the kinds of foods that worms like to eat. They like newspaper, but the glossy pages aren’t good for them. They like most food scraps, especially from fruits, vegetables, and grains. They also like coffee grounds and filters, tea bags, fallen leaves, eggshells, weeds, and lawn clippings. It is best not to feed them meat, dairy, or foods that contain a lot of fat. Avoid overfeeding to prevent odors. As the population begins to grow, the worms will eat more.
    9. Place full pages of paper on top of the soil and spritz with water until the paper is damp. Place the lid on top, and store the bin where it won’t get too hot or too cold. Check the moisture level regularly. The top sheets of paper will help keep the bin contents moist; when they get dry, spritz the upper layer of the bin with water. The worms need moisture to live, but the bin may begin to stink if it gets too wet. If this happens, simply add shredded paper to absorb the excess moisture.
    10. Discuss the important things that worms do to keep the soil healthy:
      • Worms burrow in the soil. The burrows and trails that they leave help the soil absorb and hold water. This is important for plants that need water to grow. The burrows and trails also make it easy for plant roots to grow into the soil. When the soil is full of worm burrows and plant roots, it is less likely to wash away or erode when it rains.
      • Worms eat organic matter like dead leaves. The castings that come out the back end of a worm after it has digested its food are full of nutrients and microorganisms that are good for plants and for the soil. Worms eat dead plants and other waste and turn them into food for living plants. Worms act as nature’s recyclers and make the soil fertile.
    11. Discuss the importance of soil as a natural resource that is necessary for the production of our food. Almost everything that we eat, much of what we wear, and many of the tools that we use originate from plants grown in soil on a farm. See the lesson plan The Soil Chain for hands-on activities to teach about the importance of soil.

    Activity 2: Worm Investigations

    The worms and castings from your worm bin can be used to engage students in a wide variety of investigations. A few possibilities are described below. While worms are out of the bin, keep a spray bottle handy to prevent the worms from drying out.

    1. Observe the effect worms have on soil.
      • Gather the following materials: two jars, lids with holes, dark soil, light sandy soil, water, vegetable scraps, two pieces of dark paper, and tape.
      • In the bottom of each jar, put a layer of dark soil about one inch thick. On top of this, place a one-inch thick layer of light sandy soil. Keep adding dark, then light layers until the jar is half-full.
      • Slightly moisten the soil in both jars with water.
      • Place two worms in one jar, and then add some vegetable scraps to the top of both jars.
      • Put a lid on each jar. Label the jar with the worms as “Worms” and label the other jar “No Worms.”
      • Take the dark pieces of paper and wrap around each jar. Tape tightly. Put the jars aside.
      • Have each student write down their predictions about what they think will happen in each jar.
      • After three days unwrap the jars. What do you observe?
    2. Observe the characteristics of living worms.
      • Divide the students into cooperative groups.
      • Place a few worms on a tray covered with a damp newspaper for each group.
      • Allow the students to observe their worms moving around on the tray.
      • Have the students sketch a worm, measure how long it is, record how it moves and any kind of noise made as it moves.
      • Have the students discuss which end is the head and which is the tail. Have them give observable evidence to justify their reasoning.
      • Encourage the students to gently pick up a worm and describe what it feels like on their hands.
      • After allowing the students to make their initial observations, gather the trays, and return the worms to the bin or continue with more of the following investigations.
    3. Investigate worms’ responses to light and touch stimulus.
      • Have the students predict the worms’ responses to light from a flashlight and to being gently touched with a chenille stem. Have them justify their predictions.
      • Put the worms on trays and give one to each group.
      • Shine a flashlight directly onto the worms and observe their behaviors.
      • Gently touch the worms with a chenille stem that has a small loop at that end and observe their behaviors.
      • Allow 5-10 minutes for the students to observe the worms’ behaviors. Have the students record their observations with an explanation for the worms’ behaviors.
    4. Investigate worms’ responses to barrier stimulus.
      • Give each group several items to act as barriers (a pencil, a clothespin, a block of wood, a crumbled piece of paper or a pile of soil, etc.).
      • Have the students predict the worms’ responses to these barriers. Will they initially go around a barrier? Crawl over it? Burrow underneath it? Try to keep going forward? Go backwards? Will their responses differ for different barriers? Have the students justify their predictions.
      • Give each group a tray and have the students arrange three or four barriers on it.
      • Place several worms on the tray.
      • Allow 5-10 minutes for the students to observe the worms’ behaviors. Have the students record their observations with an explanation for the worms’ behaviors.
    5. Investigate worms’ responses to temperature stimulus.
      • The day before this activity, place several slightly damp paper towels in a freezer. Place layers of waxed paper in between the damp paper towels for easy separation.
      • Prior to this activity, slightly moisten several paper towels and leave them at room temperature.
      • Just before this activity, place several slightly damp paper towels in a microwave to heat them.
      • Have the students predict how the worms will react to a cold surface, a room-temperature surface, and a hot surface and then justify their predictions.
      • Give each group a tray and a cold, a hot, and a room-temperature paper towel.
      • Place several worms on each paper towel.
      • Allow 5-10 minutes for the students to observe the worms’ behaviors. Have the students record their observations with an explanation for the worms’ behaviors.
    6. Investigate the effect of the vermicompost on plant growth.
      • Depending on the resources available, try growing seeds with differing amounts of vermicompost added or adding different amounts of compost to plants growing in the garden.
      • Have the students predict which amounts of compost will produce the best results.
      • Observe changes in the plants for two to four weeks and have the students use tape measures to record growth.