Worms for Lunch
Lesson Overview
Goals
- Explain how worm castings are better than traditional compost
- Identify ways that microbes assist worms with the com-posting process
Outcomes
Teaching Primer
There is truly something magical about worm compost. Worms transform the inputs available to them – like food scraps, soil, and decaying plant matter – into something greater than the sum of its parts. Worm castings are significantly higher in nitrogen, potassium, phosphate, calcium, magnesium, and humus content thanks to the transformation that occurs in the body of the worms. Additionally, these powerful castings are loaded with microorganisms, act as slow-release natural fertilizers, and contain more nutrients that traditional compost. All of this nutritional goodness is water soluble and immediately available to plants that can tap into its bounty.
But just how do worms turn soil and food scraps into something so amazing? Well, the truth is that much of the work is done by others…friendly microbes that is. These little friends of the red wiggler include bacteria, nematodes, fungi, protozoa, and even mold. Some live in the gut of the worm or are present in the soil and find their way inside as the worm ingests material.
Worms need help because they don’t have the enzymes required to fully digest much of what they eat. This is where the microbes support the effort. As the army of microbes break down organic matter in the gut of the worm they release nutrients that enter the bloodstream and nourish the worm. The worm then excretes its cast in the bin (or the garden) and those nutrients and microbes take on the new role of supporting the growing process for the plants we eat.
Teach the Teacher
- The Complete Guide to Vermicomposting (included w/ Worm Factory 360)
- Anatomy of the Red Wiggler Worm
Tools & Materials
- Microscopes
- Slides or petri dishes
- Magnifying glasses
Vocabulary
- Humus
- Water soluble
- Worm castings
- Enzymes
- Microbes
Method
Introduction (10 minutes)
Begin this lesson by sharing an overview of what compost and worm castings are and why they’re important in the growing process for plants. Define the vocabulary words for the Students and ask them if microbes can be seen with the naked eye. Describe the role that enzymes play in our own digestion systems. Establish that worm castings are actually beneficial to the garden as a natural fertilizer.
Activity (20 minutes)
Inspect a lower tray. Once the Worm Bin has at least one additional tray in production, pull a small sample of compost from the lower bin. This bin should contain material that is in a later stage of composting and castings should be available even in small quantities. Instruct the Students to view their sample with the magnifying glass to see if they can identify anything in its original form. This might be food scraps, shredded paper, or even the pumice. Then take a closer look using the micro-scopes. Have the Students look at the smaller sample to see if they can discern any microbial activity. Some friendly microbes and microorganisms may be present. Reserve the identification of those happy inhabitants of the worm bin for a future lesson.
Discussion (10 minutes)
How many microbes do you think are living in our soil sample? Hint: a teaspoon of garden soil can have as many as a billion bacteria, thousands of protozoa, a dozens of nematodes. If there are that many microbes in a teaspoon of soil then how many are in our worm bin? How many exist in the front yard at your house?
Assessment (5 minutes)
Use the following questions to assess the Students before and after the lesson. Tally the responses of the group in the Assessment Tracking Log for comparison:
- By a show of hands, how many of you think that worms get help composting waste?
- Now that you understand how bacteria and microorganisms help worms compost waste, how many of you think you could explain the process to someone else?
Related Lessons
Give the Intermediate or Advanced lessons a try now that you’ve completed the Beginner Lesson!
This lesson, and all other lessons on this website, are intended for use by teachers in the classroom. These lessons are protected by US and International copyright laws. Reproduction or distribution of lesson content, supporting materials, or digital creative is prohibited with written permission from Modern Steader LLC.