3 of 12

Notes for teachers

This is a semester long project with 2 parts. The first part is learning about how worms rebuild soil. Out of 50 worm bins I only had two student groups neglect their bins causing the worms to die. The second part is testing for nutrients in casting samples then using castings to sprout seeds. The goal is to draw attention to soil as a limited resource, why it is important, and how it can be regenerated.

I was really impressed by how much my students cared for their worms and treated them like a class pet. They were excited to feed them, water them, and check on them every week. They looked forward to class and they were motivated to get their work done so that they could care for their worms the last 5 minutes of class. I heard stories from other teachers of students recounting their experience of picking their worms out of the larger bin to put into their own smaller bins. I am confident that this experience had a lasting impact on my students.

List of Materials

Slide Show Presentation (Link)

This includes instructions for building the worm bins, gathering data on the worm bins and casting samples, transferring castings to soil, planting and growing sprouts, and analyzing sprout data. Includes a lot of pictures.

Worm Bin Data Worksheet (Link)
Build a Chart, Sprout Data (Link)

Introduction to Google Sheets

Example of Sprout Analysis (Link)

This is based on the type of data you gather. The goal is to construct and interpret a scatter plot for bivariate measurement data.

You will also need: red wigglers, shredded paper, potting soil, water, students can bring in their own recycled plastic containers, cheesecloth, rubber bands, thermometers for moisture and temperature are optional, kitchen scales, large worm bin, large bowls, small bowls, gloves, long spoons, small pots, variety of quick sprouting seeds, grow lights, seed starting trays with lids that students’ pots can fit in.

4 of 12

Standards

8.E1U3.8

Construct and support an argument about how human consumption of limited resources impacts the biosphere.

Standards

8.SP.A.1

Construct and interpret scatter plots for bivariate measurement data to investigate and describe patterns such as clustering, outliers, positive or negative association, linear association, and nonlinear association.

6-8.7.c.

Students perform a variety of roles within a team, using age-appropriate technology to complete a project or solve a problem.

5 of 12

Objectives:

SWBAT Investigate how red wigglers rebuild soil by processing food scraps and depositing their casts into the soil.

SWBAT Obtain, evaluate, and communicate information about data for changes in worm bins and growth of sprouts to predict how nutrient in worm castings affect the soil and plant growth.

6 of 12

Agenda (4 to 5 months)

Part 1: Worm Bins (8 to 10 weeks)

Begin as soon as you are back from Winter break and wrap these up before leaving for Spring Break. Give students about 5 minutes at the end of each class to check on their worms and/or collect data.

1) Encourage students to find a plastic container that they can use from home. If it is a large juice container, have them cut the top off before they bring it to class. They need to be able to fit their hand in for mixing food scraps, moisture, and substrate. Try to collect these before leaving for Winter Break. Also purchase your worms and foam ice chest before Winter Break. I purchased 1,000 red wigglers off Amazon.

2) Have students answer questions on the Worm Bin Data Worksheet using the Google Slides and call one group up at a time to build their worm bins. You can have two stations: one to mix and prepare substrate, and a second to pick worms out of the larger worm bins, weigh and count worms, and give advice for care and feeding. Plan on spending at least 10 minutes per group.

3) When you are ready to break down the worm bins you will follow a similar process. Emphasize that it is impossible to get all the worms out, which makes it important to keep sprouts watered and soil moist when planting seeds. Students will need at least 20 minutes to pick through their castings to get all the worms and eggs out.

7 of 12

Agenda continued

Part 2: Soil Testing and Sprouts

(8 to 10 weeks)

I will dedicate the week before Spring break to separating worms out of bins, testing soil, and planting seeds. If you are planting seeds before Spring Break, plan on watering at least twice over the course of a week. I will set up covered trays to create humidity and put them under grow lights with a 12 hr timer. You want to leave your room around 74 degrees. The downside of doing this over Spring Break is that students lose the excitement of seeing their seeds sprout. If you are going to plant seeds after Spring Break, make sure you have a way to keep the castings in the worm bins moist because there are definitely worms in them and they will die if they get too dry.

1)The challenge with soil testing is that the solids from the castings need time to separate from the water after they are shaken together in the test tube. For good separation you need to let the sample sit for 20 minutes. Students are tempted to pack the castings down into the bottom of the tube then when water is added the castings spread out and fill the whole tube and never separate from the water. Remind them they only need a little bit for a 1 part castings to 5 parts water ratio. There will be some small chunks from the castings and that’s ok.

2)When filling the pots with soil, remind students to fill the pots without packing the soil down or the roots will struggle to grow and spread out. I encourage students to plant a variety of 10-15 seeds even though they are small pots because then there will be enough to taste some of the sprouts as the grow. The goal is also to create diversity for gathering data on average number of sprouts per pot and range for number of leaves.

8 of 12

Intro/Driving Question/Opening

This project comes after a lesson on soil as a limited resource, and how human consumption of soil can impact the biosphere. We cover the phosphorus cycle, how it is broken, and how some communities are fixing it. We learn about cover cropping and how rhizobia bacteria fix nitrogen in the soil. Cover crops can also prevent erosion, preventing water pollution from too much nutrient flowing into local waterways. We compare soil formation in different climates and how different horizons form in those different climates.

This project dives deeper into composting, and specifically, how worms play an essential role in building healthy soil. There are many reasons that healthy soil is important. For example, healthy soil is important because we eat the plants that grow in it, and we eat the animals that eat the plants.

9 of 12

Hands-on Activity Instructions: Part 1

I let students pick their own groups of 2-5. Some students want to take more ownership of their worm bins while others prefer to rely on a bigger group.
I will hand out a glove to one student in a group to do the mixing and handling of the worms. Not all groups will require a glove.
The cheese cloth will keep the worms in but not the moisture. I keep spray bottles filled with water near the bins so that students can moisten the substrate daily. If students add too much moisture or food scraps and the substrate gets smelly, just add more substrate to soak up the extra moisture. The bins should not stink. Also make sure the room is temperature controlled so that it doesn’t get to cold or too warm. I keep my room at 74 ℉.
Food scraps need to be chopped into very small pieces. Students need to be reminded of the worm to garbage ratio so that they don’t overfeed their worms.
Worms prefer the dark so I save cardboard boxes for students to keep their bins in when they are done working with them. I like the clear plastic containers because the students can see the shredded paper turning into soil and these work for a temporary worm home.

10 of 12

Hands-on Activity Instructions: Part 2

Worms need to be separated from the castings before taking soil samples, however, it is impossible to get every baby worm and egg. Just do your best.
I will model how much of the castings to put in the test tube. Chunks are ok but if it doesn’t fit don’t try to pack it down. After adding the water to the tube, put your thumb over the top and shake it up really good. You can also use some plastic wrap to cover the top of the tube when you shake it. Give it about 20 minutes for all the solids to separate to the bottom.
On seed planting day you will want stations for mixing castings, soil, and water, and another for planting seeds. Read instructions for planting seeds because beans and peas will need to be soaked overnight. I think it is better to plant too many seeds so that students can sample what the sprouts taste like.
I would like to include data gathering for how many seeds sprout, how long it takes for different seeds to sprout, and sprout growth over time but I have not been able to work that into this project yet.
I will let students take their sprouts home when we are done with them. If they don’t want them I dump everything into my worm bin (foam ice chest).

11 of 12

Assessment

Worm Bins

Every other week I do a worm bin check to make sure that students are gathering data and taking care of their worms. The incentive to care for their worms and gather data is that I will give them more worms if they are doing a good job. This is when I will also give them feedback for how they can do better.

Sprouts

There is a Google Sheets assignment and a Google Slide assignment that students complete at the conclusion of growing their sprouts. ‘Create a Chart’ focuses on using data in Google Sheets to make a chart then looking at the different chart options and deciding which is best for displaying their type of data. ‘Sprout Analysis’ compares data from all classes and revisits the ‘Create a Chart’ assignment. The files I have attached to this lesson plan were thrown together as we neared the end of the school year and still need a lot of work, but they are an example of where I am starting from and they will hopefully inspire you with some ideas of your own.

12 of 12

Differentiation

Students work in groups and each group will have the same data for their worm bin and sprout growth. If a student has a lot of absences or forgets to record data, they can easily get it from someone in their group. Students are willing to share food with other worm bins when they bring in more than enough food for their own worms. Even with modeling, students can be nervous about making a mistake. Each group will elect a leader to take on the more daunting tasks.

Remediation

Extension/Enrichment

This project is a great opportunity for some students to take on a leadership role in gathering data, testing soil, and planting seeds. Most students are content with watching the leader in their group perform the necessary hands on tasks. Some students will become curious about which foods the worms like best and begin their own mini experiments.