A Composting Science Project - Our Worms Ate Our Garbage!
Worm Composting Project Procedures
This is a quick project to set up, but it will require a significant investment of time and energy from the students. Older students may want to take the project to a school wide level and compost the garbage from the cafeteria. Here is what needs to be done.
First, find an area that is outdoors and sheltered but not in the classroom is required. A sheltered spot in the school’s garden (if you have one) would be great. If not, find a sheltered area near the building that can be easily accessed. Worms can be kept in the classroom as a last resort but there is sometimes an odor (decomposition of food waste) which can be unpleasant.
Decide whether the kids will build a structure for the worms or if one will be purchased. The Encyclopedia of Organic Gardening by Rodale Press has a great set of plans for a worm farm. It is simple and easy to build using basic wood and nails/screws. A worm farm can be purchased from a number of sources; The National Gardening Association offers several that are suitable for school use. These worm farms will cost $100-$150.00.
Next purchase worms. Although night-crawlers will work OK, it is best to purchase the red wigglers specifically sold for worm farms. Although they are less cold hardy than earthworms, they do a much better job at composting. Now you have purchased the worms, have a suitable place for your worm farm and a container to put the worms in has been acquired; the project is ready to begin. If a class made worm farm was constructed, newspapers, soil or other substrate (the bricks of coconut bedding for reptiles works well) will be needed. Place the worms in the top portion of the container. Prior to feeding the worms, measure how much garbage the classroom throws out per day or per week. Compare this amount to the daily and weekly amounts thrown out during the worm composting project.
Every day, collect classroom garbage from snacks and lunches. Items that worms love to eat are breads, vegetable matter, paper napkins, paper towels, coffee grinds and unbleached coffee filters. Avoid meats, juice boxes, anything waxed, cardboard, plastics, and eggshells. The worms prefer smaller pieces, so large items like bananas peels should be torn up. Place the garbage on top of the substrate. There is no need to bury it, the worms will find it. 2,000 worms will eat approximately 8 lbs. of garbage a week.
As the worms eat and grow they will leave behind worm castings (poop). If you have a school or class garden, this is the perfect fertilizer. If not, then the castings can be sold to help offset the cost of the project setup. If using a class made compost, then the worms should be moved to a new container once a month. Just build 2 containers and keep switching. Remove the worm castings at each change. Purchased composts have several levels. The worms start in the lowest level and eat their way up toward the top. They leave the castings behind as they move.
About once a month, clear out the castings and place the empty level on the top of the compost. Some purchased units also have a spigot for worm tea. This is all of the excess water that has dripped through the castings. It is fabulous for plants. Again this can be used for class plants or gardens or it can be sold. As the worms make their advance to the top of the unit, you may notice that their numbers are increasing. If your setup is even marginally successful, you will have worm reproduction.
Make is a School-Wide Project
To bring this project to a school wide level, permission from the administration and possibly the school district may be required. The cooperation of the cafeteria staff will be essential. In addition, more worms and additional composts will have to be added. Using 8 lbs. a week per compost as an average will provide an estimate as to how many worm composts and worms will be required. Sometimes it is easier to get permission if monetary savings for the school can be demonstrated. Worm composting reduces the amount of garbage thrown out by the school. This will reduce the cost of garbage collection and maintenance man hours used to empty and clean trash cans.
This project ties into many disciplines. For science there is the life cycle of the worm, garden ecosystems, the digestive system, and environmental sciences (recycling and earth stewardship). Math, business, and economics are included if the castings or worm tea is to be sold. Older students can learn about price points, supply and demand, writing a business plan (language arts), project management, and accounting. For the very ambitious, there are grants available for classroom and school wide composting projects. The National Gardening Association is one organization that offers grants to schools. Students can research these opportunities and those who are gifted in language arts can write the application (with adult supervision).
As a final note, keep in mind health issues. Hand washing is a must after handling garbage and the worms. Children with food allergies should not be allowed to handle garbage and they should use gloves when handling the castings. This can be a fun project for students in grades 3 through high school. Modify the project to suit the student’s ability and age.