Compost Your Way To Habitat Study March 23 2010

[caption id="attachment_5429" align="alignleft" width="180" caption="Photo By Tony Crider"][/caption]

I'm fascinated by the idea that poop can be useful, and it's why I got into composting (I started with worm bins). This particular composting set up in your classroom won't involve worm poop, but will be incredibly educational for your students and helpful to our Earth.

Why Compost?

First, it's easy. Much of our natural waste can be reduced into soil that's extremely beneficial to plant growth as well as decreasing what goes in our landfills. Composting in your classroom will reduce waste produced in your school, and hopefully students will take this knowledge and practice home.

How Does It Work?

Composting works with the combination of the following elements.

Heat - The temperature can't be too hot, but not too cold...composting needs a temperature that's just right, like Goldilock's porridge. This is a happy warm temperature.

Moisture - Composting requires about half water and half dry materials. Nothing should be soggy, just moist, and much of the moisture will be in the middle of the compost heap.

Darkness and Light - Sunlight provides heat, but the bulk of the composting happens in the dark. Imagine a pile of refuse sitting in the sun. The bulk of the break down of materials is happening in the middle of that pile, where it's dark, moist and warm.

Movement - Rotating and mixing infuses oxygen into the materials, helping them to break down.

What Kind of Materials Are Required?


Be careful when dealing with waste material, and train your students to do the same. Wear gloves when dealing directly with composting material, and have your kids wash their hands thoroughly with soap and warm water when finished.

Compost Bins

The kinds of bins you use depends on what you want to do. First, there's a choice to make: a classroom bin, individual compost bins, or both?

The classroom "bin" is easy. If you already have a school or community garden on site, pick a corner for the compost pile; start with some dirt, shredded newspaper, some grass clippings and vegetable peelings. If you want, you can build a large structure out of two-by-fours and chicken wire, just make sure that in the front there's an opening to get waste in and out and to fit in a rake to turn the pile every week or so. Also good for this purpose is a large tote, just drill small holes all the way around, including the lid and bottom, so that oxygen can flow in and out and take the lid off the mix the materials with a rake.

If you don't have an onsite garden, pick a corner of the schoolyard - preferably near your classroom - and use caution tape to mark it off. If you want something a little less conspicuous, use a tote or you can find official compost bins that turn with a handle on the outside.

Individual compost bins for your students are easier than you might think. Choose a plastic container for each student and have them paint the containers black - these could be 2-liter soda bottles, small totes, or a small wooden boxes. Look around and see if there are materials large enough that can be recycled, and have your students do the same, bringing in containers that might work.

After the containers are painted black, have students place or cut holes about 5 inches apart on all sides of the container using a pair of scissors or an awl (if this makes you nervous, have parent volunteers come in and help with this part). If the container has a lid, you won't need to cut one. If there isn't an opening, however, have students draw a 4" x 4" square and cut three sides of it, leaving a "hinge" on one side; secure the opening with duct tape once the container is filled and ready to go.

Then fill the bins with compost material. Moisten shredded newspaper and place it inside the bins along with other compost material. Have students place their compost bins on a windowsill or line them up outside your classroom. Every few days, have your kids move their individual bins around to help the composting process.

The Four Elements

Mentioned above, these are heat, moisture, darkness/light, and movement.


It will take about a month to see significant breakdown in a compost bin or pile. During this span of days and weeks, have your students keep a science journal with sketches of the compost during the stages of break down, records of what was added and when as well as when the bin or pile was rotated, and temperature readings of the middle of the compost pile if possible.

What Goes In It?

There are waste materials that can go inside a compost bin, and waste materials that cannot. The basic rule I personally use is that if it is a natural material, it's probably okay. Some of these natural materials include shredded paper, vegetable peels, fruit peels (NOT banana peels), grass clippings, eggshells, coffee grounds, and water (not excessive amounts).

As a general rule, avoid putting meat, manure/feces and processed food into your compost pile or bin.

Where's the Habitat?

Micro-organisms, hence the need for gloves. If the compost pile is outside and is basically a heap, there's more opportunity for micro-organisms and other critters to join in the fun. Once the bottom and middle of the pile is filled with "black gold," have students take samples in small plastic containers and look at them with magnifying glasses. Do they see any critters in the soil? What jobs do these critters do for the break down of waste? Why are they there?

Just like worm poop, decomposers have their important place in the cycle of composting. The composting process will teach your students about helping the Earth along with presenting a micro-habitat to study.