Worm Composting with Everyday Materials


HI Mexico’s project in Jonotla focuses on teaching sustainable, organic agriculture techniques. Many farmers in Jonotla and around the world depend on chemical fertilizers and pesticides in order to maintain high crop yields. However, in the long run these chemicals rob the land of its vitality, which makes the farmers all the more dependant on chemicals. In order to end this cycle, affordable alternatives are needed that will maintain high crop yields while at the same time decreasing the need for chemical fertilizers and increasing the health of the soil.

Vermicomposting (composting with worms) is one such example. When worms are used to digest plant and food waste, the result is a rich, black compost filled with micronutrients and micro-organisms ideal for growing almost any crop. Even better, worm composting can be done with everyday materials and with almost no start up costs.

Here’s what the HI Mexico team did to get their vermicomposting system started. You can use this same simple technique to construct a worm composting system for your home!

The materials needed to build a vermicomposting bin are free: 3 old tires (easily acquired from any junk yard or auto-repair shop), water, kitchen scraps, paper garbage, and leaves.

The tires need to be cleaned in order to remove any oil—the worms won’t digest oil of any kind. Once cleaned, place the tires in a covered place so that the worms are protected from sun and rain.

Worms in nature live on the forest floor, a damp location with lots of leaves and other carbon rich materials. We can model this with wet paper, cardboard, and wet leaves. Avoid colored inks and glossy paper, because these plastics cannot be digested.

After wetting the paper, cardboard and leaves, make a layer of these items in the bottom of a tire. This will be the bedding for the worms.

On top of this bedding, add the worms. Red-wigglers are the best variety, and can be purchased at any Bait & Tackle shop.

On top of the worms, add another small layer of bedding, and on top of that add the kitchen scraps. These should mostly include vegetable scraps, fruit scraps, and egg shells. Avoid any meat or dairy products, citrus fruits and peels, oils, and other cooked foods.

Finally, add one last layer of bedding material on top of the kitchen scraps, cover the tire with a metal screen to keep out animals, and secure the screen with one of the other tires.

Maintaining the worms is simple: add kitchen scraps and bedding about once a week and make sure that the bin does not dry out. Worms like about 80% moisture content, similar to a damp sponge, so add water if needed.

After a few short weeks, the worms will turn the leaves and kitchen scraps into organic compost that can be used like a fertilizer—added to vegetable gardens, around the base of trees, or to support any other plants. Red wigglers are surface dwellers, unlike burrowing earthworms. As the worms move upward to reach fresh bedding and food, the lower tire will be left with rich compost. When the bottom tire is full, simply slide it out, harvest the compost, and replace the empty tire on the top of the stack.

The HI Mexico staff hopes that organic techniques such as this one will make it possible for farmers to transition to a style of agriculture that supports the long term health of their land and the planet.


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