Compost I: How and Why to Compost
How can we repurpose our food scraps to grow plants more successfully?
This Lesson Plan is part the Home, Gardening, and Sustainability modules of SustainEd Farms' virtual programming.
If you’ve been cooking at home more often due to the coronavirus, then it’s also likely that you’ve been producing more food scraps. An easy but often misunderstood option for disposing of your food scraps is to compost them, allowing your organic waste to be decomposed into simpler parts (elements and minerals) that eventually can be used as a soil amendment -- eventually adding to humus. While the biological process themselves can be quite complex, the basic elements of a successful composting system are not overly difficult to understand. By using a few household items, you can generate a soil additive right at home, thereby giving back to the environment.
Students will be able to...
Optimize natural processes to decompose food scraps, and distribute the resulting compost in a garden
Recognize the incongruence between that which we take from the Earth and what we give back to the Earth in our everyday lives
Identify what is and what is not compostable
Measure, qualitatively, the gains in soil quality and the decrease in waste sent to landfills
Become nutrient cycling stewards!
humus /ˈ(h)yo͞oməs/ noun. - organic matter in soil that lacks structure and helps retain moisture and nutrients
microorganism /ˌmīkrōˈôrɡənizəm/ noun. - an organism that is microscopic but may consist of one or many cells
1. Gather your materials. You will need the following supplies:
5 gallon bucket with a lid · a drill + small drill bit · food scraps · a mixing utensil, such as a garden trowel
💭Do you know... what composting really does for the environment? What does science have to say?
Applying compost to eroded and poor quality soils has shown to reduce soil compaction (allowing water to flow more freely to roots) and improve water retention properties
Perhaps obviously -- since adding organic material is adding carbon to the system -- adding compost to soil adds Soil Organic Matter (SOM) and increases the content of slow release carbon (which is nutrient rich!), thereby sequestering carbon in the soil’s carbon sink
Compost treatments increase microbial populations and subsequent activity, improving soil productivity
2. Watch the following Youtube video to see a demonstration of how to make your own compost bin, and how to compost indoors. Then, follow along with the remainder of this lesson.
3. Clean out your 5-gallon bucket, and drill several small holes into the lid at equal distances from one another (approximately 9-10 holes). Drill a slightly larger hole near the edge of the lid -- this will be where you drain excess moisture.
⚛How does it work?... Composting is possible because of the microorganisms that rely on this waste for food: bacteria and fungi. In order to thrive, each microbe, like other living things will require…
Food: What you feed your microorganisms matters!
1 part greens: these high-nitrogen-containing items include food scraps like banana peels, coffee grinds, and avocado pits, as well as plant trimmings.
2 part browns: these high-carbon-containing items include dry leaves, straw, untreated sawdust, paper, eggshells, tea bags (if compostable; if not, remove and compost only leaves), and wood chips. Consider adding soil layers from your garden as well.
What to avoid: dairy products, fats, oils, meats, bones, and several other items. Always check if something can be composted if you are not sure.
Water: Your compost pile needs some moisture for the living things, but no more than a wrung-out sponge!
Shelter: Your compost bin will need proper environmental conditions such as oxygen (which is why you will have to rotate your pile), temperature (between 40℉ and 80℉), & light exposure (which will need to be adjusted to achieve proper moisture and temperature). Additionally, you may want to chop up your compost to allow more surface area for microbes to live.
4. After reading through these rules, gather some compostable materials -- perhaps you have some from a recent meal you made! Put the materials in your new compost bucket. Stir them around with a trowel, breaking up large materials.
5. As much as once per day, empty excess moisture from your bin by pouring it through the larger hole you drilled in your lid. You will want to stir and flip your pile at least once a week to aerate it, which you can do with your trowel. Watch for odors, and if the compost pile begins to smell rancid, you should drill more holes in the top or sides of your bin, aerate your pile more often, or check for excess moisture. You should aim for an “earthy” smell.
6. Once your bin is nearly full, let the compost sit for at least a week before using. It can take several months for the compost to become completely ready, so continue to monitor and stir the pile (and think about working in some soil as well). When the compost resembles soil, it can be applied to your garden.
Download the PDF version of this lesson plan: