Composting biodegradable materials involves creating an environment that fosters decomposition through a balance of "greens" (nitrogen-rich) and "browns" (carbon-rich) materials, moisture, and air.
Understanding the Composting Process
Composting is a natural process that breaks down organic matter into a nutrient-rich substance called humus, which can then be used to enrich soil. Biodegradable materials, by definition, are capable of being decomposed by bacteria or other living organisms and thereby avoiding pollution. However, simply being biodegradable doesn't guarantee successful composting; it requires the right conditions.
Steps for Composting Biodegradable Materials:
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Choose a Composting Method:
- Backyard Composting: This involves creating a pile or using a compost bin in your backyard. It's suitable for a wide range of biodegradable materials.
- Vermicomposting (Worm Composting): This uses worms to break down food scraps and other organic matter. It's excellent for indoor composting and smaller quantities.
- Bokashi Composting: This is an anaerobic (oxygen-free) method that ferments food waste before burying it in the ground or adding it to a regular compost pile. It's good for all food waste, including meat and dairy.
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Gather Your Materials:
- "Greens" (Nitrogen-Rich): These include food scraps (fruit and vegetable peels, coffee grounds, tea bags), grass clippings, and fresh leaves.
- "Browns" (Carbon-Rich): These include dry leaves, shredded paper, cardboard, twigs, and sawdust.
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Layer the Materials:
- Start with a layer of "browns" at the bottom of your compost bin or pile.
- Add a layer of "greens."
- Continue alternating layers of "browns" and "greens." A good ratio is approximately two parts "browns" to one part "greens" (2:1).
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Maintain Moisture:
- The compost pile should be moist but not soggy. It should feel like a wrung-out sponge.
- Water the pile regularly, especially during dry periods. Avoid overwatering, which can lead to anaerobic conditions and unpleasant odors.
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Aerate the Pile:
- Turn the compost pile regularly (every week or two) to introduce oxygen. This helps speed up decomposition and prevents anaerobic conditions. You can use a pitchfork or compost aerator.
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Monitor and Adjust:
- Check the pile regularly to ensure it's moist and well-aerated.
- If the pile is too dry, add water.
- If the pile is too wet or smells bad, add more "browns" and turn it more frequently.
- If the pile isn't heating up, it may need more "greens" or moisture.
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What Can You Compost?
Here is a table summarizing what you can and cannot compost, with examples:
| Material Type | Examples | Compostable? | Notes |
|---|---|---|---|
| Greens | Fruit and vegetable scraps, coffee grounds, grass clippings, tea bags | Yes | Avoid diseased plants. |
| Browns | Dry leaves, shredded paper, cardboard, twigs, sawdust | Yes | Shredding helps. |
| **Paper Products | Plain paper, cardboard | Yes | Avoid glossy or coated paper. |
| Eggshells | Eggshells | Yes | Rinse first. |
| Meat/Dairy | Meat scraps, bones, dairy products | Yes (Bokashi) | Generally not recommended for backyard composting due to odor and pests. |
| Oils/Fats | Cooking oil, grease | Limited | In small quantities, can be composted. |
| Diseased Plants | Diseased plants | No | Can spread disease. |
| Weeds with Seeds | Weeds with seeds | No | Seeds may survive composting. |
| Pet Waste | Dog/cat feces | No | Can contain harmful pathogens. |
| Treated Wood | Pressure-treated wood | No | Contains harmful chemicals. |
| Plastics (even biodegradable) | Compostable bags, utensils (PLA) | Depends | Industrial composting required for most biodegradable plastics. May not break down in backyard compost. |
Biodegradable Plastics: A Note of Caution
While some plastics are marketed as "biodegradable" or "compostable," many of these require specific industrial composting conditions (high temperatures, controlled humidity) to break down effectively. They may not decompose in a typical backyard compost pile. Check for certifications like BPI (Biodegradable Products Institute) to ensure the product is truly compostable and follow manufacturer's instructions.
Troubleshooting Common Composting Problems
| Problem | Possible Cause | Solution |
|---|---|---|
| Foul Odor | Anaerobic conditions (too wet, not enough air) | Add more "browns," turn the pile more frequently. |
| Slow Decomposition | Too dry, not enough nitrogen, too cold | Add water, add "greens," ensure the pile is large enough. |
| Pests | Food scraps not buried properly | Bury food scraps deeper in the pile, use a secure compost bin. |
| Attracting Animals | Meat or dairy in compost | Remove meat and dairy; consider bokashi composting instead |
Conclusion
Composting biodegradable materials is an environmentally friendly way to reduce waste and create valuable soil amendments. By understanding the basic principles of composting and following the steps outlined above, you can successfully compost a wide range of materials and contribute to a more sustainable lifestyle.
