Composting is a natural way to recycle certain food and yard products. It is also an opportunity for people to help the environment and enrich the soil for plants to grow.
According to the Environmental Protection Agency (EPA), food scraps and yard waste make up more than 28% of garbage in landfills and combustion facilities. Composting can reduce the amount of food a person throws in the trash.
Composting also creates a nutrient-rich soil enhancer that can help plants grow. This final product, called compost or humus, is a dark, soil-like substance that people can use in gardens, on farms, and as mulch.
Composting may have direct and indirect benefits for the health of the planet, humans, and animals. Learn about them in this article.
Many people decide to compost for environmental and personal health reasons.
Composting helps reduce waste in landfills. Rather than throwing certain food or yard waste in the trash, a person can compost it.
This allows it to return naturally to the earth and reduces the amount of waste in landfills. It may also help a person save money on waste collection costs.
When people use compost, humus, or mulch in gardens, it enhances the nutrient content of the soil.
According to the EPA, composting:
- Reduces methane, which is a greenhouse gas that comes from landfills.
- Reduces or eliminates the need for chemical fertilizers.
- Promotes higher crop yields for farmers.
- Helps restore forests, wetlands, and habitats by improving poor quality soil.
- Helps the soil recover from contamination by hazardous waste.
- Allows the soil to maintain moisture levels, which reduces the need for watering.
- Reduces the amount of carbon dioxide in the atmosphere.
Because compost can enhance the health of the soil and reduce greenhouse gases, it may have benefits for human health.
One article states that increases in carbon dioxide in the atmosphere could lead to zinc deficiencies in humans. It also indicates that deficiencies in the soil nutrients can lead to fewer nutrients in the food that people grow in the soil.
There may be indirect human health benefits to composting as well. If a person uses compost in their home garden, they may get bigger yields of fruits and vegetables and healthier plants. Composting may make growing healthful foods at home more successful.
Using fewer chemical pesticides and fertilizers may also benefit human health.
Some evidence suggests that pesticides could have links to cancer. Some health experts feel that there is an “urgent need” to find pesticide alternatives because of their adverse effects on human health.
Learn more about the effects of pesticides on food here.
Because composting can reduce the need for these chemicals, it can be a cost-effective and environmentally friendly way to help improve the health of people and animals.
According to the United States Department of Agriculture (USDA), compost requires four ingredients:
- green matter (high in nitrogen)
- brown matter (high in carbon)
- moisture (water)
- oxygen (air)
Together, these ingredients create an environment that allows bacteria, fungi, worms, and other organisms to break down the organic matter into compost naturally.
Green matter includes nitrogen-rich organic material, which provides amino acids and protein for the compost. Green material includes:
- fruit and vegetable scraps, peels, cores, and seeds
- coffee grounds and coffee filters
- manure from herbivores, such as cows, sheep, and goats
- bread, pitas, cereal, and tortilla shells
- cooked rice and pasta
- herbs and spices
- nuts and nutshells
- crushed eggshells (not egg whites or yolks)
Brown matter is carbon-rich material. It includes:
- dead leaves
- hay and straw
- tree branches and twigs
- wood chips and sawdust (avoid ashes from commercial fire logs and charcoal briquettes)
- fireplace ashes
- shredded newspaper
- flower clippings
- loose leaf tea and natural tea bags
- dryer lint from cotton fabrics
An easy way to remember what to compost is to think about where the material originated.
Foods and other products that originated in the ground are usually safe to compost. This includes items such as fruits, vegetables, and grains, plus their scraps and seeds.
Things that do not come from the ground are not safe to compost. This includes animal products, items that come from unnatural sources, or oily foods.
Also, certain things can disrupt the composting process or may introduce diseases. Do not compost:
- meat, bones, fat, and skin from animals
- yogurt, milk, cheese, butter, and other dairy products
- egg yolks and whites
- manure from pets and meat-eating animals, such as dogs and cats
- greasy foods or oils
- ashes from commercial fire logs and charcoal briquettes
- treated wood sawdust or pieces
- diseased plants or branches
Onions and garlic may repel earthworms. For this reason, many people do not add them to their compost.
There are many ways to compost. According to the USDA, composting can take from a few weeks to a year to complete. This depends upon the temperature of the environment and the materials in the compost.
Some tips to get started include:
- Choose a bin for compost. This can be a trash can, a plastic bin, a bucket with a lid, or a metal container.
- Drill holes in the sides and bottom of the bin to allow oxygen to get in.
- Choose a level, dry, and shady place for the bin. Many people choose a spot near their garden.
- Make sure the spot is near a water source, such as a hose.
- If necessary, put the bin inside a cage or wire fencing to keep animals out.
- Start with 1 part green matter to 3 parts brown matter. Add brown and green materials to the bin in layers.
- Chop or shred larger pieces when necessary.
- When adding a green layer, add some water to it.
- Turn the pile with a shovel or garden fork at least once a week.
When the pile has turned into a deep brown, dry, crumbly material that looks like soil, the compost is finished and ready to use in a garden or yard.
People who cannot compost in their yard or home may be able to add their materials to a community compost bin.
Some cities have areas where people can drop off compostable material to reduce waste.
Compost should not have an unpleasant or strong odor. Consider the following tips to make composting successful:
- If the compost pile is too wet or has an unpleasant odor, add more brown matter and turn it with a shovel or garden fork to add oxygen.
- If the compost pile is too dry or does not appear to be breaking down, add some more green matter with small amounts of water.
- Avoid adding too much water with green waste. Compost should be moist, but not wet. Too much water can drown the organisms that break down the compost.
Composting is a safe and natural way to reduce landfill waste and help crops and plants grow. It may benefit the health of soil and food by increasing the nutrient content.
Composting may also help people use fewer chemical pesticides and fertilizers, which could have positive health effects.