Compost
Separate and compost organic materials to reduce the strain on landfills, reduce methane emissions, regenerate soil, and grow healthy food.
Composting utilizes the natural process of decomposition to turn organic materials, such as plant matter, food, and animal waste, into a carbon-rich natural fertilizer that can be used in gardens, farms, and rangelands. Composting reduces greenhouse gas emissions by diverting food and plant waste that is often incinerated or sent to landfills. It can also replace synthetic fertilizers, decreasing the use of harmful chemicals on farms. Composting has been practiced for centuries by Indigenous peoples and traditional communities and is a central component of regenerative farming and gardening. Compost’s rich mixture of microorganisms and nutrients can significantly improve soil and plant health, with cascading benefits for human and animal well-being.
Action Items
Individuals
Learn about the benefits of composting. Composting has been practiced for thousands of years by Indigenous, traditional, ancient, and historic communities. The introduction of compost to industrial society began with Sir Albert Howard, who studied traditional farmers in India using a technique that was based on a method of composting that imitated the forest. Here are some major benefits:
- Compost regenerates soil. Healthy soil is alive with billions of microorganisms, such as bacteria and fungi, which are critical to supporting plant growth and ecosystem function. Unlike industrial agriculture, which kills biological life in the soil with chemicals and synthetic fertilizers, compost can help regenerate the natural chemical and biological components of soil, restoring its health.
- Compost helps sequester more carbon in soil. Compost is one of the fastest means of improving soil carbon levels, especially in semi-arid cropland soils. The Intergovernmental Panel on Climate Change (IPCC) has suggested that up to 14 percent of carbon introduced with compost into soil can remain there, depending on conditions.
- Compost redirects waste and reduces methane from landfills. Green waste—unused food, yard trimmings, and manure—is often sent to landfills. The decomposition process in landfills is sometimes anaerobic (in the absence of oxygen), which generates methane gas, a powerful greenhouse gas. In the United States, landfills are the third-largest source of methane production. Composting green waste instead can not only reduces pressure on landfills but can also reduce methane production. See Wasting Nothing Nexus.
- Compost can help stormwater management. Compost can be more porous than compacted, disturbed soil, which helps with water filtration, absorption, and drainage in soil. Composting can also increase the water-holding capacity of the land, reducing the need for water.
Learn about the different types of compost and how it is made. There are many ways to make compost. Choosing a method will depend on your goals, materials, and environment. Most people choose “hot” composting—also called aerobic—which involves five main areas: feedstock and nutrient balance, particle size, moisture content, oxygen flow, and temperature.
- Onsite composting requires very little time and equipment and is great for small amounts of food scraps. The process is “hot” because of the heat the system generates—in excess of 150∞ Fahrenheit—which kills pathogens and weed seeds. The periodic stirring of the compost material to reintroduce oxygen to feed microorganisms is what separates it from passive “cold” composting.
- In-vessel composting refers to any practice that involves feeding organic materials into a vessel, such as a drum, silo, or concrete-lined trench, and turning it periodically for aeration. The benefits of this method include having total control over environmental conditions.
- Vermicomposting involves adding red worms to food scraps, yard trimmings, and other organic matter. The worms feed on these materials and break them down into compost called castings. The process typically takes three to four months to produce castings that can be used as potting soil or as high-quality liquid fertilizer, known as “tea,” for houseplants or gardens. See Vermiculture Nexus for more information.
- Aerated (turned) windrow composting is best suited for large volumes of compostable material generated by communities, governments, farms, and businesses. Organic waste is deposited into long rows called “windrows” and aerated through manual or mechanical turning.
- Aerated static pile (ASP) composting is a production method that creates compost within three to six months using a homogenous mix of organic waste (excluding animal products and grease). Compost materials are piled on top of perforated pipes through which air is circulated.
- Johnson-Su bioreactor composting is a low-labor form of composting. The method controls the ratio of particular types of soil microorganisms that thrive with no turning and reduced water usage. Here is a guide on how to build one in a day using simple tools.
Set up a compost system at home. Compost can benefit home gardens by maintaining and enhancing soil quality. Instead of purchasing compost, consider starting a compost pile at home:
- Learn about the basics of composting. All types of compost require three ingredients: browns (dead leaves, branches, twigs), greens (food and vegetable waste, coffee grounds), and water. A compost pile should have an equal amount of browns to greens and should alternate layers of different-sized particles. Here is a handy list on what to compost, what not to compost, and why. Here is a guide on how to store food scraps. Here is a guide to learn more about soil health and evaluate your personal plants and land.
- Identify a location. Alter an existing container (such as a bucket or garbage bin) or build your own to sit outside (pallet box, chicken-wire container). There are many low-cost ways to do this yourself. Additional DIY ideas are here. If you’re making aerobic compost (fueling the decomposition process with oxygen and moisture), make sure your container has holes, or prop it up in a way that allows air to enter from the sides or underneath.
- Identify the best system for you. Backyard composting is most suitable for those living with gardens or yards. Here is a helpful video to get started. You can compost directly into your garden using an in-situ technique. Indoor composting is an option for those who live in apartments or are without access to an outdoor compost pile. Consider purchasing a special type of bin or making one yourself. You can also use a Bokashi bin, which is a Japanese system that anaerobically ferments your kitchen waste, including meat and dairy. The process uses bacteria and yeast to break down waste in the absence of oxygen. Here is a guide on how to set up an indoor vermicompost bin. If you run into any problems, consult a troubleshooting guide such as this one.
- Give your compost away. If you don’t garden, here are some ideas on how to donate or give away your compost.
Join a curbside compost pickup program. If composting at home seems like a challenge, consider giving your food scraps to a compost pickup program, in which a city government or business will do the composting for you.
- Municipally run: Boston kicked off a curbside composting program in July 2022, with thousands of households set to have food scraps picked up for free. Among U.S. cities, San Francisco, Seattle, Washington, and Burlington, Vermont, also have curbside composting programs.
- Privately run: If you live in an area that is not serviced by your government, consider paying for a curbside collective service. Compost Queen is one such example in northern Colorado that collects food scraps from your home for a subscription fee. Here is a list of compost pickup services across the U.S.
Start or join a community compost. Regional and municipal composting communities exist all around the world. Find the closest one or start your own.
- If you live in the U.S. or Canada, you can use this site to search for composting facilities in your area.
- The city of Amsterdam in the Netherlands provides “Worm Hotels” to allow neighborhoods to compost food and garden waste on a small basis.
- ShareWaste (Australia) is an online platform that allows users to share their organic waste with nearby community composters.
- Foodscape Collective (Singapore) connects compost makers with food-scrap givers through a crowdsourced map.
- ILSR offers a Composter Training Program to support community leaders who may be inspired to install and operate composting sites in their schools, churches, community gardens, and farms.
Get involved in composting activism. Composting is sometimes difficult to access for marginalized communities who lack the time, resources, and supportive regulatory environment. Through the effort of farmers, gardeners, and activists around the world, there are expanding opportunities for composting. Here are some inspiring examples:
- NYLPI is running a “Save Our Compost” campaign to advocate for all New Yorkers to have access to composting services for food waste.
- Lexington Green Teams is a grassroots alliance of parents, staff, and students across public schools organizing for a townwide curbside composting program.
- Ron Finley is known as the gangsta gardener in Los Angeles, famed for the transformation of South Central LA’s “food prison” into a fruit and veggie oasis. His MasterClass teaches how all gardening starts from compost.
- Savita Hiremath (Endlessly Green) has spent the past decade establishing and supporting self-sustaining composting communities around India.
- Follow Black Thumb Farm and Soul Fire Farm for composting best practices, as well as information on food justice and community activism.
Groups
Schools and Universities
Start on-campus composting. Students, staff, faculty, and administrators can all play an important role in starting an on-campus composting program. Although each institution will need to select a solution best suited to its needs, here are some resources to get started:
- The Campus Composting Manual provides directions on program planning, system selection, and engaging campus stakeholders.
- Here are some lessons and takeaways from on-campus composting programs across five U.S. universities.
- Here is an overview of campus composting programs in the U.S.
- UMaine has been composting using an in-vessel system since 2012, diverting over 400,000 pounds of food waste per year.
- The Vermont Agency of Natural Resources has published an on-site composting school implementation guide.
- Green Mountain has prepared a guide for schools to start composting programs.
- Cornell Composting also has resources on composting in schools, including classroom resources for educators.
- ICAW has compiled a list of resources specifically for teachers looking to educate on compost.
Farmers, Ranchers, Landowners
Incorporate compost in your operation. Most farms have all the necessary ingredients to compost: surplus plant/animal waste, space, equipment, and soil that can benefit from compost amendments. The benefits of compost on farms and rangelands include improved carbon storage, plant growth and health, improved soil quality and nutrients, and reduced water runoff.
- Identify a suitable method of compost. The compost facility best suited for your operation will depend on your site, feedstocks, budget, labor, and desired timetable. This article walks you through key questions before setting up on-site composting. Here is a summary of options when undertaking large-scale organic composting. The Composting Handbook is a how-to manual for farm, institutional, and commercial composters.
- Include manure in your compost. Manure on its own can release nitrous oxide gas, a powerful greenhouse gas that contributes to climate change. However, if the manure is incorporated into compost, it could limit these emissions in addition to contributing to the health of the soil. Here is a story about an amateur farm that does just that, changing its grassland into a healthy ecosystem.
- Spread compost on rangelands. Tests in California have demonstrated the value of spreading a layer of compost over rangelands, as this guide explains. Benefits include improved forage quantity and quality, increased water-holding capacity, and additional carbon sequestration.
- Sell your compost as a product. Here's an article explaining the logistics and profit potential of compost as a business. Follow this story about a farm that has dedicated 10 percent of its land to compost creation and was rewarded with sales that comprised 72 percent of its income.
Companies
Start composting at your company building or workspace. Composting is a useful approach for businesses that are looking for a way to save valuable resources, divert waste from landfill, and reduce waste costs overall.
- Some large corporations that have already started this include much of the automotive industry, as well as Google, Microsoft, Procter & Gamble, and Unilever. Subaru and Toyota are even piloting programs to use methane from compost as a fuel.
- This Canadian consulting company will help you get started if you’d like to initiate a composting program at your workplace.
- This small business is working to bring composting to workplaces, local government, and schools in the Washington, D.C., area.
- This Texas business is working with restaurants’ organic waste.
- Restaurants and food vendors can refer to these tips to make composting easier.
Governance
Legislate mandatory food waste separation. Policies that require and enforce food and lawn waste separation can boost composting programs, reduce pressure on landfills, and lower greenhouse gas emissions.
- India has launched a waste-segregation program on a national scale under its Swachhaa Bharat Mission.
- The city of San Francisco has made food waste separation mandatory.
- The state of New York requires any large-scale producers of organic waste to take responsibility for bringing food waste to a composting facility.
- EU laws require governments to improve household waste sorting and collection, including a biowaste collection stream to produce compost.
Legislate targets for landfill reduction. Reducing and eliminating waste disposal in landfills does not just reduce methane emissions sources but also presents an opportunity to divert organic materials for composting purposes.
- The City of Seattle doesn’t allow food or compostable paper in the landfill garbage.
- The EU Landfill Directive sets out requirements for landfill sites, including introducing limits on all waste that is suitable for recycling or energy recovery from 2030.
- The U.S. 2030 Food Loss and Waste Reduction Goals seek to cut food loss and waste, including that to landfills, in half by the year 2030.
- Singapore’s Zero Waste master plan aims to reduce waste to landfill per capita per day by 30 percent by 2030.
Implement organic waste collection. Programs that couple mandatory food waste separation with waste collection are the most successful. Curbside pickup programs take the pressure off the citizens to deal with the organic waste themselves and provide an easy outlet for compost creation.
- South Korea has a mandatory food waste collection. Citizens are required to separate their refuse, and the city then picks it up for free.
- The state of Vermont has a mandatory food waste separation program, although it’s not enforced or supported with enough resources yet.
- Portland is considering new measures to require businesses to dispose of their food scraps separately.
- In 2013, New York City started compost collection services and has since expanded to select districts.
- The Australian government has announced a large-scale composting facility in Canberra that will process food and garden waste from across the city.
Compost in government buildings and public infrastructure. Public buildings and offices can lead the way by producing and using compost in lawns and parks.
- Maryland has a guide for composting for local governments.
- Ann Arbor, Michigan, Parks has composting bins available on site for visitors.
Key Players
Groups/Organizations
Institute for Local Self-Reliance (ILSR) (U.S.) is a national research and advocacy organization that advances local composting to create jobs, enhance soils, and reduce waste.
LA Compost (U.S.) is a community-based nonprofit creating spaces for local compost and community empowerment.
International Compost Alliance (UK) aims to advance awareness of the benefits and use of compost globally.
European Compost Network (Germany) represents thousands of experts and plant operators with more than 45 million tonnes of biological waste treatment capacity.
The Association of Compost Producers (California) works to advance organic recycling, compost manufacturing, and utilization to benefit society and the environment in the largest compost market in the US.
Recology (California) is a private, employee-owned company managing San Francisco waste since 1932.
The Ron Finley Project (U.S.) is teaching communities how to transform food deserts into food sanctuaries and teaching individuals how to regenerate their lands into creative business models.
The Rodale Institute (U.S.) is a nonprofit conducting independent research to uncover and share regenerative organic farming practices that restore soil health, fight climate change, and fix the food system.
Alianza Cero Basura (Mexico) is creating the first zero-waste tourism destination in Mexico.
Countries and Cities
"How South Korea is Composting Its Way to Sustainability" by Rivka Galchen / The New Yorker
Swachhaa Bharat Mission (SBM) – A Paradigm Shift in Waste Management and Cleanliness in India by Sadhan Kumar Ghosh / ScienceDirect
Learn
Watch
The Secret History of Dirt by Vox (11 mins.)
Why Is Composting Good for the Environment? by SciToons (2 mins.)
Composting for Kids by HighfieldsComposting (6 mins.)
Vermicompost: A Living Soil Amendment by
AllisonLHJack (9 mins.)
Beginner’s Guide to Composting | One Small Step by NowThisEarth (7 mins.)
Compost for Beginners | The Dirt by Better Homes and Gardens (6 mins.)
Beginner’s Guide to Composting by the Nelson City Council (3 mins.)
How to Build a Compost Bin by HGTV (4 mins.)
Compost Collectives in Urban Areas by Ida Kleppe / TEDx Talks (6 mins.)
Vermicomposting: How worms can reduce our waste - Matthew Ross by TED-Ed (5 mins.)
Untamed Science: Compost by the North Carolina Zoo (5 mins)
Ron Finley: Urban Gangsta Gardener in South Central LA | Game Changers by UPROXX (5 mins.)
Read
"How Cutting Your Food Waste Can Help the Climate" by Kelly Oakes / BBC
How Composting Can Reduce Our Impact on the Planet by the United Nations Environment Programme
"The Climate Solution in California’s Compost and Crops" by Justine Calma / The Verge
"Composting Is Way Easier Than You Think" by Jillian Mackenzie / National Resources Defense Fund
"How South Korea Is Composting its Way to Sustainability" by Rivka Galchen / The New Yorker
Grow Your Soil!: Harness the Power of the Soil Food Web to Create Your Best Garden Ever by Diane Miessler / Storey Publishing, LLC
Compost City: Practical Composting Know-How for Small-Space Living by Rebecca Louie / Roost Books
Listen
Waste, Worms and Windows: Domingo Morales’ Quest to Make Compost Cool by How to Save a Planet Podcast (34 mins.)
How’s Vermont Doing with Composting? by Brave Little State Podcast (42 mins.)
Changing the World with Worm Composting by Permaculture for the Future Podcast (56 mins.)
Troy Hinke, Compost Tea by In Search of Soil Podcast (111 mins.)
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