Composting is the practice of intentionally managing the natural process of organic matter decomposition with the help of microorganisms and the right conditions. Anything that at some point grew out of the ground, like food scraps, leaves and grass trimmings, even paper and cardboard products, will eventually decompose naturally, and by composting, you can speed this process up. The result of composting is nutrient-rich fertilizer that can be used in gardens, farming, or simply to enrich soil to help with water retention. In short, composting is a recycling system for organic matter.
Unless you’re a long-time gardener or farmer, the concept of composting might seem intimidating or even a little gross. If you’re cooking, for example, it can feel easier just to toss scraps into the garbage than to deal with a compost bin. But there are some major problems with organic waste going into our landfills!
Landfills are part of the waste management system meant to store solid waste. Unlike recycling or composting facilities, landfills aren’t meant to cycle materials back into the environment or economy—they’re basically burial sites for waste materials. This can be a necessary part of our waste management, especially with hazardous materials, but they’re often not the best solution for handling our limited resources. Specifically, landfills aren’t a great way to manage organic materials like food waste.
When organic materials are introduced into landfills, a process called anaerobic decomposition happens. Certain bacteria that don’t require oxygen can break down organic materials deep in landfills, but this has a major downside: it generates methane gas. Methane gas is about 28 times as effective as carbon dioxide at trapping heat in the atmosphere, meaning it’s a major contributor to climate change. Sometimes this methane can be captured and used as fuel, but often, it simply releases into the air, contributing to climate change.
Also, once organic material enters a landfill, it never really leaves it, meaning that the nutrient matter is no longer usable. Organic material contains a lot of necessary elements of the life cycle, like nitrogen, phosphorus, and potassium. These aren’t unlimited in our environment, and by burying our organic waste, we’re essentially removing necessary nutrients from circulation. Every time we grow a tomato, some nutrients are taken out of the soil to make that growth happen, and if we then throw the tomato away, those nutrients are lost to the cycle. This loss of nutrients contributes to topsoil erosion and the increased need for fertilizers to grow our food. And poor soil quality is also linked to increased water usage, as nutrient-dense topsoil is much better at retaining moisture.
The U.S. is on the right track when it comes to diverting organic matter from landfills, but there’s still a long way to go. In 1960, 92% of municipal waste was landfilled, but as of 2018, we’re down to 50%. That said, about 40% of the food we grow goes uneaten, and food waste makes up about 21% of our landfill mass. Clearly, we still need to consider how we manage our food system, and big part of that is composting!
To encourage effective decomposition, composting requires four basic ingredients: carbon, nitrogen, water, and oxygen. Oxygen comes from air, which can require turning or tumbling the compost pile. Water usually comes from food scraps and ambient humidity. Nitrogen comes from “green materials,” which is most food and soft plant waste. And carbon comes from “brown materials,” which include leaves, dry wood, and shredded cardboard and paper.
If you’re composting at home, you’ll want to include a mix of green and brown materials in your compost pile to help create a good environment for that natural process of decomposition we discussed. If you’re just collecting materials for pickup, you don’t need to pay quite as much attention to the green and brown matter thing. It’s worth printing out a detailed list of composting do’s and don’ts for reference, but for now, here’s a basic overview:
Do Compost:
Don’t Compost:
Depending on how you choose to compost, there might be some variations in what materials are accepted. For example, backyard composters usually don’t put meat, dairy, or large animal bones in their compost piles, but some commercial facilities can handle those products with no issue. Definitely do some research once you get started to see what materials are best for your compost system!
There are lots of ways to get started composting. Whether you have a giant garden and lots of outdoor space or a tiny apartment in a city, there’s a way for you to participate in composting and divert organic waste from landfills. The best option is whichever one you’ll actually use, so think about your lifestyle when you’re getting started!
The most well-known option is the compost pile. This is where you add compostable materials to a pile or container and let them sit over time, occasionally turning them over to aerate, until they decompose into the rich, nutrient-dense soil we call “compost.” The pile doesn’t have to be a literal pile—there are lots of products like tumblers that help facilitate composting and manage pests and smells.
Maintaining a compost pile takes a little work, but it’s a great option if you have outdoor space and a way to use the compost once it’s ready. Compost piles are also a great way to manage yard waste!
If you live in a more urban setting, or the concept of maintaining a pile is a little too much work, another great option is vermicomposting, or worm composting. You can purchase simple vermicomposting kits, which are self-contained, low-maintenance and great for indoor use. The result is a nutrient-rich liquid that is great fertilizer for houseplants!
If maintaining a compost system isn’t for you, the good news is that lots of communities have adopted composting programs, either through the government or local organizations. Composting is becoming a lot more popular, so there are lots of organizations that will provide you with a bin and a pickup schedule, making composting just like recycling! Here’s a good list of composting services in U.S. cities, but check with your local municipality, or even the local community garden, to see what your options are.
Managing our resource consumption and waste responsibly is a big part of fighting climate change. By composting instead of landfilling organic material, we can minimize harmful emissions, keep necessary nutrients in circulation, and protect the topsoil that we need to keep our people and planet alive.
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