Written by Claire Swetlin (Compost Coordinator 2019-2021)
Edited by PICA team
Purpose: the purpose of this post is to give an introduction to composting for students. It will give a variety of options for composting in different spaces. The post will also describe the basic science behind composting, why composting is important for your garden and the environment and an overview of our composting program at PICA.
If You’ve Never Composted Before, This Is For You
Take a good look at your trash. You might notice that food makes up a decent chunk of your trash bin. In fact, the EPA estimates that 22% of our yearly trash is food waste, more than any other category. If you are looking for ways to help fight climate change and decrease your personal carbon footprint, then I suggest diving into your trash. Composting is one major way you can lower the amount of trash you personally dump into the landfill. Composting is mutually beneficial for mother earth and for the composter. It saves you money, is a key factor in starting and maintaining a garden, it brings nutrients back to the soil, as well as being downright fascinating.
Composting benefits the individual, the community and the environment. On the individual level, there are several financial benefits. You may be able to decrease the size of your trash can and therefore decrease your waste costs. You can look into a smaller trash can or getting an insert at the Greenwaste website. Composting will also decrease your costs while grocery shopping. If you have a spare 6-8 hours each week you could cultivate a garden that regularly produces produce. This means you would be eating extremely fresh and high nutrient fruits and vegetables straight from your garden instead of having to buy lower quality foods from the grocery store. Lastly, Santa Cruz offers a Rebate Program program where they will refund you up to $40 if you buy a compost system from one of their partners. There will be smaller benefits you notice as well, such as less smelliness in your kitchen trash and a sense of personal pride that you are helping your community and your planet. An unexpected benefit I noted in my life that came from composting was that I became more conscious of the food I was eating. When you compost, it becomes very clear to you what foods you eat the most often, what foods you buy but don’t consume and what foods are absent from your diet.
Your community will also reap the benefits of your compost system. By composting, you are showing the city council that you would be open to having a city-wide composting system and you will be encouraging your friends and family to start their own composting system. The city of Santa Cruz currently has a policy that all to-go items that restaurants and businesses provide their customers with must be compostable. This is a step in the right direction, but unfortunately, Santa Cruz does not actually have a compost collection service for these items so they continue to end up in the landfill anyways, which negates their purpose.
Composting in your backyard will also help the soil in your community. When food goes into your trash can and is then dumped in the landfill, the cycle that nature depends on is broken. The food is unable to decompose and replenish the soil with vital nutrients and instead, it stays rotting in the landfill. This does several things, it takes up more space in the landfill which means it fills faster and smells worse. It means that trucks are carrying heavier loads and making more trips because the truck fills up faster. It also means that nutrients is not returning to the soil that it was taken from. Our food and our lives are dependent upon what is in the soil. A more holistic way of thinking about gardening is that you aren’t growing food, the soil grows the food and your job is to feed the soil. What’s in the soil will eventually end up in your digestive system. If the soil is nutrient deficient, then your diet will be too. Recycling your food waste instead of throwing it away means that you and your community will be eating more nutrient-rich foods.
There are several mainstream ways to compost that work for a variety of different environments and living locations. The ones I will discuss here are vermicomposting (the composting system PICA uses), tumbler composting and hot composting. While there are a variety of ways to compost and techniques to use, basically no matter what you do, the food scraps will break down. If you don’t have the time, space, energy or money to complete these composting systems exactly as they are described, that is O.K. No matter what, organic matter breaks down. These systems just speed up the process.
Some Composting Basics:
Q: What is compost?
A: Compost is decomposed food scraps and other organic material that you add to your soil.
Q: Why add compost, what does it do for the soil?
A: Compost adds nutrients back into the soil that was taken out by previous plants. Compost also improves the water retention of your soil by creating more complex soil structures that can trap water.
Q: What can I put in my compost?
A: Almost anything. You can technically put meat products, dairy and oil into your compost system but it will take longer to decompose and has a higher chance of attracting critters to your pile. I suggest against adding these items and instead adding any vegetable scraps, fruit scraps, tree clippings, leaves, plant matter and carbs such as pasta and bread. Click here for more ideas on what you can and cannot compost.
Q: How do food scraps become compost?
A: There are several things that happen that create compost. Microorganisms work in tandem with insects and decomposers such as worms to feed on the food scraps, break them down and then poop out what we call compost. These microorganisms and decomposers require an oxygen-rich environment just like us to carry out their work.
Q: Does composting produce CO2?
A: Technically yes. But it does not contribute to global warming, in fact, the exact opposite. The type of CO2 that is produced by the decomposition process is biogenetic, meaning naturally occurring and is not considered in greenhouse gas calculations. Decomposition is an essential and natural part of the life cycle, and CO2 is not actually a bad gas in the right quantities and in the right form. And while the system does produce a small amount of CO2, composting prevents the release of methane gas, which is what your food scraps produce when they go to the landfill. Methane is 26 times more potent than CO2.
Q: How do you know when you have compost?
A: The compost will be dark brown or almost black. If you see almost no food waste then you have compost. If you squeeze the compost a couple of water droplets should come out.
Q: What do you do with the compost?
A: We will be posting another blog post soon about what to do with your compost!
If you have only your patio or deck to work with or if pests are a big concern for you, then this system is what you want. This system is the most efficient, ie. produces compost the fastest. It is a form of hot composting, but instead of having to manually turn the compost pile with a shovel, the Tumbler compost system does it for you. All you have to do is a couple of times a week, give the Tumbler a handful of turns. This system does several things, it makes it easier to extract your finished compost from your unfinished compost, as well as naturally brings your newest organic material into the center of your system where all of the decomposers are. For more information on Tumber composting, click here!
This type of composting is for people with more space and less time and less money for buying a prebuilt system. Basically, this system is a stack of organic material in a box with air holes with a lid on top. This process requires a high oxygen environment for the microorganisms to break down the food in a timely manner. For this system, you will need to turn the pile with a shovel at the minimum, once a week. This allows oxygen to reach the center and bottom of the pile. The pile should feel warm because decomposition produces heat as a byproduct. For this system, you can just throw your food waste in along with some leaves or other more dry organic matter, hay works well too. Then you put the lid on top and revisit to turn the pile over. If you are feeling excited about your compost, you can turn the pile at most once a day. For more information on Hot Composting, click here!
This composting style is sometimes called a worm bin because it relies on worms to digest and decompose the food waste. For this system, you can think of it more along the lines of taking care of hundreds of tiny pets and in turn getting to use their biowaste. This system is more complex and requires more assembly, but it produces very high-quality compost. This system requires layers of food waste, dry biowaste and worms. The worms eat the food waste and produce worm castings, which is essentially worm poop. This sifts to the bottom of the bag or bin that you are using and then the worms move up the system to the newer food scraps. You can just keep adding scraps and the compost will sift down to the bottom where you can collect it. For more information on Vermicomposting and the other composting systems, click here!
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