Americans waste 30 to 40% of the food we produce. And where the waste goes is an important question because where you put it can help or harm the planet. There is no in between.
One way to dispose of your old vegetables and food scraps is to take them to a landfill. What is happening at the TPA may be different than you think.
Because landfills are deep enough and contain lots of things that will never go bad, food scraps that end up there don’t have what it needs to break down. The degraded microbes need oxygen from the air; they are aerobic microbes. They convert food waste into soil-like substances and they will release carbon dioxide (CO2), just as we do when we exhale. But not for long.
With no fresh air entering, the waste immediately switches to anaerobic decomposition, which means it breaks down with microbes that don’t need oxygen.
The problem here is that instead of emitting CO2, anaerobic microbes emit methane. And even though CO2 is a greenhouse gas, methane is 28 times worse. This means that it stores 28 times more heat than CO2. So this is not a good way to dispose of our food waste.
And that’s a shame because 30,630,000 tonnes of food waste goes to landfills in the US alone each year, according to the EPA. This makes landfill food waste a major source of greenhouse gases.
A small portion of our leftover food becomes compost. And it offers a great solution.
In 2009, San Francisco launched mandatory recycling and composting regulations. The compost is collected together with green waste and transported to the city composting center. The compost produced is used by regional farmers and wineries. Overall, in 2012 the city had achieved a waste diversion rate of 80%.
Here in Nevada County we have a municipal composting program aimed at larger food waste processors. Check out Garbage Management, the Nevada County homepage and scroll down a bit to find out more.
Into the gutter?
You can throw some of your leftover food in a landfill. What happens then is that water enters the wastewater treatment plant and contributes to the bio-solids there. Methane is produced from biological solids. Several processing plants collect methane to burn for other energy purposes, but many are still not captured.
And if you have a septic tank, RotoRooter advises not to throw your leftovers in landfills.
This method of disposal is mutually beneficial for everyone. Composting allows microbes to work to break down your leftovers and many of the other organic matter you have on hand. You make sure they have food (leftovers and other organic matter), the right amount of humidity, fresh air, and aren’t too hot or too cold.
What compost can do for you is create a fertile change to your garden soil for more and healthier vegetables, herbs and flowers. But it is not a source of nutrition for your plants. It does have some of it.
The main benefit of compost is that it provides microbes that will thrive in your soil and continue to break down organic matter to make new nutrients available to your plant roots.
After all that decay occurs, a series of chemical reactions take place and a mixture of molecules is produced. This mixture is called humus. One type of molecule that results from this process is humin, a very large molecule full of carbon. Since humus is the end product of all putrefaction, it does not break down any further. This means that humus survives in the soil for hundreds or even thousands of years.
So composting food waste helps lock carbon into the soil. Take it from carbon dioxide in the atmosphere – a major greenhouse gas, through plant growth, and convert it to carbon in the soil to last for a very long time. So, if you compost your leftovers, and put them in your soil, you will not only benefit from better soil health and garden productivity, but you are also helping in the fight against climate change!
There are so many ways to make compost! They can be very simple to get more involved. You will get more compost faster if you choose a method that requires more attention.
Basically, here’s how to make it. The organic material you need may be brown or green. Chocolate is higher in carbon and lower in nitrogen. Chocolates are things like fallen leaves, perfect for autumn collections, sticks, some paper, straw and the like.
Green is higher in nitrogen and usually also contains water. This includes leftovers (generally vegetative only), aged vegetable crops and minor pruning.
All of them already have microbes in them. Putting them together and adding just the right amount of moisture will allow microbes to multiply and destroy plant material. Turning the compost or in some other way aerating it makes the oxygen supply in the pile. If not refilled, the pile can become anaerobic. Which, as I noted earlier, releases methane. What we don’t want.
But compost can be simpler by using a cold pile that breaks down more slowly. You can even use a bucket in the garage. Or you can try worm composting. Getting fresh worm castings is one of the best things you can do for your plants, even your houseplants. And it can be done indoors.
There are countless resources for learning more about all methods. For starters, I recommend the Master Gardeners website, ncmg.ucanr.org. Check out the Compost is the Gardener’s Best Friend video from August 22, 2020, plus their resources.
There are tons of YouTube videos and books showing how to compost, several methods if you don’t have the page. Worm composting will provide you with the best fertilizer for your potted plants and can be done in a mud room, patio or garage. And composting buckets will give you something to add to even a small outdoor garden space.
Any composting keeps food waste out of landfills which will cause even more damage to the planet. And although it may sound like a drop in the ocean, it is the collective little actions of individuals that speak clearly and can make a difference to help our planet.
Doreen Fogle is a landscape designer and writer in Nevada County. More of her articles can be found on her website mydelightfulgardens.com and she can be reached at [email protected].