How to produce outdoor compost
Why is composting crucial to fight climate change?
Food production is the #1 cause of deforestation, water extraction and biodiversity loss (Greenpeace). And sadly, 33% of the food produced worldwide is thrown away. We could think restaurants and the foodservice industry in general are mostly responsible for this 33% of waste, but 43% of it comes from our households (Deloitte).
In this frenzied cycle of food consumerism, 1.7 billion tons of topsoil are lost every year (agreenerworld.org). This is happening because the soil loses its nutrients due to the use of agrochemicals that guarantee a massive production of fruits, vegetables, and grains.
A first and urgently necessary solution to this issue is reinventing our food consumption habits so as to avoid so much deforestation, water extraction, biodiversity loss, and food waste. I will dwell on this topic in a future post.
A second and just as necessary solution is to return nutrients to the soil in order to avoid losing more fertile topsoil, which adds to the deforestation, water extraction, and biodiversity loss. But how do we return nutrients to the soil? By composting our food wastes instead of sending them off to landfills.
If the earth is healthily given back its nutrients through food scraps (compost), it can retain water and greenhouse gases such as carbon and methane, because these can be processed by carbon-fixing microorganisms that live in soil. On the contrary, food in landfills adds to the global warming crisis because those greenhouse gases are directly and innevitably released into the atmosphere.
In other words, nurtured soil is alive, meaning it's full of microorganisms that do their job in keeping greenhouse gases underground, where they belong and where they can be of use to plants. Instead, a malnourished soil is dead: devoid of microorganisms and destined to erotion and to releasing all its humidity and greenhouse gases.
Therefore, reviving soil through composting is of vital importance and plays a most central role in our fight against climate change.
Types of compost
There are three types of composting:
- outdoor composting,
- vermi composting, and
- bokashi composting.
Vermi composting is accomplished with the aid of earthworms (especially, the Eisenia foetida species) that decompose food wastes inside a worm bin. This bin must be kept indoors, with an mild humidity level, and at a low temperature (so, preferably in a dungeon). Citrus must be avoided as they are harmful for the worms.
The bokashi method consists, first, of an anaerobic process of fermentation aided by a specific mixture of microorganisms one can buy for this purpose. After being fermented, wastes have to be burried outdoors in order for them to decompose.
Outdoor composting is obtained by mixing our food scraps of vegetable origin with dried leaves, sticks and soil inside a container such as a big rubbish bin. Since this is the most simple way of breaking down our food wastes into fertile soil, it's the method I'll now explain.
Outdoor composting step by step
1) The first thing you need is a big container, such as a garden rubbish bin to which you'll need to drill small holes all over in order for air to circulate though it freely. Alternatively, I suggest you buy a tumbling composter, which you can easily spin in order to mix all the content thoroughy. Please note it's more difficult to mix all the content inside a regular bin. I've had the 27.7 gallon tumbling Miracle Gro composter for almost a year and, so far, it's worked perfectly:
2) On the bottom of your container/composter, add a bed of dry leaves, sticks, and soil (about 1/6 of the size of your container). On top of this first layer, you can start adding your food scraps, which have to be exclusively of vegetable origin: un-saut茅ed vegetables and fruits without oils or dressings. All edibles of animal origin (dairy, eggs, white and red meats, fish and seafood, butter, etc.) cannot be composted this way.
3) You can throw your scraps to the container/composter just as they are, or you can chop them down into much smaller bits. This will speed up the decomposition process, which without choping the scraps, can take up to about 3 months. I know it sounds really unpractical to have to chop your food scraps every day before throwing them to the composter. So, what I do and suggest you try is collecting your scraps in a small metal, lidded bin in your kitchen for some 3 to 5 days (don't worry, they won't start to rot if they're just leftovers of veggies and fruits). And after the bin is full, you can chop all the scraps using an electric food chopper. I use the Kitchenaid Mini Food Chopper KFC0516 and it minces up my food scraps beautifully in a minute.
4) At least once a week, cover the scraps with a new layer of dry leaves and mix all the content by spining the tumbling composter, or stiring the content of the bin with your hands and a garden fork.
5) It's important to keep your compost mildly humid (nor too dry, nor too soggy). During autumn and winter, you might be able to add a layer of dry leaves to your compost every other day, which will help to avoid your compost from getting soggy. However, during spring and summer, or whenever the rainy season is where you live, you can add a copious amount of organic and sterilized sawmill once a week to your compost; this will absorbe the excess moist. On the contrary, if you live in a very dry region, you can spray your compost as needed with a watering can.
6) Once the container/composter is filled up to between 80% and 90% of its capacity, let it rest untill all the scraps are decomposed into brown, fresh soil. I recommend you only fill it up to 80% of its capacity, as the more room there is for air to circulate, the faster the content will decompose. I also suggest you have two composters, so that once one is filled up and needs to be put to rest, you can start using the other one.
7) Once the compost has all turned to soil (you should not be able to distinguish any scraps), you can add it to your plants as you would do with regular soil. Bear in mind the PH of this type of compost is more on the acidic spectrum. So, if you want to use it with plants that prefer a more neutral or alkaline PH in their soil, you might want to sprinkle a pinch of organic and responsibly sourced ashes on top of the plant's soil before watering it, to balance its PH. By the way, some of the plants that prefer a more neutral or alkaline PH are cacti and succulents.
8) A final note: During the whole process, your compost should never smell bad; it should always smell like fresh and moist earth, like the scent gardens give off after rain or dew. If your compost starts to stink, it means you might have accidentaly thrown in some scraps that were contaminated by produce of animal origin or vegetable oil (olive oil, canola oil, etc.) In such a case, throw the compost to your regular bin, wash the composter with water and organic soap, and start the process all over again.
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