Where does soil come from?
Have you ever wondered where the soil underneath us actually comes from?
And what exactly it is?
There are all kinds of things that make up soil, such as tiny bits of rock, water, air and organic matter. Organic matter means anything that was once living, so includes plant and animal waste. This stuff has decomposed, meaning it has broken down and decayed.
We know that things decay over time, but how and why?
Decay is so important - otherwise dead things would just stay as they are and nothing new could grow. Decomposition is needed for a healthy planet; it’s part of the nutrient cycle. This clever process is done by tiny organisms (living things) including bacteria, fungi and worms. They ‘eat’ the waste making it smaller and smaller until it becomes compost, which is the main part of soil. All of these processes are what makes up soil!
Do it yourself- make some compost
Why would you want to do this?
Isn’t it strange that we throw away our old food (or maybe you are lucky to have a food waste collection bin), then buy compost for our gardens? Imagine if you could avoid your food waste getting sent to landfill, and at the same time save some money on your family garden or windowsill plants. Well you can!
This whole compost making process can happen on a small scale in your own house. Vermicompost is the compost you get when worms decompose organic matter and turn it into worm castings/vermicast. Those are the circular squiggles of mud you can see in the grass. Compared to the soil you normally find in the ground, it’s packed with nutrients, and plants grow better in it.
My worm composter
A worm composter is a place where worms help food waste decompose. Mine is a large blue bucket with holes in the bottom and another bucket underneath. This gives the worms air - they need to breathe too! I began by shredding some newspaper, adding some shredded leaves and some grit such as little rocks or baked eggshells, and then added my worms. I covered it with a big towel in a spot that’s 10-20°C. I kept it moist and added in my food waste to a different place in the bucket every few days.
Where do I get the worms and how many?
I bought special worms from a bait shop online. Regular garden earthworms wouldn’t do well in a composter as they need to live far below ground. Worms are healthiest eating things naturally found in the soil, so stick to mostly vegetable waste and nothing fatty/oily/dairy/meaty.
To know how many worms you should have, first work out how much food waste your household makes. Too few worms and your food waste will start to smell, too many and your worms will be hungry. I weighed our food waste bin every day for a week before it was emptied and calculated the daily average. 100g of worms consume about 25-50g of food waste every day. How many does your house need?
Collecting your compost
I started my wormery in December and collected my first soil harvest in mid-May. I laid my soil out on a makeshift sheet and made lots of little piles. The worms kept burrowing down because they don’t like the sun and I could extract the castings. There were insects and other organisms in the compost too. We also found lots of baby worms, meaning the worms were breeding. This shows a healthy environment.
It was fun to take time just looking through the soil because there was so much life in it. When I had removed the new compost, I put the worms back into the bucket with food and shredded leaves. The new compost went into a pot to grow flowers in.
My advice
Making a wormery is an excellent way to reduce your waste and carbon impact, to help out your garden (my new flowers grew really well) and to see an important ecological process up close. However before you wriggle right in, make sure to check the following first:
Ask your parent/guardian! My mum initially wasn’t too happy about a worm composter; I had to convince her of the benefits and that it wouldn’t make a big mess. Make sure you agree on where your composter will be stored and that you take full care of it.
Do your research - sometimes problems occur e.g. if you don’t have enough air/water in your container, your worms will crawl up the side! Design your container so it has some air flow.
Be organised and get your materials ready first. Once the worms arrive they need to get into their new home quickly.
Be curious and enjoy! Even after studying biology, I learnt and enjoyed so much seeing decomposition up close.
Good luck!