GROUND BREAKING! Did you know that coming into contact with a healthy soil can help your mood? Soil contains a bacterium called Mycobacterium vaccae which, when absorbed, activates a small group of neurons that contain serotonin – the hormone responsible for mood regulation, sleep and digestion!
LET IT SINK IN! After the world’ s oceans, soil is the next biggest carbon sink. It holds around 2,500 GIGATONS of carbon, which is more than three times the amount of carbon found in the atmosphere!
Mini-Mud-Pie
Detective What’ s my soil type?
1 Collect a heaped tablespoon of dry-ish soil. Discard any large pieces of stone or organic matter.
A healthy soil is a complex ecosystem, filled with air pockets and channels left by rotting plant material and burrowing invertebrates. This helps the soil to hold more water, reducing the impact of droughts, but also acting like a sponge to absorb rainwater and reduce flash flooding. It’ s all GOOD NEWS!
Around half of a healthy soil is water, air and organic matter, but the rest is a mixture of three minerals – silt, clay and sand.
Silty soils are often found around rivers because the particles are so light that they are left behind by flood waters. A sandy soil is very free-draining and does not hold water or nutrients for long. Clayey( yes, that’ s the right word!) soils are the ones that stick to your boots – they can hold lots of water but dry out and crack in summer.
2 Add a few drops of water. Add just enough so you can make a mud worm. Clay particles make the worm stick together easily, and the more clay there is, the less the worm will crack when you try to bend it gently in the palm of your hand.
3 Now squeeze the worm between your thumb and forefinger. Can you make a ribbon? If you can, it suggests a high clay content, but a crumbly worm indicates more silt and sand.
WRIGGLE ME THIS! The soil beneath our feet would be nothing without our friend the humble earthworm! There are 26 species of earthworm in the UK alone and they play a vital role. Not only are they a food source for garden birds and mammals, but they also keep our soil healthy. They can consume their bodyweight in soil each day. Did you know that soils without earthworms can be up to 90 per cent less effective at soaking up water, which can lead to erosion and flooding?
BREATHE IT IN Because earthworms breathe through their skin, they have to come to the surface in heavy rains so that they don’ t drown.
4 You can work out how much sand by how gritty it feels. Follow the QR code to the British Society of Soil Science worksheet to work out your exact soil type.
SOIL SCIENCE
SCAN ME
Hand texturing is a quick way to assess the basic composition of your soil and its ability to drain, hold nutrients and support plant growth!
Words: Dr Sarah Bearchell. Illustration: Sally Agar
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