It’s easy to forget about soil – after all, it’s just the ground we stand on. But actually, soil is a bit of a miracle, currently being celebrated through the FAO International Year of Soils 2015 and World Soil Day on 5 December.
First of all, did you know that it can take 1000 years to create 2-3cm of soil? And that soil is a living thing? In fact, every tablespoon of soil contains more living organisms than there are people on the earth (i.e. more than 7.3 billion; that’s 7,300,000,000). The tragedy is that that living layer can be destroyed in an instant; Europe loses 11 hectares an hour due to building.
And yet we are completely dependent on soil for our immediate and long term survival:
- immediate as 95% of what we eat comes from the soil (not forgetting the contribution it makes to clothing, fuel, toiletries and medicines), and
- long-term because soils actually store more carbon than the atmosphere and all vegetation (including all forests) combined, so protecting soils contributes to preventing climate change.
In addition, soils:
- contain a quarter of the Earth’s biodiversity; each individual organism is tiny, but then so is penicillin and millions of people owe their lives to that particular mould (and we’ll need a replacement for it soon, too), and
- soak up moisture from rainfall and let it go gradually, helping prevent flooding.
So it’s in our interests to look after our soil. But the fact is that many agricultural soils worldwide are badly degraded. The UK’s garden and allotment soils are in better condition but there is always more we can do.
First of all, don’t kill it with paving or decking. There are options for creating paths and parking that don’t involve concrete. And nurture the soil you have. The best things you can do?
- Increase soil organic matter content – e.g. by adding composted vegetable & garden waste, leaf mould and well rotted manure. This will improve resilience to drought (less watering! hooray!) as well as increasing the supply of essential nutrients
- Maintain a good soil structure by
- not digging the soil when it is too wet or too dry, avoiding walking on the soil,
- adding organic matter as a soil conditioner, and
- sowing green manures over winter to protect bare soil.
- Use crop rotation
- Use pesticides sparingly and only when necessary – so as not to kill off helpful beasties as well as pests. The humble earthworm is your best friend.
There are a range of resources from Garden Organic on the “Growing Hints & Tips” page of this website. The best summary is managing your soil, but I also found the article on when and how to use different soil improvers enlightening.
Here’s hoping that Saturday’s weather will allow us to spend some time contemplating our soil on World Soil Day.