Life giving soil is so important to us all

So at the back end of the season I decided to do quite a bit of digging on dry days. I got rid of quite a bit more of my fine collection of coarse grass and turned over a few clumps of claggy soil in the hope that it would get broken up by the frost. It seems to be working. I don’t exactly have a fine tilth that you can work with a rake but I can now finally put a trowel in to plant something without feeling like my wrist is going to explode.

As soon as you get some air, a few nutrients and the right amount of moisture into soil it is astonishing how quickly it starts to improve. There are billions of living organisms, mainly bacteria, in each teaspoon of soil and they need air, water and food to survive. Fortunately that is exactly what they get in normal soil.

On average a little less than one half of all soil consists of eroded rock particles whilst 25 per cent of it is water and almost as much is air. The rest is the vital five per cent which consists of organic matter.

The living things need something to eat down there in the dark. Which is why I’ve been trying to build up a decent compost heap and will be trying to work some of it into the ground. It is also why all these wet days haven’t been much use for anyone trying to grow things. Walking on wet soil is never a good idea. It squeezes out the air and the water and leaves the ground too compacted for most forms of soil life to function easily. They simply can’t get enough oxygen.

We are all used to the idea that there is huge biodiversity across the surface of the planet. Few of us worry about the similar biodiversity that exists beneath our feet. The variety of fungi, bacteria and microscopic animal life living in each square metre of soil goes well beyond the odd worm.

The roots of all our crops need to interact with the appropriate fungi to prosper. Indeed one of my old books tells me that without the right fungi all plant life would die out within a couple of years. And humanity with it, of course. Another informs me that a single rye grass plant has such fine root hairs that they are estimated to total 7,000 miles in length. Each of them drawing in nutrients and water and frequently interacting with microscopic soil life.

Hidden down there in the soil there are also nematode worms that will fire a dart into the root of a plant and suck out some of its nutrients. Not very helpful for anyone trying to grow anything you’d think. But then there are other forms of nematode that fire their darts into slugs and snails or leatherjackets.

Since 95 per cent of all insects spend part of their life cycle living in the soil nematodes can also finish off almost anything else that might take a fancy to eating what you grow. So they destroy an awful lot of pests before any of us know they might have grown up and caused us a lot of problems.

Apparently it takes 10,000 years to make 30cm of soil and only 11 per cent of the earth’s surface is covered by any. Worldwide it is estimated that we are losing 300 tons of it every minute. So every time I turn over a shovel of soil I’m potentially helping out billions of living things and looking after a precious resource which has taken the whole length of the written history of humanity to create.

I have to confess what when I set out for the allotment I hadn’t intended to achieve anything quite so heroic. I think I might need a very large beer to recover from the effort.