What used to be known as green manures have taken on a new significance, they are now called cover crops and are used to protect and improve soil.
In many ways the benefits are the same in terms of returning nutrients but there is another crucial effect. Current research has shown how crucial the network of soil fungi are in protecting and improving soils structure and enhancing the nutrient levels available to plants.
The use of mycorrhizae fungi has increased over the last decade. Now there is evidence of the beneficial relationship between the fungi and plants roots. The roots exude sugars which feed the fungi in return the fungi breakdown organic matter into the nutrients the plants need.
The key thing to remember is that the web of hyphae, the thin, white cotton like strands of the fungi are easily broken by digging. In agriculture many farmers in the US are turning to ‘no till’ growing meaning that they do not plough after harvest but sow straight into the ground. The same applies to gardening, stop digging as it destroys soil structure!
The regime here is to remove crops with as little soil disturbance as possible, mulch with compost and sow into the mulch. During winter, the beds are covered with a crop which is cut down in spring, covered with compost and new seeds sown.
(Please note: I have no affiliation with Marshalls other than occasionally buying seeds from them.)
It was great to see an extended piece on Channel 4 news tonight about biodiversity and farming and biodiversity. They even showed a UK farmer using regenerative agriculture techniques seeding directly into the ground without ploughing up the last crop. The farmer was very enthusiastic about the quality of his soil saying it was like crumbly fruit cake.
Then there was the Derbyshire Farm that has been trialling wildflower strips and a short piece with Rosemary Furness who wants to make linked wildlife corridors.
It was all good but what irked me was some of the commentary at the beginning that implied that farmers grubbed out hedges to make higher profits. Let us get this straight, they were encouraged to ‘modernise’ to increase output by government as part of the never-ending quest for the cheapest possible food.
Farmers are not like other businesses producing items to sell on the open market for the best possible price. Instead they are contracted to supermarkets to supply a certain quantity of produce when the retailers demand it. If demand drops or the retailer finds a cheaper source, wants a loss leader or to have a 2 for 1 offer, the farmer pays. If they fail to do what the supermarket requires, they lose the contract.
The blame for biodiversity loss should not be shouldered by farmers alone as successive governments have been more than happy to divest control of the food supply to the nine supermarkets that supply 90% of food in the UK. The idea that the overriding criteria for ‘good’ food is price and price alone drives biodiversity loss.
What needs to change is the whole food supply chain from the way food is grown to the way it is sold to what we eat. If we want more biodiversity and a more stable eco system then we, as consumers need to take responsibility for the food choices we make. We need to change the way we eat, see food as more than just pit stops to fill the tank and realise that our health is directly linked to the health of the planet that sustains us.
When I had an allotment in Coventry there used to be procession of mature allotment holders hobbling around every autumn. Some would stop at the gate and ask if I had done the digging yet. When I said no, I don’t dig they would express surprise, shake their heads and shuffle off.
Now modern advances in soil management have demonstrated that deep cultivation, or any cultivation, damages soil. Thirty years ago it was still considered to be wrong, and a bad way to garden, how things have changed.
Earth works: a layer of mulch on your soil is enough. Photograph: sanddebeautheil/Getty Images/iStockphoto
An article by James Wong in The Guardian says it all:
“The natural action of earthworms in soil creates a healthy crumb structure and riddles it with tiny, air-filled channels, which digging destroys. Rather than suppressing weeds, the action of digging brings seeds that may be lying dormant underground to the surface, triggering their germination.”
So, if you want some exercise go for a walk or a swim but don’t wreck your back by digging the garden.