Digging the dirt – could do better

No doubt this derelict shack will be appearing on AirBnb sometime soon but all that glitters is not gold.

There’s a huge difference between running cattle and sheep on 5000 hectares (12,300 acres) and growing vegetables on an allotment; but the starting point is exactly the same – earth.

Having allowed my imagination to run free in the last couple of posts, it’s time to get back down to some allotment basics – after all, one of my principal aims for this holiday was to get stuck into some serious reading about regenerative farming. I certainly got stuck at first but switched course and now I’m beginning to think that I ought to make a proper list of the books I’ve been reading so readers can join me in the journey. I’ve now just about finished reading Gabe Brown’s “Dirt into soil” and although it’s hardly aimed at our 200 square metres of allotment and is really slanted towards mixed farming with grazing animals, it cleared up a few mysteries for me and turned my thoughts about soil improvement completely upside down. It’s also given me a much clearer perspective on what is, and what isn’t regenerative farming and since our UK government is talking the talk about changing agricultural practices it’s up to us to make sure they’re also walking the walk. After all for a government that announces it’s going to move towards carbon zero and then announces it’s considering opening a new coal mine – followed by the assertion that we’ll need more nuclear power stations – this isn’t an encouraging start.

Until now I’ve always thought of soil improvement as largely a matter of adding lots and lots of compost. We started off committed to organic gardening and then, a couple of years ago we went no-dig as well. This last season we grew a variety of insect pollinators and companion plants alongside the vegetables in all our beds, and it’s gone well – and with the pond we’ve had vastly more visiting insects. Of course we’ve changed so many variables and the weather has been so random, we’ve only got anecdotal evidence that our changes have worked but we’re pretty sure that the following strategies worked:

  • Netting all the alliums from sowing to harvest with fine insect net
  • Using nasturtium to draw blackfly away from food crops
  • Sowing Calendula and Tagetes on most beds
  • Butterfly and bird netting all the brassicas

Sadly the expensive treatment with nematodes had little impact on the slugs, and the beer traps sheltered more slugs underneath than drowned in the beer.

The asparagus was spared the heavy beetle attacks that we’ve had in the past, and given that our near neighbour had his plants devastated it looks as if the border of calendula and the increased parasitic insect population may have helped. I’ve written a lot about our liability to waterlog in the winter – partly due to underground streams. We’ve spent a lot of time and effort digging woodchip filled paths between the beds to drain the water away and the two worst affected beds came through the winter very well. We’ve also added grit and sand in the worst places along with masses of compost and leaf mould. The upshot has been that our need to water in dry spells has greatly decreased. We escaped the blight with resistant varieties and early cropping of the container potatoes so, looking back it’s been a pretty successful season most of which was spent battling against a headwind of adverse weather.

If you’re still with me, you’ll have noticed that every single effort to improve our earth has been via applications to the top surface. What the Gabe Brown book – and all the others I’ve been reading – brought to the top of my thoughts was to see what’s going on under the surface, and the usefulness of ground cover crops during the winter, so that the plants go on feeding the soil through their roots all year round. And there’s the revolution, because most of us instinctively think of plants as a kind of one way street for water and nutrients when in fact they’re completely biologically interlocked with billions of soil organisms which, in return for carbon in the form of photosynthesised sugars, provide the plants with many of the micronutrients they need to grow and thrive. All this mutual aid is conducted through the truly huge mycorrhizal networks that wrap the roots and occasionally even grow inside them. Plants send signals seeking specific nutrients and the fungal networks ship them in. The astonishing discoveries of science now tell us that the creation of soil can be much faster than we originally thought and that in contrast to the received wisdom that everything goes on from above, soil creation is as much concerned with the recovery of nutrients from the subsoil. Soil can actually grow from below. This is a vast simplification but it has big implications for the way we grow plants, because these networks – having evolved over millions of years – mean that we can no longer think of what goes on underground as separate from the plant we harvest. Soil microbes have the astonishing ability to break down subsoil and rock and dissolve the essential nutrients in a way that’s barely understood. We need to start seeing our crops as giant solar energy farms, converting carbon dioxide into food through the process of photosynthesis.

So when we add artificial fertilisers to a crop the plants just grab up the 25% of the fertiliser they can use and the rest goes into the soil and gets washed into our polluted rivers. Worse still, the plants get lazy and just go for the industrialised fast food and the sugar/carbon trading mechanisms get broken. When we drench the soil with insecticides and herbicides exactly the same thing happens. Industrial farmers and gardeners then start to try to make up the deficiencies with more additives and chemicals. The other way we break those mycorrhizal connections is by digging and turning the soil, and these relationships are precisely the mechanism by which carbon gets stored in the earth.

So farmers, gardeners and allotmenteers, not to mention every other human being on earth have a common cause in not ploughing, tilling and digging; not using artificial fertilisers and not using chemicals. What ought to be the good news for farmers in particular is that chemicals and diesel oil are increasingly expensive and eat into profit margins – plus, the premium value of the produce from regenerative farms means better profits. What’s not to like?

Here’s the downside. It looks as if the agrochemical business and their captive bureaucrats in the Ministry of Agriculture are greenwashing as usual in pushing no-till, direct drilling supplemented by – you’ve guessed it – herbicides to kill weeds, plus the usual pesticides and fungicides which will do nothing to solve our problems. There is another way, for instance, to suppress weeds and reduce rainwater runoff, and that’s carefully calibrated cover crops.

But it’s not all good news for vegetarians and especially vegans because the very best and most efficient way of improving the soil is by doing (or not doing) all of the above plus carefully controlled grazing – sometimes known as mob grazing. This kind of approach can capture carbon in the soil far more efficiently and more quickly than by planting trees alone. Further – and I know what question will be next – controlled grazing on healthy soil means that dung, a potent source of methane when stored in lagoons and sprayed on the soil later – is quickly broken down by prodigious numbers of insects and soil organisms and feeding the soil. Not only that, by feeding cattle on their evolved diet of grass and forbs rather than industrial grain, their digestive systems function far better and the need for constant worming and antibiotics almost disappears. Meat will, of course, become much more expensive, (perhaps more realistically priced) which should please everyone with a concern for animal welfare.

Of course this won’t make catastrophic climate change go away – we’ll still have to break our addiction to oil in every other department of life – but farmers, allotmenteers and gardeners can at least do something to help, and everyone can help by supporting change, buying better rather than blaming farmers and growers and calling out politicians when they try to pull the wool over our eyes.