A blueprint for growing carbon in the soil whilst accelerating crop growth
By: Matthew J Shribman
Tags: Farming, Ecology, Sustainability, Sustainable Food, Climate Change

(Drawing by Minty Sainsbury)

This piece of writing is about how to use ramial chipped wood (RCW) to turn our farms into carbon sponges producing much healthier food. I wrote it in November 2019, but I’ve only just got to publishing it. Sorry for the delay!

Farmers could easily be the heroes of the climate and ecological crisis, and they could be making healthier food, and more of it with less effort too.

By learning from nature and farming in closer harmony with it, farmers could be sequestering enormous quantities of carbon.

I’m going to write here about a methodology that’s based on hoodwinking land into thinking it’s in a forest using ramial chipped wood (RCW). It’s been shown to…

accelerate crop growth

minimise weed growth

“grow” carbon in the soil

It sounds too good to be true, but it ain’t.

For decades, farming has focused on using ideas from chemistry to maximise the yield of crops, by working out what crops need, and adding that into the soil, replenishing nutrients chemically once they’ve been depleted. Simultaneously, other chemicals are being used to kill weeds and pests.

But these methods, and their counterparts have inadvertently been destroying the natural biological balance that makes soil so rich in the first place.

Rather than focusing on the plants, pests and weeds, we ought to be focusing on the soil itself. If we look after the soil well, it’ll take care of the rest for us.

Balanced, healthy soil, like the soil found in old forests, has healthy fungal networks, plenty of protozoa, nematodes, worms etc. These living things keep the soil fertile, minimising weed growth, and fighting off invading pests in the process, as they have been doing for many millions of years.

How do we get started?

It’s quite apparent that, with 50% of the world’s habitable land now covered in farms, the first step is to re-wild most of the farmland that exists on Earth.

At present, the majority of farmland produces food very inefficiently, with about 80% of it producing only about 20% of the world’s food. This is because it’s producing animal products or their food.

The remaining 20% of land is much more efficient — it’s supplying about 80% of our food by producing plants for humans to eat.

We really need to do away with the majority of animal farming, so that we can re-wild much of our planet, to store carbon and restore habitats for wildlife.

Anyway, I digress!

On to the specifics of RCW…

With the islands of land that remain in the sea of restored wilderness, the strategy begins with ramial chipped wood (RCW) collected from hardwood trees.

These can be obtained by coppicing a few branches each year, so that each tree continues to regrow. These woodchips should be from branches about 7cm in diameter, because these have the optimal ratio of woody material in the centre to cambium around the edge.

The cambium is full of protein, nitrogen, K, Mg, Se, Zn etc., particularly if harvested in the autumn when all of these nutrients have been drawn out of the leaves to winter in the branches. These materials are ideal both for plants and for the bacteria in the soil.

Meanwhile, the woody material acts as ideal food for the fungi. If a different diameter of branch was used to make the woodchips, the ratio wouldn’t be quite right, and so there’d be an imbalance of fungal and bacterial growth. Too much woody material, would mean too little nitrogen, and so too few bacteria, for example. Animal manure and chemical fertilisers both have way too much nitrogen, which means too much bacterial growth, and not enough fungal growth.

The only other material that comes close to RCW in terms of having the right ratios is hay, but hay is really bad at allowing air and water to flow through it, and so, when lying in a field, it gets too wet on the top and full of slugs, whilst underneath it gets too dry and fills with mice.

The woodchips should be arranged in strips across the land. 45cm wide strips, at least 30cm deep is a good start.

In-between each woodchip strip, there ought to be a 75cm wide strip which is set up by beginning with a layer of cardboard, and then the turf from the neighbouring woodchip strip laid on top of it upside down, and finally compost made from organic household waste (though biochar could be used instead).

All the land should then be levelled by filling up the wood chip strips.

Crops are best propagated in a greenhouse, and then placed in the soil by hand.

Because the resulting soil is so healthy, barely any weeds grew (down about 80%), no machinery is required to loosen it, and the crops grow about 50% faster than normal, allowing for multiple plants per year.

But even better, the whole system restores the food web in the soil, sequestering enormous amounts of CO2 permanently into the soil. This method accelerates natural carbon capture.

A mix of crops (beans to attract aphids, rhubarb to attract ladybirds, lavender to attract bees) ensures an even healthier eco-system. A healthier eco-system means better crops and less work.

Cover crops can be used, but only if they’re killed by flattening them into the soil, rather than ploughing them in, as ploughing kills all of the fungal networks, undoing all of the good work.

Nature may look messy, but it’s actually really well organised, and by understanding it better, we can more effectively work with its ingenious design, rather than trying to re-invent it and inevitably getting it very wrong.