What is RCW?
Interview with Jack Dupety, Agriculturalist & Author
In order to understand RCW, a technique that originates from France, it's important to understand the meaning of the term.
First of all, the term refers to wood, and therefore implies trees.
In particular, the term refers to ramial wood, or young branches that have sprouted just in the past year.
These young branches are the richest part of the tree, ten times richer than trunk wood or large branch wood.
The term RCW also invokes the idea of chipping, perhaps the most obvious aspect of the finished product.
We realized that when we cut young tree branches into chips, we allowed for a greater development of fungi.
Chipping the wood open the doors for fungi to establish itself in the RCW.
If we take a branch and stick in the ground, the only entry way for fungi is the endpoint, where the branch was cut.
That's because fungi is unable to penetrate the bark of the branches.
Advantages for the soil
First advantage: Soil cover
We only use RCW during the end of automn, the beginning of winter and during winter.
The first advantage is that the RCW layer that we put on the top of the soil acts like a blanket which helps promote and support fungal growth.
Gilles Lemieux (1952-2009), Author & Professor
In the words of Gilles Lemieux, we're copy-pasting forest soil into agricultural soil, minus the trees.
The RCW layer allows the flora and fauna within the soil to flourish, protected from frost, especially.
Within the soil, fungi can grow up to -7 degree celsius (20 degrees Fahrenheit).
That's why RCW works -- perhaps somewhat slowly, but nevertheless works -- in the winter time.
Second advantage: Non-polymerised Lignin
When we take a twig in our hands, it is very supple. It won't break and we can almost bend it into a circle.
But if we take a branch with about a thumb-width's diameter, it starts to break very quickly.
The breaking point is due to the lignin molecules, which exists in all stages of wood, but which in small branches isn't yet fully formed.
The fact that the lignin is still being formed in twigs and small branches means that it's a great environment for fungi to grow in.
The fungi will start to break down the lignin molecules in formation and make it more easily digestible by the fauna which will come in later.
Fungi that finds lignin in the form of soluble, or little-polymerized, lignin secretes enzymes that help to even futher open pathways to break down the lignin.
The enzymes secreted by the fungi contain both biotic elements, like super vitamins, and abiotic elements, like antibiotics, or medicines.
These elements secreted by the fungi are associated with the humus, allowing the plant to have direct access to medication in order to respond to fungal attacks or attacks from parasites or insects.
Advantages for humans
For farmers, gardeners and growers, the advantages of RCW are numerous.
1) First advantage: saving water
We found that the net benefit in the Sahara dessert in Africa was 50% of water was saved.
On a farm in France, we measured that 80% less water was needed.
Using RCW reinforces a grower's capacity to be independent and use rainwater directly, which is reflected in terms of costs.
2) Second advantage: increased productivity
According to studies and experiences led by an intermediary at the University of Laval, productivity increases by a minimum of 150% or 160% by using RCW.
In 2006, for example, 12 feet of zucchini were planted using BRF. 160 kg of zucchini, each measuring between 20-25 cm (8-10 inches) long, were harvested.
3) Third advantage: saving energy
In agriculture, we have to use either compost of fertilzer every year.
However, the RCW approach allows for ground autonomy that lasts between 4-5 years without adding any additional RCW.
Fourth Advantage: Food autonomy
Try this: in a garden, make a 1m x 1m square area with a RCW thickness of 3 to 4 cm.
This way you'll see for yourself exactly how it works: even with a small garden, you'll get plenty of food autonomy. It's like what Pierre Rabhi alluded to at one point: " the minimum required space to have an autonomous garden."
Pierre Rabhi, Agriculturalist & Author
Where to get RCW
To find RCW in a city, ask your city hall technical services what they do with the trimmings after pruning trees around town.
The RCW technique is even being used in some of the world's biggest cities.
In some cases the city hall will even offer to deliver the wood trimmings directly to your house.
If you have a 100m2 garden, you'll need about 3m3 of RCW coverings.
If you're in the countryside and have trouble finding branches, try putting a small ad in the local newspaper.
It's good to give tree trimmings back to the earth. After all, they come from the earth.