What if I say that there is a scientific approach to agriculture that can solve the food crisis and have been overlooked for 30 years already? And what if I say that the basics are so easy to understand and to apply that you and me can do it? You wouldn’t believe it, right. Well, here is some food for thought.
We shouldn’t feed plants, but we should feed the soil. It is as simple as that. Mainstream agriculture considers the soil as a substrate for plant roots. You add the necessary minerals to the substrate, so that the plants can suck up the “food” from the water present in the substrate. Also organic agriculture thinks according to these lines. They consider the compost heap as the digester to produce fertiliser, and the compost as food for plants. Wrong, a slowly growing network of adepts to the new paradigm in Canada and France says so. In fact, the compost heap is a very energy and humus inefficient way of producing nutrients for the soil. The soil itself is far better in doing it. Why? Well because that is what a soil is supposed to do normally in forest ecosystems. It digests ”food”, like branches and leafs, into bio-active and nutrient rich humus, and the plants feed on the humus.
Professor Lemieux from the Laval University in Canada is a forest scientist, and is mainly responsible for the new paradigm change. He wondered why podzol soils, the soils originally under coniferous forests were rich but very fragile after transforming them into agricultural soils, and why the soils under broad leaf forests were among the best agricultural soils in the world, also after long term use.
His theory is that the “leftovers” after the soil has “eaten” the organic materials contain more stable humus molecules, in the form of aromatic carbon rings, if the food was from broad leafed hard wood, then when it was material from conifers. These ring-shaped humus molecules can hold large quantities of water, more than clay molecules, and are home for bacteria that bind nitrogen from the atmosphere and even for enzymes that transform inactive phosphorus into bio-active one. The lack of phosphorus availability has always been thought as the Achilles’ heel of organic agriculture, as it is present in compost only in very low quantities. Forest soils though are very rich in phosphorus but also in nitrogen, and it seems that no scientist until now really bothered to question why this was so.
Several teams of Lemieux tested his hypothesis in different climate regions and soils during more than 20 years of research. He found that, if you want to use soils for agricultural purposes, the best food for the soil was simply shredded branches spread on the soil in a layer of 3 cm thick, once in the 3 to 5 years. He called this the Ramial Chipped Wood Technology (RCW). Branches, just after they have lost their leafs contain the most interesting organic substances of the tree, like sugars, enzymes, proteins, and not entirely polymerised lignine (wood). It is the best food for the soil, and yet presently mostly burned as residue of forestry and landscape management.
After the RCW treatment, the case studies showed that no additional fertiliser was needed, production rose significantly, and irrigation was no longer needed due to the enormously improved water retention and decreased evaporation.
Depending on the decomposition rate, for the first treatment an application consists of about 200 to 300 m3 wood chips per hectare. Then after 4 to 5 years a smaller quantity is used to keep the layer thickness 2 to 3 cm. In case forests are not close, one should consider to (re)plant tree hedges. To produce sufficient wood chips for fertilisation of one hectare of crop land, one need about 400 meter of hedges, preferably hard wood like oak.
To imitate forest conditions in agricultural soils is a true revolution. At the moment, farmers just getting used to another way to conserve the soil: Conservation Agriculture (CA). In this type of agriculture crop residues are left on the soil and deep ploughing is considered bad for the soil structure and not necessary. Lemieux gives in fact the theoretical basis for Conservation Agriculture, adding one important element: wood!
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