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FOREST INK: Ramial chipped wood promotes long-term soil health

RWCs are better described as “soil upgraders” rather than fertilizers
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Columnist Jim Hilton explores how RCW (ramial chipped wood) made of tree branches, twigs and leaves, can play a role in formation and maintenance of fertile soils. (Monica Lamb-Yorski photo - Williams Lake Tribune)

Starting in the 1980s a group of scientists from Laval University lead by Professor Gilles Lemieux set out to improve the lives of the women in developing countries who produce most (80 per cent) of the local food.

Their research focused on using local resources and technologies to reverse the degradation of the soil, improve yields and improve the health of the food with minimal inputs from outside expensive sources. After decades of research they focused on a new technology, known as ramial chipped wood (RCW) for establishing a sustainable fertile soil.

RCW also known as (branch wood chips) are made from tree parts, branches (less than seven cm diameter), twigs and leaves rich in nutrients, sugar, protein, cellulose, and lignin, which all play a precise and specific role in the formation and maintenance of fertile soils. This is not the case for bark, trunk wood, sawdust, wood shavings, and all industrial wood waste material which will rob soil of nitrogen when added.

A report published in 2000 described the research which has expanded to Sénégal, Madagascar, Ukraine and the Dominican Republic. Some of the highlights are the following:

Better soil conservation due to the water retention capacity of humus; a yield increase up to 1,000 per cent for tomatoes in Senegal, and 300 per cent on strawberries in Quebec; a 400 per cent increase in dry matter for corn in both Côte d’Ivoire and the Dominican Republic; a noticeable increase in frost and drought resistance; more developed root systems; fewer and less diversified weeds; a decrease or complete elimination of pests (under tropical conditions, a complete control of root nematodes); enhanced flavour in fruit production; higher dry matter, phosphorus, potassium and magnesium content in potato tubers; selective natural germination of tree seeds.

The report describes the advantages and disadvantages of mineral fertilizers, organic fertilizers and RCW.

While mineral fertilizer additions to soil, such as N, P, K, give quick results they often contaminate ground waters and surface waters. In fact, dissolved nitrogen in the form of nitrate (NO3-) is the most common contaminant identified in groundwater. Human activities have doubled the amount of nitrogen cycling between the living world and the soil, water, and atmosphere, and that rate is continuing to climb. Organic compost has many advantages over mineral fertilizers but requires yearly application to maintain these advantages.

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“The first and single most important advantage RCW comes from the fact that soil is regenerated by a technology based on the way nature makes soil.

As a result, this technology does not require any nitrate addition. It is the only technology using the soil energy potential expressed in terms of polyphenols.

RCW potential is found in the bio-transformation process, which has nothing to do with “organic decomposition” but regulates the nutrient availability, the soil physical structure, the erosion resistance, and above all, protects and stimulates various phases of animal life, bacterial and fungus of the soil major contributors to soil formation. RCW, like compost, has the ability to improve soil water holding capacity, to fix and release nitrogen as needed by plants, and to mitigate sources of pollution.”

There is a reduced reliance on pesticides, herbicides, and fungicides by providing a balance in microbial and nutrient environments and soil porosity is favoured by the increased lignin content.

In summary RCWs are better described as “soil upgraders” rather than fertilizers or soil amendments (organic matter) because they are bringing energy for the biological enhancement of the soil, while contributing to soil structure, plant productivity and groundwater quality. Most important, they contribute to a biochemical balance responsible for all biological and physical factors of soil fertility into a dynamic process.

Read more: FOREST INK: Long-term, positive results using an organic approach

Jim Hilton is a professional agrologist and forester who has lived and worked in the Cariboo Chilcotin for the past 40 years. Now retired, Hilton still volunteers his skills with local community forests organizations.