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[Bill Jones <billj AT harborside.com>]

I thought this was important enough to share the entire text.

http://users.skynet.be/BRFinfo/anglais/abstract.htm


 The use of R.C.W. in agriculture

by B. NOEL ( translation with the assistance of C. Caron, G. Lemieux and 
L. Lachance).

This text is only a small abstract of BRFinfo, I hope I will soon have 
the time to improve it and maybe to translate all the web site (help is 
welcome).



Every one involved in agriculture sooner or later comes to the same 
conclusion: we must make soil. Chemical fertilizers, pesticides and 
ploughing destroy the fertility of the soil; organic farming maintains 
its fertility but cannot replace lost soil. The most fertile 
agricultural regions were once hardwood forests, especially oak forest. 
We now know why and how to hasten nature's work.

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HOW IT STARTED



The ramial chipped wood (RCW) story began in the mid-seventies when Mr 
Edgar Guay, former Land and Forest Deputy Minister in Quebec began 
searching for new products that could be derived from the huge piles of 
branches wasted after logging operations. The first field experiments 
with deciduous tree trimings were made during the summer of 1978. A 
research team nucleus was formed with Mr Lionel Lachance and Mr Alban 
Lapointe joining Mr Guay. In 1982, M. Gilles Lemieux, a now retired 
professor from the Faculty of Forestry at Laval University, joined the 
team to provide answers on the mechanisms involved.



The name and description of «ramial wood» was given in 1986 (Lemieux) 
under the French name of «bois raméal». Since the method put forward by 
Guay, Lachance & Lapointe (1981) was based on chipping, this «new 
material» was then called «Bois Raméal Fragmenté or BRF» in French, 
«Ramial Chipped Wood or RCW» in English (1992), «Fragmentiertes 
Zweigholz or FZH» in German (1992), «Aparas de Ramos Fragmentados or 
ARF» (1993) in Portugese «Ramoscelli Frammentati or RF» in Italian 
(1993) «Madera Rameal Fragmentada or MRF» in Spanish (1994): "Ramial 
wood" refers to twigs having less than 7 cm in diameter. They contain 
soluble or little-polymerized lignin, the base for soil aggregates and 
highly reactive humus. These small-size branches are not used as 
firewood, even in the poorest tropical countries.



Although fungi are most important for humus formation and cycling, the 
humic system performs best when fungi are associated with the fungivore 
soil mesofauna. This process, linked to virus, algae and protozoa, makes 
nutrients available when needed by plants.



In organic agriculture it is generaly believed that a soil treated for 
years with massive doses of chemical fertilizers and pesticides can be 
restored in three years with compost and a return to traditional 
practices. This belief does not take into account that the diversity of 
the molecules and the complexity of the soil ecosystem of the world's 
agricultural land has been claimed from the forest.



THE PRODUCTION OF A STABLE HUMUS



There are humic subtances that have a short life (compost and manure) 
and others that have a long life (more than 1000 years). These 
substances play an important role in the balance of the soil. The Asian 
steppes, the South-American pampas and the North-American prairies, 
being covered with herbaceous plants, have a short-life humus. The soil 
claimed from hardwood forest has a long-life humus.



In soils farmed intensively with synthetic fertilizers exclusively, a 
modified bacterial and mostly fungal biology ends up consuming the 
long-life humus of forest origin. By using farm manure or compost in 
which the only source of lignin is straw, we cannot hope that humus 
having a long life will form massively and stabilize the soil on a long 
term. This type of organic amendment brings the soil to a condition 
similar to the North-American prairie soils which derived its lignin 
from Graminaceae over thousands of years and which have not long 
resisted to intensive farming. These soils are now subject to massive 
erosion. Only the addition of ramial chipped wood can be viewed as a 
mean to return the soil to its former forest origin condition and 
restitute, in three years, a long-life humus content.



HUMIFICATION RATHER THAN MINERALIZATION



Misunderstanding of the natural forest ecosystems, especially the forest 
soil, is so deep that all silvicultural practices use agriculture as a 
model and research has been directed mostly to managed agricultural 
systems. In agriculture, as well as forestry, the entire focus has been 
placed on mineralization, with little work done on, or interest shown 
for, humification which regulates mineralization and fertility. The 
lignin of Angiosperms is central to humification and biological controls 
of fertility. It has a deep impact on most mesic soils through the 
multilevel life they bear.



HOW A FOREST ECOSYSTEM WORKS



A close look at a forest ecosystem shows a fast transformation of plant 
tissues into nutrients by soil microorganisms. Nutrients are bound to 
the organo-mineral complex and are made available as needed for plant 
growth. In temperate forests, under a deciduous tree canopy, this 
organo-mineral humic complex is stable within an internal biological 
cycle. It becomes fragile under tropical conditions. It has several 
roles and therefore must be closely examined.



The basic mechanisms lie in the role played by «white rots» which use 
enzymatic systems to produce both fulvic and humic acids from lignin, 
the base for aggregate formation (Leisola & Garcia 1989). The best 
results are achieved with deciduous trees due the chemical structure of 
their lignin. Evergreens perform poorly, due to the transformation of 
their lignin by «brown rots» which produce polyphenols and aliphatic 
compounds (Swift [1991], Larochelle [1993]).



RESULTS OF WORLD-WIDE EXPERIMENTS



Twenty years of experiments with RCW in both forestry and agriculture in 
Québec, Africa, Europe and the Carribeans have provided :

· Better soil conservation due to the water retention capacity of humus 
content (up to 20 times its weight) and the capacity of water 
accumulation and management by soil organisms;

· An increase in pH from 0.4 to 1.2 or, under tropical conditions, in 
alkaline soils, a decrease in the range of 2.0.;

· A yield increase up to 1000% for tomatoes in Sénégal, and 300% on 
strawberries in Québec;

· A 400% increase in dry matter for corn in both Côte d'Ivoire (Africa) 
and the Dominican Republic (Carribeans);

· A noticeable increase in frost and drought resistance;

· More developed and highly-mycorrhized root systems;

· Fewer and less diversified weeds;

· A decrease or complete elimination of pests (under tropical 
conditions, a complete control of root nematodes, the worst and most 
costly pest in vegetable garden growing);

· Enhanced flavor in fruit production;

· Higher dry matter, phosphorus, potassium and magnesium content in 
potato tubers;

· A soil turning from pale to deep brown in the same season;

· Selective natural germination of tree seeds;

· A thick moder turning into a soft mull under a sugar maple canopy.



SPECIES OF TREES TO USE



Some species are quickly digested (in few months) by the soil, others 
take a few years even if they seem to have vanished. Coniferous trees, 
in cold and temperate climates, generate a blockage mechanism of soil 
pedogenesis. Their lignin, once into the soil, evolves in producing a 
great amount of polyphenolic inhibitors. This type of lignin is also 
found in many tropical tree species but high soil temperatures break the 
inhibitor effect to some extent. In cold and temperate climates, ramial 
wood from coniferous species must be avoided or restricted to 20% of the 
overall content. Coniferous trees are characterized by an asymetrical 
lignin (guaiacyl).



Coniferous trees store nutrients in the trunk and eliminate competition 
by making the soil unsuitable to competitors. Deciduous trees store some 
nutrients in the soil and enhance diversity. This strategy allows 
deciduous trees to replace coniferous wherever climate conditions 
permit. Deciduous forests are much more stable and long-lasting, whereas 
coniferous forests follow cataclysm cycles. When all the nutrients are 
blocked, coniferous trees send olfactory messages to pests that come and 
destroy the stand, then fire takes over and cleans all, and nutrients 
are freed.



Species to be used can be quickly determined on an ecological basis. 
Trees that grow in association with the most superior plants are to be 
favoured. Rich stands of red oak, sugar maple, beech, yellow birch, 
linden and ash give much better results than poor-quality stands such as 
red maple or trembling aspen. A mixture of species is suitable and will 
give an amendment with positive effects in the short as well as in the 
long term.


PARTS OF THE TREE TO USE



The C/N ratio for ramial wood ranges from 30/1 to 170/1 while for 
stemwood the C/N ratio ranges from 400/1 to 750/1. Branches under 7 cm 
in diameter, without their leaves, are the best choice for shredding. In 
the North-American species, essential plant nutrients (N, P, K, Ca, Mg) 
increase when branch diameter decreases. These concentrations reach a 
minimum in branches over 7 cm in diameter, so branches having less than 
7 cm in diameter contain 75% fertilizing nutrients. The bigger the 
branches the less digestible they become. If sawdust, issued from tree 
trunks, is mixed with the soil, nitrogen will starve unless the sawdust 
is composted with farm manure. The trunk of the tree supports the 
branches which are the real biological center for wood production. The 
trunk is «dead» and does not allow lignin to be used by enzymes from 
microflora and fauna to integrate into the soil. For the forest, the 
«dead» trunk is «garbage», attacked from the outside, and transformed in 
CO2 with very little benefit to the soil.



For a first treatment, the ramial wood should be without green leaves 
because green leaves contain chemical elements easily accessible to 
bacteria. These bacteria can prevail over «white rot» (Basidiomycetes). 
When leaves are dead, these chemical elements, tied to brown pigments, 
will be released through the soil mesofauna activity in perfect harmony 
with the «white rot» activity. It must be noted that persons following 
these rules have obtained good results.



TOOLS



Chipping or crushing ramial wood is nessaryto permit massive entry of 
soil microorganisms without facing the bark barrier. Moreover, chipping 
increases the surface of the material which accelerates soil digestion. 
In tropical countries, big pieces, grossly chipped with a machete, will 
be rapidly digested by the soil.



For a good chipping the cut must be made at an angle of 57° and the 
rotation of the blade 12000 RPM for one knife, 6000 RPM for two knives 
and so on. It is better to shred the branches lengthwise than cut them 
perpendicularly. A second-hand forage harvester could do a good job on 
farms. A chipping or crushing apparatus can be custom-made or chipping 
devices collectively-owned. Many types of chipping devices can be found 
on the market, some can be activated by a farm tractor.



Mechanized chipping is costly in both labor and money. Fifteen hours are 
needed to produce enough RCW for one hectare requiring 1503 meters. This 
quantity is needed to enhance the quality of the soil and the crops for 
the following five years under temperate conditions. A RCW soil 
amendment should be perceived as an investment redeemed over a period of 
10 to 15 years.



METHODS



The basic methods called «Sylvagraire» for agriculture and «Sylvasol» 
for forestry are better known. They give the best low-cost results. RCW 
must not be composted nor ploughed under but spread in a thin layer, a 
thickness of one inch being the optimum. The upgrading mechanisms best 
perform when RCW is mixed with the first 5 cm of the topsoil. The 
fundamental mechanism relies on massive entry of soil microorganisms 
into the twigs. Therefore chipping or crushing them is essential.



STORAGE



If it is not spread immediatly after chipping, RCW can be windrowed. If 
the pile is too high or too dense, it can induce anaerobic conditions 
which are very harmful after a few weeks.

After three months of storage, RCW is seen more as compost and can make 
an excellent organic amendment but its chemical constituents and its 
impact on the biology of the sol is different from freshly-made RCW.



WHEN TO USE RCW



Under cold and temperate conditions, the autumn period sems to be the 
best time to use RCW. Added to the soil, this material, rich in carbon 
and poor in nitrogen, may favor nitrogen immobilization by the 
microorgnisms during the first few months. When using RCW, this type of 
effects can be seen during two months, after which trophic chains are 
active and the amount of available nutrients is increasing with time.



Soils treated with RCW in the spring can show sign of nitrogen hunger 
during the growing season but this will not be harmful to the production 
and will not cause necrosis to the foliage. THIS WILL NEVER HAPPEN AGAIN 
IF RCW IS TO BE APPLIED ON THE FOLLOWING YEARS. If RCW is used as a 
mulch instead of being disked in, there is no nitrogen hunger but the 
integration to cultivated soil will be much slower. The autumn period 
favors the spreading of Basidiomycetes. They remain active at 
temperatures below freezing whereas bacteria die and massively encyst 
during the cold season.



FOREST LITTER ADDITION



Studies have proven that Basidiomycetes are often absent from cultivated 
soil and trophic chains are reduced to a minimum. The several organisms 
(fungi and symbiotic bacteria, microarthropods, insects...), found in 
forest soils and essential to the RCW transformation, are not found in 
cultivated fields. They must be reintroduced with the first application 
otherwise RCW may not behave correctly (towards a coaly colour). 
Migration of some of these organisms in the soil is sometimes very slow 
(a few centimeters per year) and a natural recolonization might take 
considerable time. To reintroduce forest soil fungi requires an addition 
of 10-20 grams of the forest litter per square meter. This litter can be 
taken from an old deciduous climax forest stand or something close to 
it, at a depth of 5 cm beneath the dead leaves. The dark brown leafmould 
should be harvested just prior to the spreading in order to avoid drying.


QUANTITY TO USE



RCW must not be composted nor ploughed under but spread in a layer not 
thicker than 1 5/8 inch, at the rate of 150 to 200 m3/ha. The upgrading 
mechanisms perform best when RCW is mixed with the first 5 cm of the 
topsoil. This treatment is good for three years in temperate conditions 
and it has to be repeated by adding from 10 to 20 m3 on the fourth year 
and years after.



INCORPORATION TO THE SOIL



In cultivated fields, it is very important to disk RCW in the first 5 cm 
of topsoil. The reasons for this surface incorportion are of a physical 
and a biological order. In the forest, RCW integration requires the 
interrelationship of many organisms. When conditions are not convenient 
(which is rare in the forest where a microclimate exists under the 
canopy), the organisms will migrate deep in the forest litter to be 
protected. In cultivated fields, these migrations do not to happen 
because these organisms are vulnerable to dry spells. This explains why 
spreading RCW in the forest does not require mixing with the topsoil.



To favor the multiplication of Basidiomycetes, wood humidity must vary 
from 30% to 120%, the optimum being between 60% and 100%. Basidiomycetes 
are aerobic fungi located in the first 5 cm of soil and in close contact 
with RCW in a moist environment.



RCW vs COMPOST



RCW is a pedogenetic amendment able to optimize or generate a true soil. 
This technique must not be mistaken with composting where basic material 
comes from diverse organic sources.



The compost is used to feed the life of the soil and bring nutrients to 
the plants, while RCW can rebuild and maintain the soil structure, 
long-term fertility and soil stability. The composting process results 
in the loss of organic materials, but the enzymatic combustion favors 
the destruction of polyphenols and pathogenic organisms. With RCW 
technology, the organic material goes directly into the soil structure 
and reach the trophic chains without any loss.



Mixed with the soil RCW is sufficient because all the necessary elements 
are in it. In soils treated with RCW there is no deficiencies. As stated 
above, the C/N ratio of RCW varies from 50/1 to 170/1 for twigs less 
than 7 cm in diameter. The farmer should not worry about the C/N ratio 
once biological action works.



NO PLOUGHING



By ploughing and disking the soil, the life cycles are destructured and, 
consequently, the soil improvements with organic amendment are less than 
expected.



In a field treated with RCW ploughing should be delayed for three years 
in order to prevent deep burrying and provide aerobic conditions 
favourable to RCW evolution and Basidiomycetes enzymatic activities.



The RCW material will remain the same after years under anaerobic 
conditions in deep soil. One benefit of ploughing is to allow water 
savings by breaking pore continuity whereas a soil treated with RCW will 
retain enough moisture to prevent dryness. Ploughing, by increasing the 
roughness of the soil, could limit washing and erosion; but RCW, as a 
humic amendment and a bioactivator, will improve the soil structure and 
regulate activity through polyphenolic chemistry. This structural 
stability is the most efficient tool for regenerating soils.



RCW AND WORM POPULATIONS



RCW treatments will favor the increase of earthworm populations. In 
Quebec, up to two tons of earthworms per hectare can be found in a 
natural sugar maple stand. These worms work without harming the root 
systems.



RCW AS MULCH



RCW can be used as mulch or, better, on the soil surface. In this way, 
RCW is slow to evolve and does not play the same role. It serves as a 
mechanical barrier to drying and as a shield against UV rays which are 
lethal for the life beneath. It is an ecological niche for forest 
insects and other biotas while preventing weed sprouting and 
agressivity. It is possible that the long-term effect will be similar to 
that of surface disking. Certain farmers prefer the mulching method 
because it does not interfere with the life of the soil.



THE MOST CONVENIENT SOILS



Soils constantly wet and cold should be avoided. The anaerobic 
conditions do not allow RCW to be involved into a fertile pedogenetic 
process. The sandy-silt soils containing a sufficient amount of clay 
will benefit best with RCW application. In such soils, the pedogenetic 
process is active and efficient. The clay particles favor exchange 
complexe and the stocking of nutrients.



RECOMMENDED FARMING PRACTICES



For an agronomist, the RCW technology is a very useful farming practice. 
A good way to proceed with very low productive soil is to disk in the 
RCW material in the fall and, the following spring , sow a cereal-hay 
mixture, i.e. a legume (white clover or alfalfa) that can trap nitrogen. 
The first crop is cereal and the following two years hay crop is 
harvested. Later potatoe crops can be grown easily.



CONCLUSIONS



Branches and brushes were always seen without value for centuries and as 
trash in the modern forest economy that has developed during the last 
century. A first assessment of small branch production shows a mere 100 
million tons per annum for Québec alone and probably billions of tons 
throughout the world. Small-diameter branches can be transformed into a 
«soil food». Feeding soil microfauna and microflora is more likely to 
bring mid- and long-term benefits to both agricultural and forest 
ecosystems in redeeming costs and increasing benefits. RCWs represent 
the only large-scale upgrading technology. It involves a large number of 
shrub and tree species resulting in variable responses, all positive 
with regard to enhancement of the humic system. RCWs bring the benefits 
of the forest soil to the agricultural soil at the lowest possible cost 
[Lemieux, 1993].



Agricultural land was «extracted» from the forest. The forest can now 
help degraded soils by keeping them alive and microbiologically 
diversified. Ramial chipped wood is a good tool available to all 
societies, even the poorest, to reverse soil degradation and 
desertification. As we are now aware of the major role of RCWs upon the 
formation of a highly reactive humus system, our attitude toward the 
forest will have to change. Instead of depleting our natural forests as 
we now do to grow commodity trees, we must grow «forest ecosystems» and 
treat them like perennial gardens. From an enemy, the forest must become 
a friend. From a resource to be exploited for immediate profit, it must 
become the source of infinite wealth.



RCWs must be carefully looked at in both the southern and the northern 
hemispheres. More than 75% of nutrients are stored in twigs. Twigs are 
the center of life, stemwood being the result of the whole crown 
activity. Twigs, once chipped and brought in close contact with the 
soil, momentarily replace the rootlets that are constantly transformed 
into short-lived aggregates by the soil microorganisms. These aggregates 
are the managers of soil nutrients and energy for the ecosystem's own 
sake. They enable biological actors to play their vital role, from virus 
to mammals, using available energy and nutrients. It is of prime 
importance to understand and visualize the whole picture and the role 
played by each actor in this wonderful evolution of nature's work from 
which we now benefit after so many millions of years.



Time has come for large-scale worldwide organizations to deal with 
planetary problems. RCWs are the key to understanding the biological 
basics of our terrestrial ecosystems. There is no doubt concerning the 
value of RCWs and their positive impact in pedogenesis, which is a 
universal process. This universal biological material will have a direct 
effect in the short term as well as in the long term on soil, crops, 
economy and on both human and animal societies. It will be seen as one 
of the most important biotechnological contributions of this century 
[Lemieux (1993)].



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