LAVAL UNIVERSITY
FACULTY OF FORESTRY AND GEOMATICS
Department of Wood and Forest Sciences

Coordination Group on Ramial Wood


« REGENERATING SOILS WITH RAMIAL CHIPPEDWOOD»

by
Céline Caron, Gilles Lemieux and LionelLachance


PUBLICATION N 83


http://forestgeomat.for.ulaval.ca/brf

edited by
Coordination Group on Ramial Wood
Department of Wood and Forestry Science
Québec G1K 7P4
QUÉBEC
CANADA

REGENERATING SOILS WITH RAMIAL CHIPPED WOOD

C. Caron1, G.Lemieux2 and L. Lachance3

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.

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 trimmings 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 in1986 (Lemieux) under the French name of «boisraméal». Since the method put forward by Guay, Lachance& Lapointe (1981) was based on chipping, this «new material» was then called «Bois RaméalFragmenté or BRF» in French, «Ramial Chipped Wood or RCW» in English (1992), «Fragmentiertes Zweigholz or FZH» in German (1992), «Aparas de RamosFragmentados or ARF» (1993) in Portugese «RamoscelliFrammentati or RF» in Italian (1993) «Madera RamealFragmentada or MRF» in Spanish (1994): "Ramial wood" refersto twigs having less than 7 cm in diameter. They contain soluble orlittle-polymerized lignin, the base for soil aggregates and highlyreactive 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 thefungivore soil mesofauna. This process, linked to virus, algae andprotozoa, makes nutrients available when needed by plants.

In organic agriculture it is generaly believed that a soil treatedfor years with massive doses of chemical fertilizers and pesticidescan be restored in three years with compost and a return totraditional practices. This belief does not take into account thatthe diversity of the molecules and the complexity of the soilecosystem of the world's agricultural land has been claimed from theforest.

THE PRODUCTION OF A STABLE HUMUS

There are humic subtances that have a short life (compost andmanure) and

others that have a long life (more than 1000 years). These substancesplay an important role in the balance of the soil. The Asian steppes,the South-American pampas and the North-American prairies, beingcovered with herbaceous plants, have a short-life humus. The soilclaimed from hardwood forest has a long-life humus.

In soils farmed intensively with synthetic fertilizersexclusively, a modified bacterial and mostly fungal biology ends upconsuming the long-life humus of forest origin. By using farm manureor compost in which the only source of lignin is straw, we cannothope that humus having a long life will form massively and stabilizethe soil on a long term. This type of organic amendment brings thesoil to a condition similar to the North-American prairie soils whichderived its lignin from Graminaceae over thousands of years and whichhave not long resisted to intensive farming. These soils are nowsubject to massive erosion. Only the addition of ramial chipped woodcan be viewed as a mean to return the soil to its former forestorigin condition and restitute, in three years, a long-life humuscontent.

HUMIFICATION RATHER THAN MINERALIZATION

Misunderstanding of the natural forest ecosystems, especially theforest soil, is so deep that all silvicultural practices useagriculture as a model and research has been directed mostly tomanaged agricultural systems. In agriculture, as well as forestry,the entire focus has been placed on mineralization, with little workdone on, or interest shown for, humification which regulatesmineralization and fertility. The lignin of Angiosperms is central tohumification and biological controls of fertility. It has a deepimpact 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 ofplant tissues into nutrients by soil microorganisms. Nutrients arebound to the organo-mineral complex and are made available as neededfor plant growth. In temperate forests, under a deciduous treecanopy, this organo-mineral humic complex is stable within aninternal biological cycle. It becomes fragile under tropicalconditions. It has several roles and therefore must be closelyexamined.

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

RESULTS OF WORLD-WIDE EXPERIMENTS

Twenty years of experiments with RCW in both forestry andagriculture in Québec, Africa, Europe and the Carribeans haveprovided:

· Better soil conservation due to the water retention capacityof humus content (up to 20 times its weight) and the capacity ofwater accumulation and management by soil organisms;
· An increase in pH from 0.4 to 1.2 or, under tropicalconditions, in alkaline soils, a decrease in the range of 2.0.;
· A yield increase up to 1000% for tomatoes inSénégal, and 300% on strawberries in Québec;
· A 400% increase in dry matter for corn in both Côted'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 tropicalconditions, a complete control of root nematodes, the worst and mostcostly pest in vegetable garden growing);
· Enhanced flavor in fruit production;
· Higher dry matter, phosphorus, potassium and magnesiumcontent 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 maplecanopy.

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 blockagemechanism of soil pedogenesis. Their lignin, once into the soil,evolves in producing a great amount of polyphenolic inhibitors. Thistype of lignin is also found in many tropical tree species but highsoil temperatures break the inhibitor effect to some extent. In coldand temperate climates, ramial wood from coniferous species must beavoided or restricted to 20% of the overall content. Coniferous treesare characterized by an asymetrical lignin (guaiacyl).

Coniferous trees store nutrients in the trunk and eliminatecompetition by making the soil unsuitable to competitors. Deciduoustrees store some nutrients in the soil and enhance diversity. Thisstrategy allows deciduous trees to replace coniferous whereverclimate conditions permit. Deciduous forests are much more stable andlong-lasting, whereas coniferous forests follow cataclysm cycles.When all the nutrients are blocked, coniferous trees send olfactorymessages to pests that come and destroy the stand, then fire takesover and cleans all, and nutrients are freed.

Species to be used can be quickly determined on an ecologicalbasis. Trees that grow in association with the most superior plantsare to be favoured. Rich stands of red oak, sugar maple, beech,yellow birch, linden and ash give much better results thanpoor-quality stands such as red maple or trembling aspen. A mixtureof species is suitable and will give an amendment with positiveeffects 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 forstemwood the C/N ratio ranges from 400/1 to 750/1. Branches under 7cm in diameter, without their leaves, are the best choice forshredding. In the North-American species, essential plant nutrients(N, P, K, Ca, Mg) increase when branch diameter decreases. Theseconcentrations reach a minimum in branches over 7 cm in diameter, sobranches having less than 7 cm in diameter contain 75% fertilizingnutrients. The bigger the branches the less digestible they become.If sawdust, issued from tree trunks, is mixed with the soil, nitrogenwill starve unless the sawdust is composted with farm manure. Thetrunk of the tree supports the branches which are the real biologicalcenter for wood production. The trunk is «dead» and doesnot allow lignin to be used by enzymes from microflora and fauna tointegrate into the soil. For the forest, the «dead» trunkis «garbage», attacked from the outside, and transformed inCO2 with very little benefit to the soil.

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

TOOLS

Chipping or crushing ramial wood is nessaryto permit massive entryof soil microorganisms without facing the bark barrier. Moreover,chipping increases the surface of the material which accelerates soildigestion. In tropical countries, big pieces, grossly chipped with amachete, 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 fortwo knives and so on. It is better to shred the branches lengthwisethan cut them perpendicularly. A second-hand forage harvester coulddo a good job on farms. A chipping or crushing apparatus can becustom-made or chipping devices collectively-owned. Many types ofchipping devices can be found on the market, some can be activated bya farm tractor.

Mechanized chipping is costly in both labor and money. Fifteenhours are needed to produce enough RCW for one hectare requiring1503 meters. This quantity is needed to enhance thequality of the soil and the crops for the following five years undertemperate conditions. A RCW soil amendment should be perceived as aninvestment redeemed over a period of 10 to 15 years.

METHODS

The basic methods called «Sylvagraire» for agricultureand «Sylvasol» for forestry are better known. They give thebest low-cost results. RCW must not be composted nor ploughed underbut spread in a thin layer, a thickness of one inch being theoptimum. The

upgrading mechanisms best perform when RCW is mixed with the first 5cm of the topsoil. The fundamental mechanism relies on massive entryof soil microorganisms into the twigs. Therefore chipping or crushingthem is essential.

STORAGE

If it is not spread immediatly after chipping, RCW can bewindrowed. If the pile is too high or too dense, it can induceanaerobic conditions which are very harmful after a few weeks.
After three months of storage, RCW is seen more as compost and canmake an excellent organic amendment but its chemical constituents andits impact on the biology of the sol is different from freshly-madeRCW.

WHEN TO USE RCW

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

Soils treated with RCW in the spring can show sign of nitrogenhunger during the growing season but this will not be harmful to theproduction and will not cause necrosis to the foliage. THIS WILLNEVER HAPPEN AGAIN IF RCW IS TO BE APPLIED ON THE FOLLOWING YEARS. IfRCW is used as a mulch instead of being disked in, there is nonitrogen hunger but the integration to cultivated soil will be muchslower. The autumn period favors the spreading of Basidiomycetes.They remain active at temperatures below freezing whereas bacteriadie and massively encyst during the cold season.

FOREST LITTER ADDITION

Studies have proven that Basidiomycetes are often absent fromcultivated soil and trophic chains are reduced to a minimum. Theseveral organisms (fungi and symbiotic bacteria, microarthropods,insects...), found in forest soils and essential to the RCWtransformation, are not found in cultivated fields. They must bereintroduced with the first application otherwise RCW may not behavecorrectly (towards a coaly colour). Migration of some of theseorganisms in the soil is sometimes very slow (a few centimeters peryear) and a natural recolonization might take considerable time. Toreintroduce forest soil fungi requires an addition of 10-20 grams ofthe forest litter per square meter. This litter can be taken from anold deciduous climax forest stand or something close to it, at adepth of 5 cm beneath the dead leaves. The dark brown leafmouldshould be harvested just prior to the spreading in order to avoiddrying.

QUANTITY TO USE

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

INCORPORATION TO THE SOIL

In cultivated fields, it is very important to disk RCW in thefirst 5 cm of topsoil. The reasons for this surface incorportion areof a physical and a biological order. In the forest, RCW integrationrequires the interrelationship of many organisms. When conditions arenot convenient (which is rare in the forest where a microclimateexists under the canopy), the organisms will migrate deep in theforest litter to be protected. In cultivated fields, these migrationsdo not to happen because these organisms are vulnerable to dryspells. This explains why spreading RCW in the forest does notrequire mixing with the topsoil.

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

RCW vs COMPOST

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

The compost is used to feed the life of the soil and bringnutrients to the plants, while RCW can rebuild and maintain the soilstructure, long-term fertility and soil stability. The compostingprocess results in the loss of organic materials, but the enzymaticcombustion favors the destruction of polyphenols and pathogenicorganisms. With RCW technology, the organic material goes directlyinto the soil structure and reach the trophic chains without anyloss.

Mixed with the soil RCW is sufficient because all the necessaryelements are in it. In soils treated with RCW there is nodeficiencies. As stated above, the C/N ratio of RCW varies from 50/1to 170/1 for twigs less than 7 cm in diameter. The farmer should notworry about the C/N ratio once biological action works.

NO PLOUGHING

By ploughing and disking the soil, the life cycles aredestructured and, consequently, the soil improvements with organicamendment are less than expected.

In a field treated with RCW ploughing should be delayed for threeyears in

order to prevent deep burrying and provide aerobic conditionsfavourable to RCW evolution and Basidiomycetes enzymatic activities.

The RCW material will remain the same after years under anaerobicconditions in deep soil. One benefit of ploughing is to allow watersavings by breaking pore continuity whereas a soil treated with RCWwill retain enough moisture to prevent dryness. Ploughing, byincreasing the roughness of the soil, could limit washing anderosion; but RCW, as a humic amendment and a bioactivator, willimprove the soil structure and regulate activity through polyphenolicchemistry. This structural stability is the most efficient tool forregenerating 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 anatural sugar maple stand. These worms work without harming the rootsystems.

RCW AS MULCH

RCW can be used as mulch or, better, on the soil surface. In thisway, RCW is slow to evolve and does not play the same role. It servesas a mechanical barrier to drying and as a shield against UV rayswhich are lethal for the life beneath. It is an ecological niche forforest insects and other biotas while preventing weed sprouting andagressivity. It is possible that the long-term effect will be similarto that of surface disking. Certain farmers prefer the mulchingmethod because it does not interfere with the life of the soil.

THE MOST CONVENIENT SOILS

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

RECOMMENDED FARMING PRACTICES

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

CONCLUSIONS

Branches and brushes were always seen without value for centuriesand as trash in the modern forest economy that has developed duringthe last century. A first assessment

of small branch production shows a mere 100 million tons per annumfor Québec alone and probably billions of tons throughout theworld. Small-diameter branches can be transformed into a «soilfood». Feeding soil microfauna and microflora is more likely tobring mid- and long-term benefits to both agricultural and forestecosystems in redeeming costs and increasing benefits. RCWs representthe only large-scale upgrading technology. It involves a large numberof shrub and tree species resulting in variable responses, allpositive with regard to enhancement of the humic system. RCWs bringthe benefits of the forest soil to the agricultural soil at thelowest possible cost [Lemieux, 1993].

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

RCWs must be carefully looked at in both the southern and thenorthern hemispheres. More than 75% of nutrients are stored in twigs.Twigs are the center of life, stemwood being the result of the wholecrown activity. Twigs, once chipped and brought in close contact withthe soil, momentarily replace the rootlets that are constantlytransformed into short-lived aggregates by the soil microorganisms.These aggregates are the managers of soil nutrients and energy forthe ecosystem's own sake. They enable biological actors to play theirvital role, from virus to mammals, using available energy andnutrients. It is of prime importance to understand and visualize thewhole picture and the role played by each actor in this wonderfulevolution of nature's work from which we now benefit after so manymillions of years.

Time has come for large-scale worldwide organizations to deal withplanetary problems. RCWs are the key to understanding the biologicalbasics of our terrestrial ecosystems. There is no doubt concerningthe value of RCWs and their positive impact in pedogenesis, which isa universal process. This universal biological material will have adirect 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 beseen as one of the most important biotechnological contributions ofthis century [Lemieux (1993)].

BIBLIOGRAPHY

Caron, C. (1994) «Ramial chipped wood: a basic toolfor regenerating soils». Lincoln University, New-Zealand IFOAMmeeting, Christchurch, 8 pages, ISBN 2-921728-07-09
Guay, E. Lachance, L. & Lapointe R.A. (1982)«Emploi des bois raméaux fragmentés et des lisiersen agriculture» Rapports techniques 1 et 2, Ministère desTerres et Forêts du Québec, Québec. 74 pages.
Guay, E. Lapointe, R.A. & Lemieux, G. (1991) «Larestructuration humique des sols» Ministère desForêts du Québec et Université Laval, ISBN2-550-22289-X FQ91-3070 , 14 pages.
Koslowsky, G. & Winget, C.H.1964) «The role ofreserves in leaves, branches, stems and roots on

shoots and growth of Red Pine» Amer. Journ. Bot. 52:522-529.
Lemieux, G. (1993) «Le bois raméalfragmenté et la méthode expérimentale: une voievers un institut international de pédogenèse» inLes actes du quatrième colloque international sur les boisraméaux fragmentés» édité par leGroupe de Coordination sur les Bois Raméaux,Département des Sciences forestières, UniversitéLaval, Québec. (Canada) ISBN 2-550-28792-4 FQ94-3014, p.124-138.
Lemieux, G. (1993) «A universal pedogenesis upgradingprocessus: RCWs to enhance biodiversity and productivity» Foodand Agriculture Organization (FAO) Rome, ISBN 2-921728-05-2, 6 pages.
Lemieux, G. (1992) «L'aggradation des sols par lepatrimoine microbiologique d'origine forestière» EscolaSuperior Agrária de Coimbra PORTUGAL, ISBN 2-550-26521-1publication n: FQ92-3099 10 pages.
Lemieux, G. & Goulet, M. (1992) «"Sylvagraire" und"Sylvasol", neue Wege zum Aufgradieren von Acker -und Waldböden.Düsseldorf, 4 pages.
Lemieux, G. & Tétreault, J.-P. (1993) «Lesactes du quatrième colloque international sur les boisraméaux fragmentés» édité par leGroupe de Coordination sur les Bois Raméaux,Département des Sciences forestières, UniversitéLaval, Québec (Canada) ISBN 2-550-28792-4 FQ94-3014, 187pages.
Lemieux, G. (1995) «The basics of the economical andscientifical green revolution of Sahel» Canadian InternationalDevelopment Agency, Pointe-au-Pic conference of the Club of Sahel26 pages ISBN 2-921728-13-3
Lemieux, G. (1996) «The hidden world that feeds us:the living soil». Seminar given in Africa and Ukraine,International Development Research Center, and Laval University,Québec, Canada ISBN 2-921728-17-6.
Lemieux, G. (1997) «The fundamentals of ForestEcosystem Pedogenetics: An Approach to Metastability ThroughTellurian Biology» Ministry of Forest of British Columbia,Canada and Laval University publication no. 72, 59 pages, ISBN2-921728-24-9
Leisola, M.S.A & Garcia, S. (1989) «Lignindegradation mechanism» in «Enzyme systems forlignocellulose degradation» Galway, Ireland, Elsevierpublication pp 89-99.
Seck, M.A. (1993) «Essais de fertilisation organiqueavec les bois raméaux fragmentés de filao (Casuarinaequisetifolia) dans les cuvettes maraîchères desNiayes (Sénégal) in Les actes du quatrièmecolloque international sur les bois raméauxfragmentés» édité par le Groupe deCoordination sur les Bois Raméaux, Département desSciences forestières, Université Laval, Québec(Canada) ISBN 2-550-28792-4 FQ94-3014, p. 36-41.
Swift, M.J. (1976) «Species diversity and structure ofmicrobial communities» in J.M. Anderson & A. MacFadeneditors Decomposition processes Blackwell ScientificPublications, Oxford, p. 185-222.
Toutain, F. (1993) «Biodégradation ethumification des résidus végétaux dans le sol:évolution des bois raméaux (étudepréliminaire)» in «Les actes du quatrièmecolloque international sur les bois raméauxfragmentés» édité par le Groupe deCoordination sur les Bois Raméaux, Département desSciences forestières, Université Laval, Québec(Canada) ISBN 2-550-28792-4 FQ94-3014, p. 103-110.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


ISBN 2-921728-32-X (english)
Dépôt légal: Bibliothèque Nationale duQuébec. Mars 1998
1 Agro-ecologist, Château Richer, QuébecG0A 1N0
2 Faculty of Forestry, Laval University. QuébecCity G1K 7P4
3 Agronomist. Sainte-Foy, Québec

Areas covered include : Greater Manchester, Bolton, Bury, Oldham, Rochdale, Stockport, Wigan, Altrincham, Ashton under lyne, Glossop, Hazel Grove, Littleborough, Middleton, Sale, Salford, Stretford, Wilmslow, Blackburn, Preston, Rossendale, Lancashire, Cheshire, Sheffield, Macclesfield, Stoke, Hanley, Chester, Liverpool, Bradford, Leeds, Doncaster, Cheshire, Merseyside, Lancashire, South Yorkshire, Derbyshire, Stalybridge, Royton, Hazel Grove, Gatley, Altrincham, Cheadle, Stretford, Urmston,Eccles, Salford, Prestwhich, Farnworth, Heywood, Peak District, Warrington, Kirkby, Ormskirk,
For enquiries outside these areas please contact us