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Fred Morgan
Sponsor
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Posted: Wed Mar 23rd, 2005 10:45 am |
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I ran across this and thought it was very interesting so posted it here. It came from:
http://forestfreedom.org/cogf4/plantations.html
I have just started reading it myself - but it looks like some interesting ideas and observations.
THE JACK MITCHELL
FOREST FARMING SYSTEM
20 YEARS OF INNOVATIVE AND
DEDICATED FIELD RESEARCH
BY JACK AND RON MITCHELL
Based on extracts from the Mitchell System research records
By
Jack Mitchell O.A.M. B.E.M.
Ron Mitchell BAgrSc(Hons).GradDipAd&VocEd.MEnvEd
Key Note Speaker JACK MITCHELL'S FOREST FARMING SYSTEM
Introduction
Over the past 20 years, 1 have developed and refined a 'Forest Farming System' for the commercial production of valuable native cabinet timber tree species. This system is based on a low maintenance and ecologically sustainable approach that "learns from and works with nature" to achieve economic outcomes.
This is the only system in practice that uses compatible associations of native trees in carefully designed naturalistic 'mixed species' plantings.
Using the 'Forest Farming System' natural ecosystems processes are fast tracked and enhanced, and expensive ongoing inputs of irrigation.
Fertilisers and pesticides are virtually eliminated.
In this paper 1 will outline the historical development of the 'Forest, Farming System' and the 'whys' and 'hows' of this system, and the current plantation design and establishment methodology. I'll explain the principles of the 'Forest Farming System' and its importance to sustainable forestry in the tropical and subtropical regions of Eastern Australia.
What Forest Farming is all about
We use the term 'forest farming' to convey a sense of nature, as well as a sense of commercial forestry. It can be said that forest farming is as much about revitalising native timber industries as is about the creation and restoration of wildlife habitats.
Forest farming involves the establishment, maintenance and management of a naturalistic planting with the intention of developing and maintaining a permanent ecosystem and renewable timber resource.
• Forest farming differs from conventional commercial systems in a number of
aspects:
• We advocate mixed native species plantations, not the creation of
monocultures;
• In our plantations, there is no supplementary irrigation other than
natural rainfall;
• We advocate minimal tillage there is no ripping or cultivated prior to
planting;
• We do not clear native forests plantations are established on already
cleared land; we in fact advocate linkages with wildlife habitats of native bushland; and
• We do not advocate clear-felling the use of various species with
different characteristics ensures a planned sequential harvest.
Why the Forest Farming System works
The 'Forest Farming System' is based on specifically designed planting configurations in mixed species plantations that takes into account the natural compatibilities and interactions between various native timber trees. The system is designed with mostly 3m x 3 m spacing, which create a low maintenance regime after 2 to 3 years with full canopy closure.
This spacing, but also with appropriate form pruning, promotes fast growth rates and optimises the production of harvestable cabinet timber logs within
15 years.
The development of the Forest Farming System
1. Learning from nature
My 'Forest Farming System' is based on a lifetime of interest in our natural rainforest and in the growing of cabinet timber species in plantation form.
In the early fifties, the Queensland Forestry Department were not interested in any species other than pine. So 1 had to do all my own field research by an extensive study of how native timber trees grew in their natural environment.
1 found that the nutrient gathering root system of rainforest trees was very shallow and is designed to draw nutrients from leaf matter broken down by organisms within the microclimate of the rainforest. On the other hand., eucalypt forests have a deeper nutrient gathering root system supplied by the understorey of shortlived plants growing in the filtered light of the eucalypt forest.
Almost all of these short lived plants in eucalypt forests are nitrogen fixing. When these plants die off or are killed by fire, they release the nutrients which feed the roots of the eucalypts which are deep enough to survive fire.
The trees of both eucalypt forests and rainforests have deep root systems which can penetrate great depths for moisture and stability.
The result of these observations enabled me to design a planting system suitable for establishing rainforest cabinet timbers. This, together with my long time experience with growing plantation crops including bananas and pawpaws which also have a shallow nutrient gathering root system.
demonstrated the need for total weed control. Perhaps 90% of weeds are introduced species with high nutrient and water demands. 1 need to reiterate that total weed control is absolutely essential. Weeds are in direct competition with the root systems of these trees and crops.
2. The early plantings putting into practice what I had learnt
In 1948, 1 started growing native timber trees in old banana plantations to replace the crops which were entirely taken out at the end of their commercial life. 1 decided to plant timber trees one year before the banana plants were taken out. The trees were planted in the centre of the every second row of banana plants, so that the spacing was 3 metres x 3 metres.
These plantings proved highly successful in taking over from the banana plantation.
1 had great difficulty in obtaining the species 1 needed as nurseries were not propagating native trees with the result that 1 was only able to obtain hoop pine (Araucaria cunninghamii) plants in any quantity. This resulted with most of my earlier plantings being predominantly hoop pine, which although being high quality timber, takes too long to mature to be suitable for private plantings.
One species 1 had been interested in since the 1950s because of its
strength and flexibility as a timber, its fast growth and rapid maturity,
and its potential for cultivation was silver quandong (Elaeocarpus
grandis). 1 tried to get the Queensland Forestry Department .interested in developing this species for timber production but they did not show any interest.
3. Cabinet timber plots in tire 1990s origins of the 'Forest Farming
System'
Following my retirement from banana and pawpaw growing in 1982, 1 became interested in researching cabinet timber plantation forestry as a new industry, and started experimenting in the propagation of some of the timber species needed for planting and production.
In 1984 1 put in my first research plot. In 1986, my son Ron was assisting in this field research. In 1987 1 wrote a book on "The Successful Growing of Rainforest and Harvestable Timbers." This book was reprinted in 1993 and again in 1996.
In 1987 Ron and 1 were involved in propagation research. There were still no nurseries propagating native cabinet timber trees in sufficient quantities to enable plantings; to be established. In 1989 Ron wrote his thesis for his agricultural science degree on the success of our propagation research, particularly for two species silver quandong (Elaeocarpus grandis) and white beech (Gmelia leichardtii).
In 1990, we planted our second field research plot. The results achieved in this plot enabled a further research project in 1993 which involved planting two identical crops, one at Samford and the other at Maleny. Comparative growth rates were recorded at three month intervals. We had difficulty in having the Maleny site boom sprayed to our standard. This meant that Maleny had weed control problems for the first six months, which resulted in the trees being behind those in Samford.
As the Maleny site has richer soil and higher rainfall it was expected that the growth rates would exceed those of Samford but records show that Maleny was behind Samford at 12 months. This difference remained at the same level despite the fact that weed control management in Maleny had been brought up to par. The difference in the growth rates demonstrated the fact that weed control in the early stages is more important than soil quality or rainfall.
This fact has been fully proven in many instances since then.
Our first commercial plantings began in 1995 at Surrey Farm Park. By then we were able to use our field research findings to design these plantings to take advantage of total weed control for the first two years with a designed mix of species which are compatible.
4. The proof is in the pudding the first harvest
Our continuing field research and innovations to our planting design have enabled us to mill the early thinnings of silver quandong (Elaeocarpus
grandis) at 8 years with full maturity at 15 years. The first milling of 8 year old thinnings was in 2001 for silver quandong grown at Samford. The results of timber property tests conducted by Southern Cross University in Lismore for this milled timber revealed that the quality of this timber was almost equal to that of old growth timber.
The results that 1 have received back are very promising. From stocks Air dried on our property, several people have used this timber in the cabinet making industry. The timber has proved to be very stable and attractive. As we have proven, this species reaches full maturity at 15 years, but with the prospect of being able to use thinnings at 8 years it gives authenticity to our plantation management methods. These results indicate that private landholders have the means to become commercial foresters of the future on areas of land as small as 1 ha.
The Principles and Protocols of the Forest Farming System
1. The species that we use:
All of the species in our plantations are commercial there are no non commercial 'pioneer' or ;nurse' species. At present 1 am using a mix of 4 6 species in timber plantings out of a total of 11. The species list for nay particular plantation depends on location, soil type, and rainfall. At a spacing of 3 m x 3 m, the planting density approximates 1000 per ha. The 11 species in our plantations are:
1. Silver quandong Elaeocarpus grandis
2. White cedar Melia azedarach
3. Silky oak Grevillea robusta
4. Silver ash Flindersia schottiana
5. Queensland maple Flindersia brayleyana
6. Yellow ash Flindersia zanthoxyla
7. White beech Gmelia leichardtii
8. Crows ash Flindersia australis
9. Red cedar Toona ciliata
10. Black bean Castanospermum australe
11. White Walnut Cryptocarya obovata
2. Silver Quandong (Elaeocarpus grandis) the cornerstone species
The cornerstone species of any 'Forest Farming' planting is silver quandong (Elaeocarpus grandis). I was initially attracted to this species from observations of its performance as a fast growing and early maturing pioneer and dominant species in natural rainforests. This species has a primary role in height promotion of the other species in our designed cabinet timber plantations. This species consistently displays the fastest growth rates of the cabinet timber species and it has a superb growth form in nature. The timber has a combination of strength, durability and versatility and has always been highly prized and has a ready market.
This species has always represented 25% of trees in forest farming plantings; it now represents about 60% of the trees in forest farming plantings.
I was always determined to include this species in plantings, but initially the seedlings were unavailable. The species always had the reputation for poor germination, and one of the first research projects 1 embarked on was to develop a successful propagation methodology.
Silver quandong has a number of interesting features in its growth and development. In 1994 an observation was made in our earlier research crops that quandong growth rates slowed down at about 8 years with the locking in of crowns. Further observations of old growth forests proved the interesting fact that quandong in their natural environment had a huge spread of crown above the canopy of other species.
Therefore our conclusion a the time was that in order to achieve full maturity of quandong it was necessary to do a thinning at 8 years in order to allow the crowns to spread above the canopy of other species. We also found that buttressing coincided with the full spread of the crown and was a guide to full maturity of tress of this species in timber plantations.
3. Nature based plantation design and green certification
Timber plantations more often than not get a bad press they are generally
considered to be the arboricultural equivalent of the chemically dependent monocultural broad acre crops dominating the conventional agricultural landscape. The establishment of timber plantations is always and quite justifiably controversial when they are replacing naturally growing native forests, composed of exotic species, and planned to result in a uniform clear-felling operation.
Natural forests provide a range of ecological services from the absorption of excess carbon dioxide, to the creation of fauna habitats to soil conservation and amelioration, to the operation of the water cycle and catchment protection, to sustainable yields of non timber forest products such as honey, wildflowers and bush foods.
In our plantings we only use native timber species, involving a methodology which requires a specialised planting and management routine for a compatible mix of selected cabinet timber species. These plantations are designed for sequential harvesting, resulting in a permanent forest which self regenerates. We use buffer zones along stream banks, a strategy which has the effect of creating a wildlife corridor and a balanced ecosystem to enhance the health of our plantations as well as to provide stream bank protection. As we use no fertilisers or irrigation after the initial planting, the water quality of natural watercourses is maintained.
Our methods are based on many years of study and observation of the natural growth patterns and compatibility of the species which we use. When these trees are taken out of their natural rainforest environment to establish plantations, we must try and emulate a naturalistic approach in order to achieve the best results in terms of timber production. We therefore need to have a thorough understanding of how these trees have evolved in their natural state.
All rainforest trees gather their nutrients from the broken down leaf matter on the floor of the forest by the actions of micro organisms which only exist in the full canopy cover of a rainforest micro climate. One of the objectives to maintain the health of a plantation is the establishment of a canopy cover. This is accomplished by a mix of species designed to achieve a canopy cover within the first two to three years.
Timber plantations are now an essential component of agricultural and semi natural landscapes to meet the increased demand for timber products. While timber plantations do not always produce all of the environmental and social benefits we associate with intact natural bushland, they can be planned to ensure compatibility with natural landscapes, to provide attractive short term yields of high quality and high value timber, and to relieve the harvesting pressure on native forests.
Consumers of timber products the world over including Australia are
becoming more concerned and informed about the destructive environmental impacts associated with unsustainable and often illegal timber production from the world's native forests. It is now generally accepted that forest
resources be they in native forests or plantations need to be
sustainable managed. Consumers also need to assured of sustainable forest management.
Timber certification is a market driven consumer centred mechanism to promote production from native forests and plantations. We advocate that private timber producers become involved in the development of certification schemes. Our timber plantations are well designed and well managed, according to accepted indicators for ecological sustainability.
4. Propagation and tube stock production technology
Trees for timber plantings must come from nurseries which practise a precise and naturalistic seed propagation and seedling production methodology suitable for native rainforest species. We need to assure ourselves and our clients that the tube stock seedlings of timber trees are of ideal condition and structure and are given the best chance for establishment and growth in the field; healthy defect free tube stock seedlings with well developed and vigorous root systems, after all. are the very foundation of the plantation.
There are a number of inherent advantages to using tube stock seedlings for
tree planting projects they represent the early vigorous stage in plant
growth and establish readily; they are better suited to withstand dry conditions after planting; and they are cost effective, space saving and easily transported.
To achieve uniformity in tube stock, the seedlings are potted from seed boxes; because of erratic germination, direct seeding into tubes is unreliable. When potting plants should be held over the empty pot and the potting mix poured around the plant so that the seedling will be well shaped centralised with a straight root system. We use tubes with root trainer ribs this design has the effect of sending roots straight down the line of the pot. Smooth sided tubes have the effect of the roots circling around the pot; this circling root structure is extremely detrimental to seedling establishment and growth.
After potting, the tube containers are placed in successive regimes of shade, semi shade and full sun to promote acclimatisation and hardiness. The tube stock containers are then placed in racks with air space under the pots to enable air pruning of the root system. When the protruding roots come into contact with the atmosphere a callous is formed on the end of the root; new healthy roots are formed immediately after the tree is planted in the field.
When trees are taken from the nursery they are usually packed in flat bottomed boxes but should not be held in these containers for any longer than a week because the new roots will shoot from the bottom of the pot.
Should the planting time be any longer than a week, these plants must be placed back into air-pruning racks. Trees when held in flat bottomed boxes for longer than a week will have roots protruding out of the bottom of the pot in contact with the soil. If the seedlings are planted without the roots being trimmed, the roots will fold up under the bottom of the seedling in the planting hole causing a J root deformation.
5. Site preparation
The preparation of the planting site is an important first step as we are most often using pre-cleared sites including decommissioned dairy or crop farms; sites no longer used for the purpose for which the land was originally cleared. We can use a range of soil types for these plantings; not necessarily in areas of former rainforest.
Site inspections are necessary to determine the range of species to be used for particular locations. As mentioned previously, all plantings must consist of 4 to 6 different species. Rainfall from around 900 ml is desirable but lower or higher rainfall can produce excellent results provided a suitable species mix is selected. As most of our rainforest plants are frost-soft to some degree it is important that we know whether the particular site is prone to frost in order to select and plant the correct range of species.
When the site is originally inspected the outside measurements are taken to enable a planting plan to be drawn up. The plan shows the design of the planting with a compatible mix of species. This plan is also used to provide the correct number of each species needed for the plantation. Most of our plantings are now spaced on a 3 m x 3 m square grid. This enables ease of weed control management, which can be achieved by the use of a specially designed spray unit which can be attached to any small tractor or quad.
The best sites for plantings are those with an original cover of grass. If
grass is not present originally, it may be necessary to plant a cover crop
usually a non weedy exotic grass or legume to promote the growth of
surface organic matter which, upon herbiciding, provides a dead grass and stubble cover. Where there are regrowth trees such as acacias or eucalypts within the site they should be taken out by cutting off low and poisoning the stumps to prevent suckering. We advocate minimal disturbance of the site; we should never remove any existing trees with a dozer; doing so causes disturbance to the native soil.
The total planting area must be slashed low and left for the stubble to shoot which takes about 2 to 3 weeks. There are therefore 2 herbiciding
operations boom sprays of the entire area prior to planting, at this
interval of 2 3 weeks. If blady grass or bracken is a component of the weed population, a third boom spray is desirable. The planting can usually take place about a week after the second or final boom spray.
6. Planting and maintaining tube stock in the field
We use a very successful planting hole siting methodology. This methodology,
originally designed for large banana plantations, has been adapted for use in our timber plantations. We need to plant when there is sufficient sub soil moisture. The herbiciding operations pre-planting should maintain soil moisture as evaporation and transpiration of moisture from the soil surface is inhibited. The planting date needs to be flexible and responsive to local soil moisture conditions; particularly in a drought/El Nino scenario. After all, after planting, there is no supplementary irrigation in our 'Forest Farming System'.
In most of our plantings we still use a specially designed mattock for digging the planting holes for the trees. Although there have been several machines designed to do this work, we are not entirely satisfied with the results and the increased costs. We are investigating the design of an improved type of machine for faster and more efficient planting.
The planting holes should be 3 times as wide as the tube, but only slightly deeper. The planting holes should be finished with a saucer shape, so that the soil adjacent to the plant is about 5.cm below the surrounding area.
Slow release fertiliser is applied only once in our system at planting
time and in a shallow hole 35 40 cm away from the plant. We should not be tempted to place fertiliser in the centres of planted tree rows; doing so would create a dependency on added fertilisers. The healthiest plants in the field are those with roots systems trained to extract nutrients from the soil's nutrient cycling processes.
We now use specially designed recyclable tree guards with biodegradable mulch mats at the soil surface for each planting hole. This strategy protects the newly planted seedlings from excess weed competition, as well from extremes in temperature (including frost), spray drift, wind and animal predation. The initial extra cost and time involved with installing tree guards is more than offset with the easier establishment improved performance of planted seedlings.
7. Total weed control
Total weed control management must be in place from the early stages of the plantation. It is important that weeds not be allowed within the plantation as they are in direct competition to the root spread of the young trees. The faster growing species will have their root systems intermeshing across the rows under the dead grass and stubble within the first six months.
All dead grass and stubble must be retained as an important ground cover.
This enables the shallow nutrient gathering root system of the trees to spread out under this ground cover. The faster growing trees will have the root systems intermeshing across the rows when the correct weed control management is in place. The tree root system is so shallow that any weeds are in direct competition with the trees.
It should be remembered that 90% of the weed population in timber plantations comprises introduced species with high nutrient and moisture requirement, relative to native plants. There should be no tolerance for weeds in timber plantations; native timber trees cannot coexist with exotic weeds.
One of the greatest mistakes still being made in other timber plantation systems is where weeds are controlled only along the tree rows and the centres mowed. This practice is detrimental to the structure of the root systems of these trees, causing poor growth rates and poor root form. These slashed centres between tree rows act as root barriers which deflect the roots back to the cleared area, thus limiting root spread and exploration for nutrients.
The dead grass and stubble cover provides natural organic mulch, which not only inhibits weeds but also prevents soil erosion. An added advantage of
this natural organic mulch the direct result of pre planting herbiciding
operations is that its decomposition in situ promotes populations of soil
fauna to build up; particularly earth worms. Earthworm populations enhance the native soil's physical condition and chemical fertility.
There needs to be 4 weed control operations per year in the first 2 years.
For the first 2 years it can be stated that "the weeds control the trees"
(if given the chance). For the herbiciding operations, care needs to be taken to avoid spray drift onto the stems and foliage of the growing timber trees. The tree guards effectively protect the young trees from this threat.
After the second spraying or at about 3 months after planting in the first year, the tree guards are removed. In the second year, there is less potential for spray drift to harm the bark of trees. Upon the closure of the tree canopy cover after 2 3 years, weed control is less of a priority as the timber plantation becomes to a large extent self maintaining. After 2 years, it can be stated that "the trees control the weeds".
8 Pruning technology
Over the past 10 years, we have developed a pruning technology for our timber plantations very different to that used for eucalypts or conifers. It is essential to recognise that every cabinet timber tree species has a specific methodology for pruning to achieve optimum timber yields. Pruning technology is of great importance to the future health of the plantation.
While under pruning causes poor trunk form, over pruning causes poor growth rates. There is a direct relationship between leaf mass, trunk thickness, and plant health.
For the first three months of first metre of growth, for all trees, only form pruning is needed. After that time, we need to be aware of the various methods that need to be employed for each of the species in a timber plantation.
We have developed a special methodology for pruning white cedar (Melia azedarach). After the trees reach over a metre in height, side shoots are thrown above every leaf. Because the leaves of this species are very large and provide enough photosynthesis for the plants, these side shoots must be removed as soon as they appear, and must not be allowed to form branches.
Care must be taken when pruning not to damage the leaf system.
Because white cedars are the fastest growing trees in the first year of the plantation, these trees must be pruned every two weeks during the growing season. For white cedar, with appropriate pruning a trunk height of 4 m can be attained in the first growing season. This species is naturally short lives and has a use by date of about 25 years, during which time a well managed planting will have reached maturity. With this species die back can occur after maturity, so after a 4 m trunk height is attained these trees are allowed to crown so that they will develop good trunk form and a viable saw log will be achieved by 15 years
Pruning of other species needs to be just as precise. As a rule of thumb, two thirds of the total leaf mass must always be retained after pruning. We need to be aware of photosynthesis and its importance to the health and
vigour of the trees for larger leaved species there is a very different
approach to pruning to that of smaller leaved or fine leaved species.
Trees of silver quandong (Elaeocarpus grandis) must have four tiers of branches before the lower tier can be removed. Silky oaks and white beech are pruned very sparingly with only lower branches being removed after being shaded out. Flindersias (trees of the Flindersia genus) need very little pruning with all branches retained, until there are sufficient branches and leaf mass to allow the lower branches to be taken out.
9. Pest management
There are a number of features characteristic to our 'Forest Fanning System'
that mitigate against major pest infestations becoming established in our timber plantations: there is a biodiverse planting mixture, habitats for insectivorous birds, linkages to adjacent native bushland are conserved and enhanced, and tree health and vigour are maintained.
There is very little in terms of insect pests with any of the timber species apart from the cedars. Red cedar trees (Toona ciliata) for example are badly infected with tip moth in all our coastal regions. White cedar (Melia
azedarach) has an insect problem caused by a caterpillar which causes considerable damage to the foliage. This pest can be controlled on young trees by regular monitoring, and the use of environmentally friendly insecticides when needed. Should the insects remain on the tree until the caterpillars are approximately half grown, they migrate to the base of the tree and remain there in a cluster during the day and only feed at night. At this stage a stronger insecticide must be used.
The insects are only a problem until there is a clear trunk of approximately
4 metres and then allowed to crown usually within the first growing season.
Should the insects attack the leaves after this time the tree will shed its leaves, and after the insects have disappeared the tree will quickly regain its leaf structure which means no further insect control is necessary.
Conclusion what the future holds
Our *Forest Farming System' is based on detailed field research conducted over several years. Over time the system has evolved so that stage that there are now a number of successful potentially commercial plantings. We now have over 100 growers in Northern New South Wales and Southeast Queensland with a combined total of approximately 150 hectares. The largest single planting is at Maxville, with 50 hectares already planted, and with plans to extend to 80 hectares. Our system has now been taken up in North Queensland.
Our ongoing field research continues to result in many new innovations, the latest of which is a newly designed tree guard. We are also now carefully observing genetic differences occurring in some of the species, no doubt caused by the fragmentation of rainforests leaving only isolated remnants.
We have been able to observe mutations which cause these genetic differences. Our main problem at present is that our primary seed source comes from these isolated rainforests. There is a great need for the establishment of seed orchards so that the refinement and improvement of the quality of our plant stock is maintained for the future.
Even though we are currently having great success with our plantations, there is always room for improvement by the establishment of seed orchards, stocked by trees tissue cultured or cloned from trees of superior form, to produce quality seed for the industry. Plants produced from seed will always be essential for the establishment of good root structure.
Our mixed species planting design based on the cornerstone species of silver quandong has proved highly successful. In a monocultural planting of silver quandong, the space that has to be allowed for the development and maturity of these trees would make management difficult and the plantation unviable because of the infestation of woody weeds. The advantage of having a compatible mix of species is that the silver quandong forms a canopy above the other species but does not shade them out and in our advanced plantations they are thriving in the filtered light from the silver quandong.
There is enormous potential for a timber industry based on my 'Forest Farming System'. Most of our timber needs are currently met by imports. When our plantations are in full production, the production of specialised native timbers will not only create employment but will provide potential exports.
These timbers were once well known on the export market, and with the diminishing world supply of these specialised timbers, the domestic and export market is assured.
An important factor of these plantations of native trees, together with corridors of a large range of rainforest trees planted along stream banks as a buffer zone, is that we are creating a huge native wildlife habitat. The diversity of tree species provides a food resource throughout the year. As we do not use fertilisers or insecticides on established plantings, the buffer zones along stream banks will stabilise the banks and improve water quality within the streams and rivers of the degraded catchments of our agricultural landscapes. But best of all, we are creating a permanent
ecosystem: a self regenerating renewable timber resource.
Jack Mitchell
i.mitchell@austarmetro.com.au
ACKNOWLEDGEMENTS.
This paper is the result of many years of observation and research into the methods needed to successfully grow tropical and sub tropical timber species in plantation form.
Our work has been greatly assisted by many supporters and field workers in the process of achieving this. We would especially like to thank the following organisation and people, among the many who have helped with this research.
The Pine Rivers Shire Council, especially the mayor Councillor Yvonne Chapman for making available sites for various research projects. We also appreciate the support shown by the council's Parks Department officers. Ron Larson from the Department of Primary Industries for his support and encouragement over the years. Paula Ibell for her support in organising the timber quality analysis.
Jack Mitchell Forest Farming System, 19 Betts Road, Samford. 4520. Phone
(07)3289 1288. Fax (07)3289 1687.
Or email j.mitchell@austarmetro.com.au
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aaron_brewer@hotmail.com
Member
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Posted: Fri Mar 25th, 2005 07:22 pm |
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It's not surprising the emphasis the Mitchel system has on herbicide application in a no-till situatuion. It is the same paradox with no-till corn. When you plant into last years stubble, you have to do more weed control, because the tilling helps supress weeds. The added herbicide is expensive to apply, and has other hidden costs. Preparing the site without tillage does help minimize erosion. And, it appears that his intentions are to preserve the groundcover; more closely mimicking natural conditions.
I'm curious what kind of herbicides or pesticides, or even fertilizers are commonly used on plantations in Costa Rica? And, with what frequency?
Aaron
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Fred Morgan
Sponsor
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Posted: Fri Mar 25th, 2005 08:44 pm |
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As far as herbicides - Roundup is very common. In fact, even if you are going to start plowing, it is necessary to deal with the Brazillian grass - in fact, it requires a double treatment.
Costa Rica overall uses much more pesticides in USA. They also have a higher incidence of stomach cancer as well. I am not sure they are related since this isn't my field of study.
At Finca Leola S.A. we use a little potasium when we first plant - but many others use a lot more.
Most of the chemicals and pesticides mirror what is used up north.
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