Amazon rainforest boundary

Observing the thriving and abundant rainforest, it is hard for some to comprehend why neighboring agriculture in the region experiences quite the opposite affect, but the answer is quite simple – it’s all about the soil.

In simplistic terms, due to constant high temperature and moisture levels, and associated microorganism, fungal and insect life – the decomposition of organic matter in these regions is extremely rapid. In a healthy forest, this thin layer of organic matter is quickly cycled. In the Amazon, 80-90% of the biomass lives above ground. In the temperate regions of the world this ratio is reversed.

Source

Root systems are shallow and widely spreading, allowing the biomass above ground to grab the nutrients from this thin surface layer. Massive amounts of organic matter produced by the forest allow this cycle to be maintained as the forest is constantly mulching itself and recycling. In addition the thick canopy serves the dual role of protecting the delicate and thin soil on the forest floor from the heavy rain.

Once this biomass above ground is removed for traditional agriculture purposes, a rapid soil depleting chain of events follows. Without the humus build up due to the rapid decay, there is nowhere for nutrients to be held in the soil and structure is poor. Heavy rains, now pounding the exposed earth, leach nutrients and wash away the tiny layers of fertility that do exist. The infamous swidden (“slash-and-burn”) practices are a result. Farmers cut and then burn the forest in order to add minerals into the soil, but due to the reasons explained above, the land will only support cultivation for 1-3 years, after which time the fertility is gone and the land must be left fallow for up to 10-20 years. Farmers will continue to clear and burn land in cycles, eventually returning to their first plot too burn and plant again. Such patterns are arguably sustainable by small populations over vast areas of forest, particularly if Terra Preta practices are incorporated, however, when time cycles between cultivation shorten, the net result is forest and soil degradation.

To further aggravate the problem, when chemical or organic fertilizers are applied to these unstable tropical soils, these nutrients have no organic matter to attach to and are thus leached in to the ground water at an even higher rate, thus throwing off the delicate balance of the neighboring forest that are still intact. With populations increasing and forest rapidly decreasing (largely due to these techniques) this is clearly not a sustainable model. There’s got to be a better way and the solutions we find will be crucial to the health of our planet.

This difference between temperate and tropical soil fertilities is often seen as the reason why nations in temperate climates tend to be more advanced than tropical nations. Some tropical soil types cannot support anything but the most simple civilizations. This difference in soil fertilities, in combination with the higher population growth rates in tropical nations, probably explains why the bulk of the world’s hunger is found in tropical nations. Today about 75% of the world’s human population resides in tropical climates. This population (about 4.5 billion) is growing significantly faster than human populations in temperate climates, and about 0.8 of these 4.5 billion do not have enough to eat, and many more are malnourished. – Bruce Sundquist

The forest demonstrates the systems that work. Inspired by the abundant designs in nature, Planet People Passion has plans to develop Forest Garden techniques to create abundant systems on a recently acquired 40 acres of degraded land in the Amazon, about 60km outside of Iquitos. The Permaculture Education Center is being established in collaboration with a Peruvian based Non-Profit, The Amazonian Institute for the Preservation of the Rainforest and Indigenous Cultures which will soon be based on this land.

The project will launch, and start up cost will be funded through a Permaculture Design Certificate Course, June 22 – July 6th, lead by Andrew Jones where students will have the opportunity to collaborate in the design of the center’s early planning and at the same time immerse in the cultural treasures of the region made possible through the 10 years of shamanic apprenticeships and work by co-founder Roman Hanis.

Co-Founders, Cynthia Robinson and Roman Hanis, seek to create a model for carbon negative living, which provides abundance for the living communities on all levels. The vision is to implement a multi-layered agro-forestry model, which also incorporates and nurtures the preservation of ancestral shamanic traditions, medicinal plant, as well as exploration on ancient techniques of Terra Preta ("black earth") where ancient cultures successfully developed large areas of thick fertile soil. These ancient traditions hold the keys in both quite literally creating a sustainable foundation and then nurturing the life stemming from it.

It is crucial that we spend our energy creating small living models that are able to explore and evolve organically as we learn and live. It is through these living models that we will truly be able to collaborate with indigenous communities and pool our wisdom together. And it is through these living models that we connect to the languages of nature and develop our own intuitive knowing.

Download: You’ll see the option to download the 913 megabyte MP4 file at bottom right side of this page.

YouTube: The video can also be watched on YouTube, in four segments, here, here, here and here.

Greening the Desert II (including Part I) – Greening the Middle East
(Duration: 36 mins)
Tips for playing: If it’s slow to load, turn off High Definition (HD) on the player.
If you still have problems, click play (on low or high def) and then after it’s started,
click on pause. The video will then continue to buffer into your computer.
Play once fully loaded.

I would like to take the opportunity to thank Kelly Kellogg at this juncture. Kelly donated initial funding that enabled the purchase of the land for the Jordan Valley Permaculture Project site (aka ‘Greening the Desert – the Sequel’). But, upon watching the Greening the Desert Part II video, Kelly was inspired to donate an additional $20,000. These gifts are very encouraging to us as we try to solve problems at source (teach a man to fish…). Others who may feel inspired to donate to help us move this work forward faster can do so here.

A little background on the video follows:

Children in a school playground, Al Jawfa, Jordan Valley

When there’s no soil, no water, no shade, and where the sun beats down on you to the tune of over 50°C (122°F), the word ‘poverty’ begins to take on a whole new meaning. It is distinct and surreal. It’s a land of dust, flies, intense heat and almost complete dependency on supply lines outside of ones control. This is the remains of what was once called the ‘fertile crescent’. It is the result of thousands of years of abuse. It is a glimpse at a world where the environment – whose services provide for all human need – has all but completely abandoned us. This is a glimpse at the world our consumer society is inexorably moving towards, as our exponential-growth culture gorges itself at ever-increasing rates.

The original Greening the Desert video clip has been watched hundreds of thousands of times and has been posted to countless blogs and web pages in the datasphere. Although only five minutes long, it has inspired people around the globe, daring the lucid ones amongst us, those who can see the writing on the wall, to begin to hope and believe in an abundant future – a future where our survival doesn’t have to be based on undermining and depleting the very resources of soil, water, phosphorus, etc. that we depend on. The work profiled in that clip demonstrates that humanity can be a positive element within the biosphere. Man doesn’t have to destroy. Man can repair.

In the clip at top I introduce you today to Greening the Desert II. I shot the footage for this video last month (October 2009) and edited it on location in the Dead Sea Valley in Jordan – the lowest place on earth, at 400 metres below sea level. Much of it was shot in or near the village of Al Jawfa where I stayed, which is effectively a Palestinian refugee camp that has morphed over the decades since 1948 into something resembling a functional small town. It was first shown to delegates of the ninth International Permaculture Conference (IPC9) in Malawi, Africa at the very beginning of November and is now being released for general consumption. The video will take you to the original Greening the Desert site, letting you see its present condition after six years of neglect when funding ran out in 2003. You’ll also be introduced to our new project site – the Jordan Valley Permaculture Project, aka ‘Greening the Desert, the Sequel’ – and see some of the spin-off effects within Jordan from the influence of the original site; promises of much more to come.

The work we’re undertaking in Jordan is in accordance with what we call the ‘Permaculture Master Plan‘, where the project’s future is assured through funding from running educational courses. Project sites thus become self-sufficient, and self-replicating.

Geoff Lawton instructs students in a school yard in Jordan, one that PRI has
just created and begun the implementation of a design for, so its
many children can see, experience and learn permaculture first hand

Through this work we envision thousands of educational demonstration sites worldwide – all inspiring and teaching communities around them how to begin to tackle at root the massive challenges we now face after decades of short-term profit-based thinking has all but ‘consumed’ our planet and dismantled the social constructs that the human race has always depended on for its survival. Through this work we see desertification stopped in its tracks, and reversed. We see this century’s dire water issues getting resolved. We see productive work for millions in bypassing the irrelevant efforts of our ‘leaders’, to instead build a new kind of culture – a culture based on cooperative effort and learning. It’s a culture where its members have regained a sense of their place in creation, where they become land-based stewards of remaining resources; creating a culture where we at last find ultimate satisfaction – promoting and building peace and low-carbon, relocalised, community-based prosperity.

We have many such ‘Master Plan’ projects in various stages of development worldwide, and a steady stream of enquiries from people around the globe wanting to get involved and help widen this cooperative network. Perhaps it’s time you took a look at Permaculture? After all, do you have something more worthwhile to do?

Jordan Valley

Inter-row Eucalyptus saligna (Sydney blue gum) & Casuarina cunninghamiana (river she oak) planted in 2000

I recently had opportunity to visit a Permaculture site called ‘Dalpura Farm’, near Geelong, outside of Melbourne. Although (or perhaps, because) designed by Darren Doherty, the very well known Permaculture designer and teacher, it was dramatically different than your average Permaculture site. Rather than an urban edible garden, or a fruit-/veg-/livestock-oriented rural block, this 140-acre property was all about trees.

It’s an experimental agro-forestry project, aimed at finding the best way to produce a range of commercial products and ecological benefits from trees, with timber production being the primary focus.

I contacted Darren, the designer, and George Howson, the owner of the property, to see what it was all about.

Craig Mackintosh: With Peak Oil issues right at our door, sales of seeds and potting mix are going through the roof. But, with the ‘Dalpura Farm’ project, you seem to be saying we should be thinking beyond just cauliflowers and cabbages. Wood, prior to the industrial revolution, was always the main source of fuel for humanity. Is any of the motivation behind this particular project connected with future resource constraints?

Darren Doherty: Well the focus at Dalpura was from the start influenced by the fact that the developer was an absentee landholder and we had tenants in until just a few years ago…. They showed only a little interest in what we were trying to ultimately achieve so you could say we started at the back gate and have been working towards the back door ever since. Our main priorities were to develop a site that could achieve multiple outcomes, with a particular focus on valuable managed timber plantations and silvopastoral systems following Keyline™ Design methods, where we treat the whole site as one big water catchment rather than concentrate on using technologies such as swales as many in Permaculture do.

The soil is the cheapest place to store water and we have lifted the SOC level on these very poor, laterised Tertiary Gravels (the region’s largest gravel mine is right next door and Dalpura shares its geology!) from about 2% when we started up to around 6%+ which has made a huge difference to the performance of the various plantings on the site, and therefore the water & mineral cycles have improved radically over the whole site where we have done work. This is despite the fact that rainfall has been very much less than average over the period since we started back in 1996.

The world is short of topsoil and that is the foundation of everything and as I like to say, ‘…..we have to be Blue, before we can be Green or Black….’, meaning we need water (blue) before we can photosynthesis (green) and therefore build carbon (black). I have never been one who has focused on resource constraints as such, rather we have always developed low cost solid state systems that would ultimate yield in any situation.

New revegetation planting (2009)

George Howson: While the primary goal of the forestry plantations is to produce high quality, feature grade timber for furniture and joinery, the systems are designed with multiple products and purposes in mind. I had used a number of native Australian timbers as features in a range of energy-efficient, inner-city housing developments in Geelong in the early 1990s, and was keen to grow the timbers myself and promote their attributes. At the time I formulated the brief, and Darren designed the initial systems, the aesthetic qualities of Australian timbers were generally under-appreciated, and I saw an opportunity to do something about it on a very small scale. I was also predicating the future economic and other values on the likelihood that timber supplies from native forests will be progressively locked up, and that small scale farm forestry is a better way forward in both social and ecological terms.

Other intended products from our trees at ‘Dalpura Farm’ include harvesting seed; fire-wood; poles from thinnings for orchard fencing and garden structures; and the possible production of shiitake mushrooms on farm-grown logs. Stock fodder systems are also a core element in future planning, with integrated grazing along Holisitic Management lines an enterprise currently being explored.

Wetland Crossing Dam, a concept developed by Darren Doherty as an alternative to
conventional concrete culvert/end wall. Nothing planted: all self-established
vegetation. Built by Paul ‘Ringo’ Kean in 1.5hours with a D5 in 2007. Acacia
implexa (lightwood) & Eucalyptus leucoxylon (yellow gum) complex (1998)
in background.

CM: I noticed the trees were planted in swale-type formations, except angling up from valleys onto the slopes rather than running on contour. Could you give us more details on this, and tell us the reasoning behind such a design?

DD: There is not a swale on the property. I have never been much for swales in this part of the world or many other places where I can use the geometry of Keyline™. I understand and use swales where I feel they are an appropriate patterning, but find that in plantation (or orchard) settings the use of the geometry of topographic contours is awfully problematic due in large part to the lack of equidistance between contours, leaving turns to often occur within the planting itself: this is a pain to say the least when it comes to management operations.

The lack of equidistance of contours also gives you the following issues:

1. Can’t fit as many units into a given area
2. Can’t obtain tree offset patterning so important in tree system design
3. Much more difficult to set out the design: with Keyline™ geometry you mark one line and then do a series of 90° offsets off of the 1st line.
4. The drift of runoff (on the rare occasion it now happens) towards the ridge in our system at Dalpura is an application of the Keyline™ geometry. The rationale behind the mounds themselves were to increase the internal drainage characteristics of the soils together with water harvesting. These mounds were constructed using two opposing discs attached to the Yeomans Keyline™ Plow which was subsoiling at the same time.

Sometimes I sense that people use & recommend contours because it is an easily transferred technology, whereas Keyline™ geometry requires a much more detailed understanding of topography that is easily and very often confused. Our application of Keyline™ geometry over the years has become very complex down the point where we are able to create completely symmetrical layouts whilst working on curves. This is difficult to do and requires the following:

1. Electronic topographic survey (ie. Total Station) of the landscape
2. CAD layout planning
3. Set-out of the site using Total Station to accurately reflect the CAD design on the landscape

This might sound like a long-winded process to many, but to us it is about optimisation of all of the outcomes we are after. Namely:

1. Client Satisfaction
2. Landscape Harmony
3. Water-use Efficiency
4. System Performance
5. Ease of Management & Harvest

The use of this whole process with Dalpura’s 1998 planting was made even more important by our ground preparation contractors clearing all the scant layer of topsoil in what was an executive decision that was quite disastrous when your soil is basically gravel! So we really started behind the 8 ball when we took the job back from these contractors. This only vindicates the whole process that we ultimately undertook.

Inter-row Acacia dealbata (silver wattle), and regrowth from thinning (foreground)
with Eucalyptus microcarpa (grey box) planted in 1998. Cam Wilson centre.

GH: All the various forestry systems across Dalpura Farm are planted in tree mounds aligned on ‘Keyline pattern contours’, which direct the natural water flow from the valleys or drainage lines out across the slope towards the crest, as per the pioneering work of P.A. Yeomans. The mounds act as mini-swales, intercepting and spreading the rainfall across the site, helping to distribute it more evenly to all the trees. The gutters on the sides of the tree mounds also act as temporary catchments following heavy rainfall events, increasing the efficacy of interception and storage of run-off, & retaining moisture in the landscape for longer.

CM: You had quite a variety of tree species planted. Can you tell us about some of them, and about any particular relationships going on there. And in what other ways does Dalpura differ from your average, conventional forestry project?

DD: There are about 120 species that have been planted at Dalpura overall. In the 1998-2002 plantings we installed around 20,000 trees and about 20 species (I have detailed records at home but am in Mexico at the moment so referring to memory!). Following 2002 we then started to run out of room and we wanted to plant more trees as per our original layout plan of 1996/7, so started to plant out the pastoral areas of the property. These plantings included more non-timber product species along with timber species; plantings that were a Permaculture/Keyline™ spin on J. Russell Smith’s 1927 classic, ‘Tree Crops: A Permanent Agriculture’. I call this kind of thing Keyline™ Mark IV as neither Yeomans Snr. nor Jnrs. ever applied Keyline™ in this way to my knowledge.

The project differs obviously from the industrial forest production where large areas of single species, often with cloned genetics are grown, where often biota are controlled chemically and the whole planting is clear felled at the end of each rotation. At other farm forestry sites it is common to follow a similar process only on a smaller more integrated scale. Here obviously we are integrating and including many species, including fauna and multiple methodologies of both landscape patterning but also management regimes. It’s a lot more complicated that’s for sure.

In the 1998-2002 plantings we were intent on developing a mixed species layout where the various species complexes (typically made of two species in each complex) were placed according to soil type and aspect. We basically decided this from the initial ‘high-level’ planning and then when the rows were prepared and the trees grown and delivered we then made the decisions to ultimately place the trees as a planting team. We had a great crew with us on that job, made up of new and old heads and it was an interesting process that did and didn’t work. What didn’t work was more a function of tree genetics than anything else, plus some pest animal issues as well.

New revegetation planting (2009)

Each complex throughout these systems are composed of a non-legume (all Eucalypts except for Grevillea robusta). In the 1998 systems we experimented with inter-row layouts where we would have the following layout as an example:

The specific intent of this layout (3m x 3m) was to have the fast growing Acacias (either Acacia dealbata or A. mearnsii) grow fast and fill the canopy quickly forcing the slower growing Eucalypts to ‘search’ for the available ‘light well’ and therefore reduce side-branching and improve on their form. This has and hasn’t worked. Though with some of the species we are working with they are very slow growing and their Acacia partners were perhaps too fast, though we are still waiting to see the full effect of this over time.

Otherwise in the 2002 planting we went a lot more ‘conventional’ with the following layout:

This appears to be a much better layout overall and so we are sticking with this one by and large. We have dabbled here and there with interplanted layouts in the main forestry complexes but have found they are more cumbersome when on a larger scale. That said on some sites we have worked with such as at Geelong Grammar School (1999-2000) and at the Shell Refinery at Corio (1999-2001) inter-planting worked quite well.

This kind of layout goes like this:

It all comes down to being what works for the forest ‘sociology’, which is reflected in tree performance and how easy it is to manage the systems especially when it comes time to thin the systems. Then things start to get much more complicated. These are times when you can appreciate why industrial foresters go for single height class, single species systems: but then a forest isn’t made of one species and one height class is it?

In 2000 we planted a paddock with a interesting array of ‘Tree Crops’, most of which were exotic species. This paddock we know as TC8 (all species complexes across the farm are individually codified) and it has three rows of Tree Crops at 5m row spacings every 24m. This system includes classic tree crops such as Gleditsia triacanthos var. inermis (thornless honey locust), Ceratonia siliqua (carob), Morus nigra (black mulberry), Quercus ilex (holm oak), Q. suber (cork oak), Q.robur var. fastigiata (fastigate english oak) plus Cytisus palmensis (tagasaste) and Atriplex nummularia (old man saltbush) as interplants between all of the tree crops. This system had ‘Leaky Hose’ subsurface irrigation installed in 2003 and is going along quite well, except the tagasaste’s have been hit pretty hard by the ‘roos.

From 2004 we were filling in the gaps ‘up the back’ of Dalpura and we decided to get a lot more complex with our plantings in the remaining places free to plant. So this involved very complicated layouts with lots of species: some of which were really pushing the edges of experimentation. Some suffered accordingly as they revealed themselves to not be suited to the site whilst others have thrived and have led to further planting of those species. We also experimented with using very tall plastic tree guards due to the kangaroo predation throughout the property on some of the plantings.

Walled garden and new orchard. Polewood in foreground from 2004/5 thinnings
of 1998 plantings of Acacia dealbata & Acacia mearnsii (late black wattle)

GH: The initial native forestry systems were planted between 1998-2002. They cover ~18 hectares, and include sixteen species of Australian trees (nine species of Eucalypts, four Acacia species, two Casuarinas and Grevillea robusta). Since then we have broadened our species selection, experimenting on a small scale with mixed plantings of Acacias and Northern hemisphere hardwoods (a range of oak, ash, beech, elm, cherry, walnut, liquidamber and many others).

A key long-term goal with the timber plantations is to enhance the soil fertility within these systems, both for its own sake and to enable the growing of a wider range of species 30-50 years down the track. In terms of building soil fertility the purpose was to harness the benefits of interplanting nitrogen-fixing, leguminous trees such as Acacias with Eucalypts and other broad-leafed species. The diverse range of species leads to a richer and more complex mix of minerals and microbial life in the litter layer that is continually forming on the forest floor.

Probably the main difference between our approach to silvicultural management and that of other farm forestry growers is our system of managing the inter-row areas. We allow revegetation to occur naturally between every second row (predominantly pioneer undergrowth species such as prickly ti-tree, hedge wattle, prickly moses and also a range of native heaths, various grasses and ground covers, mosses and lichens…), mulching the alternate rows to maintain access for silvicultural management work and timber extraction. This system mimics a forest ecology, with the various tiers of vegetation performing a range of functions in the system – improving the soil below the surface through root action, and increasing the amount of organic matter deposited as forest litter (leaves, sticks, seed, branches and bark; bird droppings and animal scats…); acting as protective habitat for a greater number of birds and insects; & also reducing evaporation and mitigating the effect of damaging winds on the timber trees etc.

As well as this, we manage the coppice re-growth of hardwood species as a follow-up to our thinning regime, in order to create multiple-aged trees within a uniform-age-class plantation. Ultimately, around five-to-ten specimens of each species will be retained per hectare as semi-permanent inhabitants of the system. They will be used as a source of good quality seed for growing seedlings from that species, and will carry out all the ecological functions that mature trees perform in what will effectively become an analog forest.

Indifferent form displayed on Eucalyptus tricarpa. Poor genetics we think.

CM: As you’re trying things in forestry that might not have been ventured before, you’ll obviously be on an experiential learning curve, discovering some species and design aspects that are working well, and some that aren’t. The time frames involved in growing trees are considerable, so learning what we can from your experience could save people many years of wasted effort and expense. Can you give us some insights from your learning curve with this project. What worked, what didn’t, and what would you do differently? I noticed for example, that some species tended to be a bit crooked, perhaps not so good for using as timber, and some were stunted in growth, etc.

Some of your lessons will be location-specific, affected by regional climate, and also other factors like kangaroos, etc., but some will be lessons that can be applied in other countries and climate zones. Perhaps we should separate these for the benefit of all.

DD: As I have already mentioned the brief was the outset was clear, and George has enunciated it clearly in this interview. Quite a few well known Permaculture practitioners (including: Cam Wilson, Paul ‘Ringo’ Kean, Derek Ashby, David Holmgren and David Griffiths) have worked or advised at Dalpura Farm over the years and found things of interest there. It is a difficult site with its soils and the average rainfall since we started has been much less than average so its not what you would call an ideal site from that perspective. A few have been quite disparaging about what we have been doing, often though they have focused on some of the various system’s misgivings such as those you mentioned.

That said we felled trees in 2003/4 that were planted in 1998 and then ultimately milled and dried these for furniture after that. We have radically increased the biodiversity values of the site due to our layout style and management regime. The bulk of the systems are in good shape and we will continue ad infinitum to obtain timber and forest products from this site. We and others will continue to learn from George’s munificence and the different influences that all of the project’s players have had over the years. The current manager Matty Fahey is doing a great job and I can’t wait to see what the place looks like after nearly a year away. There is so much to see there and it is one of the sites in my portfolio that I learn the most from, and I am not the only one.

Biggest lessons?

• Start small but experiment on the edges and nooks widely
• Go and check out others sites in your region or regions with similar climates
• Do a Master Tree Growers Course (www.mtg.unimelb.edu.au)
• Subscribe to Australian Agroforestry (www.mtg.unimelb.edu.au)
• Join your local Farm Forestry network
• Use high quality tree genetics from mixed, tested provenances
• Work with high quality nurseries
• Ensure high quality ground preparation and prepare a year or two ahead of planting
• Get the fungi going – mycorrhizal when planting and saprophytic when thinning
• Practice silviculture regularly: as our great, late mate Joe Polaischer used to say, "its working man’s yoga!"

Quercus robur var. fastigiata (fastigate oak) silvopastoral system planted in 2000

GH: There is a fair amount of truth in Chou Enlai’s observation that "it’s still too early to tell". We are attempting to create inter-generational forestry systems along the model of Northern European practices starting from a fixed point in time. A number of the trees being planted are not intended to be harvested until well beyond my lifetime, and some past my childrens’ life times as well.

Part of the strategy of Darren’s design thinking was to plant a variety of species which have staggered time-lines from planting to harvest. The Acacia mearnsii and A. dealbata (Late black wattle and Silver wattle) are expected to be ready for harvest at around 15-20 years old, whereas with the River red gums and Red ironbark (Eucalyptus camuldulensis and E. tricarpa) we are looking at 35 years+. And with Californian redwoods (Sequoia sempervirens) and some other species we are probably looking at 80-100 years+.

Ironically, some of the trees exhibiting poorer form which you refer to are ones like Red ironbark and Yellow gum (E. tricarpa and E. leucoxylon), which are indigenous to this area, and adapted to growing in gravelly soils with moderate rainfall. We have found that trees do not respond entirely predictably to new and unfamiliar conditions. Experimentation with a wide range of species often brings surprising results.

Lessons applicable in region: Establishing the plantations on a Keyline layout has been invaluable, and is particularly applicable to lower rainfall regions. Our historical rainfall is around the 24" (600mm) mark, but having experienced a number of below average years since planting, capturing and utilising the available rainfall has been critical in the trees’ development, and, in some cases, survival.

One of the main unanticipated problems has been kangaroo predation on certain species, especially Blackwood and Lightwood (A. melanoxylon and A. implexa), as well as many of the exotic broad-leafed species. We have evolved a guarding system to deal with this predation, using 2m tall plastic guards attached to 7′ hardwood stakes. While the initial capital cost and follow-up labour is not cheap, we have been able to re-use the guards a number of times over.

Lessons applicable almost anywhere: Leaving every 2nd row to natural re-vegetation, and mulching to increase the breakdown of woody organic matter and provide more fungal food for soil biota.

Experiment with a broad range of species, and allow time to observe how they respond to a new environment. For example, Sugar gum and Spotted gum seedlings (E. cladocalyx and Corymbia maculata) were planted close to one another back in 1998. The Sugar gum boomed after the first couple of years, whereas the Spotted gum suffered from frost events in their early years, and were probably about 1.5m tall on average compared to the Sugar gums’ 8-10m after five years’ growth. However the Spotted gum has gradually taken off, and caught the Sugar gum in spite of the initial growth differential.

Close up of the magnificent Eucalyptus tricarpa

CM: This property is 140 acres, but do you think there’s anything the average guy on a quarter acre could be doing along these lines as well?

DD: Forestry can be done anywhere and Geoff’s ‘Food Forest’ video shows that the elements of forestry expand on the view we’ve been putting out there for a long time now: That the structure of forests never changes much wherever you are, rather it is the species that change, though their roles as life forms don’t within each forest. A forest is also made up of more than just the plants: it is a living, dynamic and ever evolving system that includes all of the kingdoms of nature.

As for your ¼ acre block, food forestry will be your best bet due to the practical issues of felling trees for timber production etc. By and large it will be non-timber forest production. That said you can do some very creative kerb-side coppicing for the rocket stove! Urban mixed species, multi-purpose agroforestry in the Zone 3 & 4 landscapes of our urban and peri-urban spaces makes a huge amount of sense as we move into the ‘new carbon’ economy (as opposed to ‘old’ or fossil carbon) where our wastes are cycled locally into a range of high quality products.

Echium candicans (pride of madiera) bee forage avenue planting (foreground) with
Cytisus palmensis (tagasaste) nurse planting in Keyline parkland

CM: And finally, a question specifically for the owner, George Howson: Investing time and money and ignoring potential lost income from the land in the interim takes some determined long term thinking. Can you give us a rough idea of investment cost, and expected returns?

GH: I think that any evaluation of the financial returns on specialty timber growing is ultimately academic, given the extended time-frames we are dealing with before many of the trees are ready for harvesting. Many of the intended returns from this project will not be measurable in economic terms. However, to answer your question as best I can, my underlying assumption has been that farm-grown timber will appreciate in value in excess of CPI over its financial life-cycle, and that the capital value of the property, and increased production potential due to increases in fertility levels, will generate growth in excess of the value of comparable rural land. Unfortunately, I won’t still be around by the time this project is really coming to fruition, and beginning to realise its true economic/aesthetic/ecological/social and farming potential.

One of the hidden benefits of working on a project of this nature has been the development in my own skills and knowledge as a designer. Working with Darren and other people such as Dave Griffiths of Geometree, and watching how systems evolve and develop over many years has been a great education. Very challenging at times, exciting and tremendously satisfying at others, but overall a richly rewarding journey.

Xanthorrhoea australis (austral grass tree) detail

A wise person once said that soil is not only more complex than we know, it is more complex than we can ever know! The good news is humans have lately achieved a level of practically applicable knowledge and experience in soil biology to be absolutely capable of massive, positive impacts on sustainable soil use world-wide! It is undoubtedly true that we’ll never know everything, but no matter – we already know enough to get very, very busy!

Renowned microbiologist Dr. Elaine Ingham kicked off the West coast leg of the first-of-its-kind Carbon Economy Course with a powerful three-day learning-fest centered on the soil food web. The bionics of biology, miracles of super-charged soils, blessings of extra-strength compost, and explosive results of super-activated compost teas were all on abundant offer in this powerful course. Such topics sparked a highly-charged, enlivening energy in the ‘brain-food-web’ of the attending students, while setting an inspired tone for the modules to follow in the series!

Thirty seven enthusiastic soil nerds, garden-geeks, and other ecologically minded farmers, permaculturists, and assorted agrarian adventurers from all over the US and beyond (many from all parts of California, Colorado and as far as Vermont) converged at the beautiful Orella Ranch for a full complement of complex food web inter-dynamics, mind-blowing biological success stories, rigorous scientific data, and no shortage of classic, coastal California sunsets overlooking the rippling Pacific (this radiance was rivaled only by the continual ‘light-bulbs’ popping on above the heads of the students in class!).

Orella Ranch, California coast

Dr. Ingham is President and Director of Research of Soil Food Web, Inc.; a successful commercial lab (with locations in Australia, Canada, South Africa and the US) which analyses soil and tea samples for their clientele, as well as providing consultation on using biology to vastly increase soil and plant health and promote a sustainable permanent agriculture. Clients include everyone from backyard gardeners to ranchers to 5,000 hectare farms and beyond (SFW, Inc. has worked with growers on over 2 million acres). A prolific author of cutting-edge research in the area of soil biology, Dr. Ingham is also a very engaging speaker and energetic teacher who is never more excited than when sharing her wealth of knowledge with students in the courses she offers regularly.

Talk about “Care of EARTH!” Most would agree this first of the Permaculture ethics begins quite literally with the small ‘e’ earth itself; soil. In this spirit, the Orella SFW course started off with a detailed introduction to the massive variety of soil organisms, from bacteria and fungi, through protozoans and nematodes, and on through the food web into micro and macro-arthopods and earthworms (An excellent condensed introduction to these can be found in Dr. Ingham’s Soil Biology Primer—a USDA publication). Along the way students learned about how the various organisms function in soils to:

• produce good soil structure
• cycle various nutrients (nitrogen, sulfur, phosphorous, etc.) and make them available to plants
• interact with each other and with the root zones of plants
• provide nutrition to plants in the right places, at the right times and in the right amounts
• improve water holding capacity and aeration
• reduce compaction
• eliminate any need for pesticides or inorganic fertilizers
• greatly reduce water use (often, up to 70% reductions)
• increase both plant yields and topsoil

All of this, along with much more learning–about the affects of aerobic vs. anaerobic soil conditions, bacterial to fungal biomass ratios in the various ecosystems of the world, as well as the steps needed to move from a conventional industrial farming model to a biological and sustainable one—was only the first half!

Next, Dr. Ingham took the increasingly energized class through a detailed and well researched explanation of creating lively composts, brimming with the good biology needed in the soils and by the plants. This included different recipes for different scales and contexts, ways to tilt your composts towards bacterial or fungal dominance depending on your needs, as well as worm-composts and general vermiculture.

Finally the course dug into the topic of using good composts to brew excellent compost teas! From teas to extracts and soil drenches, Dr. Ingham took the class through the process, explaining how to best get life—and the precise life that you want–exploding in your tea bucket, vat, or tank, and from there out into your soil, or onto your plants. In the process students were exposed to amazing slides and explanations of the various and fascinating forms of life we want to see and identify in our teas and extracts when sampling them under the microscope. By course end, having been very well ‘inoculated’ and ‘activated’ with this valuable information, everyone was itching to get brewing!

A few additional ‘light-bulb’ sparking tidbits from this excellent course:

• There is life in soils as deep down into the earth’s core as humans have sampled—16 miles! There are even bacteria adapted to a habitat of molten lava!
• Organic matter holds TEN TIMES its weight in water, and there is no upper limit to the amount of organic matter a soil can hold! 100% not impossible.
• A healthy soil will have 50,000 protozoa per gram/teaspoon. These will collectively eat 500 million bacteria (per gram) every day (about 10,000 bacteria per protozoan), releasing 400 million molecules of Nitrogen (per gram, per day), typically right in the root zone!
• Standard soil tests measure only 1% of the total pool of soil nutrient (which is the ‘soluble fraction’ existing precisely at the time of sampling). This 1% fraction gives no information about the rate of nutrient cycling and replenishment provided by the soil biology from the remaining fraction. There is, therefore, no relationship – zero – between the numbers these standard lab tests will give you and the nutrients that end up in your plants! With the right biology in your soils plants will tend to have access to all major nutritional needs regardless of ‘low’ soluble fractions shown on standard lab tests.
• Using good soil biology can even eliminate the need for the very ancient practice of crop rotation! No disease, no need to rotate. Continual nutrient supply, no need to rotate. Therefore, one need never till again, saving time, energy and money, while increasing surplus topsoil, yields and other profit margins!
• Who doesn’t like CHOCOLATE! A well made, finished compost – likely to have all the ‘good guy’ food-web organisms we want – can be COLOR checked against a 70% cocoa chocolate bar. That is the ideal color we want to aim for in our composts and even topsoils. Check it out and enjoy!

Thank you, Dr. Ingham, for your tireless efforts and kudos to the good folks at Quail Springs and Orella Ranch who are jointly organizing and convening this leading-edge series. Congratulations on a very successful start! See the links to these organizations to learn more or to donate in support of their ongoing efforts to bring sustainable land management practices to a wider audience. Also, see the Soil Food Web, Inc. website for updates on future SFW courses or to purchase Dr. Ingham’s books or lectures (on cd) and learn even more of this fascinating and powerful information.

Next up in the Orella hosted West coast Carbon Economy Series: Sustainable Land Management with Kirk Gadzia (Holistic Management – Resource Management Services) and Darren Doherty (Keyline Design, Broadacre Permaculture – Permaculture.biz ). See you there!

Owen Hablutzel performs international work in Permaculture design, consultation, speaking, and education. He is a director of the Permaculture Research Institute, USA, and can be reached at owen (at) permacultureusa.org

After driving all night from my North Georgia market gardens I arrived just before seven in the morning at the Indianapolis hotel where the ACRES U.S.A. Convention was to be held. The lines at the hotel desk were so long I left my colleague, Lorraine Cahill, to check in while I headed for the restaurant. I needed a steaming mug of coffee and a bite of breakfast to start my day. Otherwise I was in danger of fading away. Growing market veggies for 26 weeks for restaurants, markets and box subscribers had, thankfully, just come to a close before driving all night to reach America’s most unforgettable and inspiring convention. I didn’t want to miss a minute of it, but I had a booth to set up when the trade show opened and I needed more push than I had at the moment.

As fate would have it, as I joined the cue the people in front of me were Gary Zimmer from Wisconsin, Roelf Havinga from the Netherlands and a man named Rex (whose last name eludes my recall) from South Africa. We struck up conversation and all took a table together in the packed restaurant. I was the last one at my table through the buffet line, and as I took my seat I ventured that I figured the single highest priority we had as ecological farmers was to maximize the carbon we took out of the atmosphere and stored in the soil. After all, we, and all the things we grew on our farms, were carbon based life forms. “Funny you should mention that,” said Rex. “That’s precisely what I tell all my clients.”

Roelf echoed Rex’s sentiments with “You sure have got that right. When we store carbon in our soil we build life into our farms. I am all the time telling people this.”

The irrepressible Gary, who can say more in less time than all three Marx brothers talking at once, then regaled us with details of the whats, whys, hows, whos whens and the importance of catching carbon. “You can’t build soil without carbon, and the crazy thing about it is carbon is free. It’s the single most important thing a farmer can do. It’s a pity we cow farmers are demonized for releasing methane when growing grass and grazing it puts more carbon in the soil than anything else you can do.”

I had to agree with Gary that savvy graziers caught carbon more easily than any other type of farmer. The single biggest riddle I’d had to solve in self-sufficient biodynamic market gardening was how to build carbon into the soil whilst cultivation returned so much to the atmosphere. I’d discovered I had to maintain a grass and legume sod, almost as robust as my pastures, on all my traffic paths as well as growing robust mixes of the most productive crops I could find for my rotations. For those veggies like cukes, potatoes, capsicums, tomatoes, squash and ginger, mulch was the answer; but either way I had to keep the soil as fully covered as much of the time as I could, and I had to find ways of cultivation that minimized compaction and soil structure destruction.

After a delicious breakfast and lively discussion we got on with our day, each agreeing that being a good farmer meant catching carbon, first, foremost and always.

It should be no secret that excessive cultivation ranks right up there with mono-cropping and use of chemical nitrogen for driving carbon out of the soil and killing it; and yet, cultivation is what even the best organic and biodynamic market gardeners do. The trick is to not be excessive. Here is a picture of the method of cultivation I worked out. By cultivating metre wide beds between my tractor tyres and growing a mix of grass, clover and forbs on my driving strips I created heaps of edges—so beloved by observant permaculturists—whilst my paths were my biological reservoirs. There was never any spot in the field more than half a metre away from a rich diversity of plants and animals, small and not so small.

Maize or sweet corn, interplanted with soybeans, was my favourite way of catching carbon in summer. In winter it was cereal rye interplanted with a winter annual clover such as crimson clover, though I’m told arrowleaf clover or fenugreek are well suited to Australian conditions. In this mix I would also plant turnips, mustard greens, Chinese winter radishes and rape. Incidentally, corn salad, which used to grow in all winter grain paddocks, is an annual valerian that solubilises phosphorous and is known in German lore as rapunzel. The turnips, radishes and greens I harvested for market, as—like most folks—I needed a payday. The corn salad is a beloved and medicinal spring salad greens, and the grain can be cut for mulch at milk stage in the spring when it boots. Once the soil becomes crumbly and full of life, tomatoes, capsicums or cucurbits can be planted directly into the stubble with a spade—which is a pointed shovel—but don’t ever walk on the beds!

As for maize, the growing season is fairly long and earthworm populations would decline without mowing the paths for earthworm tucker about midway through the maize cycle. Earthworm populations need to be kept high in order to digest the thick stalks and soybean vines over winter after the rye is planted. Only the maize or sweet corn ears are picked, following the rule that if you want to build carbon you never export more than 8% of your biomass production. The spader pictured above has a beautiful tossing action that keeps the organic matter in the top two or three inches with just enough soil on top to plant the rye and clover mix into. The mass of maize stalks and soy vines need to be finely mowed before spading or the spader can’t chew them; but what a wealth of carbon is incorporated into the topsoil for moist, aerobic, fungal digestion! Fungal breakdown produces glomalin, which builds structural carbon into the soil.

Nitrogen management is another key. Loose, salty nitrogen burns carbon. It is the waste product of nitrogen fixing microbes, and when the soil is awash in it nitrogen fixers tend to feel like they are drowning in a dysfunctional septic tank. They say “That’s it. We’re out of here.”

What sets them on a nitrogen fixing jag is sugars. Then they produce amino acids that end up getting tied up with carbon in stable proteins in the soil reserve. On healthy soils that could easily be 3 or 4,000 ppm as stable protein nitrogen. Dumping something like raw chicken manure on the soil makes these beneficials give up the ghost and a protein breakdown cascade sets in. Then your soil loses carbon at a scary rate. Some estimate that 100 parts of carbon can be lost for every part of salt nitrogen added.

Also something else occurs—weeds. Unlike big seeds such as maize, beans and cereals, weed seeds generally are quite tiny. They depend on the soil being awash with soluble NPK and other nutrients. Their role in nature is to sop this up and conserve it. When it’s there they take off and outpace large seeded crops. Thus savvy farmers do not want much soluble nitrogen in the soil when they plant. They want nitrogen fixers to come running when large seeds start sprouting and excrete their carbs into the soil. Then there will be abundant amino acid nitrogen—all within a centimetre or so of the roots of the crop plants—while next to none will be available to the weeds even if they sprout. The picture just above shows maize with soybean at 21 days after planting.

Close inspection shows plenty of weeds which can’t get beyond the cotyledon stage because they don’t have any carbs to feed the nitrogen fixers, and they don’t have enough free nitrogen in the soil. This is an example of good nitrogen management in a vibrantly healthy living soil with plenty of nitrogen fixers living in it. And good nitrogen management is how to catch carbon and build it into the soil—even in a market garden.

To summarize, building soil carbon—the foremost imperative of every ecological grower—requires minimal, non-destructive cultivation. It also requires maximum diversity so the ecology is robust. It also requires good nitrogen management, which means keeping soluble nitrogen to a minimum and keeping plenty of nitrogen fixers alive in cultivated areas. This in turn means minimizing areas and times the soil is left bare. This also means NOT tilling in green matter which will decay and release soluble nitrogen.

And lest we forget, you want aerobic, fungal breakdown if you mix dry matter, like corn stalks, into the soil. This means you never incorporate organic matter deeply—even if it is dry—because you want fungi breakdown to make glomalin, build stable carbon and create superb soil structure.

mycelium noun the white threadlike mass of filaments forming the vegetative part of a fungus

Whilst sounding tiny in both size and significance, it is not:

Is this the largest organism in the world? This 2,400-acre (9.7 km2) site in eastern Oregon had a contiguous growth of mycelium before logging roads cut through it. Estimated at 1,665 football fields in size and 2,200 years old, this one fungus has killed the forest above it several times over, and in so doing has built deeper soil layers that allow the growth of ever-larger stands of trees. Mushroom-forming forest fungi are unique in that their mycelial mats can achieve such massive proportions. – Paul Stamets, Mycelium Running

Watch the clip to learn more about these fascinating fungi – organisms totally ignored by industrial agriculture, but which are incredible allies as we seek to decontaminate and restore soils and other habitat.

Duration: 00:18:18

The latest research tells us that Peak Phosphorus is an issue we cannot afford to ignore any more:

… a global production peak of phosphate rock is estimated to occur around 2033. While this may seem in the distant future, there are currently no alternatives on the market today that could replace phosphate rock on any significant scale. New infrastructure and institutional arrangements required could take decades to develop.

While all the world’s farmers require access to phosphorus fertilisers, the major phosphate rock reserves are under the control of a small number of countries including China, Morocco and the US. China recently imposed a 135% export tariff on phosphate rock essentially preventing any from leaving the country. Reserves in the U.S. are calculated to be depleted within 30 years. Morocco currently occupies Western Sahara and its massive phosphate rock reserves, contrary to UN resolutions. – Western Sahara Resource Watch

Marcin, the podium is yours.

Keeping Phosphorus on Farms – by Marcin Gerwin (the sequel to ‘Closing the Phosphorus Cycle‘)

Lupines. Photo: Carol Mitchell/Flickr

“Next to clean water, phosphorus will be one the inexorable limits to human occupancy on this planet” wrote Bill Mollison in Permaculture: A Designers’ Manual more than 20 years ago (1). It is that important that we design phosphorus recycling into our food systems. Phosphorus is an essential element for growing crops and no porridge, chocolate bar or cherry jam can be made without it.

Mobilizing phosphorus present in the soil

In many soils phosphorus is naturally present in sufficient amounts, however, it may be chemically locked up and not available for plants. Most of agricultural soils in Western Europe and North America are oversupplied with huge amounts of superphosphate fertilizers, which results in binding phosphorus up with other elements so it ends up unused in the soil. In consequence, the concentration of phosphorus may be as high as 750 ppm, while only 45 ppm is necessary for growing grains (2). To determine whether you have a sufficient level of phosphorus in your soil, the surest way is to make a soil test. If the amount of phosphorus seems to be okay, but your plants show signs of phosphorus deficiency (purplish leaves, stunted stems), you may need help from a specially skilled team of phosphorus extractors – fungi. Fungi are decay experts in soils. The enzymes that they secrete allow them to break up lignin, cellulose, chitin shells of insects and bones of animals, which are too difficult to digest for bacteria. A single teaspoon of a healthy soil may contain several meters of fungal hyphae, invisible to the naked eye (3).

The tips of certain species of fungi have an extremely significant function. The strong acids they produce allow them to literally dissolve rocks and extract phosphorus from them. These fungi can form a mutually beneficial relationship with plants roots and can transport phosphorus to these plants. They are called mycorrhizal fungi.

Mycorrhizal fungi can extend the surface area of tree roots by 700 to 1000 times (4). They can harvest phosphates at great distances, many meters down and away from the plant and they bring it back through the fungal net, which is called plasmic streaming. Phosphorus is brought to a tree in exchange for sugars created by plants, as fungi don’t have the chlorophyll and the ability to photosynthesize.

Seedlings of trees, shrubs and perennials can be inoculated with mycorrhizal fungi while you grow them in the nursery. Make sure you get the right kind of fungal spores for your plants. You can inoculate roots of existing trees and shrubs by digging holes in a root zone and applying spores of mycorrhizal fungi near the roots. Seeds of annuals and vegetables can be mixed with inoculum as well, however, plants from the cabbage family (Brasicaceae), beets and spinach do not form mycorrhizal associations at all. Instead of buying inoculum in a shop, you can also experiment with making your own mycorrhizal inoculum.

The optimum range for phosphorus uptake by plants is pH 6.0 – 7.5, and on either side of the pH scale phosphorus becomes immobile. A conventional approach would be to adjust pH by adding sulfur in alkaline soils or lime in acidic soils. It can be quite expensive on a larger scale. But suppose you would like to grow an acid soil loving plant, such as Northern highbush blueberry, then what? The optimum pH range for this tasty fruit is as little as 3.5 – 4.8 pH, and it can fail completely when pH is higher. Since phosphorus is immobile at this low pH level, how can this plant grow at all? Well, it can receive phosphorus through partnerships with certain species of mycorrhizal fungi which do well in acid soils and don’t mind low pH when extracting phosphorus.

You could also try to adjust the pH by increasing fungal or bacterial domination in topsoil. You can apply brown organic mulches, such as woodchips and shredded branches, to support fungi and to lower the pH. Or, apply fresh green mulches and aerated compost teas to support bacterial growth and raise the pH slightly above 7. The reason for this is that bacterial slime is alkaline and acids secreted by fungi are, well, acidic and they lower soil pH.

However, some nutrients are available for plants in low pH, while others are available in high pH. The pH of soil should vary from micro-site to micro-site and it is the role of a healthy soil biology to control it. If we leave it to applications of lime or sulfur, the whole biological system will be temporally determined by this input, and the quantity of micro-sites of varying pH will be limited. So, instead of applying minerals in order to mobilize phosphorus by a chemical reaction, you could stimulate growth of a vigorous soil food web that will ensure extraction of essential elements and support their continuous recycling.

Choosing phosphate fertilizer

There are many soils around the world that are naturally deficient in phosphorus, such as soils in the Amazon Basin, on Java or in Australia. Others have been damaged by inappropriate farming practices – bare soils were flushed by rains, which washed away phosphorus, they were depleted by overharvesting of crops and their natural soil food webs were destroyed, making it impossible for plants to feed on anything other than artificial fertilizers. While soil food webs can be restored, wherever there is not enough elemental phosphorus present, for any reason, it must be brought back by the farmer. The other option is to wait until mountain-generating processes raise the bottom of the sea, where phosphate fertilizers end up. When the new mountain ranges are formed, the rain will start to wash phosphorus out of the rocks, making it available for plants again. But this will take some time – around 10-15 million years….

For organic gardeners one of the main sources of phosphorus are ground phosphate rocks. Good quality phosphate rock fertilizer should be free of all contaminants such as fluorides, heavy metals or radioactive uranium. It can be applied directly on soil (100 kg or more per hectare) tied to organic matter, mulch, compost and compost teas, to enhance soil biology and enable feeding plants through the activities of bacteria, fungi and other microorganisms. Another way is to incorporate rock phosphate into compost with a fungal dominance, so that fungi will transform rocks into a soluble form, or preparing a special phospho-compost (8). Inoculating plants with mycorrhizal fungi improves greatly effectiveness of phosphate rock fertilizers.

It has been discovered in Costa Rica, that phosphate fertilizers can be applied on top of the mulch, rather than below it. This idea has been conceived to prevent phosphorus from being bound up in the acid tropical soil. And it worked. Yields of beans rose more than 3 times (9).

Clay washed out from between layers of phosphate rocks during mining can also be used as a fertilizer. Particles of this clay are surrounded by natural phosphates and it’s called a colloidal phosphate. Thanks to clay the phosphorus is more easily available for plants than in phosphate rocks. It can be used together with manure on compost piles or directly on soil – manure acids will dissolve phosphates, which in turn will stabilize the nitrogen in manure (10).

Superphosphate fertilizers are made from chemically treated phosphate rocks. They are not recommended for use as they are highly concentrated and reactive. When applied on the field they react with calcium, iron, magnesium and aluminium, creating within seconds compounds that make phosphorus unavailable for plants. They may react also with trace elements, locking them up and causing deficiencies of micronutrients. Superphosphates are water soluble and they can be easily washed away by rains before plants have a chance to assimilate them, which later may cause the eutrophication of lakes and rivers. Not to mention that high concentrations of phosphorus in fertilizers (above 10) are lethal to mycorrhizal fungi (11). Superphosphates, however, do have their advantage: they were purified and do not contain toxic elements such as uranium. There is a disadvantage, though. The waste product of the purification process is stored in slag heaps, that are sometimes unprotected and, since they contain uranium, they are radioactive. Fluorides leaching from these heaps may also cause groundwater pollution.

Another material that is rich in phosphorus is guano – bird or bat droppings. Bones of fish that are eaten by seabirds contain a lot of phosphates, and as a result seabird guano also contains a high level of phosphorus. Guano has accumulated over centuries on small islands on the Pacific Ocean or on the coast of Chile and Peru, where it was mined in such large quantities that its deposits are now severely depleted. In contrary to phosphate rocks, it is a renewable resource, however, only over a long period. Apart from phosphorus, guano also contains high levels of nitrogen and calcium. It can be fresh, semi-fossilized or fossilized, depending on the source.

Phosphates can also be found in mud from ponds, in freshwater mussels, in fish waste, in algae or in recent volcanic ash. Many plants, such as comfrey, lupine, sweetclovers, nettle or vetches accumulate phosphorus and they can be used as green manure. Note, however, that they don’t produce phosphorus in the way that nitrogen is fixed from the air by legumes. Rather, they just extract phosphorus from one place and you can put it somewhere else, leaving the source with less phosphorus.

Building your own phosphate factory

Bat house on a tree Photo: Birdfreak.com

If you would like to collect phosphorus from your local area, the exciting way to do this is to establish a small bat colony. If there are bats living in your neighbourhood, especially in buildings, you can build a bat house for them. Bats will come to rest there and… they will leave their droppings underneath. You can place a container under the bat house and collect their guano. The additional benefit is that insectivorous bats consume large amounts of moths, mosquitoes, flies, grasshoppers and crickets among many others. They are high-class specialists in insect control – in just one hour a single brown bat can catch 1200 mosquitoes. In fact, they are so effective in eating mosquitoes that in India an establishment of bat colonies around Calcutta was considered as a way of dealing with excessive mosquitoes numbers (12).

If bats are not your kind of animal, you may consider another type of a phosphate factory – a pigeon house. Pigeons mostly eat seeds, and these are usually rich in phosphorus. Their manure is rich in nitrogen as well, so it could be very useful on farms, and some people in the Middle East still keep them. If you are wondering how the permaculture principle of "every element should serve many functions" could be applied with regards to pigeons, there is one interesting thing that some breeds of pigeons can do: they can carry letters. Harry Potter fans may feel a little disappointed and prefer owls for sending letters, but the advantage of pigeons is that they can do it for real.

The adapted ones

Proteoid roots of Acorn Banksia. Source: Annals of Botany

A small group of plants, which includes lupines and macadamia trees, has developed a unique strategy to adapt to phosphorus-deficient soils. Instead of forming mycorrhizal associations, they create densely clustered roots that enhance phosphorus uptake. These roots received a scientific name of proteoid roots, after the Proteaceae plant family. Despite their unimpressive name, proteoid roots of white lupine have an extraordinary ability: they excrete citrate and in this way increase availability of phosphorus in the root zone (13). Well, why not call them power roots instead? Or, phosphorus-I’m-coming-to-get-you roots? They deserve a better name.

The intriguing thing about proteoid roots is that plants do not form them when phosphate fertilizers are applied. To the surprise of a farmer,

Macadamia nuts on a tree Photo: Kahuroa

macadamia trees can show signs of phosphorus deficiency even though a significant amount of phosphate fertilizer was added. When phosphorus is present in soil, even in small quantities, these plants grow well by themselves. And, when there really isn’t enough phosphorus, then compost and mulch can be used, instead of phosphate fertilizers (14).

Protecting phosphorus from being washed away

Phosphorus loss occurs especially on bare, sandy soils, where you have little trees and get heavy rains. While natural systems such as forests can lose 0.1 kg of phosphorus per hectare per year, bare crop systems can lose even 100 kg of phosphorus per hectare in one year (15). In heavy soils or loams loss is generally very small. Most phosphorus in the environment is in the insoluble form and unlike nitrogen, which can be dissolved in water, it is washed away with soil particles or organic matter.

Lupines in New Zealand. Photo: Anita 363/Flickr

Soil eroded after storms carried to the sea by Betsiboka river in Madagascar. Photo: Earth Observatory

Since this is known, protecting phosphorus is easy. A good soil structure can be created by adding organic matter and compost. Soil biology can be further improved by brewing compost teas. Together with compost they will add an army of nutrient recyclers to the soil: active bacteria, fungi, flagellates, amoebas, ciliates and beneficial nematodes. These microorganisms will retain phosphorus in their bodies and the functioning of a whole healthy soil food web will allow recycling it. It is also worth mentioning that certain species of bacteria can also dissolve phosphate rocks and they help in converting phosphorus into forms that are edible for plants (16). A no-dig system can be introduced to prevent erosion and protect soil life, and trees can be planted on at least 30% of land. And it takes mulch, mulch and mulch to protect soil from rain.

Farmers can pull another ace out of their sleeves – charcoal! It is an ancient soil amendment, tried and tested for thousands of years by Indian tribes in the Amazon. They used it with pieces of pottery to create Terra Preta, the black soil, which is still fertile today, an exceptional thing in this region of the world. The porous structure of charcoal provides a great habitat for microbes, it persists in the soil for a very long time and it retains nutrients, including phosphorus (17). Charcoal (or biochar) can be made not only from wood, but also from agricultural residues, such as rice husks (18).

Roots of vetiver grass 6 months after planting. Photo: The Vetiver Network International

To slow down run-off in the mountainous areas, crops can be grown between rows of trees planted on contour, in an alley cropping system. These hedgerows can be planted with nitrogen-fixing trees, or other fast growing species. Prunings from the hedgerows can provide much needed mulch for crops.

Instead of trees, vetiver grass can also be planted on contour. Its roots grow 3-4 meters deep and it can reduce erosion by as much as 90% and recharge ground water (19). Over the years, on steep slopes, natural terraces will form behind the hedge, as soil will accumulate there. A vetiver grass system is easy to establish and requires little maintenance. It can also be used for stabilizing road embankments, river banks, preventing landslides and for wastewater purification.

Fair share

Some say that free market is the most efficient way of allocating scarce resources. This may be true. If you are a farmer from Europe then letting the invisible hand of the market allocate the remaining reserves of phosphate rocks could be no problem for you. Let the most competitive ones win! However, if you own half an acre of land somewhere in Sub-Saharan Africa, your soil is poor in nutrients, yields are low and you hardly make ends meet, then you can easily notice a simple thing – with free market rules, scarce resources don’t go to those who need them most. They go to those who can pay most.

In 2008 some 82 million people were added to our planet. The largest part of this population growth took place in the South: in Asia, Africa and in South America. All these young people, a population four times larger than the population of New York, will need food, water, clothes and a place to live. They will need land where crops will be grown for them. And to grow these crops many nutrients are essential. One of them is phosphorus. Since the reserves of phosphate rocks are scarce who will get it?

Bill Mollison again:

Of all the elements of critical importance to plants, phosphorus is the least commonly found, and sources are rarely available locally. Of all the phosphate fertilizers used, Europe and North America consume 75% (and get least return from this input because of overuse, over-irrigation, and poor soil economy). If we really wanted to reduce world famine, the redirection of these surplus phosphates to the poor soils of Africa and India (or any other food-deficient area), would do it. Forget about miracle plants; we need global ethics for all such essential resources (20).

Field of rice in Bihar, India. Photo: yumievriwan/Flickr

It is possible to calculate a fair share of the remaining phosphate rocks for each country, depending on the soil’s condition and number of population. And that’s exactly what should be done. A global agreement is necessary for sharing the last phosphate rock reserves in a common sense way.

Planting rice in Madagascar. Photo: Gail Johnson/Flickr

Our current industrial agricultural system and the global economy that supports it are inherently unsustainable. Extracting a limited resource, such as phosphorus, and sending it to landfills or dumping it in the ocean doesn’t make much sense. Sooner or later reserves of phosphate rocks will become depleted, then what? There is some back up in the form of deposits on the continental shelves and on seamounts in the Atlantic and Pacific Oceans (21), but the cost of mining it can be very high and even if industrial farmers were able to buy them, what about farmers from Botswana? What about farmers from Madagascar or India? What will be the cost of food, when the price of fertilizers goes up? Recycling phosphorus is just common sense and it seems inevitable, if we wish to continue living on Earth. It means that the exchange of our entire food supply and waste management systems is inevitable as well. Honorable presidents, distinguished prime ministers, sooner or later we will have to do it.

Why wait till the industrial food supply system collapses from lack of phosphate fertilizers or because they are too expensive to buy? Farming the way nature does provides not only healthy soils and good yields, but also nutritious food, flavoursome food. A juicy tomato with its characteristic, charming smell, instead of a watery, tasteless, red ’something’. Our economy can be more local, so that it will be possible to easily recycle nutrients, and as a result people will be more connected. These changes can be for better, not for worse.

If we manage to close the phosphorus cycle in our countries soon enough, we will have plenty of phosphate rocks left. We will be able to use them for restoring degraded lands, for planting trees, and greening our planet once again.

References:

1. B. Mollison, Permaculture: A Designers’ Manual, 2004, p. 192.
2. Ibid
3. J. Lowenfells, W. Lewis, Teaming with Microbes, 2006, p. 53.
4. Ibid, p. 61.
5. Honglin Huanga, Shuzhen Zhanga, Xiao-quan Shana, Bao-Dong Chena, Yong-Guan Zhua and J. Nigel B. Bellb, Effect of arbuscular mycorrhizal fungus (Glomus caledonium) on the accumulation and metabolism of atrazine in maize (Zea mays L.) and atrazine dissipation in soil.
6. See also: K. Lewis, B. McCarthy, Nontarget tree mortality after tree-of-heaven (Ailanthus altissima) injection with imazapyr, Northern Journal of Applied Forestry, 25(2):66-72, 2008. In this study a herbicide imazapyr was injected to Tree-of-heaven (Ailanthus altissima), which in some regions is an invasive tree. The results showed that imazapyr injections not only killed all injected tree-of-heaven, but also 17.5% of neighboring (within 3 m) noninjected tree-of-heaven and eight other tree species 62 weeks after treatment. The possible ways of transmission of the herbicide were root grafts, mutually shared mycorrhizal fungi, root exudation and absorption, and/or leaf senescence.
7. Methodology: Integrated Production of Highbush Blueberry, edited by Danuta Krzewinska, 2005, p. 7.
8. See: chapter 9 “Ways of improving the agronomic effectiveness of phosphate rocks” in: F. Zapata and R.N. Roy, Use of Phosphate Rocks for Sustainable Agriculture, FAO 2004. Available at: http://www.fao.org/docrep/007/y5053e/y5053e00.htm#Contents
9. R. Bunch, Five Fertility Principles, The Overstory #20,
   http://www.agroforestry.net/overstory/overstory20.html, accessed on 16.01.2009.
10. P. Sullivan, Alternative Soil Amendments, ATTRA, http://attra.ncat.org/attra-pub/altsoilamend.html, accessed on 13.01.2009.
11. J. Lowenfells, W. Lewis, op. cit., p. 151.
12. Bats, The Ecologist,
    http://www.theecologist.org/pages/archive_detail.asp?content_id=352, accessed on 15.01.2009. In some parts of the world bats may carry viruses that are dangerous to humans. Before building a bat house in your backyard, please make sure there are no health concerns.
13. J. F. Johnson, D. L. Allan and C. P. Vance, Phosphorus Stress-Induced Proteoid Roots Show Altered Metabolism in Lupinus albus, Plant Physiology, Vol. 104, Issue 2, p. 657-665.
14. A. L. Shigo, Troubles in the Rhizosphere, The Overstory #70, http://www.agroforestry.net/overstory/overstory70.html, accessed on 13.01.2009. See also: G. Porter, R. Yost and M. Nagao, The Application Of Macadamia Nut Husk And Shell Mulch To Mature Macadamia Integrifolia To Improve Yields, Increase Nutrient Utilization, And Reduce Soil P Levels.
15. B. Mollison, op. cit.
16. R. Ivanova, D. Bojinova, K. Nedialkova, Rock Phosphate Solubilization by Soil Bacteria, Journal of the University of Chemical Technology and Metallurgy, 41, 3, 2006, 297-302.
17. Soil Fertility Management and Soil Biogeochemistry, Cornell University, http://www.css.cornell.edu/faculty/lehmann/research/biochar/biocharmain.html, accessed on 16.01.2009.
18. S. M. Haefele, Black Soil – Green Rice, Rice Today, April-June 2007, p. 26-27.
19. Soil erosion, The Vetiver Network International, http://www.vetiver.org/g/soil_erosion.htm, accessed on 16.01.2009.
20. B. Mollison, op. cit.
21. S. M. Jasinski, Phosphate Rock, Mineral Commodity Summaries, January 2008, p. 124,
    (available at: minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock/).

Nitrogen Fixing Trees for Permaculture

Flowers of the leguminous tree, Kowhai, the national flower of New Zealand

Nitrogen fixation is a pattern of nutrient cycling which has successfully been used in perennial agriculture for millennia. This article focuses on legumes, which are nitrogen fixers of particular importance in agriculture. Specifically, three legumes (nitrogen fixing trees, hereafter called NFTs) are especially valuable in subtropical and tropical permaculture. They can be integrated in a permaculture system to restore nutrient cycling and fertility self-reliance.

On unvegetated sites, "pioneer" plants (plants which grow and thrive in harsh, low-fertility conditions) begin the cycling of nutrients by mining and accumulating available nutrients. As more nutrients enter the biological system and vegetative cover is established, conditions for other non-pioneering species become favourable. Pioneers like NFTs tend to benefit other forms of life by boosting fertility and moderating harsh conditions.

Nitrogen fixing trees are often deep rooted, which allows them to gain access to nutrients in subsoil layers. Their constant leaf drop nourishes soil life, which in turn can support more plant life. The extensive root system stabilises soil, while constantly growing and atrophying, adding organic matter to the soil while creating channels for aeration. There are many species of NFTs that can also provide numerous useful products and functions, including food, wind protection, shade, animal fodder, fuel wood, living fence, and timber, in addition to providing nitrogen to the system.

Nitrogen: From the Air to the Plants

Nitrogen is often referred to as a primary limiting nutrient in plant growth. Simply put, when nitrogen is not available plants stop growing. Although lack of nitrogen is often viewed as a problem, nature has an immense reserve of nitrogen everywhere plants grow – in the air. Air consists of approximately 80% nitrogen gas (N2), representing about 6400kg of N2 above every hectare of land. However, N2 is a stable gas, normally unavailable to plants. Nitrogen fixation, a process by which certain plants "fix" or gather atmospheric N2 and make it biologically available is an underlying pattern in nature (see separate box on how this process works).

How to Use NFTs in a System

In the tropics, most of the available nutrients (over 75%) are not in the soil but in the organic matter. In subtropical and tropical forests, nutrients are constantly cycling through the ecosystem. Aside from enhancing overall fertility by accumulating nitrogen and other nutrients, NFTs establish readily, grow rapidly, and regrow easily from pruning. They are perfectly suited to jump-start organic matter production on a site, creating an abundant source of nutrient-rich mulch for other plants. Many fast-growing NFTs can be cut back regularly over several years for mulch production.

The NFTs may be integrated into a system in many different ways including clump plantings, alley cropping, contour hedgerows, shelter belts, or single distribution plantings. As part of a productive system, they can serve many functions: microclimate for shade-loving crops like coffee or citrus (cut back seasonally to encourage fruiting); trellis for vine crops like vanilla, pepper, and yam; mulch banks for home gardens; and living fence and fodder sources from around animals fields.

A Caution

As the goal in permaculture is to foster a productive and stable ecosystem, rather than for example to add nitrogen to the system, NFTs should be used with due care and oversight. Too many nitrogen fixing plants can over nitrify the soil and pollute ground and surface waters. NFTs are not a panacea. Most will not thrive in shade or fertile conditions. Because of their ability to thrive under poor conditions, they can easily become weedy. Therefore, if possible, use only NFTs which are already established in your area, or that have a history of not becoming weeds. NFTs can also become competitive for available soil nutrients, especially in arid areas – careful and informed management practices are advised.

Also, be aware that there are many other significant avenues for nitrogen fixation in nature, such as free-living nitrogen fixing bacteria, which should also be incorporated into a design.

Planting Nitrogen Fixing Trees

Species Selection

A survey of your area will be helpful in determining the habit and vigor of local NFTs. Some are small and produce edible shoots and pods, ideal for home garden use; others are large and fast growing for fuel wood or poles. Decide on what yields you want from your NFTs, and choose a diversity of species.

Seed Pregermination Treatment (Scarification)

In many NFTs, the hard seed coat must be scarified in order to allow absorption of water, hence germination. There are several methods: hot water is the most common. Water temperature should be approximately 70-90C° (160°F). The volume ratio should be 5-10 parts water to one part seeds. Seeds are placed in hot water for 1-3 minutes, then rinsed. Seeds may be soaked overnight at room temperature.

Seeds Inoculation

After scarification, a sticking agent such as vegetable oil or plain water is applied sparingly to seeds, and inoculum dusted into the mix. Seeds should be sown immediately. Do no expose inoculated seeds to extremes in temperature or direct sunlight.

Planting

Plant material in the form of bare root seedlings, stump cuttings and branch cuttings should be kept moist and protected until planting. Punch a small hole in the ground with the same diameter as the plant material. Seedlings should be placed in the hole with the root/shoot collar of the tree at soil level. Stump cuttings should be scarified in several places with a sharp knife to promote rooting and put in the ground about one third of their length.

Establishment

Initially NFTs require moisture and adequate nutrients, as well as protection from weed competition. The best way to achieve these conditions is to amend the soil and sheet mulch at the time of planting.

Craig Elevitch is based in Hawaii and has been working for island resource self-sufficiency since 1989. He directs Agroforestry Net, a nonprofit educational organization dedicated to empowering people in agroforestry and ecological resource management. The organization’s internationally recognized publications have guided thousands of readers in becoming more proficient in ecological food production, agroforestry, and permaculture. Craig edits The Overstory, a monthly agroforestry journal with over 8,000 subscribers in 185 countries. His books include Agroforestry Guides for Pacific Islands (2000), The Overstory Book: Cultivating Connections with Trees (2004), and Traditional Trees of Pacific Islands: Their Culture, Environment, and Use (2006), all of which promote diverse agricultural systems that produce abundant food and other resources. Further information and free downloads at Agroforestry.net.

With chapters like ‘Crap Happens’, ‘Deep Shit’ and ‘A Day in the Life of a Turd’, this is sure to be an interesting book, albeit possibly not one to read over lunch?

With this wonderful substance piling up in all the wrong places (after all, we’re running out of clean water, and yet we’re crapping in it…), this taboo topic deserves a lot more attention than it gets. Enjoy the book – and special thanks to the author Joseph Jenkins for making this freely available (warning: 22mb PDF – if you want to download chapter by chapter, scroll down on this page, or just read online here).

Oh, want a hard copy of this book? Here you go.

Written by a humanure composting practitioner and organic gardener with over 30 years experience, this third edition provides detailed scientific information on how humanure can be hygienically recycled, without fancy technological do-dads, a large bank account, toxic chemicals, or environmental pollution.

This unique handbook provides information on composting, soil fertility and microorganisms, alternative graywater systems and much more. It also gives detailed instructions on how you can build or buy your own sawdust toilet and compost bins for only a few dollars.

Defecating in our drinking water is perhaps one of our culture’s most curious, but least talked about, habits. This book gives compelling and detailed testimony as to why humanure should be constructively recycled:

* to prevent water pollution: (almost 4 trillion gallons of sewage effluent are dumped into our coastal waterways each year);
* to fertilize the soil: (rich in soil nutrients, humanure can be safely recycled by thermophilic composting);
* to protect our dwindling drinking water supplies: (nearly 1/3 of all household drinking water is used to flush toilets); and
* to enhance our health: Fertile soil not only grows great veggies, but nourishes our health and community’s well-being. – josephjenkins.com