Glomalin, Biochar and the Secret of Terra Preta Soils.

I have given periodic mention to the unfolding aspect of adding "biochar" charcoal to soils, in an effort to recover some of the benefits of Terra Preta - highly rich and fertile dark soils found in South America, in which carbon (char) has been stored for hundreds of years. In addition to locking-up carbon over a long term, as noted, the soil is more fertile than the surrounding (lighter coloured) soils and has better properties in retaining water and nutrients.

Creating charcoal and assembling a kind of synthetic "terra preta nova" has the added advantage that while the charcoal is being formed by pyrolysing biomass, BioOil and BioGas are simultaneously produced. Ideally, the gas can be used as the fuel for the pyrolysis and the oil can be mixed to an extent of 25% with conventional liquid fuel, in the intention that by 2025, 25% of the U.S. oil requirements will be met by means of it: hence the name of the "25x25" club, a political group with this outcome as its primary agendum. It's a tall order and some of the estimates of how much biochar can be made are staggering, up to 9.5 billion tonnes/year, which I don't think is realistic either in terms of land use (growing enough biomass) or building bio-mass pyrolysis capacity on this immense scale. This is an estimate by Professor Johannes Lehmann form Cornell University, whose expert opinion I respect, but I don't see it personally since it amounts to producing about one tonne of biochar/hectare on two-thirds of the entire land surface of the Earth (95 million out of 150 million km^2).

The International Biochar Initiative (IBI) are working to a more modest 1 billion tonnes/year by 2050, and I reckoned recently that almost this amount could be produced in total throughout a collection of world-wide small communities in which each person made 100 kg of biochar per year - or it was collectively made for them within the activities of their community. The latter strategy cuts-down the prohibitively massive centralised plant-engineering required, if it were done this way, to more manageable chunks.

Now, there is the proposition of a connection between biochar and microbial life in terra preta soils, in which mycorrhiza fungi thrive and produce glomalin. I have noted that there is strong evidence that this glue-like glycoprotein is significantly responsible for the storage of organic matter in soil and for soil health. There is speculation that glomalin is the secret of terra preta soils/biochar as a consequence of the elevated fungal population (thought to thrive in the carbon micropores). Glomalin is produced by hair like hyphae filament structures of fungal bodies.

Overall carbon capture and humification in soil is probably the long-term process by which terra preta soils are produced and I wonder how long it would take for a soil, simply amended by charcoal, to become a fully-fledged terra preta with the properties noted. I envisage it is not likely to be an immediate event, and probably the Amazonian indians created these soils over many years, to their fully self-generating glory. The native people described the soil as physically "growing", which may suggest an accretion process involving fungi and other microbiota.

There is an interesting discussion of some of these topics at the link address below. I would be grateful for any input from those who know more than me about these things.

Related Reading.
http://bioenergylists.org/newsgroup-archive/terrapreta_bioenergylists.org/2007-February/000042.html

Peak Oil... Demand for it, that is.

Peak Oil is the global term used to describe an eventuality when world oil production reaches a maximum, and then relentlessly falls. Such "peak" models are based on an inexorable rise in demand for oil, against an infrastructural lack by which to meet that demand (i.e. you can't pump out more). Supply-demand gaps are to be expected en route but once the peak is reached, the shortfall in supply is catastrophic. As a rider to this, it should be noted that while "global peak oil" is a numerical reality - i.e. the maximum sum of barrels of oil ever produced in the world in total, in a given year - the processes of it are rather more subtle, since different fields, under the control of various regimes will peak at different times, thus shifting the emphasis of economic and political control across the globe. Those without oil will become weak and those with plenty of it will become strong - or targets for other nations who want to grab their oil.

Now, the assumption of relentless demand has been called into question in a new report entitled "The Beginning and End of Oil" by Peter Hughes, who is a director of Arthur D. Little's global energy and utilities practice. The main issues surrounding oil, climate change, security of supply, and an amplitude of market volatility that could bring economic ruin to nations and then the world, are lucidly clear. Rather than simply waiting in a spirit of foregone conclusion for these calamities to unfold, it is likely that governments will be forced to act preemptively to anticipate and provide alternatives, which will curb demand for oil.

It is a global energy-mix that is to be contrived, rather than a single solution, which there is not. The recent hike to $150 and then a crash to $30 for a barrel of oil hand in hand with the credit crunch, makes it clear to most governments that deliberately reducing our demand on oil is a policy imperative. Of all the energy-resources, oil is especially vulnerable since more than half of the world's 30 billion barrel annual count goes to fuel transportation. The absence of alternatives to oil-based fuels has cemented the outstanding stature of oil as literally empowering the engines of progress.

However, a chain of policy initiatives spanning the globe is encouraging more energy-efficient technologies throughout the transportation sector - whether on the road or in the air. High efficiency diesel engines and hybrid and regenerative breaking systems can extract more than twice the tank to wheels miles that conventional spark-ignition/petrol engines can. Meanwhile there are aircraft fuselage designs that promise savings of 30% on fuel costs, and high-temperature aircraft engines that recover energy more efficiently from fuel, so long as sufficient quantities of metals such as hafnium can be recovered to bring them to a proficient reality.

Peter Hughes, a director of Arthur D. Little's global energy and utilities practice, said:
"As the number of new policy measures implemented to reduce reliance on hydrocarbons for transportation reaches critical mass over the next 10 years, the world could see downward pressure on demand for oil and oil-products materialize much sooner than the [oil] industry would currently concede. Depending upon how quickly the transportation sector begins its migration away from oil, we could find ourselves at a tipping point in which demand for oil peaks much earlier than the industry currently anticipates, before going into long-term decline."

In the wavering scales of the energy-balance, (the report says that) oil and gas companies should reconsider the sustainability of their business models and accelerate their moves to spread into other sectors of the "energy value chain" (not a phrase I would use but is "management speak"). A greatly increased contribution from coal, natural gas, nuclear power and "other alternatives to hydrocarbons" (whatever they may prove to be) is to be expected.

The report concludes that electricity is likely to be the main supply vector for delivering energy to customers which will "create demand for multiple sources of clean power as well as the infrastructure to deliver it."

All in all, it is better to close the stable door before the horse bolts, rather than after. We will need to make the kind of changes outlined eventually, so let's begin making them now, while we still have enough conventional energy in hand to establish new paths. Probably we are involved in a game of "tag" between reducing demand and falling supply. Whichever comes first will win-out.

Related Reading.
http://www.epmag.com/WebOnly2009/item33676.php

Glomalin - Long Term Carbon Glue.

The name Glomalin derives from Glomalis, an order of common root dwelling fungi such as Mycorrhizae that colonise the root systems of plants, and was discovered only as recently as 1996. Glomalin itself is a glue-like protein which builds a carbon-rich sheath around the hyphae (thread-like tendrils) that grow out from the fungus to form a secondary root system. Glomalin contains 30 - 40% of its weight of carbon, and it is thought might account for up to one quarter of all the carbon that is contained in fertile soils. Glomalin is also a highly resistant material, and can survive being decomposed in soils for anywhere between 7 and 42 years, thus making it potentially significant in carbon storage by soils. Glomalin also helps to glue-together soil aggregates of other organic (humus) and mineral components, and it is believed to help in the formation of humus - a complex process called humification.

Glomalin gives the soil "tilth", which is a discrete texture that allows experienced farmers and gardeners to "know" good soil just by feeling its smooth granules as they run past their fingers. It is thought that glomalin may also make the hyphae sufficiently rigid they can span the air-spaces between particles of soil. It is believed that hyphae have a lifespan of days to weeks, but the much greater longevity of glomalin suggests that the current technique of weighing hyphae samples to estimate fungal carbon storage may undervalue grossly the amount of carbon stored in the soil. Sara Wright, the discoverer of glomalin, and her colleagues discovered that glomalin makes a far greater contribution of nitrogen and carbon to the soil than is made by hyphae or other soil microbes.

Dr Christine Jones, who is an independent scientist based in Australia, proposes that changes in farming methods to those of "regenerative agriculture" are necessary for the full carbon-capture potential of soil to be realised, particularly for Australian soils. She is promoting "liquid carbon pathways", in which plants pump stable carbon-rich compounds into the soil, as part of a symbiosis with root-fungi, which in return syphon nutrients and water from the soil back to the plant via their extensive hyphae systems.

The relationship between the glomalin and the humus is also symbiotic, since the glomalin contributes to the humification and the humus increases the overall fertility of the soil. Humus is an important material in the retention of water in soil. Dr Jones thinks that the assistance of the humification process by glomalin is a reason for a found much higher accumulation of carbon in some Australian soil than had been thought possible. However, she stresses, farmers may need to rethink how they farm to derive full benefits from the process. She is of the opinion that the answer lies in establishing low-input "year-long green farming" methods which maintain green, growing plants throughout much of the year.

At the University of Aberdeen, Dr David Johnson who is a specialist on mycorrhizal fungi, said:
"Many conventionally grown crops have little or no dependency on mycorrhizal fungi because they receive lots of inorganic fertilizers that don't warrant the carbon 'cost' of forming the relationship with the fungi, for want of a better expression. So, moving to low-input farming systems is likely to encourage plants to form mycorrhizas and therefore increase carbon allocation to this group of organisms." It is also known that long fallow periods, heavy tilling of soil, and a number of agricultural chemicals (including nitrogen fertilizers) can damage the fungi and other forms of soil life.

Now, there is corollary line of thinking from the United States, which proposes that it is soil-depth that is critical to whether or not no-till methods actually result in carbon storage. In essence, no-till involves leaving crop residue on the surface of the soil rather than ploughing it underneath. This saves on labour, wear and tear on machinery, soil-erosion, fossil fuels and artificial (oil and gas derived) fertilizers and pesticides, makes the soil more productive (brings it "back to life"), improves habitats for wildlife and overall biodiversity and conserves water in the soil. If the carbon input (storage) exceeds the carbon output (lost), then the method can be considered successful, or the converse if more is lost than gained.

Results from no-till studies are found to vary from region to region, and for example 40% of Ohio's cropland is good for carbon-storage. Where no-till (practised on a mere 6% of the world's cropland overall, and most of that in the U.S and Canada, Australia and South America - Brazil, Argentina and Chile) does not prove effective, other carbon-capture methods can be applied instead; e.g. mulching, cover crops, complex crop rotations, mixed farming systems, agroforestry and biochar . A survey has been carried out of no-till land in Ohio, Michigan, Indiana, Pennsylvania, Kentucky, West Virginia and Maryland by Rattan Lal and his colleagues at the Ohio State's Ohio Agricultural Research and Development Centre, where he is director of the Carbon Capture Management and Sequestration Centre. Lal says:

"Basically, those soils that are well-drained, are silt/silt-loam in texture, warm quickly and have some sloping characteristics prone to erosion are excellent candidates for no-till. Clay soils or other heavy soils that drain poorly are prone to compaction and are in areas where the ground stays cooler may not always encourage carbon storage through no-till."Lal concludes that soil depth is the crucial factor in carbon storage. He says that if you go down just 8 inches, in general, no-till fields will store carbon better than ploughed fields. However, at depths of 12 inches and more, the situation may be reversed.

"You have to go deeper," he said. "We recommend going down to as much as one metre below the soil surface... [to establish a soil ratings guide for applying different conservation tillage systems at regional and national scales].

Put another way, you have to know your soil, as farmers traditionally do. "Soil" is part of a complex interactive system, and there is not a simple "one size fits all" solution. The means must be tailored to get the best results wherever we are. The real solution is likely to be found in the sum of many smaller "solutions".

Related Reading.
[1] http://www.ars.usda.gov/is/AR/archive/sep02/soil0902.htm
[2] http://www.farmanddairy.com/news/no-till-works-but-is-not-always-applicable-for-storing-carbon/11525.html
[3] http://sl.farmonline.com.au/news/nationalrural/agribusiness-and-general/general/soil-carbon-doubts-unfounded/1465172.aspx

George Monbiot: Cats, Pigeons, James Lovelock and Biochar.

In an article entitled "Woodchips with Everything" (Published in the Guardian, 24th March 2009) [1] George Monbiot has put the cat among the proverbial pigeons now fluttering above the biochar camp, probably singing around a fire whose wood is turned partially into a form of charcoal often called biochar to emphasise its biological merits, in particular to lock-up carbon taken from the atmosphere via photosynthesis, and in the process to produce useful fuels in the form of gases and liquids (bio-oil). It is reckoned, in analogy with the original terra preta - a highly fertile black soil (hence the name) - found in Amazonia, that adding biochar to soil encourages the growth of microbes (including fungi like mycorrhiza), which further increases the gravity of carbon in the soil and makes for better soil health. The soil also retains nutrients and water better, thus relieving the impetus of demand on these increasingly restricted resources.

In his inimitable way, Monbiot opens the batting: "It’s a low-carbon regime for the planet which makes the Atkins Diet look healthy: woodchips with everything. Biomass is suddenly the universal answer to our climate and energy problems. Its advocates claim that it will become the primary source of the world’s heating fuel, electricity, road transport fuel (cellulosic ethanol) and aviation fuel (bio-kerosene). Few people stop to wonder how the planet can accommodate these demands and still produce food and preserve wild places. Now an even crazier use of woodchips is being promoted everywhere (including in the Guardian). The great green miracle works like this: we turn the planet’s surface into charcoal." Monbiot makes the point that huge areas of land would need to be turned-over to the production of biomass and biochar, and its likely negative environmental impacts:

"Carbonscape, a company which hopes to be among the first to commercialise the technique, talks of planting 930 million hectares. The energy lecturer Peter Read proposes new biomass plantations of trees and sugar covering 1.4 billion ha. The arable area of the United Kingdom is 5.7m hectares, or one 245th of Read’s figure. China has 104 m ha of cropland. The US has 174m. The global total is 1.36 billion. Were we to follow Read’s plan, we would either have to replace all the world’s crops with biomass plantations, causing instant global famine, or we would have to double the cropped area of the planet, trashing most of its remaining natural habitats."

The Article is also at monbiot.com [2]. Monbiot does make a fair point about scale, as I have contributed on this blog and my monthly column at scitizen.com [3,4] about biochar (and indeed other schemes of "geo-engineering"). The sums are enormous indeed, and I finally concluded that biochar has its best chance if it is produced within localised communities as I gave to the Guardian in a letter which they probably won't print. The Independent newspaper have published a good few of my letters but they seem more interested in detail than the Guardian, anyway you can read it here:

"Sir:
In his article (March 24th), "Woodchips with everything", George Monbiot points out correctly that growing and converting biomass to biochar and other products, on the grand scale is no mean feat. I have done the sums, and they are staggering: http://ergobalance.blogspot.com/2008/09/biochar-atmospheric-co2-mitigation.html:

The truth is that, as fossil energy wanes, we will need to live in less transport-intensive small communities - thus de-globalising the world - within which local production of biochar (including growing algae as biomass for it) is feasible. Such small scale efforts would amount to significant proportions when multiplied by the multitude of humans there is on planet Earth.

Yours sincerely,

Professor Chris Rhodes."

Now, in today's (March 26th) Guardian [5], there is a rebuttal of Monbiot's article by James Lovelock (of Gaia fame), entitled: "James Lovelock on Biochar: let the Earth remove CO2 for us," which contends that Monbiot is right that it would be a false economy to have plantations devoted to the production of biochar, but if other biomass sources - that are simply waste otherwise - could be used, then burying carbon in the ground is a good move toward addressing the problem of climate change.

Lovelock is sceptical about carbon capture and storage (CCS) strategies, e.g. from power stations and industry, but he notes:

"What we have to do is turn a portion of all the waste of agriculture into charcoal and bury it. Consider grain like wheat or rice; most of the plant mass is in the stems, stalks and roots and we only eat the seeds. So instead of just ploughing in the stalks or turning them into cardboard, make it into charcoal and bury it or sink it in the ocean. We don't need plantations or crops planted for biochar, what we need is a charcoal maker on every farm so the farmer can turn his waste into carbon. Charcoal making might even work instead of landfill for waste paper and plastic.Incidentally, in making charcoal this way, there is a by-product of biofuel that the farmer can sell. If we are to make this idea work it is vital that it pays for itself and requires no subsidy. Subsidies almost always breed scams and this is true of most forms of renewable energy now proposed and used. No one would invest in plantations to make charcoal without a subsidy, but if we can show the farmers they can turn their waste to profit they will do it freely and help us and Gaia too."

Now I like this, because it's pretty much what I was saying about small-scale biochar production in "Thinking Positive - Carbon Capture" on scitizen.com [4]. I'm pleased to be thinking along the same lines as the guru of Gaia.

The International Biochar Initiative (IBI), who are effectively the "industry body" for the biochar movement, have also issued a response to Monbiot, in a press release today [6] which makes the point that it is not fair to simply dismiss biochar out of hand because it is maybe one of a hundred different "solutions" to the environmental problems that are posed to human ingenuity on the planet. Here we are really coming back to the matter of "scale" and that making maybe 12 billion tonnes of biochar each year for the next 50 years is probably not a credible prospect. But one billion tonnes per year as the sum total of many local productions, along with several other "biological" carbon capture schemes, as I allude in my "Thinking Positive - Carbon Capture" article [4] could create a viable mix of activity.

There is no single solution to our problems either in terms of environmental pollution by carbon, climate change or the limited store of fossil fuels, most pressingly oil and natural gas, but in the combination and symbiosis of different approaches we can find a new way.

Related Reading.
[1] http://www.guardian.co.uk/environment/2009/mar/24/george-monbiot-climate-change-biochar
[2] http://www.monbiot.com/archives/2009/03/24/woodchips-with-everything/
[3] http://www.scitizen.com/stories/Future-Energies/2008/10/Biochar-----a-Miracle-to-Save-the-Planet/
[4] http://www.scitizen.com/stories/Future-Energies/2009/02/Thinking-Positive---Carbon-Capture-/
[5] http://www.guardian.co.uk/environment/2009/mar/24/biochar-earth-c02
[6] I can't find a link to this yet, but I received the IBI press release this morning by e.mail:

Press Release: IBI Response to Recent Guardian Article on Biochar March 25, 2009: For Immediate Release:

IBI has taken note of an article by George Monbiot in the UK Guardian on March 24, 2009 that questioned the validity of biochar as a climate mitigation tool and the scientists and others who support the development of biochar.

The Guardian has published responses from several of those biochar supporters mentioned by Mr. Monbiot, including James Hansen, Chris Goodall, and James Lovelock.

IBI sent The Guardian the response below written by IBI staff members Stephen Brick and Debbie Reed. For more information, contact: Stephen Brick, IBI Executive Director, sbrick5714@sbcglobal.net Debbie Reed, IBI Policy Director, dcdebbiereed@yahoo.com Thayer Tomlinson, IBI Communications Director, info@biochar-international.org


George Monbiot is right on the mark about our seemingly irresistible tendency for embracing miracle cures. And it is refreshing to have the press remind us that the laws of thermodynamics will continue to apply in our quest to reduce global carbon emissions. But his diatribe against biochar-like most such screeds-would have us throw the baby out with the bathwater.
This has been said often, but it needs to be said again: there is no magical pathway for cutting global carbon emissions. There is only a collection of steps-complex, costly, and, politically challenging. Put another way, there is no single remedy for the whole problem; but there are, very likely, one hundred different actions that can each bear one percent of the burden. Serious people have understood this for some time, and this would include, we believe, a large fraction of the general public that Mr. Monbiot presumably wishes to warn.

Biochar, produced and used appropriately, should be considered amongst the hundred. Done right, biochar produces four value streams: waste reduction, energy production, soil fertilization and carbon sequestration. Biochar can be made from animal manures and food processing wastes. These residuals are costly to those who produce them, and create greenhouse gas emissions if left untreated. Bio-gas and oil can be used for heating, generating electricity and transportation. Biochar can reduce the need for conventional, fossil-fuel based fertilizers. Finally, biochar can lock up carbon in the soils for extended time periods.

We don't have all the answers on biochar production and utilization; indeed, the mission of the International Biochar Initiative is to seek these answers, objectively and quickly. We know that there are bad ways to make biochar, that crop monoculture for producing feedstock is not a good idea, and that biochar does not affect all soils equally. None of this should rule biochar out of court, however, as we also are assembling a body of knowledge on how to produce and use biochars that are beneficial. In this way, biochar resembles many other carbon-cutting technologies that face uncertainties. In our case, all we seek is an opportunity to be heard fairly as we move towards Copenhagen. We have no doubt that exaggerating the benefits of biochar is not helpful. On the other hand, the potential of biochar deserves serious consideration. Mr Monbiot's glib dismissal of this potential is unwarranted.

Stephen Brick is the Executive Director of the International Biochar Initiative
Debbie Reed is the Policy Director of the International Biochar Initiative

Plant Nutrition.

Plants require essential raw materials to keep them going, to provide both energy and building blocks for growth. This is true of all living organisms, including humans. Carbon dioxide is absorbed from the air along with water from various sources, mainly the soil, and together the elements carbon (C), hydrogen (H) and oxygen (O) are provided. In addition to these basic units, some thirteen essential nutrients are also required for a crop to thrive: three major nutrients, three secondary nutrients and seven micronutrients.

During the past half century, there has been a depletion of the amount of micronutrients present in plants and thus available to those creatures including humans, who eat them. There is a sanguine quote from Prince Charles, who is a keen organic gardener, and runs an organic farm on his Highgrove Estate in Gloucestershire:

"The New Scientist recently reported alarming research results from a study of the long term effects of the so-called 'Green Revolution' in South Asia. New plant varieties fed with high levels of artificial fertiliser have dramatically increased food production, to no-one's surprise. But it now becomes clear that those intensively grown crops are nutritionally deficient. They lack vital trace elements and minerals, particularly iron and zinc. This deficiency has been passed on through the food to such an extent that an IQ loss of 10 points has been observed in a whole generation of children who have a diet based largely on crops grown in this way."

Actually, years ago as a child, I lived on the Elmstree Estate which is next door to Highgrove, and whose elm tree population was devastated by Dutch Elm Disease, a scourge of the British countryside in the late 1960s/early 1970s. We lived there in a rented part of the main farmhouse (which was the original manor house), since my family are hardly gentry, having fled South Wales where I was born, in the aftermath of my father's bankruptcy. Not such a big deal now but it certainly was then.

As plants grow they remove these essential elements to a varying degree and rainwater leaches out more, so from time to time they need to be replenished and so in conventional farming/gardening this is usually done by adding artificial fertilizers. In permaculture systems, plants die and rot-down and the nutrients are returned to the soil as part of the natural recycling process. The availability of nutrients and their uptake by plants is assisted by mycorrizal fungi which are found in the rootballs of most plants.

The three Major Nutrients are Nitrogen (N), Phosphorus (P) and Potassium (K). Nitrogen (N) is required for healthy stems and leaves. It is an essential component of the amino acids which form the proteins and of the chlorophyll molecules that harvest light to drive photosynthesis. It is normally taken up into plants in the form of Nitrate (NO3-) and to a lesser degree as Ammonium ions (NH4+). Nitrates are easily leached from soil by rainfall during the winter, but when spring comes and the soil warms, nitrogen is extracted from the air and converted to nitrate by nitrogen-fixing bacteria.

When the soil is waterlogged, denitrification occurs by anaerobic bacteria. This is why plants grow better in well drained soil where air can percolate through it. Earthworms play a vital role too, in burrowing through and processing soil, thus increasing the availability of its nutrients and creating drainage channels and spaces for root-systems to grow into.

Phosphorus (P) is taken up as phosphate ions (PO4(3-)), and is a critical component of the nucleic acids, DNA and RNA. The ATP-ADP energy transfer process within plant cells requires phosphorus. It is moved around within the plant, being recycled from older parts to points of new growth. The Carbon Dioxide released during respiration reacts with water to produce carbonic acid and this assists the uptake of PO4(3-) by plant roots. The secondary root-system provided by micorrizal fungi greatly extends the reach of the primary roots and more effectively remove the phosphate ions from the insoluble soil salts.

Potassium (K) is not an essential building block of plants but plays a central role in protein synthesis and in maintaining the balance of water. It also makes plants winter hardy and improves their resistance to disease. Taken up as K+ ions, the ratio of N to K has an important effect on plant growth, the ideal being N:K = 1 for most crops and 2:3 for root crops and legumes. Magnesium (Mg2+) ions compete with K+ for uptake, but so long as the K:Mg ratio is about 3:1 or 4:1 there is no problem.

The three Secondary Nutrients are:- Magnesium, as Mg2+ ions, is the key metal element in chlorophyll, where it forms the centre of the molecule and its light-absorbing process. It is involved in the production of the cellular energy-transfer molecule ATP.
Calcium in the form of Ca2+ ions is required for the healthy growth of new stems as it is used to give cell walls their strength. Sulphur (S) is taken up as sulphate ions (SO4(2-)), and is an essential constituent of all proteins, including enzymes. Legumes have higher requirements for S than most other plants do.

As the name implies, smaller amounts of the seven micronutrients are required but they nonetheless cannot be ignored for healthy plant growth, and are usually present sufficiently in most soils. These are boron (B) as H2BO3- ions, chlorine (Cl) as Cl- ions, copper (Cu) as Cu2+ ions, iron (Fe) as Fe2+ ions, manganese (Mn) in the form of Mn2+ ions, molybdenum (Mo) as molybdate (MoO4(2-)) ions and zinc (Zn) as Zn2+ ions.


Artificial fertilizers are manufactured using fossil fuels and have been responsible for massive increases in the yield of crops achieved in the last century - "The Green Revolution". There are estimates that the yield could fall by about 75% if we stopped using them. Accordingly, it is argued in some quarters that feeding the world's population without modern farming methods and its inputs of energy and fertilizers would require much more land than is available. Others, however, including many aficionados of permaculture dispute this, and argue that if the soil is brought back to its natural state there will be plenty of food for all, albeit not the cereal-based diet we are now used to.

Interestingly, there was a news report (B.B.C. March 5th) to the effect that most of us in the U.K. are deficient in selenium because for the past 30 years we have eaten bread made from European wheat rather than from wheat imported from Canada and the U.S. The problem is the different soil, which this side of the pond is low in selenium but rich in the element in North America and Canada. Apparently selenium levels can be restored to soil by adding selenium-enriched fertilizer, but this is part of the energy intensive process that we are seeking to avoid in preparation for declining oil and gas supplies. On a personal basis, eating a daily handful of Brazil nuts maintains healthy selenium levels but these are grown and imported of course by means of gas and oil, so this is not a long term solution.

If we convert to permaculture and regenerative agriculture in general, we will need to get by without much cereal and provide more of our diet from nuts, fruits and vegetables, and from animals whose grazing helps to till and nourish the land naturally on open-plains. Another good source of selenium is garlic, however, so long as it is not cooked for too long which denatures the compounds that contain it.

Related Reading.
http://www.dgsgardening.btinternet.co.uk/
http://www.permaculture.org.uk/mm.asp?mmfile=whatispermaculture
http://www.permaculture.org.uk/mm.asp?mmfile=whatproblem
http://www.foodnavigator.com/Science-Nutrition/New-trading-patterns-blamed-for-selenium-intake-decline

Magic Fungi: Mycorrhiza.

Mycorrhizae are highly specialised organisms classified among the order Glomales, and are found closely associated with the root systems of around 95% of all plants. The term mycorrhiza derives from the Greek for fungus roots. The fungus may colonize the roots of a host plant either intracellularly or extracellularly and is an essential part of living soil. The relationship is a symbiotic one, in which both organisms derive benefit. Because the fungus cannot perform photosynthesis, to fix its own carbon, it receives some of the carbohydrates (sugars such as glucose and sucrose) which the plant passes down to its roots. In return, the plant receives essential mineral nutrients and water too, from the fungus via its very extensive mycelium which reaches out much more extensively further than the plant roots, and effectively forms a secondary root system.

e.g. On their own, plant roots may be ineffective at imbibing immobile phosphate anions, for example if they are present in alkaline soils (pH above 7). However, the mycorrhizal fungus can access these phosphorus sources via its mycelium, and pass them on to the plants they have colonised. Mycorrhizal mycelia have far narrower diameters than even the smallest root, and can hence penetrate more of the soil, so allowing absorption over a greater surface area.

Mycorrhizal plants are often more resistant to diseases caused by microbial soil-borne pathogens, and more readily survive under drought conditions because they can access water more easily. Tilling soil damages the mycelium and so they work best with no-till methods such as permaculture, where they are very useful in transporting nutrients and water throughout the growth medium.

The two principal forms of mycorrhizae are Ectomycorrhizae and Endomycorrhizae. The Ectomycorrhizal Fungi have a thick network of cells which form a sheath around the root hairs of the associated plant and do not penetrate into the cells of the plant, hence the prefix 'ecto' meaning outside (in contrast 'endo' means inside). The Endomycorrhizal Fungi are a more primitive form and have hyphae which do penetrate the root cell walls and on into the cell membrane. They do not, however, enter the protoplasm. Inside the root cells the fungal structure may be tree-like, with fine hair-like hyphae that can access plant nutrients and water through an extensive secondary root system.

One well-known Ectomycorrhizal fungus is the truffle, readily sniffed-out by a pig on a lead. There are several species of truffle, the best known being the Black Truffle T. melanosporum which grows exclusively with oak trees. It is found that when they are grown in a sterile medium plants often do not thrive without a beneficial fungal comrade. To allow new plants to become established more quickly or to get a better growth of existing plants, fungal spores can be added to the soil.

Mycorrhizal symbiosis was discovered around 100 years ago, and since then there has been much speculation as to its role in nitrogen fixation by plants. While there are numerous reports of the fixation of atmospheric nitrogen by mycorrhizal fungi in the earlier literature, it is now thought that only procaryotic organisms can fix atmospheric nitrogen and that both ecto- and endomycorrhizal fungi lack this capacity. It is important to note that many vascular plants possess both mycorrhizae and nitrogen-fixing symbiotic organs, e.g. legumes with rhizobial nodules and non-legumes with actinorrhizal nodules, with mycorrhizae that are either ectotrophic or endotrophic, or both. Nitrogen fixation in forests and other natural ecosystems has recently been attributed mainly to associative-symbiotic bacteria, i.e. bacteria living in the rhizosphere or close proximity of plant roots. Since the roots, in fact, are usually also infected by mycorrhizal fungi, a new concept of mycorrhizosphere has been introduced.

The exact nature of the relationships between mycorrhizal fungi and nitrogen-fixing bacteria within the mycorrhizosphere are as yet not well understood. Nitrogen-fixing bacteria have been found even inside the fungal mantle of ectomycorrhizae, and so the circumstantial evidence is overwhelming that an interplay occurs between the two organisms, presumably to their mutual benefit. Permaculture systems are thought of as nature acting on a series of overlapping layers, where nutrients that are captured at one level are passed down to another, or may form part of the symbiotic mechanism of an individual layer. The forest garden principle which is a series of clearings cut into forest is the supreme example of this action of biodiversity, where each layer and each organism feeds another, throughout forming a balanced ecosystem.


Related Reading.

[1] P.U. Mikola, Relationship between nitrogen fixation and mycorrhiza, World Journal of Microbiology, 1986, 175-282.
[2] http://www.dgsgardening.btinternet.co.uk/
[3] http://en.wikipedia.org/wiki/Mycorrhiza

Satellite Distances and Speeds.

In order for a satellite to orbit the Earth continually, a stable stationary orbit must exist. We can express (according Newton's Law):

F(gravity) = GMm/r^2,

where G is the gravitational constant, M is the Earth's mass and m is the mass of the satellite, with r being the distance between the centres of the two bodies. We can further express for a simple circular orbit, the centrifugal force (which acts in opposition to the gravitational force):

F(centrifugal) = mv^2/r,

where v is the angular velocity of the satellite. For a stable stationary orbit to exist, the two forces must be equal and opposite, and so we can write that F(gravity = F(centrifugal), and hence:

GMm/r^2 = mv^2/r. By cancelling the terms, m, and rearranging, we get:

GM = v^2 r.

Assuming a circular orbit, the mean angular velocity, v is the circumference of the orbit divided by the time (t) taken for the satellite to make that orbit, i.e. v = 2 pi r/t, and so if we substitute for v, we find:

t^2 = 4 pi^2 r^3/GM.

A special case is the geostationary orbit, with a unique property which is very useful for communications and weather satellites. This is a geosynchronous orbit directly above the Earth's equator (latitude 0°), with a period equal to the Earth's rotational period and an orbital eccentricity of approximately zero. Due to the constant 0° latitude and circular nature of geostationary orbits, satellites in them differ in location only by longitude. In essence, from the point of view of an observer on the Earth's surface the orbiting satellite stands still in the sky, because it moves through its orbital cycle at the same rate as the equatorial surface point below it moves round with the Earth's rotation. Clearly the satellite must sweep through a greater distance than the equatorial surface point below it does in the same time interval and hence it moves at a greater speed, as we shall see.

To compute the size of the orbital radius (r), taken from the centre of mass (i.e. the centre of the Earth), we can rearrange the above to solve for r:

r = (t^2GM/4 x pi^2)^1/3 =

[(24 hr x 3600 s/hr) x 6.6726 x 10^-11 m^3 kg^-1 s^-1 x 6.0 x 10^24 kg/ 4 x pi^2]^1/3

= (7.57 x 10^22)^1/3 = 4.23 x 10^7 m = 42,300 km.

If we subtract the mean earth radius of 6.4 x 10^6 m, we obtain an altitude of 3.59 x 10^7 m (35,900 km).

To obtain an orbital speed, we note that the circumference of the orbit is 2 x pi x r =

2 x pi x 4.23 x 10^7 m = 2.66 x 10^8 m.

The speed is thus: 2.66 x 10^8 m/(24 hr x 3600 s/hr) = 3,079 m/s = 3.08 km/s;
x 3600 s/hr = 11,088 km/hr = 6,930 miles per hour.

[For comparison, an equatorial point at the earth's surface rotates at (2 x pi 6 x 10^6)/(24 x 3600) = 465 m/s = 0.465 km/s; x 3600 s/hr = 1,676 km/hr = 1,047 mph].


Most satellites are launched at much lower orbits, e.g. 500 km in altitude, for use in navigation, telecommunications and other purposes, e.g., the Hubble Space Telescope has an orbital altitude of 559 km.

In this case, t^2 = 4 x pi^2 x [(6.4 + 0.5) x 10^6]^3/(6.6726 x 10^-11 x 6 x 10^24) = 3.24 x 10^7 s.
Therefore the orbital period, t = (3.24 x 10^7 s)^1/2 = 5692 s = 94.9 minutes.

Its orbital speed is 2 x pi x (6.9 x 10^6)/5692 = 7.62 km/s = 27,420 km/hr = 17,137 miles/hr.

The International Space Station has an orbital altitude of 350 km, and so its speed is nearly the same (27,725 km/hr; 17,328 mph), according to an orbital period of 91.8 mins.


Escape Speed for the Earth.
This is usually incorrectly called the "escape velocity" but is just a speed i.e. distance/time since there is no direction specified.

To get this quantity, which is the kinetic energy (1/2) mv^2, required to cancel the gravitational "pull" of the earth, we can write:

(1/2) mv^2 = GMm/r

where r is the earth's radius, and M its mass, and by cancelling the terms m from both sides (which tells us that the mass of the satellite is unimportant and only that of the earth matters), we get:

v = (2GM/r)^1/2

= (2 x 6.6726 x 10^-11 x 6 x 10^24/6.4 x 10^6)^1/2 = 11,185 m/s (11.19 km/s)

= 40,267 km/hr = 25,167 mph. Thus this is about half as fast again as the speed required to maintain a 500 km orbit above the Earth. Satellites will never therefore simply fly-off into space and with the virtual absence of air-resistance above ca. 100 km, there is no mechanism for efficient energy-loss so they cannot simply tumble back to earth either.

However, since there is no atmosphere, satellites are not shielded from radiation from space which tends to concentrate in the van Allen belts around the earth and causes damage to the materials they are made from, and solar cells, integrated circuits and sensors can be damaged by radiation. The inner Van Allen Belt extends from an altitude of 700–10,000 km (0.1 to 1.5 Earth radii) above the Earth's surface, and contains high concentrations of energetic protons with energies exceeding 100 MeV and electrons in the range of hundreds of kiloelectronvolts, trapped by the strong (relative to the outer belts) magnetic fields in the region. The large outer radiation belt extends from an altitude of about three to ten Earth radii (R_E) above the Earth's surface, and its greatest intensity is usually at an altitude of around 3–4 R_E.

It is generally understood that the inner and outer Van Allen belts result from different processes. The inner belt, consisting mainly of energetic protons, is the product of the decay of albedo neutrons which are themselves the result of cosmic ray collisions in the upper atmosphere. The outer belt consists mainly of electrons. I am involved in a project with the Yerevan Physics Institute in Armenia, to simulate the effects of energetic electrons on satellite components in space and under other extreme conditions. At an altitude of 5.6 (R_E) a satellite in the geostationary orbit, though away from the region of maximum intensity, will nonetheless be subject to significant radiation in the outer Van Allen belt.

Regenerative Agriculture.

"The nation that destroys its soil destroys itself" (Roosevelt 1937).

Modern agriculture is based almost entirely on fossil fuels and natural gas. The former are used to run tractors and other kinds of farm machinery while the latter is cracked in a thermal catalytic process called “steam reforming” to make hydrogen which is combined with nitrogen to form ammonia, using the Haber-Bosch process. Haber received the 1918 Nobel Prize in Chemistry for this work which he developed with Carl Bosch. He has also been described as the "father of chemical warfare" for his work developing and deploying chlorine and other poison gasses during the First World war. Haber's wife, Clara Immerwahr, who also held a PhD in chemistry, opposed his work on poison gasses and committed suicide with his service weapon in their garden, possibly in response to his having personally overseen the first successful use of chlorine at the Second Battle of Ypres on 22 April 1915.

When I was at school we were taught it as just the Haber process, but Bosch has since then been recognised in this, probably the most important reaction ever performed in the world. Indeed, it was Bosch who transformed Haber's bench-top demonstration into an important industrial process to produce megatons of fertilizer and explosives. It is the fully developed system that is called the Haber-Bosch process. After World War I, Bosch extended high-pressure techniques to the production of synthetic fuel and methanol and in 1931 he was awarded the Nobel Prize in Chemistry together with Friedrich Bergius for the introduction of high pressure chemistry, e.g. the Bergius Process for converting coal dust to synthetic diesel by reacting it with hydrogen gas under pressure. Ammonia, as formed by the Haber-Bosch process, may then be oxidised using the Ostwald process to form nitric acid, and by the combination of these two materials, the fertilizer, ammonium nitrate is created. In fact this is a pretty dangerous material since along with other highly nitrogenous materials such as nitroglycerine, it is a powerful explosive. During World War One, the Allied forces dug trenches underneath the German lines, which they then filled with ammonium nitrate and detonated it, so that the explosion was heard in London, some 30 miles away across the English Channel.

While modern farming almost entirely relies on such synthetic fertilizers in "open systems", regenerative agriculture refers to "semi-closed systems": i.e. those in which inputs of energy, in the form of fertilizers and fuels, are minimized because those key agricultural elements are recycled as far as possible. Conventional agriculture is mostly "open" and hence large inputs are necessary since much of them are wasted and it is a matter of maintaining a sufficient productive density of fertilizers, pesticides, mechanical energy, to maintain production on poor soils with much of the living matter and natural animal life (earthworms, beetles etc.) gone. Indeed, modern soils have been described as dead, and only remain productive because of artificial and voluminous inputs derived mainly from crude oil and natural gas. As the latter sources of energy and chemical materials begin to wane and finally fail, so will most of the world's agriculture.

Although they are usually more energy efficient overall, regenerative systems generally need higher on-farm labour than open systems do, as shown by a study of 1144 farms in the United Kingdom and Ireland. From a conventional economic standpoint this is seen as a disadvantage and a disincentive to move over to using regenerative systems. However, in terms of relocalised communities and economies, so long as the labour costs are practicable, there may be positive benefits, in terms of the maintenance or creation of social capital and community livelihoods: i.e. the economy is retained within the community, possibly using some kind of local currency or barter system.

Off-farm inputs for regenerative systems are rarely zero, but are much less than is the case for the open systems of conventional agriculture. Soil organic matter invariably increases as systems become more closed, and both soil quality and health appear to be related to the amount of organic matter they contain. However, the relationship between soil quality and its crop fertility varies according to the particular soil system. In specific studies, mineral fertilizers (nitrates and phosphates) and tillage were applied to compensate for the loss of soil health, and yet as this declined further, and the soil became increasingly degraded, these mineral additions became ever less effective. It might be useful if set limits were imposed to the amount of off-farm inputs since this would provide a proactive address to various current environmental concerns, in particular the energy costs and degree of environmental damage that is caused by agriculture. The greater amount of soil organic matter in semiclosed systems compared with their open equivalents, results in larger sinks for both carbon and water. Thus, both aspects of taking carbon from the atmosphere to ameliorate global warming and needing to apply less water to the land, as global water shortages ensue, are addressed.

At the Rodale Institute, in Pennsylvania, the term regenerative has a more particular meaning, which is to regenerate the soil. Over a period of more than 30 years, methods have been developed that not only minimise external inputs but literally rebuild the organic components of soil and hence sequester carbon within it. According to their figures, if all of the world's crop-land were farmed using their practices, around 40% of all human CO2 emissions could be captured from the atmosphere and locked-into the soil, simultaneously improving its health and productivity. As we see in later sections, if a soil is healthy and "organic", where its natural biodiversity has been restored, the energy inputs are minimal since the natural ecosystem is able to maintain and farm itself: bugs and worms aerate the soil, and nutrients are passed down through the layers of growth from tree-canopy to forest mulch, while a diversity of natural plants naturally protects against pests, and the soil becomes better at retaining water, symbiotically at the depth of the root systems. An agricultural system is not usually "closed" entirely because it is normally intended to grow produce that is taken off the farm. However, in a fully self-sustaining (permaculture) arrangement, full closure is possible, where those living on the farm are fed, sheltered, kept warm and supported by their own labour and by natural inputs.

We stress that current farming practices are not sustainable, and for various different reasons, some of which are connected. Some soils in the American mid-west in the 1950s contained up to 20% of carbon, but this is reduced to perhaps a couple of percent or less now. This loss of carbon plays a significant role in breaking-down the essential structure of soil which leads to soil-erosion, decreases its ability to retain water so making regions more vulnerable to drought, and decreases the natural nutrient value of the soil. The situation is worse than this because the current practices of industrialised agriculture tend to break-down the soil carbon such that it is released as carbon dioxide. Indeed, recent data from the U.S. government suggest that around 20% of the American CO2 emissions are from food production, if actual farming procedures and the manufacture and use of chemical fertilizers and pesticides are all accounted for.

Results from the oldest run continuous cropping test plots in Illinois run counter to much prevailing thinking that supplementation of soil by nitrogen fertilizers helps the soil accrue and retain organic matter. The evidence is that it does not, but merely allows plants to grow on an increasingly mineralized template, whose organic carbon quality is not improved during the process. According to the International Panel on Climate Change (IPCC), farming and the use of agricultural land may be brought culpable for 12% of anthropogenic carbon emissions. It has been argued that the application of nitrogen fertilizer encourages the breakdown of soil fungi, so realeasing its carbon as carbon dioxide to the atmosphere.

Thus, we might not only lock new carbon into the soil using regenerative organic farming methods but ameliorate a sizeable proportion of our existing emissions simultaneously. The terms "soil health" and "soil quality" are used almost synonymously, at least in the media, but in fact their semantics devolve from more specific intentions. Since the quality, i.e. in terms of a chemical analysis of the elements present, and its biological and physical properties, does not vary spectacularly between different samples of soil, the term "soil health" might be favoured, since it represents a more holistic view of soil management, while "soil quality" is more static.

It is a satisfying thought, that rather than being a key problem element, farming might become the route to salvation from the problems of carbon-pollution, energy wastage and climate change. The British farming industry has been subject to various seemingly punitive measures during the past decade, involving the wholesale slaughter of herds of cattle to "deal" with the foot-and-mouth epidemic, and of other animals, e.g. sheep and pigs, in some overkill strategy that other countries notably France, just across the Channel from us, would not adopt. Friends of ours who farm in North Yorkshire did receive compensation for the loss of their animals, but for some farmers, unable to bear witness to the slaughter of herds their family had built-up over generations, the money was not enough, and equally so for some small farmers who could not survive the intermediate cash-flow crisis that prevailed, and literally did not, resulting in farming as the profession with the highest suicide rate in Britain. The restoration of British farming is the most pressing action for the government to take, if we are to continue successfully as a nation, particularly as the dearth of cheap fossil energy becomes unequivocal.

At the Rodale Institute, it has been shown that regeneratively managed organic soils have increased their carbon by around 1% per year to a total of nearly 30% over the 27 year duration of their study. In comparison, petroleum-fuelled land has at best accrued no additional carbon and in some cases the soil carbon content has declined over the same period. Soils that are richer in carbon tend to support plants that are more resistant to drought stress, pests and disease. The sequestration of carbon in soil is principally due to the presence of mycorrhizal fungi. These fungi are able to conserve organic matter by forming aggregates of it with clay and other soil minerals. In such soil-aggregates, the carbon is less vulnerable to degradation than as free humus. The mycorrhizal fungi produce a highly effective natural glue-like protein, called glomalin, which stimulates a greater aggregation of soil particles. It is further found that more soil carbon is accreted using a manure-based system than in a legume-based organic system.

In the first Rodale trial plots, carbon was captured into soil at a rate of 875 pounds of carbon/acre/year, using a crop-rotation using manure, and about 500 lbs/acre/year using legume cover crops. However, in the 1990s, it was shown that by using composted manure combined with crop rotations, organic systems can yield a carbon sequestration of up to 2,000 lbs/acre/year. In emphasis, fields worked with conventional tillage and which relied on chemical fertilizers actually lost 300 lbs/acre/year of carbon. 2,000 lbs of carbon is the amount contained in (44/12) x 2,000 = 7,333 lbs of CO2, and so each acre can remove this quantity of greenhouse gas from the atmosphere, per year, by trapping it in soil in fields.

While it would not be easy to do entirely, it has been stated that if all the 3.5 billion acres of tillable land could be so managed, 40% of all human carbon emissions could be sequestered in its soil. Roughly that amounts to 2,000 lbs/acre x 3.5 billion acres/2,200 lbs/tonne = 3.18 billion tonnes of carbon, which is 45% of the total of 7 billion tonnes of carbon emitted per year from burning fossil fuels, and is close to the above estimate. [As most of the calculations done in this book use metric units, 3.5 billion acres equals around 1.4 billion hectares or 14 million square kilometres (km2). This is around 10% of the Earth's land area]. The United States produces roughly one quarter of the world's carbon emissions, and has 434 million acres of tillable land. If a 2,000 lb/acre/year carbon-capture was achieved, almost 1.5 billion tonnes of CO2 would be sequestered within its soil to mitigate nearly one quarter of the entire U.S. carbon emissions from fossil fuels. Assuming an average mileage of 15,000 miles per year and 23 miles/per/gallon, this is the emissions-cutting equivalent of taking one car off the road for every two acres of land, or removing more than half the number of cars there are on the highways of the United States.

Regenerative practices are also shown to result in drastic reductions in energy use, according to Rodale Institute trials. For example, a 33% reduction in the amount of fossil fuel necessary to grow organic corn/soybean is found when cover crops or compost is used instead of chemical fertilizer. Even more strikingly, by means of a no-till, organic crop rotation approach, up to 75% of the fossil fuel normally required to grow standard tilled organic crops can be saved, resulting in lower costs fewer greenhouse gas emissions. The biggest energy input in a conventional industrial corn and soybean farm is nitrogen fertilizer for corn, and then herbicides for both corn and soybean plants. The ability of regenerative farming to become a major carbon capture medium and less demanding of fossil fuels has long term implications for global agriculture and its involvement in air-quality policies and programmes. Minimising inputs of fertilizers and pesticides means less pollution and a reduction in environmental clean-up costs and cleaner waterways.

By farming organically, the soil is regenerated to its natural condition. The input of chemical fertilizers and pesticides is either avoided or substantially reduced. These actions taken on a single farm extend well beyond the farm itself, and benefit the local environment and community. As the wildlands regenerate, wildlife and birds return and help to control insects and other pests. The local rivers and streams incur less pollution from agricultural land runoff, since less is being applied. Local communities may also be regenerated by implementing recycling organic waste that otherwise needs to be disposed of, e.g. on landfill sites, or becomes an environmental problem.


Related Reading.
http://www.rodaleinstitute.org/files/Rodale_Research_Paper-07_30_08.pdf
http://newfarm.rodaleinstitute.org/features/0802/regenerative.shtml
http://www.aibs.org/bioscience-press-releases/resources/05-07.pdf

"Brittleness" of Soil and Carbon Cycling.

In arid and seasonally dry areas such as in Australia and the west-American plains, continuous grazing causes environmental disasters; essentially desertification of the land. However, a return to herding-style animal husbandry with long recovery periods between grazings allows the land to heal. In very dry regions, seeds must be planted deeply so that when they germinate the plant roots can reach groundwater. Only the hooves of animals can do this over millions of hectares. Without these actions by grazing animals, which plant seeds and recycle nutrients, dryland (arid) ecosystems become desert because:

standing dead growth chokes the growth of new plants, instead of mulching the soil;
rather than becoming well-set into the soil, the seeds instead sprout on the soil surface, and then die;
as old plants die, the amount of bare ground increases, and this loses its ability to absorb and store water;
this leads to rivers, springs, and wells becoming dry, and hence droughts become the norm.

Soil may be classified according to the degree of its "Brittleness" for which different kinds of animal management are appropriate:

A scale has been indicated (see link under Related Reading, at end of this article) from 1 to 10:

(1) Decreasingly
‘non-brittle tending’ (Rain forest).

(10)Increasingly
‘brittle tending’ (True desert).

Brittleness concerns how evenly the humidity is spread throughout the year, rather than the total rainfall. The more dry months there are compared to humid months, the more brittle tending the location is. Temperate regions are more ‘non-brittle tending’ with a fairly even balance of humidity throughout the year. In an actual rainforest, the humidity is nearly constant. In more brittle tending locations the humidity tends to be seasonal, such that there are are wetter summers and drying summers. The more various and seasonal the humidity is, the total rainfall (precipitation) drops, tending toward a true desert where every day is dry.

Non-brittle tending areas cover only up to one third of the earth's land surface (ca 50 million km^2) overall, and less than this proportion on most continents. In non-brittle regions, there is enough moisture overall to keep healthy populations of microbes, worms, beetles and bugs, which help to aerate the soil and move nutrients around. Carbon cycling is a natural feature of such environments, since grasses and woody plants are efficiently broken down by these organisms, or it is eaten by small animals who move around in small groups and contribute their manure to the system allowing its carbon to be cycled. In conclusion, it is the humid nature of a particular environment that sustains its carbon cycling mechanism.

It is the case, however, that the majority of the earth's surface is seasonal, where there are periods of extensive growth during the growing season (as shown by the Keeling Curve, and its annual oscillation, where during the growing season in the northern hemisphere the atmospheric CO2 concentration falls as the gas is taken up by plant growth through photosynthesis), followed by a period where not much grows and plants either die or become dormant. In order for the large volume of dry, standing vegetation and its carbon to be cycled before the next growing season, since it is now too dry for insects to take part in any decomposition processes, herds of large herbivores make their contribution. In their guts are populations of bacteria and other microbes, and convert the plants they graze into urine and dung, which are returned to the soil.
As they move around in herds, their hooves trample standing plants and so provide a protecting and continually decomposing cover to the soil.

Non-brittle tending environments tend to be fairly resilient to the impact of human farming practices and their carbon cycling ability is unlikely to be damaged in the long term. Any such damage that is incurred is quite quickly healed once the particular practice is stopped. The underlying problem of agriculture is that the types of farming that are fine in non-brittle regions have been adopted in brittle-tending areas which are less forgiving to them, to the level of devastation.

There has been the tendency for individual herds of wild and domestic animals to be reduced in size but more spread-out in their grazing behaviour so that the same region of land is grazed more constantly than in the natural environment. For this reason, ecosystems have broken down along with their intrinsic carbon cycling, in the majority of brittle tending areas of the Earth. But by knowing these facts, humans can change their land management practices to restore the natural brittle environment as a self-sustaining, symbiotic mechanism, by mimicking principal key features.

Related Reading.
http://www.soilcarbon.com.au/case_studies/pdf/08TL_SCCPPP_En.pdf

Land Management: Regenerative Grazing.

The same regions, thus with the same rainfall, same soils, and the same plant species can be either lush or barren, depending only on how they are managed. In particular, the degree of carbon in the soil is critical, as can be noted empirically just by looking. Hundreds of millions of hectares of grazing land worldwide in arid and seasonally dry areas have been reduced to near desert, but it need not be so. By a simple sum we may note that:

one hectare is equal to 10,000 square metres;

soil is typically 33.5 cm (about one foot) deep;

it has a bulk density of 1.4 tonnes per cubic metre;

thus the soil mass per hectare is 0.335 x 1.4 x 10,000 weighs 4,670 tonnes;

an increase in soil organic matter by just 1% means another 47 tonnes;

if we assume that about 50% of this is carbon, we have captured around another 23 tonnes of carbon per hectare;

this is equal to capturing 85 tonnes of atmospheric CO2.

If grazing animals are kept in one area, they repeatedly chew fodder plants and keep them small. Because there is a virtual symmetry between the amount of carbon in the exposed (above ground) plant and that in its root system, if the visible plant is small, so are its roots. Small leaves can only nourish small roots and so overgrazed plants will wither and die while shrubs, weeds and thorns can still reach water and thrive. It is thought that only soil is massive enough and manageable enough to capture significant amounts of CO2 over the next 30 years. All other - technological - carbon-capture schemes will probably take 30 years and more to be implemented and it is debatable how effective they will be.

Removing CO2 from power stations, at source, does not reduce the existing atmospheric carbon burden; neither does burying it in underground aquifers, deep cap rock formations and in exhausted oil wells etc. and it might take 100 years to know whether the strategy is effective or not. Simply establishing tree plantations is not certain either, since they can actually be net emitters in their early stages, and take many years to achieve their full carbon capture potential. Switching over to wind turbines and solar power doesn’t influence existing levels of carbon either, and it is debatable in what volume or how quickly such renewable energy sources can be established. The alternative means for getting-rid of carbon is to liquefy it and dump it on the ocean floor at depth, but this is likely to make the waters more acidic and impede shell formation in creatures that live there, thus impacting on the whole ecosystem.

So, how much carbon are we talking about? According to the UnitedNations Food & Agriculture Organisation "Soil organic carbon is the largest reservoir in interaction with the atmosphere." This sounds promising especially when we note that 650 gigatons (Gt) of carbon are present in vegetation; 750 Gt in the atmosphere and 1,500 Gt in soil. The U.S. Department of Energy concludes:"Enhancing the natural processes that remove CO2 from the atmosphere is thought to be the most cost-effective means of reducing atmospheric levels of CO2." The total area of grazing land on Earth accounts for two thirds of the total land surface, which amounts to 2/3 x 150 million km2 or 100 million km2 (10 billion hectares). We can thus make a simple sum and conclude that an extra 1% of carbon at 23 tonnes/hectare x 10 billion hectares = 230 billion tonnes of carbon stored.

Now we are clearly not going to cover 2/3 of the Earth’s surface with grazing animals, even if we move them around to allow grazing-crops to grow, and we are looking toward appreciable efforts in permaculture on the 15 million km2 of arable land there is available, but the point is clear that a large amount of carbon could potentially be pulled down from the atmosphere by the simple act of moving grazing animals around. Land management by moving grazers around has other environmental benefits too. For example in Zimbabwe, where a river used to run freely, the effect of overgrazing has resulted in a barren land which flash-floods when heavy rains fall. There is a severe loss in biodiversity, livestock are starving and most wildlife has gone. In contrast, a neighbouring river flows almost continually, drought is rare and wildlife has reappeared in large numbers. Again, the only difference is livestock management. The result is that the ability of the land to absorb and retain water is increased; new soil is being created; new plants are bedding-in; there are greater yields of fodder plants; greater biodiversity and a healthier landscape overall. When the livestock are not managed, the pictures speak for themselves, in that there is drought, desertification and economic hardship:

Food plants are killed by overgrazing;

new plants cannot become established successfully;

less forage grows;

the majority of sunlight and rain are wasted on bare soil;

soil loses its ability to absorb and hold water;

streams and wells go dry; livestock production falls;

wildlife disappears.

The actual amount of rain falling is not the critical parameter but what happens to the water once it has reached the ground. Again, using a simple illustrative sum: Just 1 mm more rain captured in the soil each year means an extra litre per square meter. That’s 10,000 litres more per hectare and an additional 1 million litres per square kilometre. The drought is reduced because the soil is able to discharge some of the water into rivers, springs and wells, and there is more forage for animals because the plants can access some of the water too which helps their growth. Some experimental studies done in the U.S. have indicated that by changing livestock management the soil can be made 600% more effective in absorbing water. If the useable rainfall is increased in this way, even formerly arid and barren lands can be made fertile once more.

In a 450 hectare pile of tailings from an old copper mine in the Sonoran desert, to the east of Phoenix in Arizona, life is being restored by grazing cattle on it. As they graze, the cattle push hay and manure into the mine tailings, and have created a layer of soil up to 30 cm (one foot) thick where there was none formed in over 60 years, by just leaving the area exposed to mother Nature. The soil captures water and retains it in the root zone, so rendering it accessible to plants, which flourish, all the while capturing CO2 from the atmosphere through photosynthesis. Presumably the levels of copper are insufficient to cause problems of toxicity either to plants or cattle. The strategy has proved successful even where “hydroseeding” efforts have been literally washed-away by heavy rain.

In northern Australia, unmanaged (free-roaming) cattle and donkeys destroyed a former wetland to the extent that by 1992, there was not enough food growing per hectare to feed a cow for a single day. The usual consequences occurred, or wildlife disappearing for lack of anything for them to eat, most of the rain evaporated and plants could not establish themselves, as a consequence of dry soil and overgrazing. However, by 2001, this same area was producing 800-1,100 cow-days worth of fodder as harvested in three grazings by managed livestock.

In summary, without grazing animals to plant seeds and recycle nutrients, dryland ecosystems desertify because: standing dead growth chokes plants, instead of mulching the soil; seeds sprout on the soil surface, then die; as old plants die, bare ground increases; bare soil loses its ability to absorb and store water; rivers, springs, and wells go dry; droughts become the norm. In arid areas, seeds must be planted deeply or seedlings will die before their roots reach reliable water. Only the hooves of grazing animals can do this economically over millions of hectares. Returning to herding-style management with long recovery periods between grazings heals the land.

AS an example I note that unmanaged grazing stressed forage plants in a pasture land regions in New Mexico, U.S.A. to the extent that by 1986, 11% of it was snakeweed. The standard practice of killing weeds using chemical weed-killers in fact would cement the underlying problem of low biodiversity and 46% bare ground. However, by 1990, a strategy of regenerative grazing had reduced the bare ground to 30% and the snakeweed to 1%. Nine previously dormant perennial grass species also reappeared. A well that had been dry since the 1950’s was found to have 3 meters (10 feet) of water in it too. The size of the herd and beef production doubled per hectare, while the cost to produce a kilo of beef decreased by 50%.

Regenerative grazing can also be the most effective means to restore biodiversity to a region. For example, David Ogilvie’s management of the U Bar Ranch in New Mexico has created a habitat that supports more endangered southwestern willow flycatchers than any preserve. The U Bar also hosts the most prolific population of flycatchers known to exist, and most interestingly they seem to thrive particularly well areas that they share with cattle. In 2001, 132 pairs of southwestern willow flycatchers were counted on the U Bar Ranch in comparison with a mere 7 in two nearby wildlife preserves with a similar combined area, but which are not grazed by livestock. The U Bar also has more common blackhawks and spikedice (as respective examples of a threatened bird and fish species) than anywhere else and large numbers of various other rare species. There is also the greatest density of nesting songbirds known in North America and an unusually high ratio 99:1 of native to exotic fish. Many habitats are now too badly damaged to support the wildlife that once maintained them, and simply protecting them or deliberately reintroducing wild species is usually unsuccessful. However, even in these circumstances, managed livestock practices can successfully restore then maintain these areas until their wildlife populations recover.

http://www.soilcarbon.com.au/case_studies/pdf/08TL_SCCPPP_En.pdf

Norwegian North Sea Crude Oil Samples.

Samples of crude oil from North Sea oil fields demonstrating their different properties. Taken at the Norsk Teknisk Museum (Norwegian Museum of Science and Technology), 2009.

Rebecca Hosking: Farms Without Oil using Practical Permaculture.

Rebecca Hosking is well known as a wildlife photographer and journalist, and also for her campaign against plastic bags. Modbury, in Devon, is the first plastic bag-free town since, at her instigation, all 43 traders there pledged not to sell them or give them away to customers for a minimum of 6 months [1]. It was Hosking's experience in photographic wildlife that spurred her to this campaign stance, having witnessed first hand the plight of albatrosses strangled by plastic, and dolphins and seals struggling to live, wrapped in plastic and parcel tape. I confess I was only vaguely aware of this effort and her name was brought to my attention recently through a TV documentary [3], set on the Devon farm of her formative years, which addresses the issue of how we are going to feed everyone in the absence of cheap oil. I made some notes during the programme and I see that she published a text about it in The Daily Mail newspaper, as referred to below [2].

In summary, practical permaculture, involving reconstitution and preservation of natural habitat, including hedgerows, where there is biodiversity and interacting "layers" of flora and fauna that pass down nutrients between levels, and bugs and earthworms that naturally till the soil, result in a fertile and high-yielding crop ecosystem, that is more productive than conventional agriculture; and all of this without oil or other artificial energy inputs. One day a week's worth of harvesting and around 10 days a year of maintenance is all that is necessary to keep such a system going, rather than the drudgery of farming that was the case before cheap oil. I grew up in agricultural regions, first of South Wales and then the English West Country (Gloucester) and my memory of farming and farmers is that even with oil, theirs was a life of comparative slog.

One drawback is that cereals cannot readily be produced by this means, and so a change of diet to one richer in fruit and vegetables is also necessary. Hosking notes that she had always thought of hedgerows as being simply divides between fields, and indeed that was my view too. I remember my first flight in a plane and seeing the English countryside is as though someone had drawn lines of division between the different fields, as their various individual hues and shades seemed to confirm; almost like a watercolour patchwork. However, the hedgerows not only provide habitat for birds who add a contribution of nitrogen through their droppings to the ecosystem, but are crop-productive entities in their own right - a kind of vertical field. I tend to think of the majority of arable land in the sense of flat fields, with occasional trees here and there almost as a kind of garnish; yet in reality, the most fertility is found when the landscape is effectively a forest (as most of Britain once was until the trees were cut-down to make ships and charcoal for smelting iron) with occasional clearings cut through it.

Farming has undergone a revolution during the past century, especially after WWII, as driven mainly by cheap energy in the form of oil-based fuel and chemical fertilizers. This has profoundly changed the shape of the countryside. Life on a small farm prior to then was indeed a life of drudgery. Even organic farms depend on oil, and for the reasons of imminently running short of cheap oil and potentially the effect of burning fossil carbon fuels on climate change, we are going to have to do without them or with far less of them. Colin Campbell is an oil industry insider and expert and is it his opinion that the break-year was 1981 when the world began to use more oil than it found new oil. Indeed, less and less new oil has been discovered during the past 40 years.

The precise date of peak oil doesn't matter so much, but we need to face the inevitability of a 2% annual decline in oil production. However, the present curb in new oil development infrastructure means that the decline could be a lot worse than this, and a 9% fall is one scenario that has been suggested, which means effectively a collapse of everything that depends on oil within a short time of a few years. All in all we need to act now.

Our dependence on oil and gas may be illustrated by the familiar ham sandwich, as normally provided in a pristine plastic wrapper. There is diesel needed to run the tractors that harrow the land, and dig seed in to grow grain to feed the pigs on. Then there are chemical fertilizers and pesticides, herbicides and insecticides, all of which are made from natural gas. Once the grain is harvested, it is dried using big heaters, powered probably by electricity made from natural gas, or they are gas-heaters themselves. To make the ham the pig eats around half a tonne of grain per year, and to complete the sandwich the salad is either flown-in from elsewhere in the world or produced in a heated greenhouse. It is then driven miles in a refrigerated lorry. The plastic package is made from oil and takes fossil energy to produce.

The Soil Association are rightly concerned about not only the state of our soil but of agriculture more generally, and predict there will be an energy famine by 2013 at the latest. i.e. by 2013 we will no longer be able to make as much energy as we will demand to maintain the status quo. It is thought that by 2013 Britain's energy account will be in the red to the tune of £500 billion, but if there is not enough energy available in any case, it is not simply a matter of whether we can pay the bill or not.

So, the question is, how can we farm - feed everybody - without oil? Richard Heinberg, author of the aptly entitled The Party's Over, with a nice piece of cover-art where someone is holding a fuel-gun to his head with the last drops of oil dripping from it, in an implied act of suicide, thinks we have left it too late to find alternatives and that all forms of renewable energy can't match the amount of oil we use at 30 billion barrels a day. Pretty well this is also my conclusion, as you have read through the workings of these articles. I began writing this blog in a spirit of optimism, assuming that we could do without nuclear power, and that all our energy could be provided using wind, wave, biofuels and whatever else, but I now think we will need all forms of energy we can get our hands on to tide us over the very difficult transitional period when we adapt and learn to use far less energy. Either way, by design or default, we will end up living entirely differently from how we do today. It is not a matter of "going-back" since that small-farm agrarian lifestyle was miserable and soulless for the majority who had to live it, but a localisation of our interests, economies and activities to do more with less and maybe feel a reconnected sense with one another and with nature. Otherwise a lot of us are going to die.

Currently, it takes 10 calories of energy to produce 1 calorie of food energy. The Green Revolution, that has confounded the Malthusian predictions that world population would outstrip our capacity to grow enough food to feed it, is underpinned by cheap energy, particularly from oil. Genetically Modified (GM) crops depend as much on oil as any other - you can grow more on the same area of land but this requires a commensurate increase in the input of fertilizers and fuel for farm machinery. If there is an energy famine, the United States and Australia could collapse as food exporters, and cause world famine and huge price rises in what food is available. Most of the skills in how to farm without fossil fuels have been forgotten: a good example of this the the series Victorian farm, shown on B.B.C. 2 recently. Here a team of three spent a year living and farming as Victorians, and the roles are rather traditional: Ruth Goodwin looks after the cooking, the housework - it takes practically the full week to do all the washing and ironing - and the poultry, including killing them when their time is up; while the two men learn to plough with heavy horse, build a pig-sty, harvest the crops and hay and between the three of them they do everything using at best hand-operated technology which was an innovation of Victorian engineering, hugely labour-saving than without them, but still all heavily manual.

I watched this series in wonder, but with the simmering sense of fear that we might have to return to that way of life, and if so, how could we cope with relearning so many forgotten skills, and indeed all the hard manual work. It is work for young men, at best, and the average age of a British farmer is now 60. The Victorian equivalent of a tractor was the heavy horse, so called because they weigh up to one ton and are powerful but amiable beasts. A modern tractor has a power equivalent to 400 horses, while in pre-oil times they had at most (if they could borrow another for very hard work) two horses. Indeed, the present level of energy consumption around the world, at 18 TW is equal to 22 billion slaves (the world population is 6.7 billion) working around the clock.

The farming industry has been left to die in the U.K., and the country imports around 40% of its food - brought in using oil-powered transport. The cost of such carriage can only increase and ultimately fail, as oil prices rise inexorably. There are only 150,000 farmers left in the U.K., and as noted, with an average age of 60 years. Animals need to be brought in in winter otherwise they destroy the pasture. To feed them hay needs to be harvested and this is the biggest use of energy on a small farm. At Fordhall farm in Shropshire, the cattle are kept out all though the winter, where they graze with very little in the way of additional feed being needed for them. This rendered the brother and sister team Charlotte and Ben Hollins who run the farm, almost immune to the recent oil price shocks that hit the rest if the industry hard. Their trick is to use a range of grasses natural to the area and which in combination make the land surface tough, so that it is something like a wild prairie and able to withstand the constant pummelling by the animals hooves during the winter. Choosing the best kinds of grass is an empirical matter, and whatever works best for a region is the one to select. Other kinds of grass will fit with another area: again, local knowledge is likely prove indispensable, probably in old farming records.

Their father, Arthur Hollins, a lifetime farmer, recognised that the woodland on the farm was much richer in wildlife than the fields he cultivated, leading him to believe that ploughing destroys essential nutrients in the soil by exposing them to sunlight. As Hosking notes:

"The flocks of gulls and crows squabbling behind the plough for worms and beetles is just a childhood memory for me. Today, the birds don't follow the plough because the soil is dead and there is nothing for them to eat.

"The only way modern agriculture can get away with killing the life in the soil is through the another use of fossil fuel - by turning it into chemical fertilizer containing nitrates, phosphates and potash."

At least 96% of all food grown in Britain relies on farming methods that use synthetic fertilizer, without which the soil lacks enough nutrients for anything to grow in it, and without ploughing the soil is not aerated. This seems like a stalemate situation until rather than a conflict with nature, lessons are drawn in harmony with the natural world, which was lush 10,000 years ago before humans began ploughing fields. That earthworms are able to till and aerate soil was known to Charles Darwin, and that they have done so for millions of years. Forests are able to flourish without the agricultural impact of humans, because they rely on a natural fecundity which is created by billions of microbes (bacteria), fungi, animals, birds and plants. This is the importance of biodiversity: an interconnected, holistic symbiosis of living organisms. Before the fifteenth century, most of Britain was forest-land, and most if the energy expended in preserving modern agriculture is to hold it in an artificial bubble; from returning to its natural forested state.

Chris and Lyn Dixon have a permaculture smallholding ("Forest garden") in Snowdonia, on which they are able to produce all the fruit, vegetables and meat they need, and even the fuel to cook it. The site looks like a set of small clearings in a mass of woodland, in reverse of what we normally now think of as the layout of a farm, with clumps of trees surrounded by fields. A natural woodland is like having half a dozen fields stacked one on top of the other. It works on different levels: shrub, etc., fruit trees, tree canopy, which recycles nutrients - e.g. nitrogen in leaf litter, beneficial fungi and root systems. It is reckoned that 10 people can be fed per acre (25 per hectare), or about double that by conventional agriculture. Cereals can't be grown and so it will be necessary to adapt our diet to other foods: nuts grow on trees, as in chestnuts and hazelnuts at a yield of 2 tonnes/acre which is a similar yield to wheat although from a nutritional standpoint, nuts are similar to rice. For the U.K. to become self-sufficient we need to eat less meat.

Gardening with hand tools is more energy effective (and labour intensive) and raises five times as much food on a given area in a small garden than is produced on the same area of open field. It is likely that a preponderance of small plots will take the place of fields as the latter decline in the face of a loss of oil and natural gas supplies. An analogy can be drawn with the "digging for victory" campaign of World War II, with its allotment gardens. Overall, we need more farmers, otherwise we will starve. There are just 150,000 left now and we will need around 11 - 12 million, i.e. every family will be involved rather than just those running a collection of industrial-scale farms.

Rather than asking the question, could permaculture feed Britain, it is more salient to ask whether conventional agriculture can. The answer to the latter in the long run, is no, because it depends so utterly on oil and gas, and so the only course of action is to try permaculture. It takes a long time for soil to regenerate, but if left to its natural state it does. Every plant is important in some way: e.g. bracken collects potash, birch encourages phosphate recycling through the ecosystem. Nitrogen, potassium and phosphorus are all circulated through the system by nature - animals, including worms - and so no energy input is necessary. Some creatures help with pest control whole others control drainage and others pull up nutrients from the soil; all are important in this symbiosis of biodiversity. Birds that eat insects and seeds accumulate phosphates which are returned to the soil in their droppings thus eliminating the need for rock phosphate fertilizers, world supply of which peaked, incidentally, in 1988.

According to Richard Heinberg, "The dominant demographic trend of the 21st Century is going to be re-ruralisation (or de-industrialisation). That is not to say that the cities will disappear, but the proportion of people involved directly in food production is going to increase. We will also need a lot more full-time farmers - otherwise what are we going to be eating?"

If we dug for victory during the German U-boat blockade in World War II, there's no particular reasion we can't do it again in the face of a war against declining oil.

Will homo sapiens (as his name implies) be wise enough to survive.

Related Reading.
[1] http://www.guardian.co.uk/society/2007/may/16/business.waste
[2] http://www.dailymail.co.uk/news/article-1145431/Now-farm-help-teach-world-live-oil-says-woman-banished-plastic-bags-town.html
[3] BBC 2 broadcast, Natural World. A farm for the Future. Friday, 20th February 2009, broadcast 20.00.