Wicking bed – a new technology for adapting to
climate change
The This shows that it is
virtually impossible to cut emission on a global basis. Even
if it were possible to cut emission it does not solve the problem of
global warming. The emissions are still there and accumulating. We
need the technology of removing carbon from the atmosphere. We are already suffering from
damage to our soils making food production more uncertain. Erratic
rainfall resulting from climate change will make food production
even more difficult.. This is discussed in
‘food production and climate change’ We need a new approach, with new technologies,
which will lead to a sustainable but still affluent society. We are focusing too hard on reducing emission and ignoring the obvious alternative solution to climate change. Plants already absorb 30 times all man made emission. See plants absorbing carbon. Yet the carbon that is absorbed is rapidly returned to the atmosphere. By changing our agricultural system, for example by adopting the wicking bed technology, we capture carbon which is locked in the soil and make food production better able to cope with more erratic rainfall. Changing our agricultural system so it becomes a net absorber of carbon, which is captured in the soil, is essential if we are to manage climate change and have stable food production These two aspects of absorbing carbon and stabilizing food production are totally entwined, they cannot be separated. This document aims to provide information to our
political leaders on how to mitigate climate change and adapt our
food production to the more erratic rainfall. Climate change – obstacles to
agreement
In the developed countries
there appears be widespread support for reducing emission but the
practical problems are immense. A modern city is very
different to the traditional village where food and most supplies
are obtained locally. We have an entire infrastructure, city layout
and technology based on readily available energy and transport. Energy demand can be reduced by improving
efficiency. Introducing non fossil energy sources such as solar and
wind power will further help, but not on the scale required to
achieve the cuts necessary. The situation in the so
called developing countries is even more difficult. These
countries do not comprise a homogeneously poor population. This is
why I prefer to call them hybrid societies. These countries comprise a privileged minority - who enjoy a standard of affluence not unlike the developed countries - and a majority who are at the subsistence level. These poorer people are struggling to achieve the affluence of their richer cousins. Modern information technology is ubiquitous in even the most remote corners of the world. The poor are informed of their poverty. In practice this creates a pressure which is impossible to resist. It would also be highly unethical. We just have to accept that emissions from these
hybrid or developing countries are going to continue to grow as more
people enter the ranks of the more affluent class. The developed countries simply cannot cut back
their emission sufficiently to compensate for the growth of
emissions in the hybrid (developing countries).
This article is not meant
to be a comment on political systems, only to discuss the obstacles
to adoption of a global agreement. For legislation to be
passed in countries such as Australia and the US it has to pass
through two levels, for example in Australia the house of
representatives which is controlled by the Government of the day and
the Senate, which is a house of review and can be controlled by the
opposition. In both As these countries,
particularly However if the opposition parties in Australian
and the US feel that this is still disadvantaging the local industry
they can block legislation, even though the Government of the day is
trying to pass legislation.
This is a major hurdle which
will not be overcome easily. The world’s population
grows exponentially but despite many people fears there has been no
overall food shortage. Far from being in short supply there is
an overall abundance of food and the amount of food wasted runs into
billions of dollars each year. Food production has continued to
outpace population basically because of wider use of fertilizers,
better genetics and plant breeding and the wider use of irrigation.
Despite the short term success they lead to long
term degradation of our ecological resources, particularly the
destruction of soil structure.
Many people, like me, have been concerned that
these agricultural systems are unsustainable in the long term and
have worked to develop food production systems which are genuinely
sustainable. In the long term these
sustainable practices, largely based on building up soil quality,
can be economic but in the short term there is a financial cost.
Typically growers are under great price pressure and cannot afford
this short term cost of change. The result is that
unfortunately these sustainable techniques have only been adopted by
ecologically sensitive growers with financial resources.
The wicking bed system
stores significantly quantities of water and reduces water use, in
some cases by up to 50%. This reduces the frequencies of
irrigations and in the case of rain fed crops increases the length
of productive growth after a rain. The moist conditions inside
a wicking bed are conductive to the growth of mycelium (the network
of long hyphae which form fungi). This network of hyphae adds
structure to the soil increasing its water holding capacity. They can also be symbiotic to the plants roots.
The mycorrhizal fungi may actually penetrate the root system,
effectively extending the reach of the root many times and
increasing the capacity of the plant to extract water and nutrients
from the soil. Plants absorb 30 times all
man made emission. This is a huge absorption of carbon
dioxide. At first sight this would indicate that carbon levels
should be dropping – yet they are rapidly rising – so what has gone
wrong? Unfortunately most of the carbon absorbed by
plants goes straight back into the atmosphere. Plant materials are complex
organic molecules which are readily degraded to simpler molecules,
such as carbon dioxide. This happens from a number of
mechanisms. The combination of UV light and oxygen in the
atmosphere is highly destructive to these complex organic molecules. Agricultural and forestry waste left on the
surface and exposed to sunlight quickly breaks down to return carbon
dioxide to the atmosphere. If they are not broken down
by UV light there are likely to be decomposed by bacteria working in
aerobic conditions. These aerobic bacteria will release large
amount of carbon dioxide back into the atmosphere. In other words plants absorb
large amounts of carbon but most is returned to the atmosphere.
It is often said that the largest emitter of carbon is coal fired
electricity generation followed by close seconds such as farming and
transport. This is not true, the largest
source of carbon entering the atmosphere, by far is the break down
of plant material. Some 97% of the carbon entering the atmosphere is
from degrading plant material. The level of carbon in the
atmosphere is a dynamic situation with carbon continuously entering
and leaving the atmosphere. People often make the mistake of thinking of
carbon as a static problem e.g. we should strive to take carbon out
of the atmosphere and permanently store it. This has led to the
mistaken view that forestry is storing carbon in the soil -
mistaken, because the carbon is not permanently stored. We should think of the
atmosphere as a giant lake with carbon, like water, pouring in and
out. If there is more carbon pouring in the level will rise
and if there is more carbon pouring out the level will drop. Man made emission are a
relatively small part of this carbon flow which is dominated by the
natural extraction and return of carbon from the plants. Man
has upset the balance by increasing carbon emission and reducing the
ability of plants to remove carbon. The critical issue is the
rate at which carbon is being extracted versus the rate at which it
is returned. A tropical rain forest
rapidly absorbs carbon from the atmosphere, but carbon is equally
rapidly returned. Any carbon that may be captured in the soil
is quickly washed away by the heavy tropical rain, so the system is
close to being in balance with only a small reduction in atmospheric
carbon. A temperate forest, with a
lower and more seasonal rainfall, on the other hand has a much
slower rate of decomposition so there is time for the micro
organisms to capture carbon into the soil, so there will be a
reduction of carbon in the atmosphere. Every molecule will
eventually return to the atmosphere but the rate of return will be
less than the rate of capture
so the system is not in equilibrium and the balance of the carbon
ends up captured in the soil. Individual molecules will be
entering and leaving the soil, may be at a fairly rapid rate, but
there will still be a net increase in the total carbon in the soil.
They are different molecules but still the net volume will be
increasing. Modern agriculture has of
course changed the carbon balance and land that was once forest that
has been converted to agriculture increasing the rate at which
carbon is returned to the atmosphere so the net volume of carbon in
the soil will be reduce over time. Modern agriculture is a
major net emitter of carbon. This is bad for the climate and bad for
food production. The technology of reducing the rate at which the
plant based carbon returns to the atmosphere must be one of the most
important technologies for safeguarding our future, yet it remains
in a scientific backwater. Bacteria and fungi both
degrade dead organic material, but in very different ways. Bacteria are very
effective at degrading soft organic material but have difficulty in
digesting the hard material particularly the lignin in wood. They can generate ionic bonds (Van de Waal forces)
between the organic material and the soil particles which assist in
retaining the carbon in the soil. Anaerobic bacteria can
release significant amounts of carbon dioxide and methane back into
the atmosphere. Anaerobic bacteria lead to lower green house
emissions. Bacteria are microscopic with no cohesion between
individual bacteria. Fungi are very different.
They send out hyphae to form a complex network of mycelium which can
be huge. In fact the largest living creature on the earth is a
fungus. This network reinforces the soil giving it mechanical
strength which helps the soil resist wind and water erosion.
It also increases the pore size so the soil can hold more water. The hyphae inject powerful
enzymes into the organic material which can decompose even the
hardest of woods. They can also dissolve soil particles, even
rocks, to release minerals for plant use. Certain fungi form beneficial
or symbiotic relationships with plants (mycorrhizal fungi).
The area or spread of the fungi is far greater than the roots of the
plants increasing the nutrient supply to the plant. Some fungi
actually enter the root system and in return for minerals receive
sugars from the plant. Fungi also stabilize the carbon in the soil, even
their body mass, which is largely carbon, is significant and fungi
can live for hundreds of years. Whether the problem is looked on as a way of
increasing food production or of absorbing carbon into the soil for
long periods of time fungi play a crucial role. Wicking beds can be used to
capture the carbon captured by plants and retain in the soil.
Fungi are the most effective method of converting plant material
into carbon in the soil. This retained carbon improves the soil,
increasing the water holding capacity and making nutrients more
available to the plant. Fungi are particularly sensitive to water content, Wicking beds provide this high humidity
environment in which fungi flourish and can be part of that critical
chain of converting carbon into soil. Special versions of the
wicking bed have been developed to capture carbon within an
agricultural system. We have the technology now.
Of course it can still be refined, as any technology can, but we
have simple methods that work well right now.
Technology is not a problem. The immediate problem is
that the actions of individual farmers are determined (in the main)
by short term economic considerations. There needs to be a
fundamental shift in the attitude of society and Governments away
from seeing food production as just another economic commodity to be
traded around the world and to regard the farm as a community asset
to provide us with food security in the long term and to manage the
climate. This has to be given real meaning by Government
action. The immediate problem is there is no structure -
legislative or preferably financial incentives - to make this
happen. Governments and the International community need
to set up a system of financial incentives whatever the method,
trading schemes, tax incentives, subsidies or whatever scheme is
preferred. Farmers cannot be expected to make the changes so they
can absorb carbon without some reward for their efforts and
expenditure.. The costs would be well
below other schemes such as carbon sequestration at the power
stations. In any case sequestration only reduces the rate at
which carbon is emitted and does nothing to remove carbon
from the atmosphere. The wicking bed is a new generation of
agricultural system which is more productive, improves water use and
can capture carbon from the atmosphere to stabilize climate change
and to improve soil quality. |