Create Your Own Paradise:
Improving the Soil with
Terra Preta and Biochar
By Ute Scheub, Haiko Pieplow, Hans-Peter Schmidt, Kathleen Draper
When people try to imagine paradise, they usually
think of a garden. We feel comfortable in gardens and recover from all kinds
of stress. Gardens are places of richness, of fertility, and of plenty. We
delight in them with all our senses – the warmth of the sun, the colors of
butterflies, the shapes and scents of flowers, the smell of damp soil, the
taste of fresh fruits, the sounds of rippling water and courting birds – or
simply enjoy the peace and quiet. Maybe, now and then, a fat slug slithers
through the idyll, and you imagine it chuckling to itself because it has
just feasted on a fresh young lettuce that you had lovingly tended –
something in paradise has to be annoying; otherwise, it would be boring.
Green is healthy and beneficial: people of all
cultures and nationalities prefer a natural landscape to a concrete urban
environment. Studies have shown that in hospitals a view of greenery from a
patient’s window encourages the healing process and reduces the dosage of
painkillers that would otherwise be required. Trials in Germany, Holland,
and the USA have demonstrated that Nature in the direct vicinity has a
positive effect on the contentment and health of those living and working
there. Gardening is all the more healthy, as you are moving around in fresh
air, light, and sun the whole day. And in the evening, you can reflect with
satisfaction on your day’s work – if only it wasn’t for the pesky old slugs.
So it’s not surprising that not only in the
countryside but also in cities gardening is increasingly in fashion. Young
and old; women, men, and children; those with or without employment; natives
and refugees work the land, form intercultural gardening associations,
cultivate green plots behind their houses, or tend some piece of communal
land. Some people also do it because they are fed up with the callous
production of food and the perverted globalized power of the agro-industrial
Our most important message is a hopeful one: climate
gardeners using terra preta can reduce the greenhouse effects on the earth’s
atmosphere. Climate farming – applied globally and supported by other
environmental measures – could even reverse them. If we, by means of climate
farming, were to raise the humus content of soil by ten percent within the
next fifty years, the carbon dioxide concentrations in the atmosphere could
potentially be reduced to preindustrial levels. Maybe, as the Australian
professor in earth and life sciences Tim Flannery stated in his open letter
on biochar, the use of biochar “represents a cornerstone of our future
What is Terra Preta?
Terra preta, which simply means “black earth” in
Portuguese, is also sometimes termed “miracle earth.” The latter is
certainly an exaggeration; after all, it is just a man-made fertile soil and
not a witch’s brew that you throw over your left shoulder at a full moon,
spit on the ground, and say abracadabra, and the world is saved.
Nevertheless, this ancient cultivation method used by the original
inhabitants of the Amazon region has the potential, according to a growing
community of international scientists, to tackle the global problems of
hunger, poverty, water shortage, and climate change simultaneously. Which
other methods can make such a claim?
According to current knowledge, the advantages of
terra preta techniques are immensely diverse – they encourage fertile soil,
healthy plants, and food; enable high and reliable yields within a small
area; relieve smallholders and gardeners from dependence on expensive
fertilizers, toxic pesticides, or genetic technology; transform waste
products into natural manure; solve problems of hygiene in slums and
sanitary systems; detox soils; transform steppes and poor soils into
agricultural land; and decisively lessen the effects of climate change.
What is Biochar?
How? The key component of terra preta is biochar,
charcoal made from organic residues and produced by means of climate-neutral
pyrolysis, exposure to heat in a low-oxygen environment. If you pyrolyze
organic wastes, up to fifty percent of the carbon, which plants have
extracted from the atmosphere in the form of carbon dioxide, is converted
into highly stable carbon, which can persist in soils for thousands of
years. When introduced to the soil, biochar, which is rich in pores, serves
as a fertile store of nutrients and water. How this actually happens is
explained in our book, Terra Preta: How the World’s Most Fertile Soil
Can Help Reverse Climate Change and Reduce World Hunger. Every hobby
gardener and every smallholder can produce their own version of terra preta;
if you have too little time, you can also order the necessary ingredients
via the Internet.
However, the details of what these methods can and
cannot achieve have by no means all been researched. A hurdle to its
large-scale application in agriculture, at least for the time being, is
cost-effective production of large amounts of biochar by modern pyrolysis
Conventional agricultural research institutes also
show little willingness to finance and participate in appropriate research
projects. This is hardly surprising, as there is the potential in black
earth techniques to replace, or at least reduce, agrochemistry and genetic
technology, the purveyors of which fund an increasing amount of research at
agricultural universities. Similar to decentralized renewable energy, which
in the long term threatens the existence of the central energy corporations,
the increasing spread of terra preta methods would ultimately cut into the
profits of agroindustrial players. We have to be prepared that at some
stage, those promoting biochar will feel their opposition, which may take
the form of excessively high safety regulations that the lobbyists of the
agro-industries may promote to increase barriers to entry in the
probability, we have passed not only “peak oil” — the point in time when the
maximum rate of oil extraction has been reached and after which easily
extractable oil amounts shrink and become increasingly expensive — but also
“peak soil” — the time when the amount of non-toxified fertile land is
decreasing and becoming ever more costly. Unlike climate issues, however,
the soil has, up to now, no political lobby, though its global state and the
impending climate catastrophe are closely linked.
As it is barely more than a decade since the
rediscovery of this ancient horticultural technique, the practical
horticultural experiences are unavoidably limited. There is still a huge
amount of details to research, such as which kinds of vegetables prefer
which kind of substrate and what are the ingredients of this substrate. The
more gardeners gather and share their experiences, the quicker knowledge
about terra preta will spread. Let yourself become infected by the terra
preta bug and talk about your experiences and observations with your
neighbors, or via social media, local journals, or the radio. You may also
join the new Biochar Journal and exchange your newly gained
knowledge with other climate gardeners and farmers.
How long the soil of our one and only planet remains
fertile is in our hands. With terra preta and the knowledge of how best to
use it in different scenarios, we can begin to create a modern garden
paradise worldwide where we can live better than we do now: a paradise 2.0.
* * *
Stockholm Biochar Project
The City of Stockholm, Sweden is in the process of
investing in pyrolysis plants to produce both biochar and renewable energy
from park and garden waste. The renewable energy will be turned into heat
that can be added to a local or a district heating network. The biochar will
be used within Stockholm in the public gardens. Some will also be given back
to the citizens to be used in their private gardens and allotments.
In Stockholm, trees are planted in structured soils.
Large rocks are compressed to create a stable structure, allowing the plant
roots to spread even in environments with heavy traffic. A well allows storm
water to enter the soil and gases to exit. The structured soils are made
from local leftover construction materials, but the soil that is added is
made from non-renewable materials such as peat, sand, and clay. Stockholm
started searching for a material that they could produce from local
resources to substitute the finite materials. They stumbled upon biochar,
and ever since 2009, biochar has been used in the city’s plant beds. The
improvement to the overall health of the trees has been remarkable.
Park and garden waste is collected from both the city
and the residents in Stockholm, but it is difficult to dispose of. City
managers and the energy company Fortum are focused on increasing renewable
energy production. The combination of an interest in biochar, the difficulty
in disposing of park and garden waste, and the goal of producing more
renewable energy launched the Stockholm Biochar Project.
The vision of the Stockholm Biochar Project is to
enable citizens and the city to tackle climate change while improving the
local environment by producing biochar and renewable energy from park and
garden waste. Using the biochar as a soil conditioner in public and private
plant beds, the project will create a vast carbon sink that will help reduce
overall greenhouse gas levels in the atmosphere.
* * *
Facts About Terra Preta
Terra preta is a dark, fertile soil first
made by the original inhabitants of the Amazon Basin at least
2,500 years ago.
Terra preta means “black earth” in
The key component of terra preta is
biochar — charcoal made from organic wastes (wood chips, crop
residue, food scraps, manure) exposed to heat in a low-oxygen
Anyone can make terra preta on the
smallest of garden plots, in urban or rural settings, private or
communal gardens, window boxes or square-foot gardens.
Climate gardening (aka farming with terra
preta and biochar) offers one of the few safe and proven
technologies to help draw down carbon levels in the atmosphere.
Biochar added to soils can not only help
improve food security by boosting yields, and increasing soil
fertility by increasing its capacity to retain water and
nutrients, but also can improve food safety by reducing
pathogens such as e-Coli.
Not all types of biochar are the same. If
buying biochar, it is best to buy certified biochar.
Using terra preta in both small and large
scale agriculture can contribute to the meeting of the UN’s
Sustainable Development Goal 2: End hunger, achieve food
security and improved nutrition and promote sustainable
Excerpted with permission
from the publisher: Terra Preta: How the World’s Most Fertile Soil Can
Help Reverse Climate Change and Reduce World Hunger, by Ute Scheub,
Haiko Pieplow, Hans-Peter Schmidt, & Kathleen Draper. 2016. Published by Greystone Books.