"We must achieve the character and acquire the skills to live much poorer than we do. We must waste less. We must do more for ourselves and for each other. It is either that or continue merely to think and talk about changes that we are inviting catastrophe to make. The great obstacle is simply this: the conviction that we cannot change because we are dependant on what is wrong. But that is the addict's excuse, and we know that it will not do."
—Wendell Berry

Saturday, 21 April 2012

Terra Preta

It is said that any technology sufficiently advanced is indistinguishable from magic to those who do not understand it.
There is an ancient magic trick used by the Indians of the Amazon. Black earth known as “Terra Preta”. In essence, nutrients in the soil will bond to charcoal and retain the soils fertility. Even in the wet tropics of the Amazon there are garden beds over two thousand years old that are good enough to plough and grow in today. Now this, I contend, is an ancient piece of technology that smacks of sheer bloody brilliance! And we, with all of our soul destroying civilizations, have not until just recently really understood this. Therefore magic.

Over winter I burned tonnes of cuttings from the old lychee orchard to make charcoal. Hard but satisfying work that smacks of this wizardry. You light a big fire in a deep pit and when it is hot enough, cover it and bury well. Working by the light and heat of the fire in the darkness and cold of a winter night was a surreal experience. There is a particular scent of burning charcoal that is unlike any wood fire, it stays with you. Unearth this in a couple of days when cool enough, and there is a rich haul of charcoal. Not ash you understand but hard, grey charcoal that will musically clink and ring when shovelled. And how we shovelled, but it was worth it and will have a lasting effect on that garden where it has been spread. I will burn charcoal again next winter but after that never more. There will then be enough buried in the garden that it will change the soil for hundreds of years to come. Fertility that our grandchildren can use.
The soil has become a thing of life and richness. Originally red and leached by the rains of the wet season, it has become darker and has a rich humus-like scent. In winter I dug in huge grey loads of charcoal, spread a tonne of wet straw and poured black peaty compost into the soil by the barrow load. And then soil changed as if by some magic trick. In a matter of days there was a different scent and feel. Everything I have planted has a darker and richer colour this year and grows so much faster. There is a saying that you become part of the soil as it becomes part of you. I understand that now. I have put much of myself into this garden and it feeds us, body and soul, in return.


  1. Ulf, I am wondering why you say you are just doing the "terra pretta" treatment for a couple of seasons while I understand the traditional Amazons seem to do it most years in the same area of their gardens.
    In recent months I have had a couple of fires going to boil water and as soon as I was finished I was able to pour water over the remains of the fires and both times ended up with a bucket or so of "clinky" sounding charcoal. It is in the interow area of the garden so hope it is doing good for the vegies.
    We also live in an area where we rely on indoor winter fires for heating. We keep over burning our fire box day after day and end up with just white ash. I know others in this area who insist on emptying out their fire boxes daily, and in so doing throw out a lot of charcoal and they just dump it, throwing away a valuable garden resource.