Building soil with Terra Preta – Practical workshop

2.11.2017 - 5.11.2017

ZEGG, Bad Belzig

Orientewith Achim Ecker, Brian Holden and Kerstin Neumann

How can we humans become aware again
of the paradise called "Earth"
and find our place within?
Love the earth and leave it as it is; and quit destroying it.


In this hands on workshop we share and present, what we have discovered in many years of theoretical search and 5 years of practical experimentation at ZEGG.

Terra Preta (black earth in Portugese) is the name for permanently fertile black soils in the Amazon region. Only in the 1990s it was discovered that they were manmade. They contain charcoal, our „inner valuables“ and organic waste, and are very useful.
In this workshop we want to share current knowledge, we will produce biochar and show the whole process of producing Terra Preta substrate.

Since 2013 we experiment at ZEGG with soil improvement by terra preta, and we are more than surprised by the good results.

Leaf-mulchHow everything started

2011 the town of Belzig wanted to connect us to the local sewage plant after 20 years in which we had cleaned our waste water ourselfs as an ecological model project.
Our goal was to even lower the Nitrogen and Phosphate levels in our cleaned waste water to become even better than the municipal plant.

80 % of the nitrogen and 50 % of the phosphate in wastewater come from our urine!

At the same time we noticed that nitrogen and phosphate (and potassium) are important nutrients for plants. For artificial fertilizer nitrogen is fixed from the atmosphere by an energy-intensive process (Haber-Bosch-Process), that was originally invented to produce dynamite. Phosphate mines are becoming scarce on the planet, and they are polluted by cadmium.

So we understood that we could reach at least two aims in one action:

TerrapretaLocal ressource management

Get a load off the sewage and gain valuable resources.

It seems nonsense to get rid off valuables when peeing on a water closet in drinking water, wash those valuables down the drain, get rid of them in a good purification plant, and wash the rest down the rivers where they pollute the water.

Plants need what we discharge off, including our bacteria (lactic acid bacteria), and we need what they give to us. It is meant to be – how else could it be? - a perfect cycle.

Terra preta seems to be one of the best ways to built a stabile fertile and living soil. And it is able to store moisture and keep soil organisms alive during droughts. In times of climate change terra preta can store carbon in the soil for at least 1000 years.

In the workshop we will transfer knowledge and do the practical steps

  • production of charcoal by clean combustion in a hole in the ground or a kontiki oven

  • charging of the biochar with nutrients and microorganisms

  • production of bokashi (lactic acid fermentation) of kitchen waste

  • production of effective microorganisms

  • building of compost heaps

  • working the ready substrate into the soil

In the end of the workshop the participants will be able to use and produce terra preta substrates.

Ingredients of terra preta

biochar 15-20 %, urine, clay, leaf compost, bokashi (kitchen waste fermented through lactic acid bacteria in barrels), EM (effective microorganisms), pumice, gras clippings, … and what else we have here.

The first results at ZEGG are very good! Even though we do by far not have 15% charged biochar in the soil anywhere. Plants develop well, healthy, fruits are tasty and keep in store. And our Nitrogen and Phosphate levels in our cleaned waste water have improved!

Fee: € 215
Organic food and basic lodging: € 147

application