2nd December 2024

The Biochar story

biochar up close

Getting into biochar

Much as been published on this subject in recent years, but there is still much more research to be done and work to be scaled up. My interest in this subject stretches back ten years or more now when i first read The Biochar Revolution by Albert Bates, and I have been conducting my own experiments ever since, in both its manufacture and use.

soil food web

In about 5 minutes Albert Bates gives a concise and illuminating introduction to biochar, its history and huge potential.

This 20 minute video, above is a good primer for anyone new to the subject. There is a lot to unpack, but this is a good overview and interesting to have the input from James Lovelock on this as well as more from Albert Bates, who first introduced me to the subject.

Soil life, fungi

Another concept we need to be comfortable with is that of micorrhizae, the threadlike fungi that grow in harmony with the roots of 80-90% of all plants. We need to fully understand that we are working with this complex web of soil life when we are engaged in any form of cultivation. All those traditional farming techniques like digging, ploughing and fertilizing can actually work against the life inthe soil and in the longer term lead to the degradation of soils.

The key to understanding soil

The key is to understand that soil is alive, it is a complex matrix of many different organisms that in many way support each other. The use of biochar as a soil ammendment may do many things but essentially the key is that it is adding habitat for microbes and also increasing the porousity of the soil, increasing its ability to abosrb water and also maintain air spaces. These air spaces are critical as most of the beneficial soil life is alo aerobic, just like ourselves. The key that unlocks the soil food web is understanding there needs to be at least 4 trophic levels of activity within the soil for nutrients to circulate and become available to the plants. onc we have a healthy and alive soil then our plants will flourish and will not need external inputs.

Many ways to make biochar

In a pit. The easiest way to make it is in a pit, excavated to be shaped a bit like a wok, here is Albert Bates a pioneer in this area doing a regular bamboo biochar burn at his home in Tennesee. This illustrates perhaps the most simple yet still effective approach.

In a cone shaped kiln 

This allows more control over the whole process, especially when quenching with water at the end, I see how something like this could easily be integrated into a regular farming cycle. Here in this example it looks like we have vine prunings to burn, and htese are approximately the same size and shape making them an ideal feedstock for this process.

Brick built biochar kiln, Uganda

Talent agro forestry farm produce bamboo as one of thier principle yields, they propagate many 100’s of plants each year and this also entails generating many off cuts and over the years Andrew Kalema has developed a perfect system to meet his own needs on the farm. All the bamboo waste is thrown into the kiln and  when ready the chamber is sealed by placing iron sheets over the kiln to form a roof and this is weighted down with soil, making a seal and closing the roof.  A fire is lit inside and the resulting controlled burn produces a decent crop of biochar and also cooks and sterlizes the soil. The soil is needed as a potting mixture for the many plants to be propagated and exported so a disease free soil is essential. Goat manure is composted and then mixed with both the crushed biochar and the sterile soil, providing a perfect disease free growing medium for farm use. You can see this being mixed up in the third image.

Links and other resources

UK Biochar Research Centre
Part of Edinburgh University

https://biochar.co.uk/
Our purpose is to build a community of biochar enthusiasts, advocates, back garden charmasters, gardeners, growers, farmers and businesses.

Biochar TED Talk
Entrepreneur Axel Reinaud outlines three ways to make this material more accessible to farmers — so that our food system, energy grid and the climate can all reap the benefits.

Digital Tour of Stockholm Biochar Facility
Stockholm’s biochar project is reducing carbon emissions and improving soil quality by taking plant waste collected from residents and converting it into biochar

Overview of biochar in carbon markets
Kathleen Draper, Chairwoman of the International Biochar Institute, discusses where biochar stands today in relation to Carbon Markets, and where it might go in the near future.