The Permaculture Principle Observe and Interact gives me a great excuse to bring out the ‘mad proffessor that seems to direct much of what I do. I love to read about a new technique, or in the case of this post an old technique, and then ‘play with it’. Yesterday I did just that with an experiment in Soil Fertility and burning.
Biochar, Burning Wood and Terra Preta
I have done a lot of reading on Traditional Agricultural practises. One technique that is or has been used all over the world is the burning of wood prior to planting crops. This is normally associated with swidden (slash and burn) agriculture. We have an image of indigenous people destroying forest to grow crops, depleting the soil of nutrients, then moving on. The reality is that this is a sophisticated way of farming that uses a period of building soil fertility under trees, and then using that fertiltiy to grow crops. In many ways it resembles the old English Two field rotation. One year crop, one year fallow. In fact it isn’t that long since the burning of stubble in grain fields was made illegal here. What I’ve also read is that in India the wood was slow burned, or charred, rather than burnt fiercely. This throws up some interesting possibilities to observe and interact .