Biochar

Making bio-char using the open pit method

Earlier on in Autumn we made some biochar from some of the thinnings from our Agroforestry blocks.  Biochar is a fantastic material – it sweetens acid soils, increases the water holding capacity of the soil, improves microbial activity and helps soil to share nutrients with plants.  And it does all of this for hundreds, maybe thousands of years.  It is very easy to make and once inoculated with a compost tea is ready to use – gardens, horticulture, pastures or anywhere really where you want to improve your soil. We use the ‘'open pit’' method to make our biochar which simply utilises a cone shaped hole or pit in the ground (in our case where a tree had fallen over in high winds and pulled out a big plug of soil - ideal for our purpose). Simply start the fire in the bottom of the pit and add thin layers of wood - trying to minimise the amount of smoke. Keep adding layers until you reach the top of the hole - and then rapidly quench the entire pit with water. Make sure it is properly out! Once cooled crush it to a fine powder (crushing by hand can be a bit tedious; a relatively simple way is to fill a bulka bag or similar with the char and then run a vehicle back and forwards across it). If used directly it will tend to pull nutrients and micro-organisms out of the soil, so much better to inoculate before using.