Thursday, November 25, 2010

BIO-CHAR, an easy way to make it.

Link to website of video about making bio-char.

Consists of two barrels- one fits inside the other with a few inches to spare all round. The inside barrel has no top and is filled with wood and turned upside down into the outside barrel and kindling is put between the barrels all the way to the top. The bottom of the outer barrel has holes around it for combustion- the top is closed and has a hole for the chimney which acts as a vacuum to draw up the heated gases. When done the whole thing is left to cool (The burning takes about 3 hours). The bio-char is then mixed 50-50 with good compost and watered so that the mixture is inoculated with the organisms from the compost- it is now ready to put on your garden at the rate of about 10% by weight.

Ken B


  1. Hello Ken,

    I find your use of biochar very interesting. I will be preparing mixtures of biochar with compost for different crops on my subsistence farm in Nicaragua. I have been producing and applying compost for several years now. I was wondering if you could make any suggestions regarding the amount of compost to be applied. I see that you are applying the 50-50 compost-biochar mix at a rate of 10% by weight. Is 10? the usual rate of compost application? Do you know of any application ranges used by organic gardeners and farmers for gardens, fruit trees, etc.?
    Thank you,

    Raymond Robitaille

  2. Hi Raymond!
    I have not gardened or farmed in your climate, but when I was in Abu Dhabi we used to apply about 6 inches of composted tomato haulms ( stalks and leaves) directly onto the sand to grow strawberries. This worked very well. In your case if your soil is is fairly manageable I would put about 4 inches on each year. I would also put charcoal soaked for 14 days in good compost tea and any ground rockdust you can get. For a start with nitrogen add alfalfa meal, kelp meal and maybe some lime to adjust pH. This should build up your soil so that no other fertilizers will be needed. For your fruit trees add fish meal or more kelp meal at least 6 weeks before harvest. Best of luck!
    Ken Bourne