Bio Char

Black Gold, some call it…and it is black, very black! No I’m not talking about crude oil, this a black gold that can be produced from someone else’s refuse!

We first heard about bio char at last year’s ECHO Asia Conference. Initially we were skeptical, but after learning the theory behind it, bio char really makes sense. What is bio char…it is basically charcoal; it is in fact one-in-the-same, carbon. So what is the difference? Bio char is simply the term to use for carbon that is used as a soil amendment or conditioner and charcoal is used to cook steak.

The theory behind bio char is that it works much like a sponge. It will hold on to nutrients and release them to plants as they need it. It also provides homes for microorganisms because of its porous structure. In this tropical climate bio char helps the soil retain its nutrients as it prevents nitrogen and other elements from washing from soils during torrential monsoon storms. It also helps mitigate soil compaction.

Bio char is very simple to produce. Take junk wood, bamboo, twigs, leaves, coconut husks, rice hulls; (anything that is waste, has carbon and burns) burn it in the presence of very little oxygen and bio char results. In Laos, rice hulls are simply thrown away or burnt into ashes. This free resource can easily be used to improve the soil for free.

The following pictures show the process of creating bio char.

First Start a Fire

Cover the Fire With a Sweet Metal Tube

Once Drafting Well...Add Rice Hulls

Stand Back and Admire Work

Looking down the Stack

Make Sure the Wind is Blowing the Right Way

Once Black...Remove Stack

Water to Cool

(NOTICE: The stylish face mask isn't just to look awesome, it is to prevent breathing silica dust which is contained in rice hulls. This can cause silicosis, which can lead to a lung transplant if enough is breathed over time.)

These batches of bio char will go into making potting mix for the moringa seedlings we are growing for the office. We made the mistake of making bio char and applying it the next day. Remember that bio char is like a sponge? It will suck up nutrients in the surrounding soil depriving the plant of much needed nutrition. Once the bio char is full it will then release this to the plant. It is best to ‘charge’ the bio char before mixing with the soil. It can be mixed with compost and aged or soaked in a strong manure tea. Even as little as 72 hours of soaking can be enough to charge the bio char.

Does your soil need some char?