Biochar in horticulture and agriculture

by Michael Smith (Veshengro)

Even when it comes to gardening (and agriculture) old is new and often this old is made out to be absolutely new and revolutionary.

Biochar is made out to one of those potentially revolutionary way of enhancing soil fertility but it is a gardening technique that was used by tribes people in the central Amazon basin at least 1500 years ago and this was discovered by archaeologists several years ago.

The only thing that is “new” about it is its potential to revolutionize agriculture around the globe as well as for removing greenhouse gases from the atmosphere.

Biochar is charcoal derived from tree bark and bone. It was mixed with the soil to increase fertility. According to an article in Science News, scientists report that “…charcoal derived from heated biomass has an unprecedented ability to improve the fertility of soil -- one that surpasses compost, animal manure, and other well-known soil conditioners.”

Biochar is a two for one deal it seems. Its high nutrient- and water-holding capabilities increase soil fertility and porous structure acts as a sink for greenhouse gases trapping them in the soil.

Unlike compost, manure and other organic forms of soil enrichment that decompose relatively quickly, biochar is fairly stable and remains in the soil for hundreds of years. As such its use could have a major impact on agriculture, particularly in parts of the world where chemical fertilizers, intense cultivation, and drought have significantly decreased soil fertility.

It is, however, often claimed that biochar has to be made in a different way to ordinary charcoal as you use in your barbecue but the truth is a much stranger one, namely that it was, when used by the Amazonian tribes who create the “black earth” areas in the Amazon Basin, simply charcoal and the same is true for the gardeners in England in the 18th and 19th century who also knew that charcoal was doing the soil good.

I find it always amazing and funny when the old ideas are being revamped as something new and revolutionary and I cannot wait to see reuse of glass jars and other things to be revamped in this way too as if it never happened before ever.

As far as biochar is concerned the truth is, as already said, that (1) it is a rather ancient system of soil improvement and enhancement and (2) that any type of good charcoal can be used for this. That means that you do not have to throw you used BBQ charcoal intoo the trash. Instead throw it into the compost or, better still, break it up into small lumps and work it into your garden soil.

Having said that I suggest that you do not use the so-called charcoal briquettes for this as they are made from sawdust and neither I nor you will have any idea how they were made and what they really contain. Personally I would not use them on a BBQ at all and would only use locally produced lump-wood charcoal from sustainable sources.

While my advice my upset the makers and vendors of “special” biochar, at home and abroad, the fact is that the gardeners of old did not have any specially produced biochar to add to their soil; they used simple lump-wood charcoal.

© 2013