Thursday, 1 December 2011

More interest in Biochar and Terra Preta?

It is surprising that the "Allotment and Leisure Gardener" (the NSALG magazine) has an article about biochar in it.  I knew that the Japanese have been using biochar for hundreds of years and that they thought that it had a beneficial effect on plant growth but it does not seem to have been accepted by mainstream gardening until quite recently.

I have been experimenting with inoculated, lump, barbecue charcoal  (i.e. marinaded in comfrey Symphytum x uplandicum; nettle Urtica dioica; sweet cicely Myrrhis odorata and worm bin liquid manure mix.) mixing  mychorrhizal fungi to the dried crushed inoculated charcoal before adding to planting holes and seed drills.
Charcoal marinading in the rich black comfrey liquid mix
Sweet cicely being added to the comfrey bins. It will rot down to
a rich black liquid manure which can be tapped off.
Nettles and comfrey are also added to the bins to rot down
and give a rich black humus rich liquid.

I have convinced myself that this is an effective soil amendment and that plants seem to respond remarkably well to the charcoal especially if growing on poorish soil.

As  German and American research has indicated, the biochar black earths or Terra preta of the Amazonian rain forests are incredibly fertile allowing crops to be grown for millennia while elsewhere in the rainforests crops soon deplete the soil of nutrients.

Experiments with biochar amendments to soil by modern scientists have not shown remarkable differences in the growth of plants because it needs to be inoculated with nutrients.  It does not seem that the Takesumi bamboo charcoal is inoculated with anything.  Whether the "Takesumi"  bamboo biochar is more effective than lump barbecue charcoal remains to be seen.  I would rather use charcoal that has been inoculated and used in conjunction with mychorrhizal fungi because this is what I have found to be effective.  "Carbon Gold" seems to have the same kinds of ingredients that I have been experimenting with so I would expect this to have more of an effect than the "Takesumi".

There is an offer in the NSALG magazine so I will look at the site and see if it is worth getting some and experimenting with it.

Well, as it is 70% off and it is worth having a go with, I am going to get some to see if it is more effective than using the lump charcoal.

There is thought that there may be differences in properties between woods that are used; the temperature it is charred at and the fineness or coarseness of the final crushed charcoal.  Indeed there may be a difference in the properties caused by the materials charred.  Any organic matter can be used to make biochar.  Crop waste such as the stems of sweet corn Zea mays is being used in the USA.  So finding the most efficacious biochar is an ongoing challenge.

My very limited experiments have to be restricted by the time I can devote and the amount of money that I can throw at it.  That is why I am using barbecue charcoal and crushing it with a bull hammer after inoculation.

It may not be the most effective biochar to add to the soil but it works for me.

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