[Terrapreta] Backyard Biochar

[Richard Haard]

Some interesting points to discuss, we are all interested in whatever  
observations backyard gardening with charcoal will produce.

First of all Steiners research in Brazil used chicken manure as one  
treatment in his sets of combinations with charcoal. It is a very  
rich additive and in his research came out on top of the results for  
a simple logical reason. Charred chicken manure (or dairy solids) is  
of course somewhat different but is worthy of comparison in charcoal  
in agriculture research because disposal of manure from these intense  
industrial agriculture farms has serious environmental issues. When  
it is spread on to the surrounding land these farms with a few  
hundred acres and perhaps 2000 milking cows are having surface and  
ground water pollution problems and phosphorus accumulation in the  
soils to toxic levels.

When these factory farms are in the desert the manure/liquids can be  
treated by evaporation and exported as dried manure. In places where  
climate is wet this cannot be done and as an alternative to very  
expensive anaerobic digesters a pyrolyser can make a product that can  
be exported to other places where these nutrient rich additives have  
a use elsewhere.

The point of using char or charcoal in soil is not that it is a  
nutrient bearing additive but is if there is a synergism in the soil  
that makes the available nutrients more effective and to last longer  
in the soil. In Steiners research he followed the productivity of  
field plots for years of multiple cropping in the moist tropics  
without further addition of supplements. In the temperate zone this  
kind of research also needs to be done. The paper is listed in the  
files section is you have not already looked at his work.

I am planning to use either a charred chicken or dairy solids  
product, (whichever John decides to supply to me), as comparison to  
the charcoal treatment sets in my research this spring. It will be  
important to compare it to other fertilizer treatments and to wood  
charcoal and their combinations. After all charred manure is a new  
product on the market and consumers need to understand if this is  
about the same as air dried manure or if charred manure has some  
other properties that make it superior.

Steiners study calculated the dose on the basis of carbon content  
which gave the soil a very heavy dose of nutrient in the chicken  
manure set. I am planning to set my study up on the basis of the  
fertilizer treatment levels we normally use at the farm and to  
compare this in combinations with quite heavy treatments with wood  
charcoal, most likely 30% by volume for this first test.

A larger question here:

Is if you go to the trouble to compare your char to usual practices  
how do you determine if you have had a positive effect??

The Georgia, Master Gardeners project posted in files section  
mentioned a 9 % increase in yield of market tomatoes. Other studies I  
have reviewed by Asian researchers also emphasized the physical  
features of the plant. Such as leaf, plant size, crop yield, vigor,  
and so forth. During our usual farming we find variation larger than  
this 9 % above between planting blocks of the same species. Soil and  
foliar nutrient levels are worthwhile data also.

The second even bigger question here:

Is whether this test plot will bring in a continued high yield with  
subsequent cropping without added fertilizer compared to the parallel  
plots also unfertilized and to plots with your normal fertility  
additives. ??


Best
Rich Haard

On Apr 7, 2007, at 1:20 AM, AJH wrote:

> Tom Miles wrote:
>
>> The example of Peter's chicken litter tests is not a very good  
>> one. Chicken
>> litter is an excellent fertilizer.
>
> Are you saying that this example of charring chicken litter is not a
> good example of how the biochar adds fertility to a soil because the
> chicken litter was already a good fertiliser and could have been used
> neat?
>
>> chicken litter. When you pyrolyze litter most of the nutrients  
>> like abundant
>> potassium and phosphorous stay with the char so it will make the  
>> charcoal
>> look very good.
>
> To my mind this is why a low temperature pyrolysis is a potentially
> good treatment for this waste.