Not more on terra preta Tone!!!!

I was thinking, if the terra preta is reliant on Amazonian or rain forest species of fungi and earth worm, would we be able to replicate this kind of soil in our temperate climate?

Will we just be a poor copy of the soil in the rain forests or is there a possibility that this soil is replicable. We would have to substitute fungi and earthworm for those that can survive the temperate climate.

If we can then this is a remarkable resource that can be carried around the world. If not then whoever is attempting to make terra preta – and the Germans seem to be ahead of the pack in this department – is doomed to failure.

I think that increasing fertility of soil with the use of charcoal may be as far as we can go…

Here is a good reminisce. My allotment on 2nd February 1982 just after I had taken it over. I had cleared and dug almost half of the allotment.  You can see I am skim digging.  The weeds that I have skimmed off were buried in the trench.  I took out a spit deep of subsoil, left it on the trackway and put in the weeds.  I took out a spit deep of subsoil further on in the trench and covered the weeds leaving a hole which was filled with weeds.  This is carried on until the end of the trench when I fetched the subsoil on the trackway and covered the weeds at the end of the trench.

February 1982                                                                                                                                                 From a similar viewpoint February 2010

The view from the other end.

And the soil in February 1982.  This is a typical stagnogley soil with clay enriched subsoil.  This type of soil has reduced Iron II compounds because waterlogged soils do not let air flow through them very well.  Iron II (Fe²⁺) compounds are grey or bluey grey in colour.  As this was a less permeable heavy clay and waterlogged soil,  it is grey although there is some oxidation where air has managed to get into the soil and this is where it has a mottled reddish brown colour.  This soil profile is called a Bg horizon.

Needless to say that it is not like this now.  As you can see, the bluey grey Iron II soil has been replaced by a more homogenous brown colour soil and there is obvious signs of organic matter even at the third spit - 90cm level.  With oxygen from the air the iron compounds give the soil a brown colour.  So soils that are free draining, open and porous tend to be redish brown. I think that I have won the water logging battle in this area of the allotment.

Also known as Amazonian Dark Earths. After watching The secrets of El Dorado on http://topdocumentaryfilms.com/secret-el-dorado,  I now have a new project.  I want to begin to work on developing ADE on my allotment.  It is not just down to charcoal though.  There is a complex interaction between charcoal, nutrients, organic matter and mychorrihzal fungi. I have to thank Uriel 13 for putting me onto this.  His suggestion is that it is not mychorrhizal fungi but yeast that is important in producing this kind of soil.  He is suggesting sour dough yeast.

Whether it is mychorrhizal fungi or not, yeast is another avenue to follow.  I don’t know where to get sour dough yeast from, however my local garden centre sells mychorrhizal fung.
As to producing my own charcoal, I think that I am going to experiment with various commercial charcoals first and I am going to mix them with blood fish and bone in a solution of undiluted comfrey liquid to start with.  I am  going to dry the resulting mixture to produce a powder because this will be easier to mix evenly though the top soil.

I have a particularly infertile area of soil on the allotment, (If you want to know why look on my allotment blog under benzo (a) pyrene).  I am going to set up a proper comparison plot with several sections.  Another problem is what proportions should be used to make the most efficient soil additive.  I am going on the assumption that it is the adsorbsion of nutrient into the charcoal that is the inportant factor.  Also the provision of micro habitats for bacteria and fungi may be important.  The provision of very small crevices within the charcoal may prevent predation by other microorganisms.   As yeasts can be very small, as other fungi, they may find a sanctuary within the charcoals labyrinth. The trial plots will be:

• One with charcoal on its own,one with blood fish and bone on its own,
• one with comfrey on its own,
• one with blood fish and bone and comfrey
• one with comfrey and charcoal
• and finally one with all.
• I would like to check out fungi as well, however that might make it complicated :-)).

I will  grow peas on the different plots.  They may confuse the issue because they have nitrogen fixing bacteria in their roots, however it will be the same for all plots and that is my rotation so get over it…
Trying to think of ways that the soil remake itself may not be too problematic.  The increase in microorganisms within such a fertile soil may cause it, if they are produced in enough numbers.  Any nutrient from decomposition seems to be adsorped by the charcoal and this also gives soil fungi a really good habitat.  Together with an increase in the population of roots and leaf litter from above ground you are very likely to get an increase in volume of soil.

If the film’s suggestion is correct and the plots are set up like the ones reported then I should get enough information to convince myself of the value of this method of soil management.  I doubt very much whether it is properly scientific, however it is good fun.

You know I  really do have a great respect for the agricultural and horticultural knowledge of the ancient South  American  indian civilizations.    I think that  the jury is out as to whether the terra preta soils were deliberately produced or just resulted from  humans throwing out their waste materials.  I would  like to think that they were making these soils consciously.

There seems to be some  advantage to  adding composted activated charcoal to the soil.  Looking at the  properties  of activated charcoal, it  seems to be able to adsorb large amounts of organic compounds and this  characteristic seems to allow it  to  contribute to the fertility of the soil - for  hundreds if not thousands of years.  This interests me because apart from contributing  to the fertility of my allotment it would also help to sequester carbon in the soil.

Now previously in these blogs I have berated people for  lighting smoky fires  and  allowing  the  smoke to  blow over my allotment.   However, do I have to modify my opinion of fires now?  I don’t think  so.   Charcoal burning  may well be a good way of increasing  and  sustaining  the fertility of the soil but not near my allotment.

I am told there are charcoal producers that prevent noxious fumes from  venting  to the atmosphere.   I  am dubious… However, in the spirit of scientific or at the least horticultural exploration I will indeed try composting some activated charcoal  and see  if  it adds to the fertility  of the allotment when I dig it in.  Maybe  I  will also  put some under the peas because it  seems to help with the nitrogen fixing bacteria.

Snow  has gone now and I am looking forward to  digging on the allotment again.  I will continue with my Montezuma method because I think that this will also help to sequester carbon in the soil.

Charcoal and compost I can cope with.   I doubt very much if I will make my own especially if it involves burning fish and  bones.  How about mixing it with blood fish  and bone?  Worth thinking  about Tone…