This is an excellent description of the action of biochar from Dave Yarrow who like myself is now a long time enthusiast. It provides a concise view of the various mechanisms at work and helps the reader to grasp the magnitude to the protocol. It is one thing to understand it all as an example of a solid crystalline acid as a thought experiment but much better to follow a coherent and organic description such as this.
You should leave this fully understanding biochar and perhaps a vigorous supporter.
Biochar will revolutionize all agriculture and end the present abusive p[protocols that are simply not good enough. Biochar is clearly good enough because it will end the need for imported fertilizers. I know this because it has worked in the Amazon rainforest for centuries and is still working and that is the worst case scenario.
overall, this is an excellent, clear, well-organized interview and insight.
for the most part, hats off to laurens for clarity of articulation.
but unfortunatey, lauren garbled one critical understanding:
"is biochar a fertilizer?"
here is the Q&A in the interview:
Mongabay: Does biochar replace the need for fertilizers?
Laurens Rademakers: In fact, it doesn't. Biochar is not really a fertilizer in the strict sense of the word. It is, however, a soil (structuring) element that helps maintain the natural fertility of the soil, or reduces a soil's depletion rate. In this sense, biochar can replace the need for some fertilizer. Ours and others' field trials demonstrate that biochar often functions as effectively as an organic or an inorganic fertilizer. But in practice, it is always good to mix biochar with organic fertilizers.
Laurens Rademakers: In fact, it doesn't. Biochar is not really a fertilizer in the strict sense of the word. It is, however, a soil (structuring) element that helps maintain the natural fertility of the soil, or reduces a soil's depletion rate. In this sense, biochar can replace the need for some fertilizer. Ours and others' field trials demonstrate that biochar often functions as effectively as an organic or an inorganic fertilizer. But in practice, it is always good to mix biochar with organic fertilizers.
biochar is NOT a fertilizer -- definitely NOT a nutrient source. it doesn't weather. nothing eats it. no organism can get any energy out of those carbon-carbon bonds. yes, a few minerals are embedded among the carbon atoms, but they are hard to extract and eat, packaged in all that carbon mesh. at best, some bacteria can consume any PAHs and other hydrocarbon residues remaining from the fires of pyrolysis. but while the carbon rings and chains of those oily tars and resins are food for a few simple life forms, the carbon-carbon bonds left in char are inedible and indigestible. try eating some yourself. it's harmless, at the least -- and largely tasteless -- like eating completely burned food -- plant food, not meat.
lauren answers correctly: "it is a soil structuring element." yes, at the very least, charcoal is a structural material that is used to build and organize an open, porous, expanded arrangement out of tightly packed soil particles. charcoal itself is mostly empty space -- it's hollow inside -- which is why it is so light, fluffy and easily windblown. being full of holes, charcoal naturally causes soil to lighten up and become less dense.
but more precisely and functionally, the carbon in char is in the form of absolutely huge molecules -- hundreds, if not thousands, of carbon atoms interlinked in complex mega-molecules -- tinker toys gone wild -- massive carbon mesh matrix. these huge complex carbon mega-molecules that form charcoal's empty cellular lattice frameworks are used to bundle and aggregate tightly packed soil particles into even larger supra-structures. this physical rearrangement and organization at various scales creates open spaces in the soil, softer tilth, making soil easier to work, better able to breathe, better able to absorb and release water. this physical change due to char is a great relief to heavy clays such as african and amazon rainforest soils, but also works a similar benefit to sandy soils.
further, plants are mostly water, and their physical structure is mostly microscopic plumbing -- pipes, tubes and ducts to move water around. charcoal's microscopic pores are teeny tiny sponges to soak up and hold water in soil, conserving and managing the soil's moisture supply. the soil can soak up and hold more water when it gets wet, it can stay wet longer, and will slowly release water back to the soil -- and thus to plants and other soil biology. since water is the first ingredient required to build a living cell, this water management is a great service to all soil life -- and the farmer.
but better yet, charcoal has electric properties -- partly from embedded minerals, but also from cracks, fractures, folds, warps, rings, and other anomalies of the complex carbon matrix. charcoal has hundreds, if not thousands, of electrically charged sites which can attract and hold other atoms, without actually forming inter-atom bonds. and charcoal's vast internal microscopic pores means it has hundreds, if not thousands, of times more internal than external surfaces to attract and hold other ions -- not only cations (+), but also anions (-) such as nitrogen, phosphorus, sulfur, and boron. technically, this electric attraction is called "ADsorption".
thus, charcoal dramatically increase soil's cation exchange capacity (CEC) -- the number of positively charged ions it can suck out of solution and hold loosely in its micropore matrix. but biochar also has positive charge sites to attract negatively charged ions (anions) such as N, P and S. so properly made and activated charcoal also has a huge anion exchange capacity (AEC).
so, biochar can attract and hold onto both kinds of nutrient ions out of the soil solution, reducing leaching into groundwater, and outgasing into atmosphere. further, it makes these loosely-held nutrients bioavailable to microbes and plant roots in a complex economy of exchange -- the multi-layered symbiosis of the soil food web. the charcoal isn't itself a nutrient, nor does if somehow manufacture nutrients. rather, the charcoal is a handy place to store nutrients and keep them bioavailable in the root zone.
anyway, just a glimpse into the numerous useful services supplied by char in soil -- even though it's not a fertilizer or a nutrient. and, of course, char doesn't do this a year of two, and then decay. it is documented to be stable in soil for centuries -- at least 1600 years. a rather long-term lease for the generations of micro-organisms that are available to manage your soil fertility for you -- as they have done for geological millennia.
but, of course, all things biological and geological have their limits, char in soil seems saturated at 10%. beyond that, it begins to replace oher essential ingredients in soil.
for a green & peaceful planet,
David Yarrow
Turtle EyeLand Sanctuary
802-778-0663
www.carbon-negative.us
www.dyarrow.org
www.ancientforests.us
www.nutrient-dense.info
www.farmandfood.org
www.SeaAgri.com
www.OnondagaVesica.info
www.TurtleEyeland.org
www.carbon-negative.us
www.dyarrow.org
www.ancientforests.us
www.nutrient-dense.info
www.farmandfood.org
www.SeaAgri.com
www.OnondagaVesica.info
www.TurtleEyeland.org