Ivan Weiss wrote:
Isaac Hill wrote:Up here in the northern part of America we have the capability to make pretty good humus without using charcoal.
Well I'm "up here in the northern part of America," and whereas my entire five acres, sitting on glacial till, is mostly gravel, and whereas it percs like a sieve, and whereas it rains like hell around here, and whereas it dries out altogether in the summer months, therefore I conclude that I need to add all the water-holding capacity to my soil that it can get -- to hold water in the dry months and prevent nutrient leaching in the wet months.
And whereas I have enough wood waste available to both practice hugelkultur AND burn biochar, and thereby manufacture terra preta using plenty of manure and other elements added to the biochar, and whereas that manufactures pretty good humus AND pretty good terra preta, then that's what I'll jolly well do.
See, everybody's soil is different, everybody's situation is different, and everybody's design is different, and these kind of blanket generalizations aren't really very helpful.
Hey there,
it seems you are doing some interesting work "up in the north".
What I did in northern Germany and now in Haiti is mixing the techniques and, therewith, the ingredients of the pile.
As biochar itself contains practically no nutrients for plant growth, but it has some significant advantages that improve soil quality, I build the raised beds up as follows:
- dig out a trench of about 20 cm and fill it with woody material to pile up to about 30 cm.
- add ground biochar mixed with soil to your pile, compress and water it
- add green manure as the next layer and add some ground biochar to it
- add richer organic material like kitchen waste, manure etc. with some green manure, continuously adding ground biochar to it.
- cover it all with a thin layer of biochar and about 10 cm of soil
The biochar in the pile soaks up released nutrients from the (mostly anaerobically) decomposing organic matter and makes the available for the plants. Plus it provides all the other advantages you know of (a home for microorganisms, water storage capacity, supporting funghi, etc.) and it stays in the soil for hundreds of years. This leads to extraordinary yields from beginning and to the development of a Terra Preta-like substrate.
