Science Forums 2

[Michaelangelica]

TP in NZ
Public Address | Southerly

Alfred Harris:

In Waimea, for example -- where there's hundreds of acres of what they call 'Maori soils' -- the experimental work was done on that site, and it was very clear that charcoal was mixed far further into the soil than would be expected simply from just the burning of the site.

Interviewer:

It's fascinating that two cultures so far apart should both discover the effects of charcoal in terms of agriculture. At a scientific level, how the does charcoal actually improve soil fertility?
. . .
Alfred Harris:

Beyond a shadow of doubt -- that's absolutely right. And what's been demonstrated (by the Japanese, primarily) is that the addition of charcoal can reduce the amount of fertilizer that you need to put in for the same fertility effect. And they're quite substantial differences... you're talking 20, 30, 40 per cent.

Interviewer:

Right, which begs the question -- why isn't this already standard practice for agriculturalists?

Alfred Harris:

Again, that's a really good question. See what they say all the way through, is that: "Hey, really great that it works -- but the cost of producing the charcoal, and actually incorporating it in the soil means that it's not going to work economically". And they're absolutely right, in [terms] of conventional agriculture, where you've got cheap petrochemical products, and you can fix your nitrogen from the atmosphere using [cheap] energy. But, of course, what's happening now is that the economics of all of that is suddenly changing very fast.