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So the experiment itself is comparing biochar to peat in potting media. So, a standard potting
media in the Willamette Valley is something like, 50% Doug fir bark, a bit of pearlite,
maybe 15% and then peat. Something between15-30%. And the peat really serves to hold moisture
and nutrients. The problem with peat is that it is mined in Canada. It is essentially mined
by draining peat bogs in Canada, taking those bogs and shipping them down here to use in
potting media. Peat tends to be the most expensive component of potting mix. I mean, if you think
about the three components that I mentioned, pearlite, Doug fir and peat. Doug fir is all
over the Willamette Valley, there's plenty of logging operations. So that tends to be
Doug fir bark. There's a lot of that available, it's very cheap. The pearlite is actually
produced, some of that is produced here in Oregon from volcanic rock. Sometimes pumas
are used also. So that is pretty cheap too, and the peat is the really expensive component
of the mixture. So minimizing that amount of peat that you are using is pretty important
as well. So the idea here is maybe we can use a locally
available resource to substitute peat, and I've been studying biochar for a couple years
now and it has an incredible ability to hold water. That was what my research at OSU was
about, and so it has this really amazing ability to hold water and that comes from the porosity
of the material. And now, biochar itself is something like charcoal. And a process called
pyrolysis makes it. During this pyrolysis process, you take biomass; you heat it in
the absence of oxygen. So we get our char from John Miedema from a company called BioLogical
Carbon. It's a company out of Philomath, Oregon. And he built, from scratch, a biochar retort.
Something like 15-20 feet tall, and I think it produces about 500 gallons of char at a
time. It's a really cool machine, and during that process you get a whole lot of properties
and material that are really beneficial to a lot of things. The most important property
that you get is an incredible amount of surface area and porosity. Some of the chars that
we work with have something in the order of 300 meters squared per gram of surface area.
And a gram of the material, you know, is about the size of a golf ball. So we are talking
about 300 meters squared of surface area in the size of a golf ball. And that allows it
to hold incredible amounts of water, nutrients. And we think biochar is a great application
in the state of Oregon because we have all this biomass. We have a whole lot of timber
industry in Oregon, so there is a lot of biomass available and so we've been looking at different
ways to use this sort of high value products- applications to biochar. And I have looked
at things like storm water filtration, water filtration. A lot of things having to do with
water. We found that high temperature chars have the most surface area, the most porosity.
They're sort of the best for holding water, holding nutrients, all these things that we
really want our chars to do. So we've made this char at 600 degrees Celsius and it comes
out as little, you know bits of charcoal, so we wanted to see how much processing was
needed. From our bulk char, that I had in a big drum at home, to what we use in our
mixes here to see how it effects the water holding and growth of these marigolds. And
no we chose marigolds just because, mainly because they are very easy plants to go. They
respond to a lot of environmental conditions and potting media. So they tend to be used
in different potting media trials to test media, rather than to test plants or nutrients.
So we used it as a sort of indicator species. During the harvesting process, we'll be clipping
the tops of these off, and then we'll be drying them and the same goes for the roots. We're
going to be washing all of the soil off the roots. Trying to get every last bit without
losing any of the fine root. And then we will be clipping those off as well and putting
them in a drying oven for, I believe we will put them in for about a week. And we'll do
roots and shoots are what they typically call them. And we really want to see how these
char treatments compare with peat. I mean, we're hoping to see that they are pretty similar.
That this char can be a good substitute for peat, especially as there are more and more
char producers in the area.