Hmm interesting read. Honestly that study reeks of "peat industry funded" though. the fact that they didn't rinse the coco but they added lime to the peat is very questionable for a fair study.
Its well known that coco needs to be rinsed before use as a means of preparation, much like peat needs lime. But coco also needs lime or some source of calcium as another form of preparation before being used in a grow.
What i got from that study was that you need to rinse your coco before use and maybe feed a little heavier with nitrogen.
I'm not saying coco is better than peat, or even peat is better than coco. I'd wait for more responses from people with real world experience honestly.
Now my real questions about both. Ok so its an "inert" media once properly prepared, but several sources say that as it breaks down it releases potassium. So how can it be inert but also a source of potassium?
Peat is known to make the medium acidic as it breaks down, but what else does it "release" when it breaks? Its had to believe it doesn't release some form of nitrogen or other nutrients if coco does.
hmm, is that a slight ball-bustin i'm getting?
am i lacking "real world experience here"?
or am i just being wearing my sensitive-pants today..
so first, technically you are correct, as virtually nothing used as a base in the soil can be truly inert, but that's because of the interaction of the bacterial and fungal biodiversity, humic acids, etc.
the issue of it not only not being as high of a cec as peat is a good reason, as well at it leaching potassium into the soil continuously, which i suppose would be fine if you countered that elsewhere, but in my experience a potassium toxicity is easier to come across than you'd think, especially in an organic soil that retains and holds onto cations and other nutrients much more readily than a typical hydro media
plus it's always easier to add nutrients rather than try to counter a toxicity issue by adding other nutrients, especially pertaining to cations
the topic has been discussed and by a good amount of well know veteran growers here, and the majority of them reported similar results, with many simply saying visually the plants looked the same, only smaller yields.
the comparison of the lime with the peat and to the coco isn't really applicable, it clearly said they needed gypsum to match the coco, but it's needed more so for the potential salinity issues it has, rather than ph control, and of course gypsum has that calcium that you'd need as well, my biggest complaint would be the leaching of the potassium and the imbalance of the cations
also they add the d-lime not as a source of calcium but rather to control the inherent acidity of the peat.
i'm curious why you think that study is made or influenced by the peat "industry", considering it's not linked to anything, and is done by a university....
also, really the biggest difference is that peat is a composted product, and coco is not, so therein lies the difference. So it doesn't really break down much other than the typical physical breakdown of the particles as they are mixed with the microbes and nutrients, peat is made in an aerobic condition so the microbes and such are completely different, mixing the peat with aeration and the typical biodiversity that organic soils have and essentially everything is devoured eventually, but that's how it works, otherwise the earth would be stacked with leaves and detritus that never goes anywhere.
i know this all seems like i am super pro-peat, in reality i'm not at all, in fact i would prefer a different media alltogether, but nothing I've tried works as well, the closest thing that comes to it would be a leaf-mold, but that's takes so long to make that most don't have the time/space/patience for that.
a happy medium would be to mix the two, I've done that and had good success with that.
as far as the concern of peat releasing nitrogen as it breaks down, i'd say it's safe to say none of that is going to be released in a compost/breakdown scenario, at least not in the typical environment that a soil media is.
the cec from peat is superior to coco, that enough is reason alone to use it.
I wanted to like the coco the same, but it simply didn't perform as well, especially in a re-used soil.
not saying i didn't grow some nice herb, just saying it didn't do as well as a peat based mix.
smaller yields, by around 15% or so, and it exhibited a calcium def issue around week 6-7 or so, that was on a sativa that typically ran 9 to 10 weeks
and no way in hell the plant was actually having a cal def, anyone around here that has heard me ramble on and on about it, and that is that topdressing comfrey will "keep em green till the end":
just not with coco, at least not when coco is used as the primary "base" of the soil.
