In Geoff's "permaculture soils" video he does a demonstration of 18 day compost. In the video he gives a basic ratio of Browns to greens to manures. Anybody who has the video remember what he said? I know most people simplify it to 2/3 browns to 1/3 greens but in this video he was a little more specific.....browns - greens- manures. I was hoping someone with the video can go back and check. Thanks
So, the manure *is* the greens portion. If you're going to be particular, aiming for the 25-30:1 ratio by reference to the chart from the first link looks more precise by a fair bit.
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Rose Pinder wrote:There's a big difference between 1/3:2/3 and 1:25. Does it not matter?
That is quite a confused question. a 1:25 nitrogen:carbon ratio is one way to calculate it, and a 1/3:2/3 green : brown is another entirely different way to calculate it. The two methods of calculation are not related although they can end up producing the same result, good compost.
The first method is more like a rule of thumb method. It is less exact, but it also is easy to guestimate. The second method requires a chart containing the nitrogen:carbon ratios of every component and a bit of math to figure out what ratio the final mixture will contain.
You last question? Does it not matter? is also a loaded question. One way or another organic matter will rot, resulting in compost. So no it doesn't matter in that respect. However it does matter when you are trying to get a "hot" pile that decomposes quickly.
Higher up you said something about shrinkage. I have yet to find any method of producing compost that doesn't shrink. I don't think it is even possible. A higher carbon ratio decomposes slower and shrinks less, but all types of decomposition shrink, pretty much by definition. If it isn't shrinking, likely it isn't rotting, at least not much.
Location: Otago, New Zealand
posted 5 years ago
Ok, thanks. The original question was about the recipe that Geoff Lawton uses in his soil film on how to build an 18 day compost. In that, he uses the 1:25 But he's not talking about specific ratios of each ingredient.
The bit about size reduction is a point he makes quite specifically and seems to be one of the reasons he uses this method. There's an image in the first link above.