[alfman]

 
  Hi rapahoe,I installed raised beds last winter but I still left a portion of my plot as traditional plots because I found it was more practicle to grow runner beans, broad beans, courgettes, potatoes and squashes in those because of the room they take up. Root crops,tomatoes, onions/garlic , brassicas, beetroot, lettuce and french beans  are all fine in raised beds. So I find half and half works out pretty good for me, you get the best of both worlds. After saying that, my supposed trad plots are still reachable from surrounding paths without treading on growing soil so I suppose you could term those as "raised."

[Weatherwatcher]

I'd be concerned about the long-term sustainability of that mixture, WW.

Those components do not contain the trace nutrients held in a more substantial mixture which also has soil / loam in it.  They improve soil structure but on their own are not advisable long-term unless you rely on adding fertiliser - whether organic or inorganic compounds - regularly.

Thanks for that advice, Yorkie. I'll be keeping a close eye on it as it's all very experimental at the moment. It does get such things as blood & bone added, also compost tea.
Just to add to this: the well rotted manure that comprises of 1/3 of the mix is as follows:
Hoof stock (giraffe, zebra, elephant, bison, antelope, llama, rhino, hippo and camel) manure, and bedding straw is collected from the zoo's and shredded, then put into piles before being covered with black plastic so that it heats to high temperatures.  This hot method of composting kills weeds and diseases, sterilising the compost.  Every two days the piles of compost are turned and, after approximately two and a half weeks, the compost is mixed with aged bark fines, and packed into bags ready for use.  The end result is a sweet-smelling, easy to handle, quality compost-high in nutrients.

[Yorkie]

That's impressive manure WW 

But the point remains, which I was taught on a gardening course.  Manure and compost are not fertilisers, but soil improvers.  It is far better to have a decent quality soil which is enriched with organic matter, than solely organic matter that has to have additional fertilisers added to it. 

I would strongly recommend to readers that they incorporate a more balanced mix of organic matter and loam. 

[DavidT]

I have to agree with Yorkie,manures are really just soil conditioners, a better recipe would be 50% loam and 50% sedge peat or compost.

[yorky]

Sorry ww, I have to agree with the others. Without any soil your growing mix will gradualy decompose away to nothing.