Whether your soil might need Potash, Phosphorus, Calcium, Magnesium, or any other nutrient can only be determined by a good, reliable soil test. Besides that manure what other forms of organic matter, compost, spent plants, etc. have you been putting into your soil?

The chemical imbalance of any soil is only discerned by a reliable soil test. You can do the test yourself with an inexpensive testing device available at any nursery or garden supply. Its not professional, but it can give you some idea as to what you have in your soil.

Manures have been known for years by experts to be a good addition to soils; some manures are better than others.
Bat quano---the best; rabbit, very good; chicken/turkey and other foul, very good, cattle and horse bring up the rear...so I'll put a donkey and his cousins in the same boat.
As long as the manures are well aged and you don't put them in contact with the roots, then there should be no concerns about their safety.

Manures are much the same as when the pet urinates on a lawn....a certain level of nitrogen is placed in a confined space. It can burn. Where unknown break-down of manures have taken place, its best to go slow, keep the manure away from the roots and mixed in well with the soil that the plant is presently growing in.

My raspberries plants are few with good production so my small scale example may be meaningless, but I give them nothing special other than compost. I'll leave it to others to say for sure, but could you be giving them too much of a good thing with too much N which can be great for leaves but bad for flowering on many plants? You say "the fruit production is practically non-existant" but are the plants healthy looking otherwise?

tj

thanks tsugajunkie
well my raspberries do look healthy enough -but they did so before I began to give them good mulches of my stable manure.
Seeing as the manure is well rotted when I apply it I wouldn't have thought that I would be overfeeding because I understand that the longer the manure lies rotting , the less feed (maybe nitrogen in particular ) it contains and so the more it becomes like simple compost-albeit it would be quite compact which I could see being a bit of a problem in the rainy conditions over here.(also the wall they are on is west facing and there is also shade from a nearby apple tree

hi kimmsr and thanks
well as to what else I add to my soil in addition to the stable manure it is really this:
I save all the weeding that I do in the garden , a lot of which is the top layer of soil because I scrape/shave the weeds that grow between the beds with a sharp spade (as a way of weeding) and cart the result away to the other side of the garden where it lies in a heap until the following year when I bring it back as a kind of half compost half soil (or a loam as I wishfully imagine)
This I will quite often mix 50/50 with the stable manure and this is what I am starting to wonder whether it is really as good as I imagined it was.(I am starting to purchase chicken pellets as a way of increasing the fertilizer level -I am scattering these in amongst the plants afterwards but it is early days yet and I have yet to see any results)
Unfortunately I have never done a soil test on the soil in over 20 years so I accept it is well overdue....

There are other reasons raspberries don't produce any fruit other than manure!
Too much shade, which could cause little to no pollination. Do you see flower buds in the spring? How about bees working the blossoms? Did you do any pruning and removal of last years canes?
I would do a bit more investigation.

thanks beeman_gardener
yes I do prune every year and I have had loads of bees (a wild hive in one of the old apple trees- now sadly abandoned)
The shade comes from a nearby apple tree but I didn't think that would be bad enough to prevent the development of the fruit (yes there are flowers but they don't seem to turn into anything worth while) as it is just on the one side (west) while the canes grow on the west side of a North/South running wall and make about 2 foot of growth above it.
I do wonder if the long spells of wet dull weather we get might be very detrimental.
As you say I should take a bit of effort for the year coming up (analyse the soil for example).
I did ,a few years back ,replace the canes with new stock as I suspected they might have been just glorified wild canes but that hasn't really had an effect either....

It's very possible the canes are at fault. I bought some a few years ago as mine were getting old, they need replacing after about 7 years, the ones I got never produced anything at all.
I pulled them out and replaced without any changes and now get good crops every year.
Don't buy them from your previous supplier.