Is it a pure manure, or a mixed general compost that contains other organic matter along with the manure?
I'd spread it as a mulch for now, maybe about 25-35 mm thick. That's for your established plantings.
Some people prefer to not mulch right up to the bases of the fans, but for me, that would depend on how deep the crowns are. If they're shallow, I don't see a problem with applying it uniformly everywhere. Re-apply as necessary throughout the summer, and if you want to, in the fall you can turn it in lightly, then apply a little more as a top-dressing.
It's tempting to want to dig and till, but the idea is to disturb the soil as little as possible in order to allow it to re-establish a natural structure. The mulch will provide a comfortable, moist environment for worms, etc. encouraging them to populate the upper levels of the soil. They'll consume and slowly move the organic matter throughout the root zone. Their action will keep the soil open and porous.
