I wouldn't know the levels of fertilisers in my soil. I rely on how everything grew during the season and take it from there.
I suppose in an ideal world, you would analyse your flower/vegetable beds each year to see what is present.
This would mean sending off samples to specialised laboratories for testing. I was told many years ago that soil testing kits you can buy do not give accurate representations of true fertiliser levels as what you need are levels of N,P,K available to plants, conductivity of the soil, etc, which is a different matter and these kits do not account for that.

Anyway, organic fertilisers I use every few years are Bone meal for N and P.....more P than N.
Hoof and Horn for N and P....more N than P.
Those are used before winter for overwintering soil preparation.

For quickness and for spring, summer top dressings Superphosphate for P and sulphate of ammonia for N.

Thanks Scrumps :)

I agree with what Scrumpygrat has said. We have a neutral pH soil, silty but has had plenty of humus added over the years. In the ornamental garden I will add bonemeal whenever I prepare a new bed otherwise I might just throw a little bonemeal around some bulbs if I ever get round to it - not very often.
In the vegetable garden I use garden compost only. This has a very variable fertiliser value but it does not seem to matter.
I also grow a lot of plants in pots. I make my own compost and add bonemeal and woodash as fertilisers. Years ago I worked out a system whereby I could measure the fertiliser by volume in small pots to give a compost 'similar' to John Innes formulations. Mine is very much bucket chemistry but as long as the plants are happy then it is working OK for me.

Thanks for those responses! Good to know:)