???
well it all depends what fertiliser you're adding.
I dont see the point actually. Just add the manure, thats all it needs. Have you any idea what what the current pH and NPK balance of the soil is ?
I'm of the understanding that you don't get the best from your lotty after adding manure for a couple of years after you have spread it or dug it in, I've had two years of adding manure and also three years ago I planted Mustard, so nothing will be put on next year apart from top dressing when needed, personally I think it is a good idea to leave part of your lotty manure free for certain veg like carrots, but then I suppose it is up to the individual to do what they want with their lotty, :)
Well, I personally have spent 4 years putting any type of organic stuff I can get on my plot - horse and cow manure, straw mulch, leaves, compost and even buried uncomposted waste - and from year to year I can see the soil getting richer and darker, full of little critters, and have noticed many signs that it is the whole ecosystem of it is getting better - more insects, very good results with flowers and a greater variety of veg (especially greedy veg like squash and beans which did very well this year), good water drainage and excellent soil texture.
I have just put 14 big barrowfuls of manure all over the plot and I fully intend to do that every winter as all I can see is good from it.