manure quantity

Hi, I hope I've got the right subforum for this

My plot is approx 90ft x 20ft so 180 sq ft. The soil is clay.

I want to manure the whole area. How many 25kg bags of very-well-rotted horse manure do you reckon I need to cover it to a depth that will make a difference? The land was covered in weeds previously.

I don't think it can be directly calculated with any accuracy, hence the question. In other words, it needs an answer from someone who has used horse manure as fertiliser over a reasonable area. Right now I don't know if it should be scattered 2 inches thick or 12 inches thick

Make that 1800 sq ft mate    200 sq yds

A meaningful dosage is a proper barrowful to 2 sq yds.  10 barrowfuls to the tonne means 10 tonnes needed to give approx 2" coverage.  That would be 400 bags so bulk load is better

oh my god. my maths. You can tell I'm knackered can't you
And the coffee tastes awful!  :x

cheers for working it out, I'll use your figures