...and didn't get a definitive answer, so I'm asking again.

I have noticed in farmers fields, huge piles of what appears to be a
blueish/greyish stone, I work in the construction industry and to me it
looks like MOT, or crush & run, but blue.
Upon closer inspection (IE picking it up) it has no odour, feels like soft
stone and the 'stones' range from 3 inch down to grit.
The piles of this I have seen in various (crop growing) feilds range from 50
to 100 tonnes, and the farmers spread it over the entire field round about
this time of year....last time I asked, it was suggested that the farmers
were having drives laid or tracks for farm machinery to drive on, since I've
recently seen it being spread, I know this is not the case, I cannot believe
that it's for any kind of drainage neither and I imagine it's fertilizer of
some sort, has anyone else seen this? - does anyone know what it does or
what it's called?


TIA