Discarded

I came upon this apparently discarded piece of farm machinery whilst out trying to track down a Grasshopper Warbler, no luck there! You do see quite a lot of stuff like this lying about in fields and it always throws up lots of questions for me. How long has it been there? Will it be used again? Is it being kept 'in case it comes in useful? I suppose if I ever plucked up the courage to ask the farmer I'd find out, but that will never happen!