Collecting grass off waste land

[agrotron]

I usually flail mow some roughing industrial land approx 40acres. I haven’t done it for a couple of years and now they are asking if I can do it and collect the grass to be disposed of on site. (Presume it is to promote wild flowers etc). I wouldn’t like to mow it with a normal mowing machine due to stones etc. If I flailed ,it would it row up and bale or would it be to smashed up to form a bale? Any advice on best machine for the job. A grass sweeper like on small tractor would be ideal but is there a large version?

 

[Tractor Tim]

Done it before depending on how rough it is and the amount of stones sticks from dog walkers or even mattress springs from where some one has had a fire we don't normally go near it with a baler. Row it up with a single rotor rake into a big swath and push it up and load into a trailer never done more than 20 acre in a go through