[Tagging] Footpaths through crops

[John Sturdy]

Yesterday I GPS-surveyed some public footpaths, one of which went
through a crop (sugarbeet, I think).  The surface was harder to walk
on than dirt or grass, with lots of lumps (beet); the farmer had only
marginally complied with the law:
http://www.ramblers.org.uk/info/britain/footpathlaw/footpathlaw2.htm#crops

I've tagged the path with "surface=crops" for now, but is there any
convention on how to tag such paths?  Of course, what the individual
crop is will be different each year, if normal rotation of crops is
used; but it is quite different to walk on than "surface=dirt" or
"surface=grass".

__John