Since the 1990's FEPA - the Food and Environment Protection Act - put paid to most of UK crop spraying. Along with public opinion and miles of red tape it wasn't economical.
Aus and NZ are good places for it. NZ for fertilizer top-dressing, and Aus for amongst others, rice sowing. I was offered a job, but couldn't take it due to work permit problems, so changed tack to commercial aviation.
The first pilot that I knew that died was a crop sprayer. A tree got in his way.