Those "lovely" fields of endless bright yellow are a monoculture, usually sprayed with insecticide. One year I walked across 3/4 mile of oilseed rape (on a public footpath) on a sunny May afternoon and didn't see or hear a single insect or bird. A bright yellow desert. The rapeseed oil is very controversial apropos of health risks and is subsequently being superseded by canola oil, which is highly processed and which is generally a GM crop. Fine if you're happy with that. Not for me, thanks.