There has to be demand for that produce. The market ultimately decideds how much food we need to grow.
Where I'm from (New Zealand) there are various schemes in place to encourage farmers to retire low productivity land and fence/plant buffer zones around waterways.
Humans are pretty good at creating excessive demand (it's what lots of marketing is about).
With food: "oh, this apple has scratch marks from insects, throw it in the bin" — this is just one of them. "Best before" dates in the past results in lot of untasted food go to waste too. Etc.
We are already overproducing food, that doesn't prevent us to try to produce more.