When you build a farm plot, the default setting for fertilize is on, as fertilize. You can pres "f" and it sets the farm plot to cancel fert, meaning it won't be fertilized. If you set farms to cancel fert, save and reload those same farms will have fertilize back on.
I'm pretty sure that's not right. "f: fertilize" means "if you press f, this plot will be fertilized, but right now it's not", and "f: Cancel fert" means "this plot is being fertilized, so pressing f will cancel fertilization". I'm basing this off of personal experience (I've
never had a plot fertilized, so I'm pretty sure it's not the default), and the fact that fertilization counts are only displayed when "cancel fert" is displayed, which would be pretty useless if "cancel fert" meant "fertilization is inactive". I'll admit that it is inconsistent with other menus, though.
Also,
this page says you need to press "f" to enable fertilization. However, you might find the "s"easonal fertilization option more helpful - the "f" option might be a one-time thing.
Oh and btw an idea for Autobucher. Is it possible that one more thing would be included in those options and that is to be able to set collect eggs on/off for every "race". The don't collect eggs option, should be possible by a script that setts forbid on certain race eggs in the nest box. It sucks locking and unlocking or forbidding eggs. This option would perfectly round up the autobutcher tool.
I tried making a separate plugin to forbid eggs once, and found that it was a lot harder than I expected. It might be easier now that we have ways to cancel jobs easily, and I've been meaning to look into it again at some point.