Giving a field a year off and cover crops have been done for hundreds of years by farmers who also till.
There are a lot of different combinations of variables done for both tilling and not tilling depending on many factors.
Years off don't work great when coupled with high land prices and taxes.
> Giving a field a year off and cover crops have been done for hundreds of years
Even the old testament talks about letting the land sit fallow for a whole year, so thousands not just hundreds of years.