> I suspect that many have switched over to other crops.

On the margins. However most farmers consider their soil health and long term plans. All good farmers (especially the mega corps) will intentionally plant most crops not based on what they expect out of the market next year, but what their soil needs. Most fields will not produce well if you don't consider what was grown on it last year and in turn what you want to produce next year. A few fields (millions of acres worth, but still only a few) there are options and those will adjust, but for the vast majority you have to follow a long term plan or your soil will fail and bankrupt you long term. Even the fields that do have options, it is just this year, and next they will have to return to a long term plan with no option. That where I live you have go [corn, corn, soybeans] or [corn, soybeans, corn], but [corn, corn, corn] is not an option. (I'm not aware of anyone doing two years of soybeans but maybe it happens)

> Most fields will not produce well if you don't consider what was grown on it last year and in turn what you want to produce next year.

I've never worked at a megacorp farm, but my observation is that the majority of farmers aren't thinking like this. Granted it might be different because the crops around me which are most commonly grown are wheat, barley, and hay. IDK the effects of soybeans/corn on soil and it's possible they have a much more pronounced effect. For wheat, barley, hay, most the farmers I know will plant it YoY and use fertilizer to counteract soil deficiencies.

Crop rotation, AFAIK, is mostly employed to reduce the need for fertilizer.

It definitely is a problem because farmers tend to over-fertilize which can cause nasty problems the runoff water.

I also expect this will likely become something a lot more farmers start to practice as fertilizer prices spike.