If you think food is expensive now, it will get much worse. There's a lot of talk in the US about Canadian oil becoming more expensive. That affects the cost of logistics. By percentage, we're less dependent on Canadian oil than we are potash. As far as I know, manure doesn't provide a lot of it, although someone working in ag might know something I don't.
This means our food supply is going to get taxed from more than one angle.
https://www.producer.com/markets/tariffs-could-heat-up-boring-potash-market/