The long term effects seem harder to judge. Fertilizer imports likely increased. Some farmers likely started using fertilizer more effectively because higher prices encourage investment in efficiency improvements (reduced waste).
Looking at youtube farmers I follow... They reduced usage of fertilizer in exchange for lower yield. In the bottom line, they made as much profit due to higher prices and less expense. But for consumers it means raised prices. Food processing industry will have problems with sourcing raw material. Exports will drop and internal consumption will be more expensive for several years.
Presumably at higher prices, otherwise the European plant fertiliser industry wouldn't have been in active the first place.
> higher prices encourage investment in efficiency improvements
As far as I can understand agribusiness is already highly efficient, not sure it can make up for a double-digit decrease in availability (or increase in prices) for one of its core inputs.
Also, guess who is one of the bigger fertilizer manufacturers? Russia & Belarus. For example Belaruskali. Wonder how much of re-badged fertilizer will make it into EU...
Also, perhaps some factories will reopen.