Earlier quoted context omitted.
Alfalfa is especially good for adding nitrogen, but clover can do the same for a home garden. You are correct on the number of years between plantings, but really only 2-3 years off are needed to clear the fungus. Alfalfa just lasts longer. As another comment mentions, some other common crops have the same disease risk, so avoid potatoes and eggplants too many consecutive years. Fallowing it an option, but a little n…
I have this issue right now with my tomato plants. Am I right in my understanding that you don't necessarily need to crop rotate and just supplementing the soil with nitrogen would be sufficient?
Nitrogen is necessary for proteins so you can get larger yields, but if some other nutrient is missing then nitrogen alone won’t help. K and P also need to be present in good quantities, as well as a mixture of iirc 17 elemental trace elements. I’d use a well-rounded fertilizer like 7-7-7, and if it wasn’t growing then assume there was a disease or pest at play.