You can do solar -> hydrolysis -> hydrogen -> ammonia-> fertilizer, rather than methane -> steam reforming -> hydrogen -> ammonia -> fertilizer.

So it's technically feasible. Not quite there in terms of cost and scale but if the alternative is a blockade then probably worth investing in.

Ironically some of the best locations for production are in the middle east.

You can run the numbers the cost isn't that bad to do it that way.

I think South Africa gets most of its diesel from the Fischer–Tropsch process. You could use electrolytic hydrogen as an input for that. About 40% of the energy in gasoline is from hydrogen burning.

It's not great but it would allow you to run current vehicles off about 40% solar energy.

Best part you can probably miniaturize entire process into panel itself and 5 panels per hectare would be enough...