Thank you for the answers!

> If it is not efficient it will cost more than it yields, a loss.

I was thinking about less efficient, but still profitable. I presume it's not a binary, and farms aren't operating barely above EROI of 1.

> According to FAO 70% of worlds land surface is not suitable for planting crops.

That's... super surprising to me. I would have expected something closer to 50-40%. Perhaps it hinges on the definition of "suitability"? I'll look into those stats.

> About a third of all fertilizers for farming used in Sweden is natural.

That's also surprising to me. Is this number so large because there are so many ecological farms in Sweden, or natural fertilizer is just so popular?