The Haber–Bosch process that powered the green revolution is merely a way of converting fuel into heat into fertilizer.
Calories per hectare is one way of measuring food systems, and a great way when we assume fuel inputs are infinite, inexhaustible, and cheap. Calories per unit of inputs is another way.
The green revolution was not only a result of the Haber-Bosch process, although that's an aspect I wasn't thinking about.
Hybridization of crop plants increased the calories per hectare per year produced. Again, I don't know if the plants were actually producing more edible nutrients per pound of fertilizer.
