We are currently burning (or applying as fertilizer) 10 calories of petrochemical energy to get 1 calorie of food energy --- we need to rebalance this equation somehow.
A tiny percentage of sunlight energy actually makes it into the agricultural product’s chemical energy.
Is it possible to actually improve?
Corn yields between 1940 and present went up an enormous amount, averaging 25ish bushels per acre in 1940 and before to 180ish today. 7x increase with the same sun, but improved plants and agricultural practices.
Look up C3 and C4 photosynthesis to see differences in energy capture. There are plenty of axes on which agricultural productivity can be increased.
