You also can't ignore the energy cost of running the farm and transportation.
I suspect that it may actually be more efficient to skip pesticide applications and harvesters, and use domesticated insects to harvest grains and fly those food calories directly to a local processing facility.
Certain species are already natural grain harvesting machines. Certain species are already natural pest predators. Those could be exploited and bred for a purpose. Humans plant the corn. Domesticated insect-predator insects patrol the fields and protect the corn from unauthorized eating before it is ready to harvest. They return to the hive, breed for the next season, and get eaten. Domesticated harvester insects then mature, fly out to eat the corn, and then fly back to the hive, breed for the next season, and get eaten.
Whatever is not eaten directly by humans can be fed to farmed fish or poultry.
I suspect that it may actually be more efficient to skip pesticide applications and harvesters, and use domesticated insects to harvest grains and fly those food calories directly to a local processing facility.
Certain species are already natural grain harvesting machines. Certain species are already natural pest predators. Those could be exploited and bred for a purpose. Humans plant the corn. Domesticated insect-predator insects patrol the fields and protect the corn from unauthorized eating before it is ready to harvest. They return to the hive, breed for the next season, and get eaten. Domesticated harvester insects then mature, fly out to eat the corn, and then fly back to the hive, breed for the next season, and get eaten.
Whatever is not eaten directly by humans can be fed to farmed fish or poultry.