What Does "Caloric Power" Even Mean?

When it comes to feeding a lot of people efficiently, the size of the farm will be a major consideration. Whether I plant indoors or outdoors, the bigger the farm, the more labor, materials, and time it will suck up — all of which is typically in short supply. So during the opening stages of this project, my biggest concern is going to be the calorie yield. I want to find the crops that can produce the most calories, in the smallest area, and the shortest time.

But first I have to measure it.

I call this measurement the caloric power of a crop, and it encapsulates three key metrics: how many calories are contained in a pound of crop, how much space is required to grow the crop, and how many days it will take to mature. The final value (expressed in cals/day/sqft) can be used to quickly estimate how large a crop will need to be planted in order to sustain a given number of people, since each of them will consume 2000 calories each and every day.

Caloric power doesn't seem to be a metric that's tracked or reported by the agricultural market — or at least I haven't found anything about it yet — so I've computed estimates for some likely crops to get things started. As the project continues, I hope to refine and improve these numbers — either through more accurate calculation methods or by improving growing methods to improve efficiency. Ideally, this could also become a target for crop researchers to consider when developing new varieties, but that seems like a much harder sell, so I won't be holding my breath.

In the meantime, the current values were calculated by looking first at farm reports: how many pounds or bushels of crop are produced per acre? We then consult nutrition guides to compute how many calories are typically in a pound of that food, so we can estimate the calorie yeild per acre. Then we can divide that by 43,560 (the number of sqft in an acre) to get the calories produced per sqft.

This tells us how many calories will eventually be produced per sqft by a given crop, but we don't yet know how long those calories will take to mature, so we then divide by the average crop cycle time. Now we know how many calories that crop will produce, per sqft, per day. And since we know humans need 2000 calories per day, we know how many sqft of crop needs to be in constant production to keep one person fed indefinitely.

There are lots of other dietary metrics to consider (mineral content, fibre, fat, etc) but calorie content is the key to finding the most efficient crops to investigate, so that the largest number of people can be supported from the smallest infrastructure.

The next step will be figuring out a crop balance that will produce the required daily amounts of all major minerals and vitamins. But for that, we're going to need more data.