What's the most efficient means of turning sunlight into human food?

I’m not totally sure what I’m asking here, so please bear with me.

I’ve heard that crops are more “entropy-efficient” than livestock. In general, it takes less resources to get the same amount of Calories out of a plant than an animal. What would it look like if we took this conservationalism to an extreme? What crops produce the most nutrition per hectare per year? Assume technology is not an issue. Like, we could have robots and underground excavations and stuff.

I’m picturing a huge algae farm in the Pacific. Can humans even eat algae?

Thanks in advance.

Problems with monoculture aside not every crop yields well in every environment. Land and climate suitable for wheat may not have enough water for corn or potatoes. Rice is a staple crop for much of the world because it’s efficient but good luck growing it on the prairie of eastern Montana.

Algae isn’t hard to grow at all. Just put some in a tank of water in the sun. Good luck getting humans to eat it without processing though. It takes a lot from the crop’s efficiency when you have to turn it into soylent green to make it palitable. The most efficient foods require the least processing. That’s why grains and potatoes are some of the most common food crops.

Photosynthesis is pretty hard to beat.

Soy beans grown with natural sunlight probably represent an ideal form of efficiently produced protein. I doubt there is another way of creating a life sustaining food that uses less energy per calorie.

Okay, so algae is out until we can perfect the Mikey gene.

I hadn’t really considered how crops vary with location, so I guess I’d like an answer for all the various climates. What’s the best solution if we have to grow our food in Iowa? In Antarctica? In the middle of the ocean? In the middle of the desert? On the moon? In space?

I also hadn’t thought about how a diet should be heterogenous. Is soybeans alone enough to live off? What’s the most efficient set of crops if you want a well-balanced, sustainable diet?

I’m not sure I entirely agree with that. I think one reason that grains are such a staple is because most people live far from the ocean. In areas with long coastlines (e.g., Japan), seaweeds (nori is a form of red algae) are commonly consumed. Of course, many Westerners have negative reactions to the idea of seaweed as a food source, but that bias is not common to all humans.

Oh, the grains quinoa and amaranth are also good sources of protein.

Well, the big thing all of us lucky modern types forget is that grains can be stored. For years, if care is taken, meaning that you can put some away to defend against a bad harvest or two, and still live.

As far as potatoes go: they require just about no work, and are quite forgiving in terms of (cold) climates. But they don’t store as well. Read up on the Irish potato famine yet again.

Ah, now that’s exactly what I had in mind. :slight_smile:

Also, I did mention this earlier, but I meant to reiterate it. I’m assuming we have some good hydroponic greenhouse technology, or something like that. We’d probably need it for Antarctica and the desert, and certainly for the moon and space.

So now I’m curious about something else. Why are tofu products more expensive than corresponding meat products?

I don’t know where you’re shopping at but tofu is usually way less expensive than most meat.

Well, I just checked out the local supermarket. They had:

Ground beef for $3.29-$3.79/lb.
Morningstar Farms plant protein ground beef substitute for $3.79/12oz. = $5.05/lb.

I guess it may not have technically been tofu, but this sort of thing is what I had in mind.

I think that for sheer calories, it is hard to beat potatoes. Corn is more efficient that wheat if the temperature is above 80 F; it uses a different photosynthetic pathway. And in the tropics, bananas (including plantain) are a major source of food.

Spoken like a man who’s never grown potatoes. The actual growing isn’t too hard, but digging them up is a lot of work. However, they do require very little land, and to the nineteenth century Irish, land was a lot more expensive than manpower.

Soy products may be more expensive than meat due to market forces. In the U.S., most of the people eating soy foods aren’t doing so for economic reasons, they’re eating it because of various ethical or moral considerations. They’re willing to pay more for their convictions, so the free-market food providers will charge what the market will bear.

Remember it isn’t that we don’t have enough FOOD- it is that we can’t distribute it well enough. Meat is concentrated food, and is easier to distribute- besides, it can walk on it’s own legs. <g>

Morningstar farms = Several boxcars a day.

Hormel = Several boxcars a minute.

Any questions?

How do insects factor in here, I’ve heard they are very nutrishous and can eat plants (and for that matter shit).

Another thing to keep in mind, going back to the whole “efficient means of turning sunlight into food” angle, is that cattle is actually fairly efficient, when you consider that the food they eat is inedible for us humans. Granted, many (if not most) cattle are fattened with corn and such before slaughter to make the meat tastier (mmm… cow…), but a cow can be raised on pretty much nothing but grass, and that grass will grow in places that are inhospitable to most crops. Cows are a great way to convert unusable land into burger-based food factories, even if you’re technically losing efficiency in terms of calories per watt of sunlight.

Dammit, now I want a burger.

That is a book all by itself. The question is just to broad to be answered. As ElJeffe just said, producing meat is the most efficient over much of the rold. Good luck trying to grow any human crops at all in Lapland. But reindeer meat grows quite well. That is the most efficient crop. The same goes for most of the world’s warm temperate and tropical grasslands. Nothing grows as well and as reliably in these areas as grasses, and nothin is as efficient at converting grass to human food as ruminants.
But that’s just reality. The OP says we are allowed to assume infinite technology. Infiite amounts of fresh water from desalination plants, no transportation restrictions, the capacity to construct multi-level eleltrically heated greenhouses etc. Since that’s the case we can grow whatever we want wherever we want with absolutely no pests or diseases and no need to refer to climate or soil conditions. Then all we need to do is look at gross yield of calories per hectare under idea growth conditions and cover the face of the planet with greenhouses meeting those conditions.

Working with those (rather implausible) restrictions then we simply grow hydroponic rice over the face of the whole planet. As a protein source we could grow soybeans, since we have no energy restrictions on the industrial process necessary to detoxify this deadly poisonous legume.

Of course this is a all a bit meaningless if you are talking about “the most efficient means of turning sunlight into human food” since with no technological restrictions we wouldn’t be using juts, or maybe even primarily, sunlight. If for some reason we do need to be restricted to sunlight despite our nuclear powered, artificially heated, multi-level, desalination plants cum greenhouses then all we need to do is find out what the most efficient crop is under ideal circumstances at any given latitude. I don’t have those figures and I doubt anyone does since it’s not an issue in the real world.


So going to sushi bars and eating edamame’s gonna kill me?

Commercially available soy has been subjected to an industrial process to detoxify it. Even so consumption of large amounts of soy products has been linked to several diseases. The detoxification processes aren’t perfect, and the traditional fermenattion methods least of all.

But try eating soy as you would string beans or other edible legumes and you will die quite rapidly. The beans are poisonous in their natural state.

Just one. I understand now why tofu is more expensive than meat. I just want to know what you meant when you said “tofu is usually way less expensive than most meat”. Did you just mean it’s cheaper to grow?

Okay, fair enough. I don’t want to make anyone do a whole research paper for me. I’m most interested in the harsh climates I mentioned - ocean and desert.

This is what I was wondering. I was imagining we had the technology to construct and maintain the greenhouses, but not infinite energy. The whole idea of using the least resources possible. If crop A takes up 2 million hectares and one fusion plant, while crop B takes up 1 million hectares and 4000 fusion plants, then I would say crop A is the winner. But, I guess unless I give you a formula, you can’t really tell me which is optimum, even if you had all the information you needed.

That’s okay. I just wanted to get some ideas, so I had a better understanding of the problem, even if I didn’t get the answer.