Food, or what should we raise to eat
Jun. 14th, 2018 08:20 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
chris_gerribI’ve periodically written about space colonization. (No, I am not obsessed about space. I can quit thinking about it any time I want to.) While doing that highly-important task of dinking around on the Internet, I came across this Twitter thread.
The author, Dr. Sarah Taber, is an expert in agriculture, and does a lot of work in support of greenhouses and other agricultural endeavors. She was talking to somebody about how a vegetarian diet is more sustainable for the Earth. Perhaps surprisingly, she’s not in support of that. Some key points she makes:
1) Many human societies (Bedouin, Mongols, Maasai, Inuit) have all or very high meat diets.
2) Many of the early human societies that didn’t eat a lot of meat (The Ganges valley, ancient Egypt, China, much of early Europe) had two things in common:
a. Lots of rain
b. Hierarchical societies that could enforce a low-meat diet
3) Humans can only eat a relatively small part of a plant. We need seeds and soft leaves. As she says, “we eat straw, we’ll poop straw” without getting any nourishment from it.
4) Large parts of the world, to include the current lettuce capital of the USA, Arizona, naturally only support “scrub plants.” We can’t eat them, and the only way to get what we can eat to grow there is to irrigate the hell out of the place.
5) Cows and other animals with multiple stomachs can, on the other hand, eat these plants just fine. All you need for cows is drinking water.
Then the good doctor does the math. 10 cows could graze on 73 acres of land and consume about 67,000 gallons of water a year. To get food crops out of the same chunk of land, you’d need 79 MILLION gallons of water. Now, it’s true that you can feed more people on 73 acres of crops then you can on 10 cows, but only if you’ve got the water. So, in dry areas, it makes sense to let cows graze, and in wet areas one grows crops.
Now, let’s tie this to space. It’s traditional to assume that space colonists will eat only plants. But water is heavy, and even the best recycling system will have some losses. I suspect, therefore, that at some scale of agriculture it would not make sense to grow plants for protein. It would be better to raise animals – especially animals that can eat the stalks and shoots of plants we can’t.
The author, Dr. Sarah Taber, is an expert in agriculture, and does a lot of work in support of greenhouses and other agricultural endeavors. She was talking to somebody about how a vegetarian diet is more sustainable for the Earth. Perhaps surprisingly, she’s not in support of that. Some key points she makes:
1) Many human societies (Bedouin, Mongols, Maasai, Inuit) have all or very high meat diets.
2) Many of the early human societies that didn’t eat a lot of meat (The Ganges valley, ancient Egypt, China, much of early Europe) had two things in common:
a. Lots of rain
b. Hierarchical societies that could enforce a low-meat diet
3) Humans can only eat a relatively small part of a plant. We need seeds and soft leaves. As she says, “we eat straw, we’ll poop straw” without getting any nourishment from it.
4) Large parts of the world, to include the current lettuce capital of the USA, Arizona, naturally only support “scrub plants.” We can’t eat them, and the only way to get what we can eat to grow there is to irrigate the hell out of the place.
5) Cows and other animals with multiple stomachs can, on the other hand, eat these plants just fine. All you need for cows is drinking water.
Then the good doctor does the math. 10 cows could graze on 73 acres of land and consume about 67,000 gallons of water a year. To get food crops out of the same chunk of land, you’d need 79 MILLION gallons of water. Now, it’s true that you can feed more people on 73 acres of crops then you can on 10 cows, but only if you’ve got the water. So, in dry areas, it makes sense to let cows graze, and in wet areas one grows crops.
Now, let’s tie this to space. It’s traditional to assume that space colonists will eat only plants. But water is heavy, and even the best recycling system will have some losses. I suspect, therefore, that at some scale of agriculture it would not make sense to grow plants for protein. It would be better to raise animals – especially animals that can eat the stalks and shoots of plants we can’t.
One step further
Date: 2018-06-14 02:42 pm (UTC)Re: One step further
Date: 2018-06-14 02:55 pm (UTC)Still
Date: 2018-06-14 04:38 pm (UTC)Unfortunately for humans, this line of reasoning inevitably leads to conclusion that humans should stay on Earth and send self-replicating robots to asteroids and other planets.
Re: Still
Date: 2018-06-15 01:56 am (UTC)L-5 colonies! Gerard K. O'Neil! Whee-ee!
[Personally, I always thought it would be easier and more sensible to roof over lunar craters. Hail Tycholand!]
Re: One step further
Date: 2018-06-15 05:03 pm (UTC)Do you remember a 1950s SF short story, about how the commander of Our Lunar Base had chronic heartburn / incipient ulcer, really needed milk on a regular basis, but of course the cost of freighting that from Earth was prohibitive to say the least! - so some bright boys had malobukov's idea, to literally make a cow! The story went into detail; as I recall the one thing they couldn't synthesize was the pancreas, of all things, so they had one of those sent up, but in the end they had this machine - in one end you fed cellulose, in this case waste paper (government bureaucracy generates a LOT of waste paper, even on the Moon!) and the other end dispensed this white liquid…
Does that ring a bell?
Re: One step further
Date: 2018-06-15 05:29 pm (UTC)Re: One step further
Date: 2018-06-15 06:16 pm (UTC)https://rationalwiki.org/wiki/Fun:You_have_two_cows
I didn't find it right off, but I fetched up against this.
no subject
Date: 2018-06-15 01:53 am (UTC)I figured a long time ago that the only “green revolution” we need is to gin up a human equivalent to the cellulose-digesting enzyme that ruminants have, that we don't. Then we could eat hay! Or tree bark, or anything else that animals eat. This might not actually be a good idea…
[Back when I was a bean sprout I was fascinated to learn that milk digesting comes from just such an enzyme - and if you stop drinking milk, it dies out and then you can't! Long before Professional Victimocracy made “lactose-intolerant” a household word, Third-Worlders who received gallons of milk from well-meaning Westerners white-washed their pueblos with it - heck, they had to do something with the indigestible stuff!]