Pigeon Towers: A Low-Tech Alternative to Synthetic Fertilizers (2016) | Hacker News Reader

Pigeon Towers: A Low-Tech Alternative to Synthetic Fertilizers (2016)

notechmagazine.com

159 pointshacsky80 comments

I learned from the book "How to Hide an Empire" that an initial motivation for US imperialism in the Caribbean was to harvest bird droppings for fertilizer, even to the point of conflicts with Britain and Venezuela: https://www.vox.com/2014/7/31/5951731/bird-shit-imperialism

There was a 1856 law that encouraged US citizens to claim land for the country if there was bird poo on it: https://en.wikipedia.org/wiki/Guano_Islands_Act

This law is how the US originally got possession of Midway, which became very well-known during WWII (I always wondered how the US got it originally): https://en.wikipedia.org/wiki/Midway_Atoll

Peru and Chile fought a war over seabird guano:

https://en.m.wikipedia.org/wiki/War_of_the_Pacific

Guano deposits..is that the same root as iguana?

I doubt it. "guano" comes from an Andean language [0], while "iguana" comes from thousands of miles away, from the Caribbean [1]. Both are pre-Columbian words that entered English via Spanish.

(I'm not an expert; I just looked up the "etymology" links on Wiktionary).

[0] https://en.wikipedia.org/wiki/Quechuan_languages#Vocabulary

[1] https://en.wikipedia.org/wiki/Taíno_language#Vocabulary

I always though the guano was desired for saltpeter, which is used to make gunpowder. It doesn't seem economical to transport as fertilizer.

I thought so too, but Wiki says fertilizer was in fact the main usage. I suppose you get many extra units of grain per unit of added guano.

https://en.wikipedia.org/wiki/Guano

"As a manure, guano is a highly effective fertilizer . . . Guano was also, to a lesser extent, sought for the production of gunpowder and other explosive materials. The 19th-century guano trade played a pivotal role in the development of modern input-intensive farming."

Chicago should build new designs of these around Millennium Park, and maybe reduce their strife with what is both native wildlife and a productive resource. They really can't stand pigeons.

Hopefully the snake population is low.

You need only nitrogen for explosives, but nitrogen, phosphorus, and potassium for fertilizer. Therefore guano (which contains all three) is overkill for explosives but great as a fertilizer, while synthetic nitrogen compounds are insufficient as a "complete" fertilizer and have to be supplemented with the two other elements from other sources.

Well argued!

In a world without synthetic fertilisers, and where farming is economically important you'd be willing to go to quite some lengths to get fertiliser.

Odd that at the same time the Passenger Pidgeon[1] was hunted to extinction.

[1] https://en.wikipedia.org/wiki/Passenger_pigeon

It's not odd at all. Power, such as technology, can be used to accomplish various things.

In Ian Flemming's first James Bond novel, the 1958 Dr. No, the eponymous villain is "a Chinese operator of a guano mine" (https://en.wikipedia.org/wiki/Dr._No_(novel)).

Lots of pigeon towers in the countryside in France, nice pictures here:

http://www.alaingillodes.fr/patrimoine/pigeonnier/tarn.htm

Do you know if they were used for the same purpose?

Genuine question: what else would they be used for?

(Other than harvesting the guano / fertilizer and possibly eating the birds and/or their eggs, what else could one do with a pigeon tower?)

purported benefits include seed dispersal, bug catching

I do not know. I never owned pigeons. But yeah: Eating them. Eating their eggs. Using them as mail pigeons. Selling them to BF Skinner... Or some other use I might have never heard of entirely. I mean, the idea the people kept pigeons for their droppings was completely new to me as well.

I remember seeing a modern experimental structure that invites pigeons to nest, but due to its design, the nests are not stable and the eggs fall down, thereby reducing the pigeon population. The structure itself was similar to these in size and shape, maybe inspired from these.

Very interesting. Like the "ovitrap" [1] for mosquitoes.

[1] https://en.wikipedia.org/wiki/Ovitrap

Dove cotes (holes in the side of a barn) are common in the UK. My understanding it was mainly for the food.

Tongue-in-cheek answer: research into the origin of species.

[0] https://www.gutenberg.org/files/1228/1228-h/1228-h.htm#chap0...

> First, unlike chickens or ducks, wild pigeons are extremely low-maintenance

Until there are 5000 of them on the crop you've just sown. I've shot crop protection before. A large flock can destroy a crop in a few hours.

This whole thing relies on your crop not being the crop they want to eat.

It would be most beneficial if the type of bird was one that ate insects (pests) instead of seed.

On our small farm, we use ducks for fertilizing our fruit trees. We put a temporary fence for them around a tree.The ducks are out during the day, at night inside the fence. After a week or so we move the fence to another tree.

Instead of a "chicken tractor" you have a "duck tractor".

The imagery alone will be my daydream material for a few days.

Hmmm. I suppose you never heard of a "chicken tractor", have you? Try searching for it on Google. It's a thing.

In 1957 Fleming wrote his sixth James Bond book, Doctor No -- in which the eponymous villain runs a guano mine in the Caribbean.

Even some decades after the Haber–Bosch process was invented, stripping massive islands of these resources was still lucrative.

We tend to think mankind is becoming smarter and effective. But in reality we just started caring about profits in just near future.

When started reading your post, I was certain the end would be different:

- "We tend to think mankind is becoming smarter and effective. But in reality we just rely on birds' shit."

I've heard talk that we are getting dumber as individuals.

Delayed gratification is extremely beneficial and hallmark of personal well-being

"We tend to think mankind is becoming smarter and effective. But in reality we just started caring about profits in just near future."

Sri-Lanka decided to become smarter all of a sudden and ban all synthetic fertilizers. Now they don't have anything to eat.

Actually, the government banned synthetic fertilizers with a view to improving the country's highly negative trade balance. It was an extreme measure improvised in a rush by a country on borrowed time. Sri Lanka isn't even being supplied in oil now, nothing to do with the ban.

Profits? The Green Revolution[1] is credited with widespread reduction of poverty and hunger. The Haber Process provided the fertilizer which was one of the keys to the revolution.

[1] https://en.wikipedia.org/wiki/Green_Revolution

The green revolution is also responsible for turning farming in to an industrialized process that destroys soil and farmer well-being. Not everyone thinks it was a good thing for the world.

https://m.youtube.com/watch?v=Yk9ZuB9YvpM

Farmer wellbeing? Would you rather be a modern farmer or a c17th farmer?

Also farmers were destroying soil well before that. The dust bowl for one.

The video is only three minutes long. I would love for you to respond to it.

If you have 10,001 pigeons residing in a pigeon tower with 10,000 holes, will there exist a hole with more than one pigeon?

I think they nest in pairs, so there would likely be plenty of room.

I understand that they are defensively territorial, and unpleasant when nesting near people.

"The young will double in size in a day and a half. Making them one of the fastest growing vertebrate in the world...

"In another study, Pigeons were able to recognize themselves in a mirror. This makes them one of six species and the only non-mammal to be able to do so...

"Pigeons have the ability to see about 26 miles."

https://www.wild-bird-watching.com/Pigeons.html

https://en.m.wikipedia.org/wiki/Pigeonhole_principle

Polyamorous pigeons, maybe? Who am I to judge.

>Provide water and shelter, and they will come

I find this hard to believe. There has to be a lot more to attracting the pigeons?

Reminds me of a recent trend, at least in Sweden - Bee hotels. Small bird house like things that are said to attract bees. Everyone started selling them for a while. I bought a few of them to friends. But I don't think they got used.

Putting up a structure and expecting it to just work seems a bit optimistic. Is there more to the secret sauce?

If they're the ones I'm thinking about, with the pieces of bamboo, holes drilled in wooden blocks, etc. I've seen those in Germany, Switzerland, and the US. Can confirm that they work in Western Washington, but they're for solitary "digger bees", not your standard honey bee.

I've seen those structures used to attract Mason bees in Colorado, and they seem effective.

Considering that keeping pigeons from nesting in buildings and structures is an industry in itself in many cities, I find it very easy to believe a tower made for the purpose will attract then!

It worked in heroes of might and magic. And field of dreams

> It’s no surprise that the region that gave birth to agriculture has also refined innovative sustainable agriculture methods for thousands of years. Pigeon towers were one such innovation—and they helped Persian farmers cultivate all kinds of crops on previously arid, thin-soil land.

Didn't ancient Persia originally have much more fertile soil, but unsustainable practices (like the introduction of goats) destroy the soil quality? I guess both can be true, initial poor practices necessitated the introduction of more sustainable techniques.

Not sure about Persia, but I think in Eygpyt the main issue was mineral build up from irrigation. I could be misremembering.

I'd heard that with the fertile crescent, not the Nile valley.

Pigeons don't fix nitrogen, so how is this an alternative to synthetic fertilizers? The N has to come from somewhere.

Assuming the N comes from whatever they eat.

This is so cool -- it's a pity that it's not economical to do this.

I would be interested in seeing if that stays true in an increased number of niches, especially with fertilizer shortages and prices likely to play into the near future.

Pissoirs to do the same with humans ;-)

There was recently an article about that in the New York times. https://www.nytimes.com/2022/06/17/climate/peecycling-farmin...

As for economical in the "traditional" sense, maybe not. I don't know how much success they're (still/actually) having but if you want a little glimpse into what should be possible in easily digestible docu-film format, look up "The Biggest Little Farm" (it's on Netflix for example).

One thing I took away from that is that it's maybe not economical in a "have a one crop pigeon poop farm" (i.e. you sell pigeon poop from feeding pigeons), you can have a farm that sells a lot of things that uses a lot of different animals and crops in combination in order to not have to buy in things from the outside that "traditional" farms have to.

Yes, I was thinking of the wholistic approach in your second paragraph -- where the fertilizer is used on site or traded with neighboring farms.

And that source gets it from? As I said, the natural nitrogen fixing processes are insufficient to supply agriculture for nearly 8 billion people. And that N is more efficiently used by exploiting the nitrogen fixing sources directly rather than by filtering it through pigeons. In no way are pigeons a substitute for artificial nitrogen fixation.

I largely agree with your sentiment: articles should educate, so it's important that the average reader ends up learning say in this case the dependency tree, i.e. knowledge that some species of organisms have the genetically coded skills to say fix nitrogen while others don't.

The problem is that for those who don't already know this, these article are typically not that educational, and that for those who already do, any potential advantage of these pigeon tower is not explicitly elucidated either.

For example I can come up with self-concocted explanations why this is senseless in the sense you describe: i.e. fundamentally the bird is not a nitrogen fixer, so it ate the fixed nitrogen compounds from which the compounds in its faeces derived.

On the other hand I can come up with explanations despite its not being a nitrogen fixer why it still might be a net positive decision: perhaps the land has some insect pests anyway (pigeon towers or not), so that having the pigeons around results in them eating predators of your crop, while recycling those predators into useful nitrogen compounds...

The problem is that I know its just a wild guess I make.

Ideally we would read an article and understand under which conditions the pigeon towers make a net positive versus a net negative.

I am not trying to take a dump on the article: I'd rather know such structures existed and know I don't fully understand when they make sense than to know nothing about it at all... understanding must start somewhere.

Pigeon, like most bird poop is very high in N.

https://en.wikipedia.org/wiki/Guano#Bird_guano

So? The N still has to come from somewhere. The natural sources of N (nitrogen fixing plants, NOx from lightning or natural combustion), filtered through the birds, will not come anywhere close to what synthetic fertilizers can supply.

As many as 80% of the N atoms in your body were fixed artificially by the Haber-Bosch process. Natural sources, using pigeons or not, are not up to the task.

Nitrogen fixation occurs naturally in the soil by bacteria. As the nitrogen is consumed by different species up from one trophic level to another, from plants to insects to bird, the nitrogen gets more and more concentrated.

Birds are fairly high up the food chain, and their excrements are very rich in various nutrients, including nitrogen, phosphorus and potassium.

The Haber Process is faster but requires a lot of energy, and provides no phosphorus or potassium, so you have to source it elsewhere. Also it requires no technology and can be installed pretty much anywhere.

I suspect that this can work for low intensity farming, like fruits and vegetables, but if you want to feed the cattle of the earth, you'll end up running out of pigeon food.

If you want to feed all the people of the earth, you will run out of pigeon food. Ecosystems contribute to food inputs for food consumers.

One of the best solutions to out fossil fuel problems is to simply have less people. We need to dramatically reduce the number of humans. Perhaps then the pigeons can help.

ps: I recommend we let current humans die of old age, and make less new ones. Not attempt to get rid of humans already here.

Given that our economies are built off of the idea of infinite growth and increases in consumption, there's likely to be conflict involved.

I'd phrase it as "reduce the number of mouths to feed". That way it could be achieved by reducing the amount of cattle grown for meat and we could eat more grains etc... ourselves instead of feeding those intermediaries.

>> One of the best solutions to out fossil fuel problems

Mankind has survived just fine since ancient times without burning anywhere near the amount of fossil fuels burned over, say, the last 200 years.

With wind and solar, we are an the cusp of extremely cheap electricity.

>> is to simply have less people.

Feel free to follow your own advice.

Yes, nitrogen fixation occurs naturally. But the amount fixed is insufficient to achieve the yields of modern industrial agriculture on a global scale.

Pigeon shit has existed for a little while longer than the H-B process has.

Pigeons transport N from non-farmed areas (like forests) to farmed areas (where the towers are).

"Natural sources, using pigeons or not, are not up to the task."

Sure they are. Just not on the current scale (for the current processes and preferences). It raises an interesting question about how many people the earth can sustainably support though.

It’s bioaccumulation. There is some potential for them to be extracting phosphorous from the rocks in their gizzards, but that will mostly be bioaccumulation too.

It does not require fossil fuel heat or feedstock. So it's net 0 at least.

The article said that this has historically been used for nitrogen-demanding crops, so it must have some value.

"Pigeon towers became a crucial part of the agricultural economy, providing much-needed fertilizer for melons, cucumbers, and other nitrogen-demanding crops—cornerstones of Persian cuisine."

They do most of the work... The N comes from Urea. When mixed with the soil and the rest of the bacteria-rich bird litter, it's exposed to various ureases to create NH3, which combines with water for NH4 which plants can use.

Something that stands out to me is that these structures look very time consuming to produce by hand, but the designs are well suited to 3D printing from concrete or similar materials. Though I don’t know if 3D printed concrete can accomplish “bridging” as is done with plastic 3D printing.

It's nice but it doesn't scale to the level of fertilizer use required today.

Most people are innumerate (including people who should know better and could run the numbers) so they don't have a grasp of scale.

The issue you need to mitigate using this method is bird flu. Still, having an alternative to synthetic fertilizer is nice

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