As every farmer knows: it's not the weight that matters but the soil compaction, and that's a function of weight over surface area of the contact patches of whatever drive train your tractor has. That's also why tractor tires are so wide, and high flotation tires are commonly used.
Another way in which farmers combat soil compaction is by aeration and tilling.
It's true though that tractors are getting larger and heavier, but farmers are pretty knowledgeable about these things and usually take them into account when deciding what kind of machinery (on what kind of tires) to use for their soil, after all, if they get it wrong they may end up negatively impacting the yield of their land.
Finally, crops tend to be planted in rows for convenient mechanical processing, and while walking behind a tractor you can actually see the soil rise again after the tractor has passed, usually because the soil acts as a sponge, the tractor squeezes the water out and once it has passed the soil will spring back. It's a bit strange to realize that the ground you walk on is so springy because you normally don't notice it.
The main take is "while surface contact stresses remained nearly constant over the course of modern mechanization, subsoil stresses have propagated into deeper soil layers and now exceed safe mechanical limits for soil ecological functioning".
i.e. they state that the stresses propagate deeper into the soil, regardless of the pressure imparted on the surface.
I dont understand it exactly, but thats what they are saying. I guess its something to do with the increased overall mass being supported by and compressing the underlying soil layers, rather than the (relatively) shallow sub-surface compaction we are usually concerned about.
Let's say you have a load of 1000 kg on a 1 square meter steel plate on a field. What is the compression 1 meter underground directly below? Less than at the surface. What about compression 1 meter underground and 0.5 meters to the side from the center, ie below the edge of the plate? Even less. And 1 meter to the side, even than that. The load spreads underground. From a small point load, it dilutes fast with depth.
What if you add a similar load directly adjacent to the previous one. Pressure is same but area is added. What is the compression 1 meter underground, at the border between the plates. It's more than in the previous case, since both loads now contribute to it.
So there is a sort of load pyramid that has to form underground to support each point load. And the more point loads you add in a grid, the deeper you go, the pyramid overlap more together. So with constant pressure, the wider area you have, the more there is stress deeper down, and the worse the effect gets with distance.
I think thats only a minority of cases where land grows arid and is sold and this arid land is also valuable enough where homes can be built and immediately sold. I've lived in areas on the suburban/rural boundary and its not really like that. The farms are very productive, its just a suburban tract with homes starting at 400k makes a lot more money than a soybean harvest so when a developer comes a knocking farms are eager to sell. The children don't want to be farmers like their parents, they want capital for investment in other ventures and are happy to exit the farm business. Around these new housing tracts fields are still being plowed and harvested because the soil is still productive.
Plus with modern agriculture its hard to get arid land unless you are broke and cant afford fertilizer. Plants need nitrogen, phosphorus, and potassium. they will grow in a cup with some inorganic gravel or on a pile of rusty screws or in some pocket lint if you put these three things in water.
Is that because they didn't know what they were doing or because they saw the writing on the wall and planned their exit?
Low margin industries tend to have a lot of things that are done "wrong" by the calculations of the clipboard warriors that dominate online discourse because said calculations tend to assume constants for things that should are variable (like the regulatory situation, state of technology in an industry or rate of progression therof) and assume amortization timelines that are unrealistic. When your margin is razor thin it often makes the most sense to do things in a manner that's non-optimal on paper but yields guaranteed returns today. Do that every day and you stay in business. You might make less money in the long run but you aren't taking on risky capital investments or boxing yourself into a risky corner with inflexible business practices.
There are two metal recycling yards local to me.
One is part of a chain, run by a subsidiary of a public company. All they do is scrap metal and they are highly efficient at it. Things are clean and run by the book. The facilities are orderly. The machines are new. You can't scrap a car, a street sign, or anything else that's suspect without giving them all sorts of ID. On paper, they do everything right.
The other one is a 150yo family own business. They do scrap metal but have a handful of other income streams using the same facility (everything is for sale, basically). I don't think they have a single tool or piece of equipment that was made this century. The facility is always overflowing with piles of various materials that come and go in no apparent order. Their workplace safety is fine, but absolutely rife with tiny things they could get fined for. They pay their employees crap and make up for it with perks (free lunch every day, free fuel oil in the winter, can use company trucks and facilities for personal projects with permission, etc). I'm pretty sure you could scrap a stolen cop car there if you brought it in the same day that the full train cars of processed material go out. On paper all this is wrong. The clipboard warriors would have a field day making it "better"
Guess who weathered the pandemic with nary a slowdown and guess who couldn't retain staff or keep their machines running and cut back hours?
What builds the resiliency in the latter compared to the former?
If it's "turning a blind eye to regulations" that leads to follow-up questions. Is the intent of the regulations that are not appropriate? (i.e., the requirements are wrong?) Or is it that the former is inefficient about implementing the requirement? (i.e., the process is bad). Both of those have fixes that are outside of the dichotomy proposed in your post.
The by the book business isn't hiring young people and teaching them how to drive heavy equipment. If their employees felt exploited they'd have problems retaining them.
I think their employees care more about the perks and the fairly laid back work environment than they care about all the fire extinguishers on the property having an up to date tag. I know I did back when I worked those kinds of jobs.
>fire extinguishers on the property having an up to date tag. I know I did back when I worked those kinds of jobs.
This is a problem with how you're thinking about low probability events. Yes, rules only matter when the low probability event occurs. Do you, for example, not care about up-to-date A&P logs on the aircraft you fly in as well?
I'll be the first to admit that regulations can go beyond what should be considered an acceptable risk, but we have to at least acknowledge the risk they are meant to mitigate before determining if it's a reasonable regulation. That often involves understanding the consequences of low probability events, something we're usually not good at thinking about very well on a day-to-day basis.
> If their employees felt exploited they'd have problems retaining them.
That is not usually true. Lots and lots of people feel exploited by their employers, yet stay in their jobs. Generally, they have financial obligations, need money and benefits, and jobs aren't so easy to replace.
The family scrap yard is hiring able bodied young men and training them to drive heavy equipment (which they then presumably slap on their resumes). I know they get free lunch and (used/questionable) fuel oil/diesel because I've discussed it with an employee (last July/August or thereabouts). Based on the demeanor of everyone there it seems like a great place to work if you don't mind working outside and a fair amount of physical labor. I don't know what they're paid but all things considered it's probably crap. They wouldn't be hiring highschoolers if the pay was good. Considering how permanent some of their employees have been over the years despite being at an age where one is typically "leveling up" quickly.
I feel very comfortable saying they're not exploited.
I don't have the same visibility into the "corporate" yard because I only go there when I have to (they are only closed Sundays and federal holidays) and they have organized their workflow to keep their customers at arms length.
What do you conclude? How does one person's perception of one example impact the overall issue?
> Based on the demeanor of everyone there it seems like a great place to work
If you mean it is your family scrapyard, I will suggest that many employers have formed that impression - often mistakenly (myself included!). I've heard it many times. My favorite was someone who told me how people loved working there and they didn't have the absurdities so common in business. Then we were walking around the cubicals, and it was observed how many Dilbert cartoons were posted.
I meant it is a family business, not my family business. Like their website has a picture of their ancestor hauling a boiler on a cart pulled by a team of oxen and it's currently run by two brothers of the same last name and the same name as the business (so I think it's a safe bet it's still in the same family). The point was to contrast it with BigCo that has MBAs writing the rules and shareholders it's accountable to.
I do a substantial amount of business with that yard (and less of the corporate one, because they won't sell material and are generally way higher friction to do business with) and it looks like a very fine place to work. But this is also coming from someone who has worked in adjacent low margin industries so I have no delusions of ping pong tables in the break room.
To reiterate what I said before, they're taking young able bodied men who are willing to do physical labor (this is a demographic that can basically find new jobs at will, you can't really trap them in a shit job) and teaching them marketable skill. The fact that those employees don't just turn around and get a different job with that skill says something about the value proposition of working there.
Is it really so unbelievable to you that a business can not follow the letter of the law and not treat people like crap at the same time?
I find it completely believable, and I suspect that such practices make up some kind of norm for generational family businesses. I've known many California restaurateurs that behave this way.
Farms fail all the time for a variety of reasons, but even successful farms can be less valuable than suburban residential subdivisions. If the farms in question were further from the city, better farmers would buy/rent them and the land would be productive again.
If the farms in question were further from the city, better farmers would buy/rent them and the land would be productive again.
1. You are assuming "better farms" have the capital and will available to purchase the land.
2. Just because a competent farmer purchases the land does not make the land arable. It could take decades to undo the damage from improperly cared for land.
I am assuming a functioning market for farmland. As I have observed over several decades, and my father and grandfather observed for much longer, the market for farmland is brutally efficient. (Insufficiently-regulated monopsonies arrange society so that their inputs are as cheap as possible.) Lots of rural land lies fallow, and much of that has ruined some poor farmer who tried to grow or graze ground that wouldn't pay him back. My point is just that while we can draw that conclusion about empty fallow ground, we can't draw it about ground that currently sees more remunerative use than farming.
I don't think we can really know anything for sure about point 2 for hypothetical internet discussion agricultural ground. It is probably true that some land has been so damaged, but it is also possible for farmer B to have better results than farmer A on the same land. This is possible even if they are in some sense equally skilled and capitalized. It doesn't rain the same every year...
When someone wants to sell a field the real estate agent will ask for copies of the forms you submitted for government insurance, and other forms of proof of that it yielded. you don't have to give this, but it is a red flag to most farmers (not all farms collect this data, they are not worth as much). Giving incorrect information is fraud.
Of course there is always information asymmetry, but farm buyers are aware of it. In most cases the buyer already lives in the area, so they know just be driving by over the years what really happens.
He may also just be working the land of let's say Bill gates and not care much for it's longterm potential. I feel like a lot of us in this thread are just throwing guesses out there.
One of the problems goes back to the reason cities are where they are to begin with. People settled where the farming was best. More people came to join them, the farms became settlements, the settlements towns, and the towns cities. Now all our best land has been paved and farmers are out trying to grow stuff on land that previous generations passed over as not sufficient.
Cities cannot be supported by the farms nearby and must be located near an easy place to ship goods. That was water for most of human history, until the train happened.
Small towns happen all over because of farming reasons, but even then access to trade was a consideration, but only secondary to close to farms. (which is to say if there was good farm land far from any way to trade there will still be a town someplace - you see this more with mines as mineral often are in places that are difficult to get to by trade, while farm countries implies enough water which implies rivers)
At the limit (infinitely wide load), the max sum somewhere in the middle is just going to be the point load at the surface (plus the weight of the dirt). The load you've described isn't an infinite motion machine.
I guess you're saying constant pressure x wider = more weight? So is GP, but the other way around: more weight divided by more width keeps pressure constant.
>So there is a sort of load pyramid that has to form underground to support each point load. And the more point loads you add in a grid, the deeper you go, the pyramid overlap more together. So with constant pressure, the wider area you have, the more there is stress deeper down, and the worse the effect gets with distance.
This only works in the land of spherical cows.
In reality the pressure is never going to be higher than what it is at the contact patch and while a much wider area is bearing the load friction between particles and height of overburden dominate.
If what you are proposing was true many sorts of construction projects would be much simpler
Completely anecdotal case in point: I live on what used to be a farm. Last year was the first where the well below the house did not carry any water despite moderate rain throughout the year. Instead, heavy rainfall in the last days carried away the top soil layers and washed them off the fields and onto streets and playgrounds.
To me, the explanation that lower layers have been compacted and now block the water seem pretty reasonable.
In fact you SHOULD have a layer of clay between the surface and the ground water you are drinking. You don't want a fast path between surface contamination and your well water.
You want a compromise. You need water to get to the well somehow. It needs to get there fast enough to replace what you use, but not so fast that it isn't filtered first.
While it’s better to avoid it in the first place, farmers have long dealt with subsurface compaction using an implement called a subsoiler, which breaks up the compaction and restores normal drainage.
The article didn’t address that, but did speculate about the ecological intentionalities of sauropods. I suggest the authors do more field work, preferably with a horse and a moldboard plow.
Recently I read an article in which someone pointed out that while compaction in the root zone can be mitigated by better management practices, compaction at the bottom or below this are will remain until the next glaciation period.
That is very, very bad. Practically our only option at that point is to build soil up which is not something modern farming remembers how to do.
Tillage combined with fertilizer. Tilling fluffs up the soil temporarily, but it can and often does compact down harder than it was before.
Organic farming started down this path, but semantic diffusion killed that, and the mantle was taken up by the no-till and permaculture people, after their own fashions.
The question of whether animals help or hinder is still a bit of an open one, but there is some evidence that in the wild, herd grazing was a net benefit to prairie health specifically because predator pressure keeps the herd moving. We see a similar thing in forest settings. In areas where wolves have been removed, the deer end up damaging the trees.
A number of farmers have been working on rotation grazing strategies, typically using movable electric fences and short intervals between moving the animals. Joel Salatin and Gabe Brown are two people you can find on youtube (and in Gabe's case, at the book store). IMO Gabe's videos have more information, while Joel's a better salesman.
Edit to add: There's also controlled fires, but that's a far tougher sell in this day and age.
You can contact your local ag university. Building soil up is hard, if you are building a mm of soil every few years you are doing great - good luck measuring that.
Other posters have mentioned no-till: it takes about 7 years from the time you decide to go no-till until the time when your land yields as much as equivalent land that has been tilled all along (assuming all else is the same), but after those 7 years no-till yields better than tilling the land. Thus the question is are you willing to make that investment.
Search for “regenerative agriculture” and “permaculture“. It’s not necessarily something we “lost”. While some ancient farming techniques can be regenerative, exploitative practices have been part of agriculture since its inception. In its modern form, industrialized agriculture is essentially strip mining.
Symbiotic relationships take things from the other party, but they are repaid in kind.
We can't live without eating things, and in our turn we are eaten. That's life. 'Extract' can have a connotation similar to 'exploit' and if you hear anyone talking about 'extractive' in reference to the environment, that's usually the connotation the speaker is after. But 'exploit' and 'extract' can also mean something closer to 'leverage', which I think is generally the sense one associates with a symbiotic relationship.
My read on this is that humans get a bad rap because so much of recorded history and popular culture is colonial, and the most efficient conquerors also conquered the land, not just the people. Annual plants transport well, and transplant well. A civilization that survives on walnuts or figs or dates or fish can take land from another tribe and thrive immediately, because neighboring tribes have pretty similar diets and agriculture. But conquering another civilization? More efficient if you can bring your agriculture with you, destroy theirs, and replace it with yours. Even if you leave, that scar will last for generations.
Conquest is less effective if you have to assimilate first. Which is not to say that it doesn't work (eg, the Americas) but your competition might get there first. The people with attachment to place were better stewards, but that attachment makes you vulnerable in other ways.
Indeed, which is why the title is so strange. Sauropods are a strange thing to compare with anyway, I would compare it with other methods actually used for working the land.
The comparison comes because they're trying to draw conclusions about the effects of large sauropods on the prehistoric environment from modern experience with mechanized agriculture.
"As the total weight of modern harvesters is now approaching that of the largest animals that walked Earth, the sauropods, a paradox emerges of potential prehistoric subsoil compaction. We hypothesize that unconstrained roaming of sauropods would have had similar adverse effects on land productivity as modern farm vehicles, suggesting that ecological strategies for reducing subsoil compaction, including fixed foraging trails, must have guided these prehistoric giants."
This is strange because the subsoil composition of today vs. 65+ million years ago, let alone 250 million years ago, is substantially different. Mostly different insects, different bacteria, and though Earthworms did exist for much of that period, other types of worms did not. Lignin was already in trees and mushrooms were already in the ground, but soil as a living ecosystem was far less developed and alive than it is today - it was probably closer to regolith at least in the 250-100 million year ago period.
I've been listening to Nick Offerman read The World-Ending Fire: The Essential Wendell Berry. Wendell talks about using horses instead of tractors - the impact on the land and the economics. (using horses is just a small part of the economics - a community / local approach being a large aspect of Berry's writings)
Coming soon: Chris Pratt using a team of sauropods to farm in the next Jurassic Park movie.
Sauropods are presumably the heaviest things we know to have worked the land in anything like a sustainable way: being herbivores they obviously can't survive for long as a species if they permanently damage the soil to the point of being unproductive simply by walking on it.
It would be fair to object that what was unsustainable by plants then might not be a problem for more modern plants, but I'm not sure what your comment about other methods aims at. The uncertainty comes from machines reaching previously unexplored weights, comparing with soil effects from lighter methods is unlikely to tell you if there's something bad coming.
All we know is that it apparently worked for Sauropods, not what the upper limits are, and it need not have been sustainable, that depends on how big an area they were covering and how many of them there were, that it was sustainable is something the article seems to assume without further consideration.
Other methods are more applicable because we actually have data on what works and what doesn't with respect to soil loading, farmers really do not want to damage their land ('damage it in an hour, take a decade to recover') and have learned the hard way not to overload the soil already.
The resistance of soil to compaction is totally different in a forest with mighty trees and roots, where these beasts presumably roamed, and a barren field of dirt.
And secondly, 'sustainable' to a heart of wild beasts does not mean harvest every year - maybe the heard comes back in 20 years when soil has recovered.
Lastly, maybe they wheren't sustainable, after all they are extinct.
> Lastly, maybe they wheren't sustainable, after all they are extinct.
I mean, they existed for tens of millions of years (according to wikipedia), which is 1000's of times longer than the entirety of human farming; I think this easily classified as "sustainable".
Yes. I think GP’s point is that dinosaurs and big tractors are different enough that it’s unwise to dismiss concerns about this as “well, it worked for the dinosaurs.”
Mass and ground loading is just one part of the picture. Roam area, root structure, etc make a difference.
The point of the article is that from the fact current heavy tractors are ruining soils we should wonder how Sauropods managed to survive despite being worse for the soil.
Oh, thats easy - we are 8 billion, sauropods were a few million. We can't digest cellulose, and sauropods could. We eat mean, and sauropods didn't.
If you can digest tree bark and have 5 square kilometers per person you can damage the soil as much as you want, something will still grow.
But if you want civilisation to survive, we need a regular harvest of 40 tons per hectare for potato, and if that number falls to 20 there is a famine.
The Sauropods where around for over 20 million years though, but moving at an average of 1 m/s it doesn't take even a year to visit all square metres inside the allotted box.
That number was for a human - a hectar of land can feed a person, so 500 hectars can feed a person even if you are inefficient, damaging the soil, etc.
You are the one advocating we live like Sauropods, so you should be telling us what was the roaming range of one - a male bobcat has roaming range of 20 to 70 sq. Kilometers
I just skimmed the abstract but it sounds like they made the comparison because sauropods already compressed most soil everywhere. So it simplifies it a bit in the title, but it's about exceeding the level of compression already established anyways due to sauropods.
Also the weight over area might become less relevant the deeper you go because it naturally spreads outwards anyways.
> because sauropods already compressed most soil everywhere
That happened long ago that I don't think that you can state that with such certainty about the state of soil today. It makes zero sense. Sauropods lived at the latest 66 million years ago, and quite possibly longer. Unless there is some other link that the article tries to make but I've missed.
> Another way in which farmers combat soil compaction is by aeration and tilling.
The problem is that constantly aerating and tilling the soil is destroying microbiomes and fungal networks. It's one of the fundamental principles of regenerative farming. In good industrial fashion, we destroy nature (overfarming) and try solving it (chemical fertilizers) only to destroy it further (mono cultures, no biodiversity, leading to soil degradation, reduced yields), so we try to fix it again (huge machines, more mono cultures), and now these machines are destroying the soil because they are too heavy. It's time to dial back and rethink what we're doing.
Yes, there's an actual no-till movement with organic farmers as well. It's popular for two reasons:
- It's a lot less work (no tilling, less need for getting rid of weeds). Especially for private gardeners, interesting to know probably.
- You can actually get good results with it. Healthy soil means plants have an easier time (less pests and diseases, which are generally signs of plants not doing great).
Simply using nature to work for you instead of trying to against it can be a huge time saver.
IMHO there are a few positive trends in agriculture:
- farmers are starting to like some of the organic farming practices. They work and produce good results. Also the produce is more valuable.
- high tech farming is all about being smarter with resources; including water, soil, labor, energy, fertilizers, pesticides etc. Low tech, intensive farming is mostly about blindly doing things at scale. It works but it isn't necessarily very efficient.
- vertical farming is much more efficient with land and increasingly used for producing high value produce. There might be some future breakthroughs with more nutrient rich things like rice or grains but that seems to be not possible currently.
- synthetic meat grown in a lab gets rid of a lot of CO2 issues associated with cattle.
So, the agriculture sector might look very different in a few decades. Plenty of new and exciting things happening.
Most (by far) farmers practicing no-till aren't using nature to work for them, they are using chemistry... specifically herbicides, like glyphosate.
That's not to say it's wrong; in a lot of cases using herbicides instead of tilling is actually more sustainable... many soil types will degrade very fast with tillage, and while herbicides surely also have damaging effects (in terms of microbial composition, etc), the evidence so far suggests strongly that tillage is worse.
>synthetic meat grown in a lab gets rid of a lot of CO2 issues associated with cattle.
I mean if you isolate for certain things like methane released trough farts sure...
But from what i've heard it's still a process that requires a lot of hard to add up factors which aren't accounted for and is difficult to scale to boot.
In a vacuum it seems like your meat was great and neutral for the environment. The gathering, production processes, logistics, etc of all the chemicals, materials, etc involved might make it all a bit more vague.
I don't think chemical fertiliser is a solution to overfarming; it's a way of increasing yield. Although I guess that could be what you mean by overfarming? The yield per hectare should be whatever is naturally sustained?
The idea that farmers already know this and manage it through tilling is contradicted by the abstract:
> We demonstrate that modern vehicles induce high soil stresses that now exceed critical mechanical thresholds for many arable soils, inducing chronic soil compaction in root zones below tillage depths and adversely affecting soil functioning.
I’m also skeptical that farmers are aware of what’s going on below root zones.
Programmers who frequent HN are known to be multifaceted specialists who can debunk and upend entire swaths of advanced study by only skimming the abstract. That is why we come here, to see that magic first hand.
Speaking as a farmer, the "plow pan" is an old and well known concept. While it is true that routine tillage does not reach these depths, there are various techniques, including what is known as deep tillage, to try and address the problem at those greater depths. With the advent of GPS, controlled traffic farming moved to keep the machines on the same tracks to limit the damage to specific paths in the field in recognition of the same.
Maybe the study is talking about something else, but if that's the case I'm not sure it has made itself clear. We are very much aware of what goes on below the root zone and understand the potential yield loss impact that can come of it if not managed well. We work closely with the scientific community to ensure that we are aware of these types of things.
When we bought our farm it had been conventionally farmed for decades. Not even by the biggest tractors in the world. But the compaction is real, and the hard pan that develops over time is as well. Tiling and aeration release a lot of carbon into the atmosphere, and while they offer some short term benefit, they also destroy the soil structure over time. This is why “no till” is a popular buzzword these days; people are trying to find ways to replace tiling in the effort of rebuilding soil.
This isn’t new — when “Tree Crops: a permanent agriculture” was written last century, it focused on the ever depleting top soil in the United States and elsewhere, and inspired the concept of Agroforestry.
This “as every farmer knows” is naive. Many farmers are smart and capable people but both them and the increasingly dominant ag-corporations are primarily interested in short term economic survival/success and are working within a system of often perverse incentives. Most farmers might not enjoy ruining their lands but plenty have done so, sometimes knowingly, because it works for them in the short term.
Stand close to railroad tracks when a train goes by. You'll feel the ground sink and spring back.
At the right speed and springiness of the track, the train can create a standing wave in front that builds (like a resonant frequency does) until the track comes apart.
I know that in the Netherlands this has huge implication. In the Netherlands the groundwater level is artificially maintained. Farmers have a large influence on this level historically because they don't want it to be too high or else they wouldn't be able to use their heavy equipment. But since there has been quite a drought in the summer in recent years many other parties want to increase the ground water level.
As I understand it the problem is rather (as the article disccusses and as others here have commented) the long-term damage to deeper layers of the soil, resulting in "hardpan" [1].
as a person that worked in farming analytics I can promise you the average farmer makes tons of mistakes of that kind because either lack of knowledge or planning.
They do say in the article that this is impacting root area below tilling depth, which I presume means that deeper tilling could help, but I'm unaware of whether this level of tilling involves turning a dial, or designing new equipment.
When you over produce crops you tend to plant them in narrow rows which overloads the soil hence the need to use fertilizer. Note, it's been this way since the 1940s in USA and Europe.
Or in short words we are not being effective in feeding the world and are wasting efforts on capitalistic goofs rather then using more effective solutions.
Native American Indians used a technique borrowed from South American Indians where they refused to do monoculture, instead they grew 3 to 4 crops in the same field.
If we want the future world to starve we will stay on Monoculture.
If we want to save the planet then we need to move away from Monoculture.
> Native American Indians used a technique borrowed from South American Indians where they refused to do monoculture, instead they grew 3 to 4 crops in the same field.
Are you talking about crop rotation or growing multiple crops in the same field at the same time?
Same field, same time. This allows each crop to share different proportions of the soil nutriments, but also help each other because you reduce the pest load as pest do not target the same way the different crops.
This is the same principle we have in mixed forestry (where I have more experience).
They did that, but modern science has checked it out, and found the crops competing with each other means all crops are harmed. Crop rotation - where you grow a different crop every year is a much better answer.
I would be interested in your publications because doing a simple search[0] and reviewing a couple of papers provide me with more positives than negatives.
Nobody has ever disputed that mechanization and intensive use of herbicides, pesticides and fertilizers will increase yields in the short term. But what we are currently experiencing are the long-term consequences, which together with the effects of climate change and the vulnerability of global supply chains pose a real danger to food security around the world.
We are much better off with them than without them. Someone might say, when their car breaks down, 'being dependent on this car is causing me serious problems; I'm better off with a horse'.
It’s not a “with or without” question. Is a “do we want to rely on the behavior of a country like Russia or China, or do we want to assume that these supplies are risky so let’s model and mitigate that risk” question.
It kinda was a with or without question in the parent comment, that we will starve and the planet will die if we use monocultures. Hence my comment. Of course I agree with you that agriculture can be more robust, but 'native Americans did this technique with low intensity method to feed a small population so we should' is about as facile as the 'trade cars for horses' example
With the impeding electrification we might eventually see walkers on skis-shaped feet, as a compromise between load distributed over a large area and a narrow tread not usable for growing. They'd also excel in the metric of total traction per peak surface load.
Key technology of electrification would be tethered drone swarms that feed from the cable they carry, because I'd assume that you'd want to separate batteries from your actors so that they are flexible you work from grid infrastructure just as well as from some battery truck tagging along on an access road (which brings us back to surface load, you wouldn't want the battery loading soil you still want to grow in).
As a John Deere Employee I have to be careful what I say.
I will say (because this is obvious from public information) that we are "looking" at electric tractors, but making them work is hard. 10 years ago we stuffed as many batteries as we could in a 100 horsepower tractor, and for 45 minutes it when head to head with a similar diesel tractor, then the batteries were dead. 100 horsepower just above a small tractor these days. Remember a Tesla might be able to produce 500 horsepower (I can't be bothered to look it up, but something very large like that seems reasonable), but to maintain speed on a freeway it only needs about 20 horsepower. A tractor is expected to produce the rated horsepower for 10 hours non stop.
Your idea of a feed cable is something we have looked at (you can find an announcement, though it might be in German). There are a lot of issues with making it work in the real world, though it might be where things go if diesel gets a lot more expensive.
It seems people (outside the agriculture industry) underestimate what todays tractors (and even more so harvesters, etc) can do and how much power that requires. Harvesters running 12-24 hours a day for days or weeks seem way out of reach of what the current battery technology can accomplish.
I'd bet on hydrogen engines (at least in the next 5-10 years) for larger machines.
On the other hand tractors are multipurpose tools and it highly depends on what it will be used for. If the tractor is only expected to run a few hours a day then batteries might actually work
Since the infrastructure already exists wherever there is serious agriculture, we should probably call that "liquid anhydrous ammonia engines". NH4 is a more practical carrier for hydrogen than its elemental form.
Basically when ya chart out gravimetric and volumetric density stuffing batteries doesnt seem to make sense. There may be some other options (feed cable, slower cycle, etc.)
Has anyone tried standing up a cable car-like system where overhead lines pull (and power) the tractor? You could use wind turbines as the poles that keep the wires up in the air (though I suppose you could also use subsurface cables but that would reduce the growing surface a bit; then again, there's always space between rows of crops).
In the horse age things like that were tried. It isn't practical to setup in a large scale, but if fuel prices continue to go up weird things might be more practical than fuel...
I would have thought electrification might work well on very specialist machinery - perhaps around horticulture, vinyards, greenhouses, etc.
But part of the appeal of a big powerful tractor is their huge versatility - you'd loose a lot of that if you needed additional infrastructure in place.
Not sure why you are responding to my comment either... but what you are saying makes no sense to me.
Obviously the pressurised air itself has mass, but I think its more to do with tyre deformation modifying the contact surface area. The air inside is just to distribute the load across the contact area.
I don't know. Googling, I was able to come up with some examples, but I've never seen them in real life despite growing up in a farming community.
My speculation: you only harvest in dry weather (so traction differences don't matter), and harvesting goes faster than say tilling, so maybe tires are preferred. You'll also see big fleets of combines going down the road to the next field; I think tracked vehicles are frowned upon on public roads.
Because treads are worse than tires for compaction overall. As a soils expert explained to me (phd in the subject), compaction is a function of weight, but the function is something like 0.2*(weight) (obviously it is more complex than that and depends on the exact soil type). Compaction happens only where the tires/treads touch the ground, and tracks touch a lot more ground when you turn so even though there is less damage across the field you lose all of that and more when you turn around. Not to mention tracks have to slide sideways to turn and that is bad for your topsoil.
> Not to mention tracks have to slide sideways to turn and that is bad for your topsoil.
It's unusual and perhaps not suited to large tracked vehicles, but there is an alternative to using differential track speed for turning: track warping. Basically the vehicle bends the tracks one way or the other to induce a turn. The turning radius sucks though.
>The whole point of tank treads is to maximize the ground surface area that the vehicle weighs on.
The treads don't spread weight much more than the wheels - look at tank treads in practice - they are somewhat loose between wheels. Most treads are somewhat loose, meaning the tension in them is not enough to be supporting tank weight. The exist to provide traction when they catch uneven surfaces, where wheels perhaps no longer make contact.
Their point is to allow the tank to catch on non-flat ground when things jut between the wheels. Treads allow grip on non-uniform surfaces.
But most of the time the weight of the tank is completely on (only a few of) the wheels.
explained a few comments above - the question isn't that of direct pressure (that could indeed be solved by using tracks), but sub-surface pressure. Probably how the overall structure is held together and distributes weight in depth under the overall vehicle surface.
In that sense, it would probably help making tractors more like ships...
Or like airships, floating above the crops and only touching it with the whatever devices are used... Fun aside, agricultural devices on rails are not uncommon, although definitely not for such large areas like a normal field (yet?).
Actually a dirigible fixture could probably reduce the weight on the wheels by an order of magnitude for (relatively) little cost. Assuming little maintenance for the dirigible fixture and reduced maintenance for the smaller drivetrain, this might actually make financial sense. But it would require a hanger for parking.
This article considers stresses further down, where the load has already had a chance to spread substantially over a large are.
Loosely speaking, at some depth it's the entire column of soil below that supports the weight of the machine, and piling on more weight will exceed the uncompressed strength from the column, and so it compresses to handle the load. The problem being that compacted soil is bad for plants ability to grow there.
Only where it the tires travel (and a bit to the side), which is why one heavy tractor are still better than many small light ones doing the same job: the heavy tractors does a bit more damage to a small area, but the light tractors do a bit less damage to a lot more area.
>This is the new normal and is largely all an entire generation of farmers knows.
That might be true for farmers, but what about big/institutional farmland owners? If the practice is killing future productivity, surely they'd be incentivized to protect their investment? If you're a landlord you wouldn't be cool with renting your units to some crackheads for "the biggest short-term payday".
Corporations have fiscal obligations to their shareholders, in quarterly cycles. "Renting to some crackheads" (a great analogy!) is always on the table if one literally believes that they have no long term obligations. Not saying ALL are so short sited, but there are serious systematic problems in agriculture and corporations are certainly not leading the way on any solution.
On our farm we would use an attachment called a ripper. It was a series of blades that would reach down 18 to 20 inches to break up the soil. Behind each blade was a 3.5 inch diameter bullet shaped slug (called a mole) that would create an underground tunnel, not unlike what an actual mole creates. We grew carrots, so it was imperative that soil compaction was limited or it would stunt the length of the carrots.
When you destroy/squeez fungus in the forest it takes centuries to recover[1]. In Prussia when they started with scientific forestry, productivity of the forrest dropped significantly after around 100 years[2].
Good times to come. I wonder why we look the other way, even when we have all the knowledge on our hands.
Two great books:
[1]: The Hidden Life of Trees
[2]: Seeing Like a State
In fact no. Bigger heavy machines do less damage than smaller ones overall. You have to look at the whole field, not just where the tires touch. Where the tires touch the ground the heavy machine is worse, but the smaller machines touch the ground in a lot more places and so do more damage.
Farmers are now using GPS to ensure all the tires that touch the field drive exactly the same place every pass, every year. Where the tires touch the ground is hardly worth farming, but the rest of the ground is undisturbed and so much healthier.
> smaller machines touch the ground in a lot more places an so do more damage.
That’s certainly possible but not a given, and I think the somewhat obvious implicit suggestion was to use smaller machines with a lower weight to surface area ratio, no? Damage isn’t a function of how many places the ground is touched at all, it’s only a function of weight per unit area.
Is it possible we could design small robots that weigh less per unit area than the large tractors? Sure, why not? We could have smaller machines with bigger tires, we could design machines with weight reducing features like propellers, we can choose to use lighter weight materials & designs for machine frames & engines. It seems like there a plenty of possibilities that are not in fact impossible.
The function multiples weight by a very small factor though, so area dominates. (I have no idea what the function is, I've just had conversations with soil experts who tell me this)
What area? What weight? We need specifics in order to make claims one way or the other. It’s not just possible, but easy to design machines with lower weight to surface area ratio, so it’s just wrong to conclude the answer to the question can do we better is somehow no.
You can get a phd answering this question, something I do not have. What I have done is talk to such phd's - 5 years ago. I'm not giving more details because I don't remember more. I remember this much because it stood out to me as so non-obvious.
That first one is incredible and the second looks like a more cost effective option. Most don’t realize that organic farming isn’t pesticide free but this gives farmers that option without resorting to hand-weeding.
There's also the trade-off between width of the worked area and the treaded surface made unusable for the season. If you have any tractor work steps between seeding and harvesting, you want all those runs done in exactly the same tracks to minimize waste.
A "small robots" revolution might still come, on the coat-tails of agrovoltaics: if/when someone in the right position begins thinking the panel scaffolding as dual use, doubling as a "rail network" for robotic tools. I believe this could become a feature of agrovoltaics installations as unremarkable as overhead cranes on factory floors.
This is the idea of controlled traffic. Use the same track over and over again to not compact the soil where the plants grow. An example of a large machine doing so is the Nexat. There are videos on youtube and some detail on their website https://www.nexat.de/controlled-traffic-farming/
Going larger there increase the percentage of growing soil vs track soil.
Reading articles like this always amaze me, not so much for the problem itself but for the existence of the problem and millions like it that I never even consider in my day to day. The more you know the more you realize there is so much you don't.
This article is total BS, they could actually research the yields/soil between farms that use Steiger/John Deere 50,000lb tractors tractors (or smaller) versus farms that use Big Bud or other insanely large tractors.
Truthfully ballast limit on most normal machines is around 60,000lbs for many years now which I am guessing is the realistic maximum the soil can handle and manufactures have already figured this out.
I recently read a fascinating book about trees. It was called The hidden Life of Trees.
One study they talked about in the book, tried to find out why pipes were often destroyed by tree roots. Most people assumed it was from water leaking or condensation around pipes. However, the study found that it was actually because the soil was far looser and less compact around the pipes.
It is almost impossible to really gauge all the ramifications of any choice within the analog system we live in.
It feels like there should be a more direct way to grow stuff. AppHarvest is doing something interesting. Why plant in dirt outside and rely on lossy transmission of fertilizer and water to the plant? Plus fungus, parasites, etc. A controlled environment where you can get the nutrients and water directly to the plant seems a lot more efficient. I know the capex is huge but still. We probably should all be eating less (and wasting less) food here in the US.
Mostly it's just economies of scale. Who cares if 20% of the crop is lost to random soil related problems if you can grow ten times as much stuff in dirt than in a controlled environment. Land is so much cheaper than indoor farming.
However, I think the critical thing that is going to make indoor farming commercially viable will be water prices. At some point, the heavily subsidized water in the western US is going to finish collapsing. Indoor farming lets you milk every drop of water into product. We're talking 10:1 ratios of water usage between outdoor and indoor farming.
Currently, water to grow iceberg lettuce is about 12% of the total cost in California at $216 per acre foot. Currently it is possible for those rates to triple or even quadruple in the next few years. We may be seeing a lot more indoor growing soon!
I, on the other hand, don't like the design of the article viewer on PNAS because it doesn't show anything useful if javascript is disabled. I would rather it just point at a PDF or epub.
Not in agriculture, so I don't really know what I'm talking about, but...
Isn't that pretty much everything that's wrong with our agriculture today? Isn't large-scale monoculture, which this system obviously aims to support, a part of the environmental problems we're facing?
The original article points to the unsustainable course of the current trend, so while the caterpillar system and the ability to roll on less land solves the immediate problem described, it fails once you look at the bigger picture, I think.
There's no reason why a giant machine can't manage multiple different crops/plants at once. The problem in industrial agriculture isn't the geometric layout of straight rows/columns... It's the monoculture (and fertilizer/pesticide usage and soil compaction and plastic pollution!).
It would be interesting to see a farm get a new voronoi-style layout each growing season.
Given that the problem is effectively 'total force over the entire footprint of the vehicle', you would need a platform that doesn't press down on the ground. I guess helicopers would work. Maybe a hovercraft too, but I suspect a hovercraft effectively transfers all the force into the ground anyway.
There is a lot of active research in this domain but it is hard to make something that is as reliable, usually the goal with those systems is not to allow for lower soil compaction but to be able to work in places where wheeled vehicles can't.
The obvious solution is automated tractors. The main drive for larger and larger tractors is to maximize the amount of ground covered per time / operator. If the tractors can work tirelessly day and night that is somewhat mitigated.
The actual driving part is obviously much more trivial than autonomous driving on roads. However there are a lot of hard to automate adjustments and maintenance items going on with many tractor implements.
As I understand it (and I don't understand it, I'm not source of authority here) the tractors don't need to work day and night, they need to work during the important planting and harvesting seasons. That happens to be the same time that your neighbour wants to do it. Efficiency is key here so that one harvester can work several farms 24/7, for a limited period of time.
As you outlined, uptime is critical during these periods. I spent a lot of my time in remote locations, and reliability trumps everything. The cost of a hotshot is significant - however I was far more remote than the farms where.
Paying a person to drive the tractor doesn't seem like it's the large cost. It's the machinery you need 1x per year, at the same time everyone else does.
Not really. The larger you make a powerplant, the more thermodynamically efficient it can get. This is why things like trains and supertankers make sense where they are available.
I don't see that a more complex vehicle would have a significant affect. All that matters is the weight/surface area contact with the ground. You can achieve that by using tracks or just bigger and more tires.
If you're making the case that heavy farm machines reduce soil function, why would you throw the sauropod analogy into the mix to complicate things? I guess it would be a bland paper without that bit...
I read this “research” and the quality is laughable. Farmers, paleontologists and soil researchers will all find hilarious passages that make it seem like a high school project.
> [...] chronic soil compaction [...] negatively impacts various soil functions (9, 26). These are manifested by a persistent decline in crop yields (13, 27, 28), limited water infiltration capacity (8, 10), and a decline in other soil ecosystem services (29, 30).
It is a pity the article calls these effects as "well known" and does not explain them deeper.
The answer is yes, bearing in mind this study is actually about bioremediation of the toxic residues of (some!) explosives.
I struggle to think of a way that a guncotton deflagration could contaminate soil, this could just be a failure of imagination on my part but the idea isn't completely insane.
Another pathway has been described in Pseudomonas sp. strain JLR11 and involves nitrite release and further reduction to ammonium, with almost 85% of the N-TNT incorporated as organic N in the cells.
Yep, I know. Still, using explosives on a mass scale to counter the actions of tractors is rather impractical. The only place it might be considered useful could be the Ukrainian war. In all other places, digging the earth to plant the explosives will do more for tilling the soil than the explosives themselves.
Yup, it is NOT just the pressure/surface area (which does apply to the top layers of the soil), but the total weight supported by the soil (which compacts the also-critical deeper soil layers).
This is just one of the problems of massive monoculture farming.
It is insanely destructive and unsustainable.
On a recent-ish trip to the midwest US, driving away from the airport/city seemed lovely as the landscape turned rural. Then, it started to get really troubling as we'd realize that the fields were so endless and unbroken, creating vast areas with essentially zero habitat for anything other than the farmed crop - from the lowly soil fungi to top predators - nothing. In many ways, far more unnatural than many paved cities.
Elon Musk and his ilk are 100% wrong about the "need" to continue increasing human population. We survive literally by extracting yields from the excess carrying capacity of the biosphere. At some point, we can exceed that capacity, and the result will be collapse.
This will occur like with any other population that outgrows its resources - arriving at a state where the population's needs exceed resources by 10-20% does not result in 10-20% deaths, but 80-90%, because the shortage is spread throughout the entire population - they don't just say "we're 10% over so you 10% take one for the team and die this month, sorry", but everyone is undernourished to the point of unsurvivability.
This is merely one example of how the entire system is unstable.
> "we're 10% over so you 10% take one for the team and die this month, sorry"
While it is indeed not entirely like that, it does come a lot closer to the truth than you would expect (and it has always done that).
In the 18th century when France did not have enough food, almost everybody was worse off, but most people were not actually hungry, they just paid more for the food they ate.
Because inequality is so big and following a power-law (as you go closer to the top, people have exponentially more) the prices go up a little until demand of the top x% is met, and the bottom x% cannot pay and goes hungry until starvation. And because of the exponential difference, the bottom will starve while the top will actually notice very little. There is a group in the middle between those extremes that has trouble paying more and goes undernourished, but it's not actually that large of a group. The larger the inequality is, the smaller the group in the middle.
Think about how many people in the US will go hungry because of the worldwide wheat shortage as compared to some African countries. The small price difference will be barely noticeable in the US, a country which adds on tons of other value by turning the wheat into salmon bagels in a complex process. But these price differences are huge for many African countries, which only grind the wheat and mix it with water.
Yes, inequality does indeed mean that the shortfall is not fully evenly distributed, and the rich and well-off would be fine for quite while.
But I'm not talking about collapses in the range of economics, but more of a collapse of a food chain, with no real replacements. This would behave much more like populations of, for example, deer, when they overbreed substantially past the carrying capacity of their range, and the range is constrained by geographic barriers (so migration is not an option). In that situation, populations often collapse 80%, even with only a technically 10% shortfall, because every individual gets too little to survive for too long, so expires.
Your point about inequality and stored capacity in human economies is well taken and certainly applies in the case of 1-2 year crop failures or events like the Russian assault on Ukraine and its grain production & export capabilities.
If we lose key components of the food web such as pollinators, phytoplankton, forests, etc., economics will play a role, but I doubt we'd get to the point of 'we're 10% short so you 10% starve in the next 50 days and the rest of us are fine'. Sure only about 9% of the world lives in extreme poverty of less than the equivalent of $1.90/day [1], but I'd be astonished if the losses would be constrained to that class. I'd expect it to immediately affect everyone in the 'ordinary poverty' category of $5.50/day, which was 43.5% in 2017 [2]. And frankly, it's probably be a lot more. Sustained famine over 50-80% of the population will kill a lot more than 10-20% of the population, even if the actual shortfall is only 10-20%
Why are farm vehicles so big anyway? Is one very large vehicle more efficient than multiple smaller vehicles, or are human operators the main constraint, i.e. because of labor costs it's cheaper to hire one guy to drive a bigger tractor than 3 guys to drive 3 small tractors? Maybe this is a problem that will be solved in the next few decades by driverless tractors, or just tractors that are autonomous enough for one operator to "drive" several at the same time.
I could see other advantages to having multiple small tractors: redundancy (one breakdown doesn't stop the whole show); easier transport; easier scaling (can increase or reduce capacity in smaller increments; buying one tractor no longer requires a huge equipment loan)...
The human factor is definitely big here. You want to plant as much as possible with as few humans doing it as possible. So, big tractors == faster work.
Some of this has risen because farming has (over my lifetime) shifted from small time individual operators towards giant corporate farmers. Except for high value crops, it's hard to compete with the economies of scale of a mega farmers. They in turn use their profits to get bigger and better machines than the individual farmer can afford which further allows them to outfarm the individual.
Simple example, irrigation.
Small time farmers would have hand lines that need to be moved every day manually. Those typically cost about 1 to 2 human hours per line to move daily (sometimes longer).
Mid size farmers "splug" on "wheel lines" which have motors to move the lines (at around 10k for the motor and another 1k or so for the rest of the line). Those cost about 10 to 20 minutes per line daily to move.
Large operators pretty much universally use "pivots" which cost about $1 million+ to install but are completely automated with very low maintenance. Those often don't have a daily cost (more like 20 minutes of month at most for maintenance. Some years, the maintenance amounts to turning it on and off. And even that, is increasingly being able to be handled remotely).
The equipment being pulled has become smarter and smarter over the years allowing a lot of control over the planting which has increased yields. They're necessarily heavier to contain more sensors and actuators though which requires a larger/heavier tractor to reliably haul them around fields. The tractors have also gotten significantly more advanced from tractors used in the past; enclosed cabs with climate control, autosteer to follow a programmed path, etc.
> They're necessarily heavier to contain more sensors and actuators though which requires a larger/heavier tractor to reliably haul them around fields.
This is a bad assumption
Tractors are heavier because they have larger engines to be able to handle larger equipment which in turn allows them to do the same job in less time. The weight add for creature comforts and sensors is insignificant, easily less than 500lbs in a 20k lbs machine.
They are heavier because they are themselves wider or can handle wider equipment. In effect, their "drag" has been steadily increasing which increases the size of the engine to overcome it.
> They're necessarily heavier to contain more sensors and actuators though which requires a larger/heavier tractor to reliably haul them around fields.
I'm not buying this causal chain: Sensors do not weigh much; I don't see a reason why the number and weight of actuators should change because the machines have more smarts.
I suspect tractors and implements get bigger because that's an obvious path to higher operator productivity.
You suspect correctly. Tractors weigh more because they have steadily increased in size which decreases the number of passes a tractor needs to make over a field.
Like having a 20 inch lawnmower vs a 50 inch lawn mower. The 20 inch mower can be self propelled with a tiny HP engine. The 50 inch mowers are pretty much all riding because the extra drag and engine size increase to cut the grass is large enough that adding bigger wheels and a steering wheel makes more sense than having someone push it. Obviously, the 50 inch mower will work a lot faster.
Although wheels are much more efficient than flight, I wonder if low cost solar charged and battery powered fleets of drones will be deployed for seeding and harvest in our lifetimes.
Infrastructure that's used how often per year? A dozen times? Rail lines that get a dozen trains per day tend to not get electrified...
As I've stated elsewhere, I expect a future with drone swarms that carry a power line while feeding from it. Certainly not cheap (high performance cables are never cheap, think hundreds of meters of supercharger cable?), but it would be a near-universal base technology for many application fields so it would have all the possibility a technology might need to start in some an niche and grow from there.
So many problems with cable-fed drones over farm-sized distances: (1) Cables rapidly exceed the vehicle weight; (2) keeping cables off the ground requires extreme tension beyond the forces capable by the drone; and (3) aerial drones are very sensitive to thrust-to-weight. You'd effectively need a swarm of drones just to lift the cable...
A swarm of drones to lift the cable is exactly what I meant: basically a cable with a set of thrust motors spliced in every n length units that can be coordinated to make the cable levitate. The total length of the cable is kind of irrelevant, it all boils down to how much cable (length and transmission capacity) you can levitate per dollar, and per watt.
I dunno - it's a thought I hadn't seen put out there and you're 100% against it within minutes. The field ain't going anywhere - why not have permanent solar-powered infrastructure to recharge robotic agricultural enthusiasts?
The commenter who stated he works for John Deere put out the same thought here, but like the parent expressed that diesel would have to become a lot more expensive for the infrastructure costs to pencil out.
You'd need a zeppelin sized bladder to lift a moderately sized farm vehicle. I think it would likely be impractical due to wind.
I think sets of 3 towers with cables between them so tools could be translated within their boundaries, kind of like a delta-style 3d printer, could work well.
Another way in which farmers combat soil compaction is by aeration and tilling.
It's true though that tractors are getting larger and heavier, but farmers are pretty knowledgeable about these things and usually take them into account when deciding what kind of machinery (on what kind of tires) to use for their soil, after all, if they get it wrong they may end up negatively impacting the yield of their land.
Finally, crops tend to be planted in rows for convenient mechanical processing, and while walking behind a tractor you can actually see the soil rise again after the tractor has passed, usually because the soil acts as a sponge, the tractor squeezes the water out and once it has passed the soil will spring back. It's a bit strange to realize that the ground you walk on is so springy because you normally don't notice it.