A belated answer…

This is such a weird line of reasoning. A farmers land is their most expensive asset, are you just assuming they’re all morons who want to throw that away?

I have another question: In an irrational world, why would farmers be rational?

Some examples: EU farmers buy Brazilian rainforest soy/corn to overproduce EU-subsidized chickens which are then sold into African markets, thereby killing African agriculture because African farmers generally aren’t subsidized and can’t compete on price. Half the food in the EU is thrown out, largely because it doesn’t adhere to visual norms, can’t be sold before the BBE date, or is thrown out by consumers because of the BBE date or cosmetic flaws. Most industrialized nations have subsidies to overproduce animal products, despite this massively increasing monetary, environmental, and health costs. Does any of that sound remotely useful to you?

Even if you really want to farm sustainably, there are quite a few hurdles:

• Stupid subsidies. There are many stupid subsidies, and even more of them existed in the past. For example, in Germany, you used to get money for removing trees from your field. Which is, essentially, a way to make it easier for the purveyors of tractors to sell farmers bigger machinery. But these days, some farmers are starting to use agroforestry (again), i.e. they are waking up to the fact that trees on the field can be extremely helpful: They keep water in the soil, help against soil erosion, provide a bit of shade, increase biodiversity, and when you cut them down after a few decades, there’s an extra revenue streams. Some countries now have subsidies for putting trees on fields again, which is good. But a lot of subsidies are still focused on generating unnecessarily large amounts of feedable and human-edible biomass, no matter the quality, no matter whether it’s actually needed to sustain the populace.

• Lobbies. Producers of farming equipment, chemical products, and GMOs throw around a lot of marketing money. That obviously influences their worldview, especially since many of the farmers left went all in on the trifecta of monocultures, big machines, and pesticides and they don’t want to be proven wrong. You can also see this warped worldview in many farmers’ opposition to nature preservation societies. In a better world, farmers and environmentalists would be natural allies; but they aren’t. Like in every other aspect of modern life, these lobbies often sell little conveniences that cost just a bit more, but going back on conveniences tends to be hard for all people anywhere.

• Buyers, including private buyers, wholesalers, and supermarkets. Most buyers have high standards regarding uniformity, immacularity, and freshness of food. Some of that is certainly useful (you don’t want an upset stomach all the time), but in many cases it just leads to useless waste. A two-ended carrot tastes just as good as a regular one, but it simply can’t be sold in most supermarkets. There are even field machines that automatically sort out the smaller vegetables and leave them to rot on the field.

• Lenders/investors. If you need to expand your farm or buy new equipment, you have to talk to a bank or an investor. Guess what? They don’t give a hoot about sustainability, they want their money back quickly.

• Tradition. Farmers tend to be pretty conservative people, for whom it takes a bit to take bigger steps or even just to reverse steps that the generation before them made. Even some very traditional farming techniques, something as basic as plowing are in fact maybe not quite as helpful as farmers think – plowing destroys some life in the soil and it also releases CO2 stored in soil. In an ideal world, farmers would either all be biologists or at least listen to and iterate along independent biologists (but see above about lobbies).

And when is this collapse happening anyway? I’ve been hearing about it coming in a few years for decades now.

Sure, you can’t be sure it’s happening until it does, I guess. But we do have good science on worldwide insect/bird/fish count, on soil health, on climate change (granted, while farming is an issue, it’s not primarily the fault of farming). And these all data points point in a certain unfortunate direction.

Meanwhile, in the real world, there are hundreds of soil management systems, because of course farmers understand that their dirt is the most important thing they own. They want to keep it working optimally, so the ones who aren’t cartoon villains manage it carefully.

This is not about cartoon villainy. I am not a cartoon villain either but I know that I (as well as 99+% of the people in this society) lead live in a way that will make our planet uninhabitable in a matter of decades (cue climate change). So, I have zero trust in your assertion of “if it was dumb, they wouldn’t do it”. Much of our live is staked on pretty dumb premises and we still live that way.

What is very much a problem is that farmland is indeed an ecological deadzone, but it’s been like that since we discovered farming.

This is just wrong. Human-managed land is not automatically a dead zone. It only becomes a dead zone if management is bad. We just need to learn (again) to amend rather than completely fuck up natural cycles.

There are plenty of e.g. organic farms that will prove you wrong on this point too.

You get optimal output when you waste as little growth as possible on non-production plants, and that results in a perfect monoculture.

Monocultures are a product of the idea that farms need to produce standardized, industrial products, nothing else. I’d guess that the kind of monocultures we see today were an absolute rarity before WWII.

And even that is not always a problem, as long as you set aside plenty of actual nature area. Earth is one big, indivisible system.

That’s an incredibly flawed way of looking at it. For one, you can’t neatly separate your farmland from the forest or brook next to it. If you use pesticides or fertilizer, as soon as the next rain arrives, it will influence those neighboring areas.

For two, humans have been grabbing so much land, there is simply no way to just zone off any more “nature areas” that are uninhibited by humans. Where those zones sorta kinda exist, e.g. in the Amazon, they are rapidly shrinking or on the verge of collapse. In industrialized nations, we have zero areas that are untouched by humans–but that wouldn’t be an issue if those areas were managed well. And therein lies the issue.

The real problem is when people demand less effective farming practices. Because less effective method require more land for the same production, and I would rather have biodiverse nature there than farmland.

Glyphosate may, in the short term, be a part of “effective farming practices”, but it is certainly not part of efficient farming practices. For one, if anything, we need a lot less farming, as half the food in the EU is in fact trashed – and everyone in the EU who goes to bed hungry is a victim of injust and ineffective distribution rather than too little production. Second, it does not help us that we are overproducing now while depleting the soil for the future. I won’t even go into how much land and effort is going into the nutritionally counterproductive raising of excessive numbers of livestock, because this post got too long anyway.