Why would a near future society struggle to grow crops on a large level?

Question

I have a world where its mostly in ruins. But its run practically by corporations and smaller factions. A large part of the world is recovering from ecological collapse, massive pollution that travels by air and sea, warfare, lingering effects of bio and chemical warfare etc and intense radiation in certain areas. Essentially the environment is decaying. Basically, the world of Armored Core 4/4A if anyone's familiar with it.

The story takes place later, where there is some reclamation of land pollution cleaning attempts. While large swaths of land are uninhabitable or non-arable, there's just enough safe zones to form larger factions that somewhat resemble early nation states.

One of the issues I had was with food production. I want to make crop yields limited, essentially a food scarcity of sorts or the threat of a bad harvesting season causes major problems across the world. My research and some conversations have led me to the fact that a modern society with decent technology can make some pretty resilient crops. That and seeds/plants by themselves are pretty resilient. Chernobyl for example has fauna and even edible plants growing around the exclusion zone. Israel has done significant work in growing crops and making some very tough plants and seeds as well.

Why would an otherwise near future/modern world with advanced technology in a somewhat post-apocalyptic/ environmentally challenged world struggle to grow crops/produce seeds on a consistent basis for the foreseeable future? Even if said world is on the slowest of slow paths to recovery when it comes to arable land

Population for factions can range from city states to small countries or confederations.

Answer 1

Topsoil loss

After you ruin the ground, topsoil does not just come back. topsoil can take hundreds or thousands or millions of years to recover naturally.

Meters of topsoil loss can happen in a few years if you destroy the vegetation, which everything you listed can do. will it every place, no but it will effect a lot of places.

this is the type of soil loss deforestation creates.

This is caused by bad farming practices mixed with climate change.

both of these took only a few years and everything you listed can and will result in massive soil losses. Using technology to rebuilding soil is incredibly difficult, incredibly expensive, and incredibly slow, even with advanced technology hundreds or thousands of years would be a generous timeline.

to quote an old saying,

Man — despite his artistic pretensions, his sophistication, and his many accomplishments — owes his existence to a six inch layer of topsoil and the fact that it rains.

Answer 2

Short answer: A man-made volcanic winter seems most plausible to me.

Thanks to biological and chemical warfare, I see two main possibilities:

Heavy metals could cause severe problems for food production. Maybe the plants themselves are fine, but they could contain heavy metals in concentrations that are poisonous to humans. Only in a few regions that were less affected, concentrations could be low enough so the plants are edible. Organic poisons might work as well, but they can be degraded more easily. This would probably mean, that some factions with less contaminated land might produce much more food than other. In theory it might be possible to engineer plants that would not take up the metals. This is why I like to following idea better:

Simple thermodynamics cannot be engineered away. Even if your society is able to engineer plants as they like, the energy the plants use must come from somewhere. If incoming solar radiation is reduced, your plants will grow much worse, no matter what anyone does with them. This is quite plausible, it happens with volcanoes from time to time and it caused huge problems for societies before (https://en.wikipedia.org/wiki/Volcanic_winter). Given the scale of the pollution and the weapons used, I could imagine that some of them would be able to cause this. Especially if a big nuclear bomb is directed at an unstable volcano or as side effect from large-scale chemical weapons. Unlike to first scenario, this would be more of a global problem but would still benefit some warmer regions.

Answer 3

Desertification

A biologically ruined planet is going to be lacking in vegetation, of course. This leads to some issues similar to what the central USA experienced during the Dust Bowl, and that African countries surrounding the Sahara already experience: desertification. Even if these population centers manage to grab hold and reclaim some land from the rampant pollution and clean it up, no amount of technology can instantly restore the top layers of soil in an area that has been blown to sand and dust.

Wind

Even if your groups can reclaim and restore enough vegetation in one area to establish consistent footholds for crop growing, they will need to deal with the wind. Farmers in the central United States will tend to plant rows of trees to act as wind breaks, because high-velocity straight-line winds can and will destroy crops by simply blowing them over. Even short crops can be damaged as their leaves and stems are ripped away by the winds. Your ruined location will not have trees, and it will take years of hard work and careful maintenance to grow wind-break trees, or to build and maintain wind-break walls of sufficient size.

Growing Cycles

I don’t know what kind of climate the ecological destruction of the planet has caused, but that is a big issue. If your planet has inconsistent growing cycles, even the heartiest will fail or come out poor in terms of yield. Even in our modern era we have issues with intermittent hot and cold cycles messing with plants, causing them to sprout early in unseasonably warm weather, which leads to lower yields, and then be destroyed when the cold returns suddenly and wipes out the vulnerable, sprouted crops. This phenomena also affects the next category of issue.

Pollinators

Virtually no plant yields without pollination, and also seeds would be difficult if not impossible to grow. Given the relatively ruined biosphere of your planet, those insects and creatures that perform the powerful job of pollination are going to few and far between. That means that, as the ecosystem slowly recovers, pollination will be a manual process for the humans maintaining the crops. This would be a very time-consuming and resource-intensive process regardless of the tech level of the groups.

Conclusion

There are a number of factors that would make maintaining plants and crops difficult for a high-tech society on a dying planet. Take your pick, mix and match, and have fun making life difficult for some fictional folks.

Answer 4

No workers.

https://www.euronews.com/2022/06/10/it-s-just-not-happening-crops-go-to-waste-as-uk-farmers-struggle-to-find-workers

There are limited crops in your world because people don't want to work in fields. Crops rot in the ground because they are planted by hopeful farmers who then cannot find people willing to do the work of harvesting them.

It is not that there are no people capable of doing this work. It is that these people choose to do other things, or nothing. Same as our world.

Answer 5

Germ Warfare

In the late stages of the war, both sides used airborne pathogens to attack each others' crops.

As you say in a comment, "What happened during the war is in the air".

The germ warfare was especially devastating since modern GMO crops have negligible biodiversity. So it was easy to devise a virus to infect all the corn in America or all the wheat in Europe. Both wilted and turned black in the fields.

Based on the principle that it takes much longer to make a bake than to eat a cake, the effects of the pathogens linger half a century later. Even using further bioengineering to make the crops resist the pathogens, it is still difficult to grow crops.

The solution was to return to heirloom crops. These produce far less food but, since they are all different, it is unlikely the entire harvest will succumb to this season's new virus.

Oh did I mention the virus mutates every year? It mutates every year.

Answer 6

Indoor Farms

Other answers have focused on how to make a food shortage, but the OP seems more interested in how to make the food supply unstable with some years/areas producing good yields while others suffer from major failures.

The soil and atmosphere was completely ruined in the collapse; so, agriculture was forced to turn completely to indoor hydroponics/aeroponics farms because food had to be grown in doors in clean air. While the world's ecology is beginning to recover, these high-tech farms now hold a monopoly on food production, making them as hard to inch out of the food market as the oil industry is to push out of the energy market today. So even if alternative, more reliable food supplies become possible, lobbying and capitol advantages will keep the indoor farms in power long after their problems become apparent.

So what makes these indoor farms so much more vulnerable than outdoor farms? With thier sophisticated climate control systems, you'd think they'd be super resilient, but that resilience breeds a very dangerous sort of trust. Farmers today are encouraged to produce over projected needs to account when low yields happen, but when your indoor farming complex always produces exactly 5 million tons of food every year, you learn to produce everything on tighter margins to improve profits... only these farms can not ALWAYS produce this much. Using artificial grow lights means a power grid failure could kill off an entire region's food supply in days. The need for specialized bulbs and synthetic fertilizers meaning your supply chains could be very easy to cut off during times of unrest also leading to massive crop failures. Also, your food production is much less spread out; so, a natural disaster like a fire or flood big enough to destroy a few acres of open farmland could now wipe out the one farming complex that feeds your entire city. And because everyone is maximizing profits, there is not much reserve available to be purchased from other places to cover your needs.