Estimates that mineral levels in vegetables have dropped by up to 90% since 1914

Life expectancy may be longer in present times, but quality of life is in some ways lower (a notable exception to that is the status of even relatively minor infections, which were frequently fatal in pre-modern life).

Fertilizer is like doping. It works! But it comes at a long term cost. Anyway, now we can go down two paths, hyper-modern indoor farming which is expanding in Europe and organic farming that is growing in the US and Europe. Conventional industrial farming is going to get hit from both sides.

Also, the big things keeping corn going is sugar duties and ethanol subsidies. Without those, alot of the crop would disappear.

This is a pretty interesting (and correct) point, and there's a lot to say about it from a few different perspectives.

You get much higher all-inclusive yields from a unit of land by growing several different crops in the same space. They (can) complement each other, using different resources from the ground and providing resources to each other.

American agriculture is not set up to do this. Instead of optimizing yield as a function of land input, we optimize yield as a function of labor input, because we have tons and tons of fertile land relative to our small-for-the-size-of-the-country population. If you have one person growing food on a thousand acres of land (remember, one acre is originally "the amount of land one man can plow in a day"), it makes more sense to give that one person just one thing to do. There's no way they're going to be able to care for 5 different crops simultaneously, or even adjust their practices to better suit the specifics of individual fields. We prefer to get a lot of land under low-labor cultivation, even though the cultivation isn't very effective, because our tiny population doesn't require high agricultural yields per unit land.

A more traditional model involves starving peasants intensively cultivating scarce land. With cheap and abundant labor inputs, you can get much more from one unit of land. But most of that increase goes to feeding the peasants who provide the labor. This is similar to how models of the effect of immigration on American GDP tend to show large increases in GDP -- the benefits of which, if you account for them, mostly accrue to the new immigrants.

I don't think there's an easy way to combine the ideas of "infinite cheap peasant labor gives us higher agricultural yields" and "a middle-class lifestyle should be in reach for everybody". Americans are rich, from a historical and current-rest-of-the-world perspective, specifically because we use so few people to grow food. One guy with enough food to feed three million people is a huge benefit to the rest of the country, and he's personally stinking rich. Five million peasants in huts who collectively produce enough food to feed 5,100,000 people are all dirt poor, and they produce only a minor benefit to the rest of the country.

I'm not seriously suggesting we all move to 100% cardboard-tasting goo, but if you are worried about one or more of your daily intakes, this could be an easy way for some people to get a good dose every now and then (for example for lunch on weekends, I notice that I'm often in the middle of something fun and will neglect to have lunch).