A society that relies on cheap food also relies on cheap labor. Look at the meat-processing industry.

Worker conditions are so wretched, so little changed from Jungle days, that Human Rights Watch saw fit to issue a scathing report on the industry last January.

Because meat is perishable and prohibitively expensive to keep frozen over long journeys, meat processing cannot readily be sent overseas — unlike, say, manufacturing. So the trick, as the Human Rights Watch report shows in wrenching detail, is to recreate working conditions prevalent in places like Guatemala, here.

Things are different in the large-scale fruit/vegetable business. Tomatoes, for example, can be picked green, shipped long distance with minimal refrigeration, and gas-ripened near the point of sale. Will vegetable farming move overseas? For a few months now, media reports about a farm-labor crisis have been emerging from industrial-scale vegetable production areas like California’s Central Valley and Arizona’s Yuma County. Tales of fruit rotting on the vine abounded. In short, not enough Mexicans are sneaking across the increasingly well-guarded border to harvest fruit and vegetables.

And the ones who do are tending to forsake agriculture for the booming construction trade, which tends to pay more and offer steadier work.

In the past week or two, as California and Arizona prepare for the winter-vegetable harvests — the source of much lettuce now gracing supermarket shelves in places like Chicago and Boston — media reports have grown more shrill. Talk of crop loss continues; but farmers are now talking openly of shutting down.

A recent piece in the Christian Science Monitor quotes one Central Valley lettuce farmer, who says he’s 200 workers short on this year’s winter harvest, thusly:

I lost $250,000 because of this problem last year … This year I am concerned I could go under completely. If I miss making my contracts with some of the big stores, they could look to China, Canada, Mexico, and elsewhere, and even if I recover my labor later, it may be too late.

I believe these mega-farmers when they say a simple wage hike won’t solve their problem. First, just 2 percent of the U.S. domestic population works in agriculture. Two or three generations off the land, what native-born U.S. citizen wants to earn $8 or even $12 per hour spending all day stooped over, repetitively snatching lettuce heads out of the earth? Especially when the work is seasonal, builds no transferable skills, and doesn’t even offer workman’s comp. Hell, even Wal-Mart offers a better deal.

Second, even if a pay hike brought in a flood of new workers, those mega-farms could still go bust. Another recent piece on the farm-labor shortage, this one (free registration required) from the LA Times, puts it well: “Foreign competition and the supermarket industry consolidation are leaving growers with fewer buyers and less leverage over what they can charge.”

As supermarkets consolidate — a drive dramatically hastened by Wal-Mart’s big move into groceries a few years ago — their ability to grab profit from farmers grows. The LA Times article gives a stark example of this phenomenon:

As of last week, winter growers were collecting 19 cents for a head of iceberg lettuce that was selling for $1.29 in Southern California grocery stores … The return for farmers is down from 34 cents during the same week a year ago, when grocers were charging 88 cents for the lettuce.

Thus supermarkets managed to jack up the retail price of lettuce nearly 50 percent, while hacking nearly 50 percent off of the farmers’ take. This, at a time when not only labor but energy costs have leapt on farms.

One farmer trade group spokesman put it bluntly to the Times: “Our crops are going to be harvested by a foreign workforce either here or somewhere else.”

Such stark language may partly be political. Bush is currently hammering out a guest-worker policy, clumsily straddling the line between right-wing nativists chasing the chimera of a sealed border and the demands of domestic industries such as agriculture and construction.

But it also points to a real trend. Unlike grain production, which has largely become mechanized, vegetable production requires lots of human hands. If we are to produce vegetables industrially, that means a steady supply of cheap, expendable labor.

An upcoming post will tease out the environmental implications of a collapse in domestic vegetable farming, and discuss a progressive policy agenda for rethinking how we grow food here.