Obviously no one is suggesting turning the US into a tomato monoculture, but tomatoes seem like a easy, if not necessarily accurate, proxy for the sort of fresh vegetable passed diets that some people advocate as a solution for the entire nation. If the did the same calculation for lettuce, the numbers would likely be much worse. If I did it for sweet potatoes, I’m guessing they would be substantially better.
There is a very useful resource on growing tomatoes made available by the Iowa State extension service. They estimate yields of 12,000-16,000 pounds of tomato per acre. A pound of tomatoes contains 86 calories. That means an acre of tomatoes yielding 14,000 pounds per year is creating 1.2 million calories of food per year or enough to feed 1 and 2/3 people for a year (at 2000 calories per day), the comparable figure of a midwestern cornfield is 29.5 people per acre. In the US we currently farm a bit over 400 million acres so, assuming that expanding tomato production to all land currently farmed wouldn’t result in much lower average yields (a big assumption considering tomatoes are probably grown on the land best suited for their production at the moment), we could, in fact, feed 657 million people (or approximate twice the current population of the US) by converting to tomato based agriculture. And this doesn’t consider greenhouse based production, which accounts for ~10% of current tomato production in the US and has markedly higher yields, although the cost of production is also higher.
According to my back of the envelope calculations, we could feed our entire population with tomatoes.
- I already mentioned the first one, much of US agricultural land may be unsuitable for tomato production.
- Since tomato production occurs only in the summer (outside of greenhouses and idilic climates like California) and tomatoes to not store well (unlike dried grains and beans) much of the year would be spent living on canned and dried tomatoes.
- I’m guessing conventional tomato production results in higher pesticide application rates than production of grains but I couldn’t find any numbers on the subject, so feel free to ignore that one.
- An acre of fresh tomatoes requires at least 200 hours of labor per growing season, with the growing season lasting ~4 months, 18 weeks (probably a lot less in some parts of the country). Assuming workers work only 40 hours weeks and using my calculations above we only need about half of our current 400 million acres of farmland to keep everyone in tomatoes year-round we can make the following calculation. To grow and harvest 200 million acres of tomatoes would require 55 million farm workers or 1 in six americans. But of course not all americans currently work. Our workforce stands at ~140 million people. Almost 40% of them would spend their summers working in tomato fields (working for minimum wage unless we’re willing to drive the price of tomatoes even higher but that’s my next point)
- The average retail price per pound of tomatoes in april of 2008 (most recent numbers I could find) was $1.77 per pound. To get 2000 calories today, each person in the US would have to 23 pounds of tomatoes a day (more than the average person in the US eats in a year right now), costing more than $40 a day equalling a $14,600 a year food budget. (For comparison, a person working full time earning the (new increased) minimum wage earns $15,080 a year.)
So in conclusion, yes we could feed our nation with tomatoes, but there would be some major unintended consequences. Just to be clear no one is suggesting we feed ourselves with nothing but tomatoes. I just thought it’d be an interesting calculation to make.
It does raise an interesting question. Since I’m pretty sure most vegetarians aren’t eating 23 pounds of fresh vegetables a day, can any vegetarians reading comment on what foods you get most of your calories from? Personally when I’m trying to cut back on my meat consumption, most of my energy comes from rice, bread, and beans. (With honorable mentions to peanut butter and cheese.) But I don’t know that my own experience is representative (in fact I’m pretty sure it isn’t).
If you enjoyed this post may I suggest:
How Viable is Local Food (there’s nothing wrong with trying to buy more from local farmers, in fact there’s a lot right, but it isn’t physically possible to feed everyone all the time with locally produced food without forcible relocating a whole lot of people)
All Flesh Is Grass (an acknowledgement of the grains, a small group of plants which enabled practically all of human civilization)