You never know where the good professor is going to lead us, he keeps things interesting.*
From IEEE Spectrum:
The world’s food supply is now unimaginable without the tomato, which although often called a vegetable is actually a fruit of the Solanum lycopersicum species, native to Central and South America. It gradually diffused through the world after 1500, finally becoming the world’s largest “vegetable” crop, with recent harvests around 180 million metric tons a year, nearly twice that of dry onions, five times that of peppers, and more than six times that of cauliflower and broccoli. The tomato’s versatility explains its rise: eaten unadorned when fully ripe, as part of countless salads, made into purees (Italian passata), soups and sauces, sliced, chopped, baked, fried, and dried.
Given about 90 days of warm weather, growing tomatoes in your garden isn’t too hard. When cultivated in modern intensive ways, it requires fuels and electricity to make synthetic fertilizers and pesticides and to produce and power the machinery and supplementary irrigation. Field tomatoes need as little as 0.8 megajoule (about 190 kilocalories) per harvested kilogram. A typical tomato, bought at retail, weighs about 125 grams, of which 95 percent is water and most of the rest is carbohydrate and fiber. Its nutritional value lies in its vitamin C and A content. A tomato of that size contains only about 22 kcal (or 22 calories, in the colloquial but incorrect usage that is common in the United States). That is just slightly less than the commercial energy, in fuel and electricity, that is needed to produce it. An energy economist might call them 1:1 tomatoes.
But, increasingly, store-bought tomatoes are grown not in fields but in greenhouses, usually hydroponically—without soil—either under glass or in long, plastic-covered tunnels. Here the energy cost of production is substantially higher. Direct energy inputs include electricity, gasoline, and diesel fuel; indirect energy costs involve the production of fertilizer (particularly nitrogen), pesticides, fungicides, and plastics and metals (not only for covers but also for cultivation troughs and copious pipes and heaters).
In the United States, tomato greenhouses are concentrated in California, Minnesota, and New York. The world’s largest concentration of plastic greenhouses lies in the southernmost part of Spain’s Almería province; you can see it on satellite images, and you can even move between some of them using dystopic Google street views.
A 125-gram tomato of Almería that is grown in an unheated plastic tunnel requires about 150 kcal; one grown in heated structures, about 560 kcal. It provides about 22 kcal of food energy, making the two kinds approximately 1:7 and 1:25 tomatoes. And with economies of scale favoring large-scale centralized production and long-distance shipping, the required storage, packing, and trucking to a regional distribution center raises the total energy cost to 460–875 kcal/125 g, raising the ratio to between 1:21 and 1:40. And because these tomatoes are grown in the relatively warm Mediterranean climate, they are far from being the world’s most energy intensive: Tomatoes produced in heated greenhouses in many European countries require 40 to 150 times as much commercial energy input as they yield in edible food energy....
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This type of analysis becomes more and more important as the SoftBanks and Jeff Bezos' of the world attempt to steer us toward food grown in greenhouses and vertical farms and we start seeing more headlines like this from Bloomberg last June: ""Pricey Greens From Indoor Farms Are Thriving in the Covid Era"" and this from February 3: "ICYMI: Indoor Farming Company AppHarvest Came Public Via SPAC (APPH)".
AppHarvest is not just any indoor farmer. Including the SPAC deal they have raised close to a half-billion dollars to build the world's largest greenhouse. To grow tomatoes.
Indoor Farning: AppHarvest Raises Another $28 Million To Fund World's Largest Greenhouse (and more)
For more on the centi-billionaire farmers:
"2-Acre Vertical Farm Run By AI And Robots Out-Produces 720-Acre Flat Farm"
Always keeping in mind that vertical farms are growing the highest-value crops to justify their cost. So no beans or wheat or rice or potatoes or barley or any of the other crops that supply the majority of calories that humans consume....
*Some of our Smil links can be found in "Vaclav Smil: Planet of the Cows"
Our readers may know Mr. Smil as a big deal in the Thinking-about-Energy biz. Here he is thinking about bovines....
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