Vegetables // Current

Which fruits, vegetables, and other crops have the smallest environmental footprints?

We've already been over the environmental benefits of choosing poultry over beef and anchovies over haddock. But you're right to suggest that the same sort of logic can apply to picking vegetarian foodstuffs. Certain crops require loads of phosphate fertilizer, for example, which is mined from the ground and can eventually cause stream-choking algal growth. Other fruits and veggies are grown with heavy doses of pesticides, fungicides, and other chemicals that can pollute waterways and cause reproductive problems in animals. So how do you know which crops are best to eat? Here's the Lantern's rule of thumb: Try to keep your more extravagant fruit cravings in check, but don't sweat the low-impact calories that come with your carbs.

As it turns out, it's not hard to find digestible data on the use of fertilizers. The United Nations Food and Agriculture Organization offers a handy list of various crops and their associated fertilizer loads. (Check page 60 of this PDF.) Bananas consume the most by a very large margin, requiring a whopping 427 pounds of nitrogen, phosphate, and potash fertilizer per acre of cultivation. Sugar beets and citrus crops are next, followed by vegetables, tubers, and grains. Peas and beans require just 35 pounds per acre, in part because they have capacity to absorb nitrogen from the air. In short, eat more beans.

Numbers on pesticide use can be found in a database of California crops maintained by the Pesticide Action Network. According to the information compiled there, raspberries are the worst offenders, accounting for an average of 20.2 pounds of chemicals dumped on every acre of treated land. Other particularly noxious crops include carrots and strawberries. Wild rice also fares poorly by this metric, requiring nearly 6 pounds of pesticide per acre. In the middle of the pack are the tree crops, like avocados and oranges, and at the clean end of the list you'll find broccoli, leafy greens, beans and grains—which are grown with an average of less than 3 pounds of pesticide per acre. (Remember, we're talking about risks to the planet here, not risks to individual health. The Environmental Working Group has a list of the fruits and veggies that show up in stores—and on your plates—with the highest levels of pesticide residue. But that doesn't make them the worst offenders against the environment.)

It's useful to know the amount of pesticide or fertilizer that goes into each acre of a given crop, but there's more to the story. Some crops make more efficient use of the land than others, so their environmental impacts may be less intense on per-calorie basis. To figure out how all this fits together, the Lantern whipped out his solar-powered pocket calculator and compared overall pesticide and fertilizer use with California's agricultural yields from 2007 and nutritional information for each of 12 conventionally grown crops. White rice came out the big winner here, returning more than 2 million calories per pound of pesticide used and 82,000 calories per pound of phosphate. Onions and sweet corn ranked nearly as efficient as rice when it came to pesticide, but were only so-so in terms of fertilizer; the opposite was true for oranges and apples. Lingering at the bottom of both lists were strawberries, which returned just 121,000 calories per pound of pesticide, and 5,300 per pound of fertilizer.

http://www.slate.com/id/2234783/?from=rssWe've already been over the environmental benefits of choosing poultry over beef and... more