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  • From: "Tradingpost" <tradingpost@lobo.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] How green are those veggies?
  • Date: Tue, 17 Nov 2009 16:58:49 -0700


THE GREEN LANTERN
How green are those veggies?
http://www.washingtonpost.com/wp-dyn/content/article/2009/11/16/AR2009111602667.html?nav=rss_nation/special/8


By Brendan Borrell
Tuesday, November 17, 2009

I know you can buy local or buy organic, but I've heard that some crops are
simply more resource-intensive than others, regardless of how or where they
are grown. So what's the key to picking foods that have the smallest
environmental footprint?

We've been over the environmental benefits of choosing poultry over beef in a
previous column. 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 report.) 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. Peas and
beans require just 35 pounds per acre, in part because they can 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 six pounds of pesticide
per acre. In the middle of the pack are the tree crops, such as 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 three 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.)
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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.

What does all this fancy number-crunching mean? Considering that about
one-third of greenhouse gases emitted from agriculture in the United States
come from fertilizers and pesticides, identifying low-impact crops can be at
least as important as sourcing your foods locally. For instance, switching
from strawberries to oranges in your fruit salad cuts pesticide use by half
and fertilizer use by a factor of 10. For those who can't do without their
berries, your best bet may be to buy from a truly sustainable source that
avoids the worst pesticides, sticks to manure and other organic fertilizers,
and prevents excess nutrients from flowing into waterways.

What about organic vs. conventional produce? When it comes to dietary staples
such as corn, wheat and rice, the choice isn't so clear.

David Pimentel of Cornell University has estimated that it takes about 30
percent less energy to grow organic soy and corn than it does to grow the
conventional kind.

On the other hand, organic doubters, including the recently deceased father
of the Green Revolution, Norman Borlaug, have suggested that the spread of
fertilizer- and pesticide-free agriculture would result in more land's being
cleared for crops to match today's conventional yields, a view that has been
supported by a British government report. The USDA has just started surveying
some organic crops, and we'll have to wait until all the data are in to issue
a final verdict on that front.

As for fruits and vegetables, going organic is the eco-friendly choice. The
switch will reduce your impact on the soil and water and won't require a vast
expansion of the agricultural footprint.

For all this, one of the simplest ways to ballpark the impact of a
conventionally grown fruit or vegetable is to glance at its price. The trick
doesn't always work, but, in general, the cheaper one probably required less
fertilizer, pesticide, land and energy.

Is there an environmental quandary that's been keeping you up at night? Send
it to ask.the.lantern@gmail.com, and check this space every Tuesday.




  • [Livingontheland] How green are those veggies?, Tradingpost, 11/17/2009

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