Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step


June 29, 2006

Why Is Fertilizer A Factor?

Category: Conservation,Economics,Save Fuel,Sustainability,Technology – Tom Harrison – 11:41 pm

All crops need fertilizers to grow. And what “fertilizer” really means is nitrogen that plants can use. Hell, air is 80% nitrogen, but it’s not in a form plants can use. But plants need nitrates (chemically NO3) which is oxygen bound to nitrogen in a particular way. This occurs in nature in two ways: lightening creates NO3, and bacteria eating organic materials (a.k.a. “compost”) make NO3. All good. What if you need more NO3? Well, in 1903, two German guys got the Nobel prize for figuring out how: the Haber-Bosch process creates ammonia, which is the basis for synthetic nitrates, and fertilizers.

And guess what you need to make ammonia? Natural gas accounts for about 3/4 the cost. And because natural gas is not easily moved around, nitrate fertilizer is made close to the source. About 1/2 of the fertilizer we use in the US was shipped from all the same countries that ship us other petrochemicals; the other half comes from natural gas produced in the US.

OK, most of this information was shamelessly paraphrased (I’m avoiding the word “plagiarized”) from this excellent article in the San Francisco Chronicle by Deborah Rich.

So let’s see: plants won’t grow without nitrates, and there’s only so much lightening and compost for use by organic farms. All the rest, and that means that vast majority of our agricultural produce, uses synthetic fertilizers. So we use natural gas and oil to make fertilizers, then we move it around on ships and trucks and farm equipment (which use fuel oil) to get it into the ground, where it miraculously produces abundant crops. I’ll ignore the environmental damage caused by all those nitrates running off into our water to someone else’s blog. So back to our food.

We could eat the crops, and yes kids, eating vegetables is a very good thing. Or we could feed the crops to cows, pigs and chickens, and they would eat 10 or 20 servings of feed in order to make one serving of meat. I am not a vegetarian by any means, but meat is … expensive. So whether we eat the crops, or we eat the meat that eats the crops, we grow a lot of crops, and they use a lot of fertilizer.

Based on one estimate I read, about 25% of our consumption of oil and gas is used to make fertilizer. Yes. Not for cars, trucks, ships or airplanes … 25% to grow our food. And that does not count the cost of actually getting the fertilizer (or food) to your dinner table. I think these numbers are about right, but here’s my original post on this subject with links to some sources of actual data.

So now, the latest idea is to use ethanol for fuel for our cars. E85 is 85% ethanol and 15% gasoline, and it’s relatively easy to change our current car engines to run on E85 or gasoline. And E85 is made from crops — the same ones we eat, or which we feed to the animals that we eat. If I were a cow, I might be worried that a car was competing with me for food.

So E85 is all the rage these days. But remember to ask: how is E85 made? Some of it is made from materials that might otherwise be wasted — the part of the corn or wheat that we don’t eat or feed to animals. And with the push for E85 vehicles from GM (and today, from Ford) demand for ethanol will increase, and this translates to demand for natural gas and oil to grow the crops to make the ethanol.

On the bright side, we are less dependent on other countries for natural gas than for crude oil, and yes, we can produce some E85 from the leavings we might otherwise waste. So as a transitional fuel, it’s better than the alternative … a little.

So in the end, ain’t nothin’ for free. Except perhaps fusion energy, but sadly this is not one of the energy sources Bush was referring to when he said we are on the “threshold” of great technical advances.

1 Comment

  1. […] most of the weeds (I do pull a few dandelions and crabgrass by hand, but not a lot). So a little organic fertilizer in spring is enough to give the grass a great […]

    Pingback by Lawn Aerator Shoes, Electric Mower, Organic Fertilizer, Water, Bike | Five Percent: Conserve a Little Energy — September 16, 2008 @ 11:15 am

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.