The Nitrogen Fix: Breaking a Costly Addiction

[OKIsItJustMe]

http://www.e360.yale.edu/content/feature.msp?id=2207

05 Nov 2009: Analysis

The Nitrogen Fix:
Breaking a Costly Addiction

Over the last century, the intensive use of chemical fertilizers has saturated the Earth’s soils, waters, and atmosphere with nitrogen. Now scientists are warning that we must move quickly to revolutionize agricultural systems and greatly reduce the amount of nitrogen we put into the planet's ecosystems.

by fred pearce

A single patent a century ago changed the world, and now, in the 21st century, Homo sapiens and the world we dominate have an addiction. Call it the nitrogen fix. It is like a drug mainlined into the planet’s ecosystems, suffusing every cell, every pore — including our own bodies.

In 1908, the German chemist Fritz Haber discovered how to make ammonia by capturing nitrogen gas from the air. In the process he invented a cheap new source of nitrogen fertilizer, ending our dependence on natural sources, whether biological or geological. Nitrogen fertilizer fixed from the air confounded the mid-century predictions of Paul Ehrlich and others that global famine loomed. Chemical fertilizer today feeds about three billion people.

But the environmental consequences of the massive amounts of nitrogen sent coursing through the planet’s ecosystems are growing fast. We have learned to fear carbon and the changes it can cause to our climate. But one day soon we may learn to fear the nitrogen fix even more.

A major international survey published in September in Nature listed the nitrogen cycle as http://www.e360.yale.edu/content/feature.msp?id=2192">one of the three “planetary boundaries” that human interventions have disturbed so badly that they threaten the future habitability of the Earth. The others — according to the study by Johann Rockstrom, of the Stockholm Environment Institute, and 27 other environmental scientists – are climate change and biodiversity loss.


…

[JonQ]

1. I've heard that because of overuse of manmade chemicals

like nitrogen the earths atmosphere now contains upwards of 78% of the colorless, odorless gas!

Natural fertilizers are free from harmful manmade concoctions of nitrogen, phosphorous and potassium that you simply don't find in nature.

Also they cause autism and depression.

[OKIsItJustMe]

3. Carbon Dioxide is a naturally occurring chemical

Do you dispute that we might cause problems by changing its level in the environment?

[JonQ]

4. I dispute that we can change it's levels

CO2 is different, you can make that. Nitrogen is an element though, not a molecule. Unless we've figured out how to make fusion work on a massive scale we really can't change that.

And as it already comprises the majority of our atmosphere, and is harmless, and does not cause global warming, I fail to see the comparison.

[OKIsItJustMe]

5. It's not really Nitrogen per se that we're talking about here

Farmers, for example, do not spread Nitrogen on their fields. It's a gas, you cannot spread it with a tractor. http://en.wikipedia.org/wiki/Nitrogen_cycle#Nitrogen_fixation">Nitrogen must be "fixed" in order to be used by plants (the title is a pun.)

http://www.e360.yale.edu/content/feature.msp?id=2207

…

Most of the man-made nitrogen fertilizer ever produced has been applied to fields in the last quarter-century. Nature has some ability to reverse man-made fixing of nitrogen, converting it back into an inert gas — a process called denitrification. But last year, Patrick Mulholland of the Oak Ridge National Laboratory in Tennessee reported that the system is being overwhelmed. Many rivers in the U.S. are now so nitrogen-saturated that they are losing their ability to denitrify pollution.

…

[JonQ]

9. But you don't want soil to denitrify

soil without nitrogen is dead.

[OKIsItJustMe]

10. No danger here

We're putting more nitrogen on it than it can handle.

[XemaSab]

20. You can inject gasses into the soil

Our friend Anhydrous Ammonia is a gas that can be put into the soil.

It'll melt your eyeballs too. :D

[OKIsItJustMe]

22. Well, yes…

However, it still isn’t (elemental) Nitrogen.

[zipplewrath]

8. Poorly written

As is so often common in general literature when writing about scientific topics, the wording leaves much to be desired. Their complaint isn't really so much about nitrogen as it is ammonia. It is pooling in the water supplies and creating "dead zones" in water systems including the ocean (well, they assert anyway). Late in the article they also discuss acid rain as well, which doesn't really have anything to do with fertilizer.

The part I couldn't sort out from the article is the difference between pooling ammonia, and just the presence of fertilizers (of any form) causing imbalances in plant growth in water systems. I've heard of that problem before, but I also know that it tends to "clean" itself up once the infestation is stopped. The implication here is that the ammonia is not being dissipated but instead accumulating.

[eppur_se_muova]

12. Not just ammonia, but also nitrate and nitrite.

The usage of 'nitrogen' to mean nitrogen in all forms is quite common. If specifically 'elemental nitrogen' is meant, it will usually be named as such.

Unfortunately, this flexibility of terminology does cause confusion. Just look how many people go apeshit over the "discovery" that water contains hydrogen -- utterly failing to distinguish between hydrogen as one of the constituents of a compound, and elemental hydrogen, H2. Thus we get the frequent "INEXHAUSTIBLE SUPPLY OF FREE FUEL FROM WATER!!!!" posts.

This article is treating all fixed nitrogen as one big reservoir of nitrogen, since microbes do interconvert ammonia and nitrates. The slow step is the actual fixation of N2 from the air, so this is a reasonably valid approach -- they just don't explain that they're doing it, but then it is a fairly short, nontechnical article.

One other detail omitted is that the production of ammonia is just one step in a longer process. Ammonia can be burned to form nitric acid, which combines with more ammonia to form ammonium nitrate, by far the most commonly used nitrogen-containing fertilizer (and explosive). So what is applied to fields is both ammonia and nitrate, which is quickly converted by microbes to a mixture including nitrites and N2O. (BTW, NOx reacting to form acid rain also leads to nitrite and nitrate, hence the reference in the article. Again, unclear without more background.)

Of course, wikipedia has a nice chart showing the Nitrogen Cycle, with all its components. Note that there are both nitrifying and denitrifying bacteria, just because evolution permits anything that doesn't violate physical law.

http://en.wikipedia.org/wiki/Nitrogen_cycle

[NickB79]

16. We aren't so much "making" CO2 as we are releasing it from storage

Through the burning of fossil fuels that removed CO2 from the atmosphere over the past 300 million years. Similarly, we are taking atmospheric nitrogen, which is mostly stored away in the atmosphere away from use by non-nitrogen-fixing plants, and releasing it into the ecosystem in the form of ammonia-based fertilizers that crops can now use.

"And as it already comprises the majority of our atmosphere, and is harmless, and does not cause global warming, I fail to see the comparison."

The products of nitrogen, such as nitrates and nitrites, are NOT harmless. They can pollute groundwater, create oceanic dead zones, and alter the species composition of native ecosystems that evolved with low nitrogen levels, such as the US prairie. And, the products of excessive nitrogen fertilizer applications DO cause global warming:

http://www.scientificamerican.com/article.cfm?id=nitrogen-fertilizer-anniversary

"Fertilizers release significant quantities of nitrous oxide, a greenhouse gas with 300 times the heat-trapping capacity of carbon dioxide (CO2). A 2007 analysis by Nobel laureate Paul Crutzen of the Max Planck Institute for Chemistry in Mainz, Germany, and his colleagues suggests that for most current biofuel crops, corn included, any CO2 savings will be wiped out by higher emissions of nitrous oxide and nitrogen oxide. The latter destroys so-called “good” ozone, which shelters life from damaging ultraviolet radiation; it also fuels production of ground level ozone, the main constituent in smog that is widely known to exacerbate human respiratory ailments. According to the U.S. Environmental Protection Agency, millions of Americans live in areas that exceed the national standards for ozone exposure."

[Birthmark]

2. Anthropogenic Global Warming will soon fix this sort of thing.

Once humanity is whittled down to a couple of billion or less by climate change, problems like these will largely or almost completely disappear. Tough medicine, but it will work.

[Nederland]

6. If you want to use more land, ban fertilizer

The simple fact is that if we stopped using chemical fertilizers we'd end up using a lot more land and even then a lot of people would starve. The growing of food is a chemical process, and nitrogen is one of the inputs. Stop using fertilizer and your yields will plummet. If you want to carve up the currently undisturbed savannas of Africa into patches resembling the US mid-west, by all means stop using fertilizer. Here is a good explanation from an environmentalist on why chemical fertilizers are necessary:

http://74.125.155.132/search?q=cache:VQC6Fc0NdM0J:www.utviklingsfondet.no/Utviklingsfondet_-_forsiden/Ungdomsorganisasjonen_Spire/Information_in_English/%3Fmodule%3DArticles%3Baction%3DArticle.publicShow%3BID%3D1802+why+we+use+more+fertilizer+today&cd=17&hl=en&ct=clnk&gl=us

<snip>

What is your view of movements that support organic farming?
As long as they desire an organic farming that leaves out chemical fertilizers entirely, I don’t support them. Organic farming is not a precondition for a sustainable agriculture, and cannot alone solve the food problem today. It is also difficult to operate organically today because it requires far too much land.

Do you see problems with our recommendations of ecological agriculture?
Not as long as you are proposing good cultivation techniques. As said, this means good management practice and knowledge on how to best cultivate the soil. In addition, I take for granted that ecological principles must be used. These principles must be a foundation before adding the use of chemical fertilizers! But, you should not advise against the use of chemical fertilizers; these are completely necessary because the earth needs the addition of many nutrients. As long as chemical fertilizers are used in a sensible manner, it is completely necessary.

<snip>

[OKIsItJustMe]

11. Can Organic Farming "Feed the World"?

http://www.cnr.berkeley.edu/~christos/articles/cv_organic_farming.html

Can Organic Farming "Feed the World"?

Christos Vasilikiotis, Ph.D.

University of California, Berkeley
ESPM-Division of Insect Biology
201 Wellman-3112
Berkeley, CA 94720-3112

…

Comparisons of organic and conventional chemical farming systems

A survey of recent studies comparing the productivity of organic practices to conventional agriculture provides an excellent example of the wide range of benefits we can expect from a conversion to sustainable agricultural methods. The results clearly show that organic farming accomplishes many of the FAO’s sustainability aims, as well as showing promise in increasing food production ability.

• Sustainable Agriculture Farming Systems project (SFAS) at UC, Davis.

An ongoing long-term comparison study, SFAS is an interdisciplinary project that compares conventional farming systems with alternative production systems that promote sustainable agriculture.

The study examines four farming systems that differ in crop rotation design and material input use: a 2-year and a 4-year rotation conventional system, an organic and a low-input system.

Results from the first 8 years of the project show that the organic and low-input systems had yields comparable to the conventional systems in all crops which were tested - tomato, safflower, corn and bean, and in some instances yielding higher than conventional systems (Clark, 1999a). Tomato yields in the organic system were lower in the first three years, but reached the levels of the conventional tomatoes in the subsequent years and had a higher yield during the last year of the experiment (80 t/ha in the organic compared to 68 t/ha in the conventional in 1996). Corn production in the organic system had a higher variability than conventional systems, with lower yields in some years and higher in others.

…

[Nederland]

13. They just used manure instead of chemical fertilizer

Organic farms have the same problem that all farms do: how do you replace the chemicals depleted when you grow food. Instead of using chemical fertilizer, organic farms use manure. The study you cited used chicken manure. The problem is there isn't anywhere close to enough manure to fertilize the acrerage we currently cultivate. US livestock operations generate only one billion tons of manure per year, not nearly enough to fertilize the 382 million acres that are currently used for crop production.

[OKIsItJustMe]

14. True enough

I was distracted by the references to “organic farming” in your posting.

The original posting was not an advocacy piece for organic farming:
http://www.e360.yale.edu/content/feature.msp?id=2207

…

What can be done? To meet the target cited in the Nature study requires a transformation of the world’s agriculture as profound as the transformation of energy industries needed to meet targets for cutting greenhouse gases. There is an urgent need, says Smil, to breed crops that are far more efficient at absorbing the nitrogen in fields, and for developing farming systems that manage nitrogen far better.

…

[IrateCitizen]

18. Then perhaps we're not discussing the true predicament we face

It seems to me that the true predicament we face isn't whether or not there is enough fertilizer. It seems that it is that we simply have vastly exceeded the carrying capacity of our ecosystem.

I'm not saying that there's an easy way out of this situation, because there certainly isn't. I'm just saying that, by acknowledging the many problems resulting from the use of synthetic fertilizers, as well as acknowledging the fact that there simply is not enough manure to adequately maintain crop production for the current population, the source of the problem seems to be overpopulation.

[NickB79]

15. Really caught between a rock and a hard place, aren't we?

If we keep using nitrogen-based fertilizers at current levels we risk short-circuiting a vital ecological cycle that makes life on this planet possible. But if we cut back significantly on using that nitrogen we risk seeing billions starve to death.

Dilemma, dilemma! The only way out that I can see is the introduction of a new variety of crops (probably genetically modified) that can fix their own nitrogen from the air. That, or we start eating a LOT more soy.

On edit: thinking about it a bit more, would nitrogen-fixing crops really change anything? Humans wouldn't be applying gobs of fertilizer to the soil any longer, but the plants would. We would just be moving the source of excess nitrogen addition from our hands to the hands of our creations.

[Nederland]

17. I disagree

Use of fertilizers is not always bad. When you grow anything you need to replenish the chemicals the soil has lost. The trick is to be smart about it. Different crops use different amounts of different chemicals, and so you need to be careful to replace only what you've lost and nothing more. The problem is that too many farmers just take the attitude "Fertilizer good--I'll use more." That leads to the soil containing too much of this or too much of that, and then it rains, ends up in the ground water and rivers, etc...

[IrateCitizen]

19. A large part of the problem is monoculture as well.

Crop rotation can address many of these problems. Too many of our farms focus on growing one or two different crops -- and corn, one of the most popular, is absolutely ruthless in sucking nutrients from the soil.

The typical farm of 100 years ago was much more diversified. Of course, back then more farmers were actually deeply aware of the dynamics of crop rotation and maintaining soil fertility as well. Too many farmers today -- especially on large-scale factory farms -- are just technicians who put "inputs" into the soil in order to extract "outputs" in the form of a crop harvest, with little concern over what the impact is on the soil or surrounding ecosystem.

[XemaSab]

24. I don't believe that growing legumes and other N-fixing plants would cause the same problems

I think in Nitrogen-fixing plants the Nitrogen isn't just hanging out loosely attached to the cation exchange sites, but instead it's literally inside the structure of the plant, meaning that release would happen over the long term. One of the other factors is that some organic farming practices encourage a healthy soil flora and fauna, while many industrial chemicals destroy that soil life. Increasing the soil organic matter would also increase the number of cation exchange sites, making application of fertilizers later in the cycle less likely to overwhelm the system.

(I also don't think that N-fixers are as eager to fix Nitrogen in situations where there is excess Nitrogen already in the soil, but don't quote me on that.)

[XemaSab]

21. This is an oversimplified argument

One of the factors that makes it oversimplified is that a massive amount of nitrogen is used on corn, a massive amount of corn is used to feed cows, and a massive number of cows are used to feed people.

I'm not saying that everyone should go veg, but taking a good, sober look at factory farming practices would cut down on the amount of land used for corn under an organic or near-organic scheme.

(I'm thinking that putting a lot of that land into long-term cycles of fallowing and farming might help, and we could range cattle on some of the "fallow" land, but I haven't heard anyone else push this as a solution, so I feel like there must be something I am overlooking. :shrug:)

[OKIsItJustMe]

23. That’s the way my Grandfather did it

He was a “farmer” in the classic sense, raising both vegetables and “live stock.”

He rotated crops, and grew clover to replenish the soil along with spreading manure. He was an anachronism even then. His practices (thanks to the cooperative extension agent, and his botanist wife) were more scientific in many ways than other farmers in the area, and yet he ran a smaller farm than many of them.

[hunter]

7. A nearby city recently posted notice that it's water had violated EPA standards for nitrates.

We have a wretched problem with nitrates in the ground water in our valley. You can really mess up your kid if you make baby formula with nitrate polluted tap water. It can also mess up kids if a pregnant or nursing mom drinks the polluted groundwater.