Too much of a good thing: Human activities overload ecosystems with nitrogen

Oct 07, 2010
At Lake Atitlan in Guatemala, excess nitrogen promotes algae growth, which leads to eutrophication. Over-nourished by excess nutrients including nitrogen, which drains from nearby farms, swirls of blue-free algae form. The eventual decay of the algae robs the water of oxygen, and thereby creates a dead zone where other plants and animals cannot survive. Credit: NASA Earth Observatory image by Jesse Allen, based on data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Humans are overloading ecosystems with nitrogen through the burning of fossil fuels and an increase in nitrogen-producing industrial and agricultural activities, according to a new study. While nitrogen is an element that is essential to life, it is an environmental scourge at high levels.

According to the study, excess nitrogen that is contributed by human activities pollutes fresh waters and coastal zones, and may contribute to . Nevertheless, such ecological damage could be reduced by the adoption of time-honored sustainable practices.

Appearing in the October 8, 2010 edition of Science and conducted by an international team of researchers, the study was partially funded by the National Science Foundation.

The Nitrogen Cycle

The nitrogen cycle -- which has existed for billions of years -- transforms non-biologically useful forms of nitrogen found in the atmosphere into various biologically useful forms of nitrogen that are needed by living things to create proteins, DNA and RNA, and by plants to grow and photosynthesize. The transformation of biologically useful forms of nitrogen to useful forms of nitrogen is known as nitrogen fixation.

Mostly mediated by bacteria that live in legume and soils, and other components of the nitrogen cycle weave and wind through the atmosphere, plants, subsurface plant roots, and soils; the nitrogen cycle involves many natural feedback relationships between plants and microorganisms.

According to the Science paper, since pre-biotic times, the nitrogen cycle has gone through several major phases. The cycle was initially controlled by slow and lightning and then by anaerobic organisms as started. By about 2.5 billion years ago, as appeared on Earth, a linked suite of microbial processes evolved to form the modern nitrogen cycle.

Human Impacts on the Nitrogen Cycle

But the start of the 20th century, human contributions to the nitrogen cycle began skyrocketing. "In fact, no phenomenon has probably impacted the nitrogen cycle more than human inputs of nitrogen into the cycle in the last 2.5 billion years," says Paul Falkowski of Rutgers University, a member of the research team.

"Altogether, human activities currently contribute twice as much terrestrial nitrogen fixation as natural sources, and provide around 45 percent of the total biological useful nitrogen produced annually on Earth," says Falkowski. Much of the human contributions of nitrogen into ecosystems come from an 800 percent increase in the use of nitrogen fertilizers from 1960 to 2000.

Another problem: Much of nitrogen fertilizer that is used worldwide is applied inefficiently. As a result, about 60 percent of the nitrogen contained in applied fertilizer is never incorporated into plants and so is free to wash out of root zones, and then pollute rivers, lakes, aquifers and coastal areas through eutrophication. (Eutrophication is a process caused by excess nutrients that depletes oxygen in water bodies and ultimately leads to the death of animal life.)

In addition, some reactions involving nitrogen release nitrogen oxide into the atmosphere. Nitrogen oxide is a greenhouse gas that has 300 times (per molecule) the warming potential of carbon dioxide. In addition, nitrogen oxide destroys stratospheric ozone, which protects the earth from harmful ultraviolet (UV-B) radiation.

Methods to Reduce Nitrogen Overloading

"Natural feedbacks driven by microorganisms will likely produce a new steady-state over time scales of many decades," says Falkowski. "Through this steady state, added from human sources will be removed at rates equivalent to rates of addition, without accumulating."

But meanwhile, the Earth's population is approaching 7 billion people, and so ongoing pressures for food production are continuing to increase. "There is no way to feed people without fixing huge amounts of nitrogen from the atmosphere, and that nitrogen is presently applied to crop plants very ineffectively." says Falkowski.

So unless promising interventions are taken, the damage done by humans to the Earth's will persist for decades or centuries. These promising interventions, which would be designed to reduce the need to use fertilizers that add nitrogen to ecological systems, could include:

  • Using systematic crop rotations that would supply nitrogen that would otherwise be provided by fertilizers;
  • Optimizing the timing and amounts of fertilizer applications, adopting selected breeding techniques or developing genetically engineered varieties of plants that would increase the efficiency of nitrogen use;
  • Using traditional breeding techniques to boost the ability of economically important varieties of wheat, barley and rye to interact favorably with the microbial communities associated with plant root systems and do so in ways that enhance the efficiency of nitrogen use.
"While the processes of eutrophication have been recognized for many years, only recently have scientists been able to begin placing the anthropogenic processes in the context of an understanding of the broader biogeochemical cycles of the planet," says Robert Burnap, an NSF program director. This is an important article because it concisely develops this understanding and also provides reasonable predictions regarding the economic and policy dimensions of the problem."

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joefarah
2.3 / 5 (6) Oct 07, 2010
OK, finally. I was waiting for the Next scare. This is it isn't it? Might be too closely related to the CO2 issue - which I think is solved by growing trees - to take off. BTW trees store a LOT of Carbon and do so efficiently. So it's true - want to collect carbon and store it away -grow a tree.!

Now I'm not sure if this article is telling us not to grow things, like trees. Seems plants are bad, especially if they produce food for humans. Now let's see - all humans could comfortably fit in the Carolinas, with enough land to feed off of. So maybe God mad a mistake my creating an entire planet. Or maybe He created it to fit 500 billion people, or even more.

But the main message continue - Population Control - continue Hitler's quest!
Skeptic_Heretic
4.4 / 5 (7) Oct 07, 2010
So it's true - want to collect carbon and store it away -grow a tree.!

It'd serve to store nitrogen as well and generate topsoil locally. We should all grow more trees.
all humans could comfortably fit in the Carolinas, with enough land to feed off of.
Eh, no not really. You'd need more land than the Carolina's to feed the population of the world. You could fit us all in the carolinas but who would want to be living in that close proximity to that many other people?
dilbert
5 / 5 (3) Oct 07, 2010
@joefarah - Why does any article that suggest humans are changing the Earth have to be scary to you? Take your tin foil hat off and pick up a few science books.
Corban
5 / 5 (1) Oct 07, 2010
@Skeptic_Heretic - Japan seems to be doing just fine. Of course, they're very homogeneous, whereas the US (to say nothing of the world) is very heterogeneous.
Quantum_Conundrum
2.5 / 5 (2) Oct 07, 2010
Aeroponics:

5/3 to double the food in the same time, and for 33% less water usage, not to mention, no run-off or erosion and no "wasted" fertilizers.

If all our food was grown aeroponically, we could easily feed 11 billion or more people using 1/3 less water and significantly less fertilizers than we currently use world wide, and without even changing anything else; particularly since many countries aren't even as advanced in agriculture as the U.S. is right now.
Skeptic_Heretic
3 / 5 (2) Oct 07, 2010
@Skeptic_Heretic - Japan seems to be doing just fine. Of course, they're very homogeneous, whereas the US (to say nothing of the world) is very heterogeneous.

Yes, but we're talking about confining the population of the world to the Carolinas. That's quite a difference in scope.
If all our food was grown aeroponically, we could easily feed 11 billion or more people using 1/3 less water and significantly less fertilizers than we currently use world wide, and without even changing anything else; particularly since many countries aren't even as advanced in agriculture as the U.S. is right now.
Except the energy costs for aeroponics are tremendous, and I'm speaking from experience.
rynox
5 / 5 (1) Oct 07, 2010
Maybe someone smarter than myself could develop a process of making human sewage clean enough to fertilize crops. That would solve two problems at once: 1- What to do with human waste, and 2- The proliferation of chemical fertilizers.
Bob_Kob
4 / 5 (2) Oct 08, 2010
But the main message continue - Population Control - continue Hitler's quest!


While population control would solve a lot of issues currently faced, a growing population is required for the pyramid scheme that is capitalism. No population growth = collapse of economy.
TechnoCore
5 / 5 (4) Oct 08, 2010
@joefarah:

It's not the next scare. This has been known for decades. At least where I'm from. (Sweden)
Look at the Baltic sea, huge areas of the sea floor is basically sterile because of agricultural nitrogen has been washed into the water.

Now I'm not sure if this article is telling us not to grow things, like trees. Seems plants are bad, especially if they produce food for humans.


It clearly says that if you are going to use
fertilizers, you better make sure all of it winds up in the plants you are growing, and not just washed out into the oceans.

Quantum_Conundrum
1 / 5 (2) Oct 08, 2010

While population control would solve a lot of issues currently faced, a growing population is required for the pyramid scheme that is capitalism. No population growth = collapse of economy.


While this is more true for capitalism than any other economic model, the fact remains a growing population is required for any economic model that has a social security program or a retirement program.

Somebody has to support the sick and the elderly, and of course, that "somebody" is the next generation.

The earlier people are allowed to retire the worse the situation.

the fewer children each generation has, the worse the situation.
Quantum_Conundrum
2.3 / 5 (3) Oct 08, 2010

It clearly says that if you are going to use
fertilizers, you better make sure all of it winds up in the plants you are growing, and not just washed out into the oceans.


Greenhouses, hydroponics, aeroponics. No wasted soil or fertilizer. Little or no pesticides needed.
otto1932
5 / 5 (1) Oct 08, 2010
Aeroponics:

5/3 to double the food in the same time, and for 33% less water usage, not to mention, no run-off or erosion and no "wasted" fertilizers.

If all our food was grown aeroponically, we could easily feed 11 billion or more people using 1/3 less water and significantly less fertilizers than we currently use world wide, and without even changing anything else; particularly since many countries aren't even as advanced in agriculture as the U.S. is right now.
You got a powerpoint showing $$ figures per acre to replace what we got with your structures and plumbing? Link please.

I would need to see sources for raw materials, labor and transportation costs, as well as lifetime analysis, replacement costs, glass cleaning and overall maintenance, etc. Make it flashy- the monsanto boys like that stuff.
Skeptic_Heretic
5 / 5 (3) Oct 08, 2010
Greenhouses, hydroponics, aeroponics. No wasted soil or fertilizer. Little or no pesticides needed.
So you have zero experience with what you're talking about.

Where you have crops you will always have pests, fungi, disease, and other such malady that must be addressed.

As for fertilizer waste, you've never had to clean out the salt buildup from a hydro or aero system.

As for the greenhouse, Otto summed it up nicely as the maintenance costs for the structure and the various components allowing light in.

Try before you insist.
Quantum_Conundrum
2.5 / 5 (2) Oct 08, 2010
Try before you insist.


1) I never said anything was perfect, now did I? Oh yeah, I kinda grew up farming, as my parents and grandparents all had farms. Used to pick several acres worth of corn every year, not to mention beans, squash, and other crops.

2) to otto: The best figure I can give you right off hand is from a news report about two years ago in which this large tomato farm had converted from open fields. They were spending 1 million dollars per acre for one million acres to convert it to greenhouses, and found that they could pay off the project in 10 years with the increased income from increased productivity. 5 acres worth of solar panels could power the entire operation.

The number cited was that they could produce 15 times as many tomatoes in these greenhouses as compared to open fields, so then by year 11, they would already have paid off the project, and would have 15 years worth of income from similar open field farms they already had before.
Skeptic_Heretic
5 / 5 (1) Oct 08, 2010
So how many of those acres were aeroponic?

That is the crux of your stance. You're pressing for aeroponics, when if you had any actual experience you'd be pushing for NFT or semi-saline DWC. You're far out of your depth here as this is what I wrote my dissertation in Biology on and garners the majority of my attention.
otto1932
not rated yet Oct 10, 2010
Max Yasgar was a farmer, so what?

"Tomatoes are the leading greenhouse vegetable crop in the United States and Canada. In the U.S., the total acreage in greenhouse tomato production increased by 40 percent between 1996 and 1999. Statistics for 1999 show that the U.S. had about 800 acres in greenhouse vegetable production, with tomatoes accounting for 750 of those acres."
-Total US- 800 acres in 1999. I submit your figures came from out your ass. God would be ashamed of you.

Tomatoes are apparently a suitable greenhouse crop. As for corn, potatoes, or much else, ?
otto1932
not rated yet Oct 10, 2010
Aeroponics:

5/3 to double the food in the same time, and for 33% less water usage, not to mention, no run-off or erosion and no "wasted" fertilizers.

If all our food was grown aeroponically, we could easily feed 11 billion or more people using 1/3 less water and significantly less fertilizers than we currently use world wide, and without even changing anything else; particularly since many countries aren't even as advanced in agriculture as the U.S. is right now.
So to return to your original post, there's no reason to assume that any of it is real either? Did you make all of this up QC?
Quantum_Conundrum
1 / 5 (1) Oct 10, 2010
-Total US- 800 acres in 1999. I submit your figures came from out your ass. God would be ashamed of you.


Last time I checked, this is near the end of 2010, so that news cast was probably the end of 2008 or beginning of 2009. It was on WAFB, a local Louisiana news station.

God knows I'm telling the truth.

So to return to your original post, there's no reason to assume that any of it is real either? Did you make all of this up QC?


No, those were numbers given by a leading NASA scientist and consultants on an episode of Modern Marvels.

And of course, you do what works best. Grow potatoes and other tubers and similar crops aeroponically.

Grow tomatoes in modernized greenhouses, etc.

This isn't that hard to comprehend that you use the technique that works best for the crop in question...
Quantum_Conundrum
1 / 5 (1) Oct 10, 2010
I was able to find this very similar operation after a little searching. This may be part of the same thing, or it may be something different all together, but much of the solar and water technology is the same.

http://www.altene...t_id=199

http://greenhouse...e-plans/

But, enthuses Despommier, the most exciting thing about CEA is the variability and the yields. Hydroponics has nearly 20 times the yield rate of conventional agriculture (depending on the crop, strawberries are up to 30 times). And all the variables can be controlled. "Imagine a world in which there is no more weather-related crop failure."

"With indoor plants, our crop loss is 2 percent," said Despommier. "Corn? You can grow 18 ears in 3 feet. You can harvest it every 5 to 8 weeks by idealizing the conditions."


http://agrosoftbr.../354.htm
Corban
not rated yet Oct 12, 2010
The key to using sewage as effective fertilizer for crops is to separate the human waste from the inorganic trash. Composting and filtration work well on human waste, poorly on the other stuff. The other stuff also takes up space and reduces throughput. A city would have to change plumbing and teach people not to throw weird stuff down their toilets. However, it's been done before. The only question left is price.

What price your convictions?
otto1932
5 / 5 (1) Oct 12, 2010
QC says:
They were spending 1 million dollars per acre for one million acres to convert it to greenhouses
Otto says:
-Total US- 800 acres in 1999. I submit your figures came from out your ass.
-And QC retorts:
Last time I checked, this is near the end of 2010
-So otto spends 2 min. on google...

"WORLD'S LARGEST FARM; Situated in Northwestern Canada and Contains 100 Square Miles. A RANGE FOR "YOUNGER SONS" Owned by an English Syndicate and 45,000 Acres Under Cultivation"

One million acres is obviously, uh, wrong. QC is impervious because he thinks gods goodness favors him:
God knows I'm telling the truth.
-God would also know you have no clue about facts or how to assess them, that is if he existed, which he does not. He would know that you are too lazy and prideful to check sources and would thus charge you with committing at least 2 of the deadly sins.

You should plead lack of adequate faculties, thereby putting the blame back on him. See what he says.
otto1932
5 / 5 (2) Oct 12, 2010
Just to further embarrass you:
How many acres are in a square mile? 640; largest farm in the world: 100sqmi x 640 = 64,000 acres
-which is less than 1,000,000 acres

Also:
1 million dollars per acre for one million acres to convert it to greenhouses = a ridiculous amount that even the Grand Troll would have caught before she posted it.

Because of obvious puke like this, nobody here can believe anything you say.

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