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		Wikipedia for Schools
	Nitrogen cycle is included in the Wikipedia for Schools, see Nitrogen cycle at Schools Wikipedia. Please maintain high quality standards; if you are an established editor your last version in the article history may be used so please don't leave the article with unresolved issues, and make an extra effort to include free images, because non-free images cannot be used on the DVDs.

What this page could use is a lovely diagram if anyone artistic is inclined to do so... -- Booyabazooka 03:17, 31 Aug 2004 (UTC)

The current diagram is lovely, but slightly too small to read easily. Suggest using original version (slightly larger) http://www.epa.gov/maia/images/nitro.jpg

Done Onco p53 22:45, 5 Feb 2005 (UTC)

Contents 1 Human Influences on the N Cycle 2 Wastewater 3 “Nitrogen Cycle in Aquariums” Section 3.1 Fact-checking About Nitrobacter 3.1.1 Update 3.2 Natural nitrogen cycle 4 ammonia thoughts 5 what would life be like 6 Missing anthropogenic NOx -> eutrophication, foliage damage 7 Diagram 8 Fixation by Lightning

[edit] Human Influences on the N Cycle

Hi, I'm writing an article to expand upon Human Influences on the N Cycle. I may just make a new page and link this one to it. I'm new to this, so please let me know what you think!

[edit] Wastewater

This section uses the phrase "several states". If "several states in the U.S." is meant, it should say that, since Wikipedia is international; otherwise if "Several countries" is meant, that would be clearer language.. —Preceding unsigned comment added by Harel (talk • contribs) 21:48, 25 February 2008 (UTC)

[edit] “Nitrogen Cycle in Aquariums” Section

[edit] Fact-checking About Nitrobacter

I'm no biochemist, but I've seen other sources on the web that claim that while Nitrobacter spp. are primary oxidizers of soil-based nitrites, in aquatic environments, Nitrosospira spp. and Nitrospira spp. (which are apparently under a separate phylum or something) appear to play a dominant role.

Here is one research paper that appears (to my chemistry-challenged mind) to assert this: “Identification and Activities In Situ of Nitrosospira and Nitrospira spp. as Dominant Populations in a Nitrifying Fluidized Bed Reactor”

Here is another: “Nitrospira-Like Bacteria Associated with Nitrite Oxidation in Freshwater Aquaria”

Are there any biochemists out there who have access to current peer-reviewed, journal-published research on this point (and maybe more importantly the know-how to understand the gist of this research and to translate it elegantly into layman's terms)? Thanks! —Iguana Scales 16:24, 11 December 2006 (UTC)

[edit] Update

Oops. Well, apparently the “Nitrogen Cycle” subsection under the “Aquarium article” addresses this point nicely.

However, the “Nitrogen Cycle in Aquariums” section under this (“Nitrogen Cycle”) entry hasn't been updated to reflect these more recent research findings re Nitrospira.

Additionally, the assertions under Aquarium→Nitrogen Cycle aren't accompanied with citations. So I think I'll add the two sources I included above to that article. Anybody with solid biochem credentials can certainly overrule me on this and/or replace my citations with more recent/representative ones. —Iguana Scales 16:48, 11 December 2006 (UTC)

Okay, well I just added the footnoted citations in this section, not the one under the "Aquarium" article. —Iguana Scales 18:37, 11 December 2006 (UTC)

[edit] Natural nitrogen cycle

Does the aquarium-related stuff really belong here? --Satyrium 17:15, 1 August 2006 (UTC)PABLOHUARTE

I personally think there should be a level-two section called something like "Nitrogen Cycle in Aquatic Environments." There could be a few brief subsections under this: "Freshwater-based Nitrogen Cycles," "Saltwater-based Nitrogen Cycles," and "Man-made Applications." (Or a more PC title for the last subsection might be "Human-engineered Applications".)

The last category should cover not just things like hobbyists' aquariums but also applications such as biomass-driven wastewater treatment (see this) and include links to the appropriate main Wikipedia articles/sections that elaborate in greater depth on the topic.

What say all of you? Again, chem/biochem-trained folks, help us out here! —Iguana Scales 17:05, 11 December 2006 (UTC) PABLO YEA

[edit] ammonia thoughts

Treatment plants with NPDES permits under the US Clean Water Act are restricted in their (toxic) ammonia discharge, but not their (nontoxic) nitrate discharge. Furthermore nitrate plays a relatively insignificant in eutrophication relative to phosphorus, water temperature and oxygen demanding constituents (raw waste, garbage, fuel, lubricants). I toyed with the idea of a bold rewrite of thissection, but in the end I have to agree that nitrate plays some role in contributing to eutrophication.

Nitrate is bound weakly to an anion exchange capacity comprised mostly of humic substance, another reason why a soil with high organic matter is more protective of the environment than the same soil with low SOM

Denitrification isn't literally the reverse of nitrification or it would produce ammoinium from nitrate.

A exceedingly minor, hair-splitting, point to make here. Nitrogen isn't lost out of the nitrogen cycle to the atmosphere, it is returned and remains within the cycle. A poor comparison but I am reminded of the old adage, you don't buy beer in a saloon, you can only rent it for a few minutes. <soapbox> The oxidative power of nitrate is too attractive for it not to be used by the soil microbial population anytime a flush of metabolic activity causes oxygen demand to exceed supply. That is a good and natural phenomenon to celebrate (its alive!). To bemoan denitrification as a loss is to take a narrow anthropocentric zero-sum mass balance point of view that doesn't have much to do with what the nitrogen cycle really is. </soapbox>

Paleorthid 18:34, 8 January 2006 (UTC)

The article says Nitrogen has contributed to severe eutrophication problems in some water bodies.

I can't recall any specific instances of this being verified, only speculated. I'll search around and possibly amend the above sentence based on what I find. Paleorthid 18:41, 8 January 2006 (UTC)

Probably some way to work this in: Non-parasitic micro-organisms that degrade soil amendments and release nematicidal compounds, such as the bacterium which degrades chitin to produce ammonia (Spiegel et al., 1991), are likely to kill most nematodes in soil. 1 Paleorthid 02:18, 18 January 2006 (UTC)

[edit] what would life be like

where would we be if 78% of our atmosphere wasnt nitrogen.How would wildlife be complete without Nitogen?I would like everyone to think about these comments.if that russian guy would've not thought about this periodic table maybe we would still all be in ahh.now some may think im a comedian scientist or maybe just a dumbass but i think im just another curious person who thanks you all very much for reading my comments.PEACE 2 all!

I am not quite sure where this should go under.. but what happens to all this nitrogen that gets fixed? Will we ever run out of nitrogen.. I mean its not exactly recycled into the atmosphere but 'fixed' permanently..

It is recycled, that is why it is the nitrogen cycle. Denitrification converts nitrates to nitrogen. As for what the planet would be without nitrogen, basically on fire as the atmosphere would be almost entirely oxygen. Smartse (talk) 01:42, 11 August 2009 (UTC)

[edit] Missing anthropogenic NOx -> eutrophication, foliage damage

Rather important! See: Fenn, M.E., Ecological Effects of Nitrogen Deposition in the Western United States., BioScience, April 2003, V53 No 4. Scedacity (talk) 15:31, 16 May 2008 (UTC)

[edit] Diagram

The current diagram is incorrect in that it does not show any of the human processes. These now exceed the natural processes and the diagram needs to be changed accordingly. Smartse (talk) 12:20, 16 April 2009 (UTC)

Use this as a source Smartse (talk) 22:30, 31 August 2009 (UTC)

[edit] Fixation by Lightning

Isn't fixation by lightning a significant source of terrestrial nitrogen? —Preceding unsigned comment added by 24.9.94.224 (talk) 18:19, 28 November 2009 (UTC)

Check the link in the above thread, it is a pretty tiny contributor in the scheme of things. The current wording of "Some fixation occurs in lightning strikes, but most fixation is done by free-living or symbiotic bacteria." seems ok. We don't have anything about it in Nitrogen fixation though, feel free to add something. Smartse (talk) 21:11, 28 November 2009 (UTC)