The rapidly rising levels of carbon dioxide in the atmosphere affect plants’ absorption of nitrogen, which is the nutrient that restricts crop growth in most terrestrial ecosystems. Researchers at the University of Gothenburg have now revealed that the concentration of nitrogen in plants’ tissue is lower in air with high levels of carbon dioxide, regardless of whether or not the plants’ growth is stimulated. The study has been published in the journal Global Change Biology.
Researcher Johan Uddling has been working with Swedish and international colleagues to compile data on how raised levels of carbon dioxide impact on plant growth and nitrogen absorption.
Plant quality impaired by increased carbon dioxide levels
The study examines various types of ecosystems, including crops, grasslands and forests, and involves large-scale field experiments conducted in eight countries on four continents.
“The findings of the study are unequivocal. The nitrogen content in the crops is reduced in atmospheres with raised carbon dioxide levels in all three ecosystem types. Furthermore, we can see that this negative effect exists regardless of whether or not the plants’ growth increases, and even if fertiliser is added. This is unexpected and new,” says Johan Uddling, senior lecturer at the Department of Biological and Environmental Sciences at the University of Gothenburg.
Significance of food quality, biodiversity and productivity
When carbon dioxide levels in the air increase, crops in future will have a reduced nitrogen content, and therefore reduced protein levels. The study found this for both wheat and rice, the two most important crops globally. The study also reveals that the strength of the effect varies in different species of grassland, which may impact on the species composition of these ecosystems.
“For all types of ecosystem the results show that high carbon dioxide levels can impede plants’ ability to absorb nitrogen, and that this negative effect is partly why raised carbon dioxide has a marginal or non-existent effect on growth in many ecosystems,” says Johan Uddling.
Accepted “truths” do not hold
Reduced nitrogen content in atmospheres with raised carbon dioxide has previously been attributed to a kind of dilutive effect, in which nitrogen absorption fails to keep pace with the increase in plants’ photosynthesis and growth.
“The findings of this study show that this interpretation is simplified and partly incorrect. We are seeing reduced nitrogen content even when growth has not been affected. Moreover, the effect is there in trials with powerful fertiliser, which indicates that it is not down to limited access to nitrogen in the soil. Future studies should look at what is causing the effect, but it appears to be linked to plants’ capacity to absorb nitrogen rather than to changed levels in the soil,” says Johan Uddling.
###
Link to article: http://onlinelibrary.wiley.com/doi/10.1111/gcb.12938/abstract
And a video that suggests this study might very well be off the mark:
As I’ve always written, natural laws apply everywhere in the universe except the realm of climate “science”.
exactly…..they just discovered that plants grown with CO2 limiting….increase their nitrogen uptake to make up the difference
“They” didn’t actually discover anything. The paper is pay-walled, but the supplemental information makes it clear that this is a meta-study, not an original experimental scheme. It’s based on the work of four other studies completed between 2004 and 2011.
“This is unexpected and new,” says Johan Uddling, senior lecturer at the Department of Biological and Environmental Sciences at the University of Gothenburg.”
+1 DJ Hawkins
Yes that’s right, and their hypothesis, for that is what this is, is based on a distortion perhaps of this earlier paper, published in the journal of Functional Plant Biology in 2008 : “Why is plant-growth response to elevated CO2 amplified when water is limiting, but reduced when nitrogen is limiting? A growth-optimisation hypothesis”
by Ross E. McMurtrie et al.
(Functional Plant Biology 35(6) 521–534
http://dx.doi.org/10.1071/FP08128
In the abstract, it is stated :
“The optimisation is represented in terms of a trade-off between LAI and stomatal conductance, constrained by water supply, and between LAI and leaf [N], constrained by N supply. At elevated CO2 the optimum shifts to reduced stomatal conductance and leaf [N] and enhanced LAI. The model is applied to years with contrasting rainfall and N uptake. The predicted growth response to elevated CO2 is greatest in a dry, high-N year and is reduced in a wet, low-N year. The underlying physiological explanation for this contrast in the effects of water versus nitrogen limitation is that leaf photosynthesis is more sensitive to CO2 concentration ([CO2]) at lower stomatal conductance and is less sensitive to [CO2] at lower leaf [N].”
1. Note that they are writing here about atmospheric Nitrogen, and not soil borne nitrates. Since the atmosphere generally contains a huge proportion of Nitrogen (about 78%), it is difficult to imagine what circumstances might lead to a “shortage”, It is the case that is there is a higher humidity level however, then the H2O vapour will be expected to displace some of the Nitrogen percentage by volume. That process is not influenced at all by the addition of small amounts of CO2 gas measured in thousandths of a single percentile.
2. Note also the conclusion arrived at, that “The underlying physiological explanation for this … is that leaf photosynthesis is more sensitive to CO2 concentration at lower stomatal conductance and is less sensitive to CO2 at lower leaf N”. They are not claiming that total leaf area is reduced because of any elevation in CO2, nor is it the case that in wet years additional CO2 had reduced leaf area. What they had stated was that their MODEL predicted that the leaf area would not increase by as much in wet years as opposed to dry years.
3. It is not suggested that increased CO2 will actually reduce plant growth.
Call me a cynic, but maybe when, they speak glibly of “CO2 enrichment experiments”, what they really mean is that to read the absolute proofs, of their hypothesis, a reader must stump up 35 bucks for the privilege of a PDF download, or “Rent” it for two days for 6 bucks !!!
Scientist to rent = Cab for hire
Sigh.
Arthur Ainslie:
“Note that they are writing here about atmospheric Nitrogen, and not soil borne nitrates. ”
No they are not. They are speaking about biologically available nitrogen. There are no plants that can use atmospheric nitrogen, though some can access it indirectly by way of symbiotic bateria. That they speak of “High-N years” and “Low N-years” should be proof enough, because there is always 78 % N2 in the atmosphere.
Here are a couple of links that Connolly may have not gotten into.
Cropland impacts:
http://www.co2science.org/subject/f/summaries/faceag.php
Forest impacts:
http://aspenface.mtu.edu/pdfs/Zak%20EcolApplic%202003.pdf
It is important to watch the pea under the cup, as Steve McIntyre is fond of saying. It is by now indisputably accepted that more CO2 causes plants to grow faster. That is, increased CO2 causes them to gain more dry mass.
However, that increased dry mass is presumably mostly cellulose, starches/sugars, and lignin. None of those molecular types have any nitrogen. Even so, that extra growth is still certainly highly useful to the plants (and to the animals that eat them).
As a PERCENTAGE, nitrogen may make up a smaller fraction under CO2 enhanced growth. This ought not to surprise anyone since plants can only uptake that nitrogen which is actually present, and putting more CO2 in the air does not somehow magically put more NO3 in the ground.
So, big surprise. Plants are gaining more mass, but since more CO2 does not put more nitrogen in the ground, the total nitrogen mass is not increasing. The problem with that is what, exactly? Sheesh.
A paper from the archives of University of Illinois, Champaign soy face experiment program:
http://www.igb.illinois.edu/soyface/welcome
Interesting title Published in 2006:
Rogers A, Gibon Y, Stitt M, Morgan PB, Bernacchi CJ, Ort DR, Long SP. Increased C availability at elevated carbon dioxide concentration improves N assimilation in a legume. Plant Cell And Environment 29 : 1651-1658, doi: 10.1111/j.1365-3040.2006.01549.x
Well what do you know.
Richard,
You may be assuming a pretty high level of knowledge in the readership here, but for those unfamiliar with plants, legumes are the exception to the rule I suggested above. Legumes are very unusual in that they actually can fix nitrogen. For that plant group, increased vigor due to higher CO2, would indeed be expected to result in higher nitrogen uptake.
TY
the obvious suggestion for those worried about nitrogen deficient cereal grains would be to plant/eat more peas and beans. Or meat.
Re: Legumes and all that
Yes Richard and TY, what you state is right, and I would go further and say that scientists like these are probably not actually horticulturalists, and they assume that the farmers who grow crops, know nothing about the crops they grow.
Every farmer knows that if you grow cereals and don’t use additional nitrogen fertilizer, then you must rotate your crops, and include a legume (or a clover) which has the Nitrogen fixing nodules. Stubble burning and plowing in after harvest does enrich the soil with particulate carbon matter, which does slowly oxidize during the next growing season creating CO2 gas which rises up from the ground in significant amounts, and does create additional biomass.
“Field” experiments by scientists who are unaware of these practices will have compromised their hypotheses, because a measurement of atmospheric CO2 at Mauna Loa observatory is irrelevant with respect to what is going on in a farmer’s field. Similarly atmospheric reduced Nitrogen concentrations measured at wherever you like, will have less effect on a field which had in the previous growing season been cropped with clover or legumes.
I believe it is the case, that in none of those papers referenced, was any consideration given to farming practices at all, though obviously this must have an effect on plant growth and chemical compound content. As such I believe that most, if not all of these papers are seriously compromised, and even perhaps irreconcilable,
But, but, but, “The findings of the study are unequivocal.” After all, greenhouse keepers are not scientists, are they? We must listen to the scientists and read their peer reviewed papers to find out the truth. (/sarc)
It’s become painfully obvious that research into climate has long since not been about attempting to understand the climate and it’s many natural variations (at least by the usual suspects), but it is tailored to find something, anything, no matter how bogus the paper or research is, that specifically refutes any particular skeptical fact. These “papers” tend to come in waves, with large numbers released just prior to any major climate conference to allow the news media and politicians to wave the memes like battle flags in an attempt to shut down any argument or discussion. And sadly they are far too effective, as the constant bleating of the 97% “consensus” shows.
“These “papers” tend to come in waves, with large numbers released just prior to any major climate conference to allow the news media and politicians to wave the memes like battle flags in an attempt to shut down any argument or discussion.”
I totally agree with you! Also the British Bias Corporation save their climate propaganda util we get “extreme” (we never get that in UK) weather, to support their stance.
I have yet to hear anything good about AGW from the warmunists either, it is all doom and gloom; there MUST be some positives (and I don’t mean feedback either!)
In my years in college, we had a CO2 enhancement experiment going on in one of the greenhouses. this was in the early 70’s -anticipating the imminent “Ice Age.” that was to
descend. This the biggest load of bravo sierra i have ever read…
Well, in the last few days anyway..
Yes, the recent spike in ‘news stories’ about climate has been very noticeable.
“For all types of ecosystem the results show that high carbon dioxide levels can impede plants’ ability to absorb nitrogen, and that this negative effect is partly why raised carbon dioxide has a marginal or non-existent effect on growth in many ecosystems,” says Johan Uddling.
——————-
Except on planet Earth, where NASA satellites have documented a 25% increase in the biosphere.
On the plus side for governments,, this “study” is fodder for Paris Climat 2015.
The wild flowers where I live in the UK are a great deal larger than normal this year.
“The wild flowers where I live in the UK are a great deal larger than normal this year'”
This may be in part due to another aspect of elevated atmospheric CO2: This past very cold winter, caused by “global warming”.*
This may seem paradoxical, but long, cold Winters often lead to such occurrences as you describe.
*snark/off
What this really is saying is that Plants that are grown in CO2 poor environments will require more nitrogen fertilizer in their soil to be able to grow and plants that are grown in CO2 rich environments do not require nearly as much Nitrogenized soil AND grow better as a result.
Plant 101
Plants will grow OK in a Nitrogen rich and CO2 Poor environment
Plants will grow OK in a CO2 rich and Nitrogen Poor environment
Plants will grow best in a CO2 and Nitrogen rich environment
+1
Now there is a reason to say CO2 harms plants…Its even a peer reviewed study, doesnt matter that the paper is crap. Next target softdrinks, need a study showing CO2 in drinks is making people fat…
In the real world, dont expect sales of CO2 generators for greenhouses to go down..
FWIW the study likely used levels of 5000 parts or more…
“FWIW the study likely used levels of 5000 parts or more…”
I have many questions about how these trials were set up and maintained, and how uniformity and QC were achieved and verified.
I am very curious how this FACE (Free Air CO2 Enrichment) process is set up.
It would seem highly problematic to increase CO2 in a broad outdoor area for an extended length of time.
And what about CO2 in the soil?
In an enclosed space, CO2 enrichment will extend into the growing medium.
It seems doubtful if the same could be achieved outside.
Enclosed conditions with great care to achieve uniformity, and eliminate all but one variable at a time, in addition to a double blind methodology, would seem to be what is called for in order to reach any scientific conclusions.
Sounds too much like real science.
Plus, we don’t have time to do all those controlled studies, we have a world to save.
I too am interested in their method of increasing CO2. Either it’s enclosed, which likely contaminated their experiment by whatever method they used to enclose it, or it is not enclosed, in which case the CO2 levels in the area varied wildly with every gust of wind, which is completely unlike the situation that would exist in reality.
CO2 is heavier than air but as someone else noted, wind is of course a problem.
I would think that achieving any degree of uniformity as to concentration of CO2 over a wide area for a prolonged period would be, if not somewhere between difficult and impossible, at the very least incredibly expensive.
Ditto for the continuous monitoring to ensure that the conditions they are trying to achieve are in fact being achieved…and sustained.
I’m looking forward to the day the greens take on the Royal Horticultural Society Chelsea Flower Show ladies, growing prize winning blooms in CO2 enhanced greenhouses, and tell them they can’t use their CO2 generators anymore.
https://www.rhs.org.uk/Shows-Events/RHS-Chelsea-Flower-Show
The test in the video would have to be repeated with various levels of nitrogen in the soil. In a nitrogen-rich soil, the ability of the plant to absorb nitrogen might not be important, while in a nitrogen-poor soil it might be.
The number of variables is immense, as is the possible factors which can confound any conclusions.
Optimum levels of various nutrients for a given crop will of course vary considerably if other factors are varied.
…and agricultural suppliers will provide a fertilizer combination best suited to deal with the changed environment. I think we are now seeing what the dumbing down of the population through education is producing in our universities and colleges.
Climate science has now crossed the boundary line from unreality into lunacy.
What, just now?
Bahahahahaha!
http://www.co2science.org/
A good source of this kind of info
Ok! So we just go out and pee more on plants?! See “problem” solved!
Now you are thinking.
I am a bit surprised that Anthony did not pick up on a couple other points in the abstract:
“… As the ecosystems were markedly N limited, plants with minimal productivity responses to eCO2 likely acquired less N than ambient CO2-grown counterparts because access was decreased, and not because demand was lower.”
Translation: these studies took place in already-nitrogen-starved ecosystems.
“Effects of eCO2 on productivity and N acquisition did not diminish over time, while the typical eCO2-induced decrease in plant N concentration did.”
While acquisition was not altered over time, the claimed N deficiency DID reduce over time, although plant growth enhancement was sustained.
I hardly see any reason for alarm here. And… I am also curious as to how they provided a consistent and calibrated concentration of CO2.
Please look up items such as the Australian AGFACE [ Agricultural Free Air Carbon dioxide Enrichment ] or FACE experiments which are open air field crop experiments, ie wheat , barley, pulse crops ie peas, beans chickpeas, Lentils etc where CO2 is released on the upwind side of a some many metres diameter ring of CO2 release points and the controlling CO2 measuring sensors.
These open air field CO2 enrichment experiments using similar ring type field located, open air, sensor controlled CO2 enrichment across the rings are being conducted world wide by a number of country’s Agricultural and horticultural researchers to try and put numbers on yields changes and increases, fertiliser use, and grain and forage qualities and etc under higher global CO2 concentrations.
Our local Ag crop Research Institute’s FACE experiment results and etc;
http://www.piccc.org.au/research/project/252
http://www.regional.org.au/au/asa/2010/climate-change/co2/7128_nortonrm.htm
The concentration of CO2 is maintained across the ring [s] by the sensors which measure and control both the amounts of CO2 being released and also to ensure that the CO2 is being released from the upwind release points to drift / blow across the growing crops for the duration of their life cycle of some months from sowing to maturity .
Yields of grains such as wheat are up by very considerable percentages but grain N levels and consequently grain Protein were down.
Nitrogen fixing pasture legumes will likely have increased fixation of soil Nitrogen as the amount of soil N fixed by pasture legumes is directly proportional to the dry matter production of the legume / nitrogen fixing plant.
Grain legumes / Pulses ie; peas, beans, chickpeas, lentils and etc first fix soil N during growth and then draw back that soil N during seed set and fill when creating the [ high] protein generally to be found in the pulse crop’s grains.
What is not said in the paper is the fact that researchers are currently using current commercial field crop varieties for the FACE experiments that have been bred and adapted to our current CO2, Nitrogen, fertilizer, water and temperature and day length criteria.
The genetic resources and variability of the plant kingdom including the humanity adapted grain, oil seed and pulse crops are immense.
It will be little more than a normal genetics selecting and crossing program to both find, cross and breed plant varieties that can both benefit substantially more in yield increases from enhanced CO2 and also have protein levels and grain qualities that are quite adequate and match today’s crops in those desirable and essential qualities.
And with GMO technology advancing rapidly, the modification of the internal genetic characteristics of grain crops without introducing any other foreign genetic material as in some current convential GMO’s will likely be able to compensate for lower N and protein levels in humanity’s main crops but still enjoy the much enhanced yields from the higher atmospheric CO2 of the future IF that higher CO2 does eventuate.
A proposition that might well be a chimera and a mirage as Nature just does what Nature does and the hell with what [ some of !? ] mankind in his arrogance and hubris believes he is capable of doing to change the whole course of Nature’s progress and inherent aeons old patterns.
_________________
When you can convincingly prove to me that you can control a Volcano then come back and we will discuss the controlling of the Earth’s climate.
Somebody should tell these dopes about nitrogen based fertilizer.
How can they keep producing this crap?
“How can they keep producing this crap?”
Seems fairly easy. Once you’ve lowered the bar, anything goes and it pays well too.
When you start lowering the bar, there is a point when it becomes fun to go … underneath it.
LIMBO !
How can they keep producing this crap?
Because it continues the Narrative:
• Global warming never stopped
• CO2 doesn’t help plants grow
• We are at war with Eastasia
• Evil is good
• Ignorance is strength
2 + 2 = 5
&etc.
“2 + 2 = 5”
Humph, and what did George Orwell say about that claim?
“Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.”
Well, at the moment WE are still free to say the correct answer “4” but the truth seems no longer to be “political correct” anymore, since even (formerly) respected universities try to teach us “2 + 2 = 5” today.
I conclude that we are somewhere between freedom and tyranny now, and hope urgently that true and unbiased Science will break free before we reach the second state definitively…
With large enough error bars for “2” (or rounding down, say, 2.4628732 to 2), sure 2+2 can equal (or close enough) to 5. It’s dishonest and misleading of course and Marketing Mathematics.
Manure add nitrogen to the soil, so it is solving the problem that they claim to have discovered.
So plow these studies under for better crop yields?
I hope the AGW fans see Johan’s comment;
“…….raised carbon dioxide has a marginal or non-existent effect on growth in many ecosystems”
So, no probs, eh?
“….Alice in Wonderland makes quite a sane read,
Compared with climate scientists’ rants and ravings.
Let’s lock them away in an asylum somewhere,
Just imagine the huge cost savings!”
From: http://rhymeafterrhyme.net/climate-compensation-and-cop19-its-alice-in-wonderland-revisted/
Well, I don`t think the farmers will believe this claim – especially greenhouse farms.
I recently had a phd level “scientist” involved in climate “science” tell me that I was lying when I said that greenhouse owners artificially increase the CO2 levels in their greenhouses.
It is a multibillion dollar industry:
https://www.google.com/search?q=greenhouse+co2+generator&sourceid=ie7&rls=com.microsoft:en-US:IE-SearchBox&ie=&oe=&gws_rd=ssl#q=greenhouse+co2+generator&tbm=shop
Should have recorded him saying that! Use a mobile phone to record what these mongrels say. Any mobile from the past ~decade will or should be able to record anything these people say.
Crabby, that phd and I have the same employer, and I’ve already gotten in trouble for getting the cash cows upset.
Yeah, and in some places it is a crime to record a person without their knowledge. Gotta be careful ’bout dat stuff.
“involves large-scale field experiments” Would someone please tell these bozos there ain’t no such thing as a large-scale field experiment. The very essence of experimental design involves the ability to control for all factors so that “all other things” are equal. This is an impossibility in the field, it’s exactly why the people in clinical trials are closely monitored, in some cases with 2-3 contacts per day.
Assuming you have 4 regions 8 types of soil 10 crops, each with 3 or 4 varieties, nitrogen and CO2 as continuous variables, other plant nutrients, (8 each at 5 levels), variation in temperature rainfall, not to mention the method of cultivation, (e.g., no-til, low-til, etc.) … anyway. And then there’s the sophistication of the agronomist at each site. I’m coming up with 1.44 billion combinations, or cells in a MANOVA, and then there’s the correction for unequal sample sizes.
Wow, what a crock of …. manure, which is often used to help plants obtain nitrogen
Exactly Mark.
It seems we had the same thoughts at the same time.
Blindingly obvious to me that in such a study, as described in the article, it would be impossible to eliminate the bias of the researchers.
Well, large-scale field experiments were conducted quite a while ago with spectacular results:
http://sealevel.info/ScientificAmerican_1920-11-27_CO2_fertilization.html
You can also see such currently going on at Duke University and others by just searching on the web.
Who cares. Wheat and rice aren’t very good sources of protein anyway. If you want protein, eat something else.
“If you want protein, eat something else.”
You must mean insects? Red meat is taboo, too much water usage, too much methane, too much land use, too much…
Pound for pound, I’m not sure which produces more methane, cows or termites.
Commiebob:
” If you want protein, eat something else.”
You mean my all-pasta diet is probably not a high protein diet?!? Dang! I guess I’ll have to throw on a meatball now and then.
And I suppose I can’t depend on beer for my daily minimum requirement of protein, either. Oh wait! Does the little worm at the bottom of the tequila bottle count as protein? I’m probably good, then.
/sarc
Why assume that protein levels are reduced?
Why not actually measure the protein levels?
Shouldn’t be that hard, they have the actual plants, just test them.
My suspicion is they did measure protein, and it did not give the results they wanted. So they skipped that.
Obviously the conclusion would be much more powerful, and powerfully stated, if they measured protein. And after a years long trial, costing Lord only knows how much money, why on Earth not directly measure the parameter they are drawing a conclusion about?
The protein content of wheat flour is important for the different products made from it . Millers analyse and grade the incoming flour , usually by NIR spectroscopy.
An extract from the NABIM website gives appropriate info:
“Protein
The amount of protein in wheat determines how flour
performs. It is also used for a trading specification. The wheat
protein is quoted at 100% dry matter and most laboratories
will test it using a near infrared (NIR) spectrometer, calibrated
against the reference method. In the reference method, a
ground sample of wheat is burnt at 1000°C and the gases
produced are analysed for their nitrogen content. The protein is
the percentage of that nitrogen gas multiplied by 5.7. Millers
typically look for a 13.0% minimum protein for bread wheat,
whereas for a biscuit wheat, a typical level is 11.0 – 11.5%.
In the UK, France and Germany protein levels are normally
between 10 – 15% whereas levels in North America are
usually 15.5 – 17.5%.”
NABIM is the National Association of British and Irish Millers .
I would imagine that their records over the past 30 years, of increasing global CO2 levels will contain all the information that you need to know about whether this is a problem or not.
If the protein content is used as a trading spec it has to be accurate or a thousand lawyers will be sharpening their quills.
But this study did not claim to measure protein in specific grains, or even specific parts of specific plants.
It seemed to be referring to the whole plant, across a range of habitats, including many different sorts of plants.
If it was regarding specific foods, or seeds, or edible portions of commercially important plants, that would be one thing.
I saw nothing to indicate that was the case.
That’s exactly what I thought. If they want to look at plant protein then shouldn’t they be looking a legume?
“…the journal Global Change Biology.”
————
Fight Global.* Change!
“Increased carbon dioxide levels in air restrict plants’ ability to absorb nutrients”
Isn’t this just another way of saying that with higher CO2 levels plants need less nitrogen fertilizer in order to grow?
Thus reducing non point source pollution…
http://www.ncbi.nlm.nih.gov/pubmed/21830824
Abstract
Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds, respectively. Analysis of δ(15)N-NO(3)(-), and δ(18)O-NO(3)(-) indicated wastewater was an important nitrate source in urbanized streams during baseflow. Negative correlations between δ(15)N-NO(3)(-) and δ(18)O-NO(3)(-) in urban watersheds indicated mixing between atmospheric deposition and wastewater, and N source contributions changed with storm magnitude (atmospheric sources contributed ∼50% at peak storm N loads). Positive correlations between δ(15)N-NO(3)(-) and δ(18)O-NO(3)(-) in watersheds suggested denitrification was removing septic system and agriculturally derived N, but N from belowground leaking sewers was less susceptible to denitrification. N transformations were also observed in a storm drain (no natural drainage network) potentially due to organic carbon inputs. Overall, nonpoint sources such as atmospheric deposition, wastewater, and fertilizer showed different susceptibility to watershed N export. There were large changes in nitrate sources as a function of runoff, and anticipating source changes in response to climate and storms will be critical for managing nonpoint N pollution.
Does the paper say what the optimum level for CO2 is? If less than 180ppm is bad and increasing levels are equally bad then there must be an optimum. I can’t see it in the abstract, but my guess would ne somewhere around the 350ppm mark (it has to be really doesn’t it).
Professional greenhouse folks would probably put it somewhere north of 1000 ppm.
But, as you seem to surmise, that paper would imply that the approximately 400 ppm that we now enjoy is too high.
For all trees and most other plants, more is better until about 1300 ppm.
So our present alleged 400 ppm is much better than 200 ppm, but 600 ppm would be better still, 800 even better still, 1000 better yet and 1200 best of all.
Actual paper is pay-walled. Abstract refers only to Nitrogen concentration, not total plant nitrogen.
If carbohydrate concentration is increased relative to total plant weight, then of course N concentration will be lowered.
Do they have an actual mechanism whereby the roots of the plant have diminished capability for nutrient uptake?
If productivity is increased, then it would seem to be alarmism at it’s finest to grab at some measurements of relative ratios of whatever to claim that there is a problem.
I can only imagine how different the reported result would be if someone were trying to demonstrate benefit, rather than ignore any beneficial effects and try and find something that advanced the alarmist agenda.
Besides for this, what exactly is “powerful fertilizer”? Fertilizers do not have power ratings.
They can be slow release, sustained release, water soluble…
When one wants to optimize plant growth, one seeks to supply an optimum level of macro and micronutrients. Too much of any one or several nutrients will impede growth.
The use of the term “powerful fertilizer” is very odd and seems unscientific and not one that an experienced grower or field botanist would use.
I wonder what the results would be if someone were to analyze the nutrient concentration of various field crops that were grown years ago, and compared these to the same crop grown in the same place today.
I wonder if anyone has examined the nutrient concentration of separate trees rings on he same tree, in order to compare 300 PPM wood to 350 PPM and 400PPM wood?
.
I agree, the Abstract is not enough to pass any judgment on this paper.
How nitrogen (protein) was extracted, measured, how was the quantity expressed, how much lower (10% decrease is not enough info and if indeed only 10% how reproducible or important is this?) etc. all missing in the Abstract.
We don’t even get the CO2 concentrations used.
I also do not think nitrogen should be what is measured if they are drawing conclusions about protein. They should measure protein.
And break it down by tissue type.
We know that plants in high CO2 air have fewer stomata. They do not need as many.
They are not measuring what is important to anyone, and drawing conclusions that seem speculative.
Menicholas,
I skimmed over the paper. They didn’t collect any of the original data. Instead they took data from multiple papers which had already been published and analyzed that. Thus they couldn’t use protein data because that wasn’t what was available. Plus, although they extended their conclusions to protein, they were interested trying to measure total nitrogen in order to assess nitrogen uptake, so measuring just protein would have been restricting to what they were trying to measure. For what it’s worth, because so much of a plant’s nitrogen is locked up in protein, there is a really strong correlation between protein content and total nitrogen content. Not that it matters in this case, though, since the conclusions of the paper are pretty flawed because they have no support for their assumption that decreased ability to absorb nitrogen is creating a limitation.
“When carbon dioxide levels in the air increase, crops in future will have a reduced nitrogen content, and therefore reduced protein levels.”
——————————————————–
Is this from a model?
You can judge a paper by an abstract. This abstract is very poor, almost as if on purpose so that you don’t really learn anything without paying to read the entire paper.
Horsepucky-we all know plants grow better with higher CO2 concentrations.
The claim about the plants having lower nitrogen is also garbage-that’s not what you would measure,you would measure nitrogen content in the wheat or rice,as that’s where all the nitrogen the rots absorb end up-in the end product.
Farmers around here-(NE Ohio,and N central Ohio where my hunting property is located)-use anhydrous ammonia to provide nitrogen after the plants reach a certain point-I asked a couple of them.
When the corn seeds are planted in the no till fields,ammonium nitrate fertilizer in placed in the ground,under the seeds,so the roots can absorb the nitrogen. The ammonium nitrate used when seeds are planted in mixed with a product called Nserve that prevents the ammonium nitrate from breaking down.
This is the stuff he uses…
http://www.dowagro.com/en-us/nitrogenstabilizers/
I asked the farmer next to my hunting property last spring,as he was planting,because I was interested in the attachment to the tractor-it’s similar to a ripper claw on a bulldozer in appearance,but it drops the fertilizer,plants the seed,and covers it back up as it goes down the rows.
Then he hits the corn with anhydrous ammonia by side dressing the rows when the plants are about a foot tall.
Info on ammonium nitrate fertilizers-
http://plantsci.missouri.edu/nutrientmanagement/nitrogen/practices.htm
It’s the end product that matter-the ear of corn,the grains of rice or wheat,the soybean,etc.
Measuring the nitrogen in plants that are ready to be harvested will always lead to a low amount in the plant-it’s in the end product of the plant.
In climate religion (we can’t seriously call it climate science any more):
Their Devil is CO2.
Their God is… other people’s money.
Here is their bumper sticker:
Follow Me to…
The Crystal Ball Cathedral
Church of the Omnipotent Greenhouse in Carbon
“Believe or be prosecuted.”
Come on people; this one is really easy.
Increased levels of CO2 cause plants to grow faster. Increased CO2 may not cause nitrogen absorption to increase. So, plants grown in a CO2 rich atmosphere may have a lower nitrogen, and thus protein content.
But, since the plants are growing faster, the overall impact on the amount of protein produced per unit of time is probably unchanged. The authors’ results do NOT suggest that higher levels of CO2 will reduce our ability to feed the planet (although this is what they are hinting); they only suggest that animals reliant on vegetable protein may need to chew through a little more food to get the protein they need – food which will be more plentiful due to faster plant growth.
This is a truly ridiculous study and incredible waste of financial and human resources.
I would agree Willie, about the waste of financial and human resources. However, for the sake of CAGW propaganda, it is pure gold.
And the mindless eco-lemmings will accept this nonsense unquestioningly, because it feeds their confirmation bias.
Previous research has concluded that it is nitrogen dilution on account of higher overall plant productivity that causes this, like you say, but this research has concluded that higher CO2 somehow inhibits the plant’s ability to uptake nitrogen from the soil.
To be accurate, the N concentration is lower, but the overall N content is higher. Studies on both wheat and tapioca.
Is it readily absorbable nitrogen which is impeded as a result of increased growth due to an exhaustion of readily available N in a high CO2 environment ? Or just a case of an experiment in a closed system seeking answers to a foregone conclusion yet again ?
One has to wonder when such experiments obviously collide with the real world result of the recent increase in global CO2 having produced the exact opposite on a global scale with a greening of the planet.
I do not think they used a closed system.