| Author | Message | ||
     Ft_bstrd |
CO2 Enrichment and Plant Nutrition It was noted in previous posts that for crops with C3 photosynthetic pathway the current levels of atmospheric carbon dioxide are limiting to plant growth. Crops are currently starved of CO2 in a similar way to being starved of water, nitrogen, phosphorus, light etc. Current atmospheric levels of CO2 can thus be regarded as a plant stress, which weakens them and makes them inefficient. At higher levels of CO2 this stress is reduced, and the plant copes better with all other types of stress, including heat and cold, atmospheric pollution, root pathogens, as well as shortages of water, minerals etc. Sylvan Wittwer (Professor emeritus at Michigan State University, who directed the Michigan Agricultural Experiment Station for 20 years and chaired the Board on Agriculture of the National Research Council) has remarked: There has been and still remains, a great reluctance on the part of many climatologists and ecologists, and especially environmentalists, to accept the concept that the rising level of atmospheric CO2 could be more beneficial than harmful for plant growth, food production, and the overall biosphere…Yet the scientific evidence is overwhelming. Summary data from 279 published studies is shown below in which plants of all types were grown under paired stress (red) and unstressed (blue) conditions. For resource-limited plants the benefits of increased CO2 are astounding.  Wittwer points out that of the hundreds of scientific reports documenting the benefits, Al Gore carefully selected five reports and a personal communication to emphasize possible negative aspects to enhanced CO2 on plants. Gore knew what he was doing, of course – he either deliberately rejected the facts, or gave instructions to researchers for his book only to cherry pick papers that support his alarmist agenda. Again we see him as a lying propagandist. In Physiological plant ecology: ecophysiology and stress physiology of funcional groups (Springer, 2003), Walter Larcher writes: According to over 3000 scientific publications on the biology of CO2 effects, a broad spectrum of growth responses to CO2 enrichment exists. Since elevated CO2 often reduces the plants’ demands for other resources, CO2 effects on growth do not simply follow Liebig’s law of the minimum. Plants exposed to elevated CO2 need less enzymes (and thus lower quantities of leaf proteins and nitrogen), lose less water (can cope with less soil moisture and often operate at smaller stomata openings) and need less light (because of a shift in the light compensation point for photosynthesis) to reach the equivalent, or even higher photosynthetic rates than plants growing under control conditions with “normal” CO2 concentrations. We will show from the literature the tremendous benefits of enhanced atmospheric CO2. The benefits are much more marked in crops that are subject to resource limitation. Under ideal conditions, where there is no shortage of water, light, nutrients, trace elements etc, the benefit of doubling atmospheric CO2 may be 40%. However, where plants are resource limited a doubling of CO2 can enhance growth of crops by over 100% in some cases. This is particularly important in regions of the world where the soil is poor for many reasons, since increasing atmospheric CO2 will enable crops to be grown efficiently where they currently cannot be grown without first improving the soil and irrigation. In this post we will briefly mention minerals and other essential nutrients (nitrogen, phosphorus, iron etc). For example, iron deficiency is severely limiting to crop growth in calcareous soils, which represent 30% of global land area. Increased atmospheric CO2 enables plants to extract higher levels of iron from the soil. Jin et al in Elevated Carbon Dioxide Improves Plant Iron Nutrition through Enhancing the Iron-Deficiency-Induced responses under Iron-Limited Conditions in Tomato (Plant Physiology, May 2009) demonstrated Plant growth was increased by elevated CO2 in both Fe-sufficient and Fe-limited media. Shoot fresh weight was increased by 22% and 44%, respectively, and root fresh weight by 43% and 97%, respectively, compared with plants grown in ambient CO2… Improved nutrient and water uptake has in some cases been traced to greater root mycorrhization (a symbiotic fungal extension of roots). Mycorrhizae also improve plant health by protecting roots from pathogenic microorganisms. In Effect of Carbon Dioxide Concentration on Growth and Dry Matter Production of Crop Plants (Japan. Jour. Crop Sci, 1978) Imai and Murata showed that after 10 days of treatment with nitrogen at 350ppm and 1000ppm CO2 the dry weight (DW) of rice plants was as follows: 350ppm CO2, 30 mg nitrogen per plant DW = 835 mg per plant 350ppm CO2, 120 mg nitrogen per plant DW = 1,081 mg per plant 1000ppm CO2, 30 mg nitrogen per plant DW = 1,199 mg per plant 1000ppm CO2, 120 mg nitrogen per plant DW = 1,862 mg per plant This demonstrates that at higher levels of atmospheric CO2, food crops have considerably lower requirements for fixed nitrogen for the same growth; alternatively, for the same nitrogen treatment they achieve considerably enhanced growth. Higher levels of atmospheric CO2 lead to greater biological nitrogen fixation from the atmosphere, so less is required to be added as fertilizer. This is especially important in legumes, which are also able to improve their uptake and usage of phosphorus with increased CO2. Legume /bacterial symbiosis leading to nitrogen fixation is significantly increased at elevated CO2 levels (Reddy et al, 1989; Reardon et al, 1990). Philips et al (1976) demonstrated increased nitrogen fixation in peas, and Sherwood (1978) found the same in clover. A classic study by Hardy and Havelka (1975) showed that a tripling of atmospheric CO2 results in a six-fold increase in biological nitrogen fixation (from 75 to 425 kg per hectare) by rhizobial bacteria in nodules attached to the roots of soybeans. Increasing atmospheric CO2 is an unmixed blessing – it will bring currently unproductive land into use and bring greater yield from existing land without additional fertilizer use. This is a wonderful benefit in being able to feed an increasing world population. These effects can be subjected to routine experiment and observation, can be demonstrated and reproduced, and so are sound science, unlike the specious pseudo-science underpinning the supposed effects of CO2 on climate. (Message edited by ft_bstrd on December 17, 2009) | ||
| Methed |
Nice work, sir. Well presented and succinctly scientific--I hope it is read in its entirety and causes folks to respond. | ||
| Ft_bstrd |
Doubtful. True believers tend to be intentionally obtuse. | ||
| Ourdee |
Up to a 200% increase in growth is why propane is burnt with a catalytic converter in a hydroponic grow room. note: I claim no real or imagined knowledge of such things. | ||
| Crusty |
Did you know that if you eat Broccoli with cheese sauce and Stove Top Stuffing, your farts could power a small wind farm? | ||
| Aesquire |
Sorry Crusty, I doubt you'd get enough sustained velocity. Better to go with methane recovery. ( a much more potent greenhouse gas ) | ||
| Chadhargis |
All I know is my teeth have never been whiter and my garden is spittin' out 50lb tomatoes.  | ||
| Aptbldr |
Yeahbut, lots of big plants attract dinosaurs ... | ||
| 99savage |
Interesting and no doubt that all of the above is true BUT if I did my math correctly the normal atmospheric content of CO2 in air is something a little less than 400ppm. (i.e. just past the 1st data points on the curves) The above concentrations are pathological & unlikely to occur if we burned all the coal. - Tho it must be noted that agricultural output keeps going up. - When I was in college Obama's science adviser told us we were all due to starve just about now. | ||
| Aesquire |
I think the CO2 level rose after the sun warmed the oceans. Effect, not cause. Heat a Coke and watch it go flat faster. http://www.drroyspencer.com/2009/05/global-warming -causing-carbon-dioxide-increases-a-simple-model/ or http://www.skepticalscience.com/co2-lags-temperatu re.htm I don't just read science I think I will agree with. The Jury is out on the real world effects of man made CO2. It would be nice to keep studying this. It might actually be important. The Computer models are....models. I have one that says I'm the Master Chief and have to defend the planet against alien attack. I think it's a pretty good model, since I get killed a lot, and very quickly, which is what I think WOULD happen. Except for the restoring & keep going thing, which is just so the scenario's may be better explored. Or, so the game isn't 2 minutes long. | ||
| Ft_bstrd |
The concentrations MAY be pathological, but that isn't really the point. There is a natural balance to even pathological levels of CO2 production. According to Gore, the CO2 is going to increase infinitely and turn our planet into Venus killing us all. The last time the CO2 levels were "pathologically" high, the Cambrian era, the CO2 levels were at 7000+ PPM.  The average temperature and average CO2 levels are closest to the late Carboniferous and Permian periods. Every other period in Earth's history has had higher temperatures and higher CO2 levels. How much fossil fuels must we burn to raise the global CO2 levels to 7000 PPM? | ||
| Sifo |
The levels being discussed are no where near being pathological. I got interested in that point a short time ago and from what I could find you start to notice CO2 having a negative effect at around 2% CO2 levels. Even then it was just associated with slight lightheadedness. That would be about 20,000 PPM. The above chart shows levels to about 1,400 PPM. Even 1,400 PPM is much higher than the alarmists are talking about from burning fossil fuels. Or to put it another way... CO2 LEVELS HAVEN'T BEEN THIS LOW IN HUNDREDS OF MILLIONS OF YEARS! OUR PLANTS ARE STARVING TO DEATH!!! Of course that seems a bit alarmist.  | ||
| Madduck |
Look these idiots are just looking to transfer wealth from the US and Europe to the "underdeveloped" world. They also have the vast majority of the "starving" plants. I have no interest in paying them to prevent Global Warming. I have even less interest in feeding their starving plant. We do not need radicals like you giving them another insane idea for this wealth transfer. By the way I think they have a website "REDD" is in the title. | ||
| Aesquire |
http://www.pjtv.com/video/Afterburner_with_Bill_Wh ittle/Nopenhagen%3A_The_Truth_is_Missing_From_the_ Climate_Debate/2889/ | ||
| Sifo |
Aesquire, that's a great video. He makes some excellent points that just can't be countered. The Climategate memos get pretty hard to understand what most of them mean out of context. Having some of them put into context by the people being discussed in the memos is very enlightening. This article makes it clear that the scientific process and peer review process have been severely compromised in climate science. | ||
| Aptbldr |
Video/guy reminded me of a preacher. Presented temperature chart, "the right one", extends WAY back in time. During most of it's time-width, not much lived here. I want a nurturing & sustainable future environment for my DNA: grandchildren rule. Like video/guy, I support truth. Absent knowledge of truth, I'll choose to balance rewards & risks. | ||
| Sifo |
During most of it's time-width, not much lived here. I want a nurturing & sustainable future environment for my DNA: grandchildren rule. During the period of the Dinosaurs the temperature was warmer and there was more CO2. This was a period of far more biodiversity than our modern times. I see no worries for your future DNA. | ||
| Ferris_von_bueller |
Sifo, you're wasting your breath. | ||
| Sifo |
Will my breath help the ice that is fall out of the sky onto my driveway right now? They are predicting ice today, tonight and tomorrow when I have to drive 360 miles. This may just suck! | ||
| Drkside79 |
Blah blah blah ....... | ||
| Aesquire |
IMO this subject is valid for discussion. Many people want to take your money, at gunpoint if need be, for what is certainly a scam. ( see my link above please ) How's the ice storm, midwest badwebbers? | ||
| Aesquire |
Absent knowledge of truth, I'll choose to balance rewards & risks. how? I'll tell you that I'm absolutely sure that we are going to go into an ice age. I am certain it's the TRUTH. I have ample evidence that it has happened before and is cyclic. Most scientists agree that there were ice ages before, and there will be again. Some day that cycle will stop...but we don't know when. Certainly when Sol swells and engulfs us in nuclear flame, but for the next few million years...it's still an ongoing cycle. I don't know of a single scientist that will disagree with the above statement. ( I admit, I haven't met them all  ) Now, I don't know when the next ice age begins. You can't tell until well down the temp. slope and looking back at the collected data. How are you to balance in the absence of some inkling of what is truth? | ||
| Aptbldr |
In this case, absent knowing, I chose less environmental risk. Environmental protections seem fundamental; especially as the lab grows more crowded with rats. As an example, consider fresh water protection. Ground aquifers, rivers, and lakes are mere farts in the windstorms of time; mankind's choices are immaterial to that truth. Graphs can be drawn. But, we realize our actions do have consequences on fresh water supplies and we've come to manage those behaviors productively in developed nations. The science of fresh water protection remains debated and a political football today. But, in my experience in middle America, there's been progress. How does one realize they're in the "inkling" zone, without knowing the truth? |
