Positive Effects of Carbon Dioxide for Plant Growth

Many articles have been written about the negative effects of carbon dioxide. Sick Building Syndrome, loss of concentration due to high levels of carbon dioxide, asphyxiation in breweries or wine cellars, all these things spring to mind when we hear the magic phrase carbon dioxide. Yet, perhaps today when Venus passes across the face of the Sun, we should remember that our original atmosphere consisted of nitrogen and carbon dioxide. Free oxygen is something that is not really chemically possible. Yet we have it as a result of plant life busily photosynthesising and converting carbon dioxide into oxygen during daylight hours. This is the original use of solar energy!

Plants require carbon dioxide to grow and why not help them by increasing the level of carbon dioxide? Normally, this is something that is undesirable, since carbon dioxide is the original greenhouse gas, as our neighbouring planet Venus can testify. But in a controlled, genuine greenhouse environment, there is no real reason why the level of carbon dioxide should not be enhanced in some way.

Indeed, tests have shown that increasing the level of carbon dioxide in a greenhouse to 550 ppm will accelerate plant growth by 30 - 40 %. The natural level of carbon dioxide in the atmosphere is around 450 ppm, having increased from about 250 ppm in the last ice-age, so this slight increase may not appear significant at first sight. The point of the matter is that the level of carbon dioxide in the average greenhouse with the ventilation system closed will drop sharply due to uptake by the plants and will lie around 150 - 200 ppm if nothing is done about it. In summer the ventilation system will be open and the fresh air circulation will augment the level to a useful degree. But what about those long, cold, dark northern winters? Most commercial greenhouses will have lighting and heating systems to encourage plant growth, but you still cannot open the ventilation and allow the cold outside air into your heated greenhouse without losing all the early crops. The only real solution is to augment the natural level of carbon dioxide in some way. Where it is used, the general rule of thumb is to augment by about 1000 ppm when the sun is shining (or all the lights are on!) and keep the level around 400 ppm during times of darkness. This will require monitoring, since there are so many variable factors involved and a simple control unit using an infrared sensor will be able to keep the concentration of gas constant at all times.

Rate of consumption varies with crop, light intensity, temperature, stage of crop development and nutrient level. An average consumption level is estimated to be between 0.12 - 0.24 kg/hr/100 m2 of greenhouse floor area. The higher rate reflects the typical usage for sunny days and a fully-grown crop. This equates to roughly 150 litres of carbon dioxide per hour.

There are many processes that naturally and unavoidably produce carbon dioxide: Fermentation and combustion are two classic examples. In temperate zones it is necessary to heat a greenhouse (glasshouse is just another word for the same thing), and this heating will almost always involve the burning of fossil fuels, producing carbon dioxide. This leads to the natural urge to re-circulate the exhaust gas from the heating system into the greenhouse and so achieve a double advantage for the plants. This will require careful monitoring of the flue gas to ensure that there are at the most only traces of carbon monoxide being passed into the greenhouse. This is not only bad for the plants but also potentially lethal to the people working there! Such technology is available with gas monitors that will measure the carbon monoxide concentration continuously and have analogue outputs that can be used to regulate the burners or operate a trip to switch the unit off should problems occur. The combination of breweries with greenhouse systems is also serious business in some areas. Generally, these methods are to be approved and should really be worthy of government support. Not only are they producing crops, they are removing a pollutant that would otherwise be vented into the atmosphere.

Monitoring of the added carbon dioxide is essential, however, since high concnetrations of carbon dioxide can lead to dizziness or even unconciousness of the personnel. Some plants will require higher levels of nutrients to compensate for some of the changes that occur. Particularly tomatoes and violets are sensitive to increased levels of carbon dioxide, hence the need for constant monitoring of the ambient concentration.

Simon Fowler studied Mechanical Enineering at City University in London, UK and now works in Vienna, Austria for madur electronics, a manufacturer of infrared sensors. http://www.madur.com/

In The News:


ThinkProgress

If You've Wondered Why So Many Politicians Deny Climate Change, Science ...
ThinkProgress
Scientists have known for a long time what's causing current climate change. What's been less clear is why so many U.S. politicians aren't listening. Sure, there's been falsely balanced media coverage of climate science. And there are both financial ...

and more »

New York Times

Video Feature: Apps That Bring Science to Life
New York Times
PHYSICS, chemistry, biology and lots of other sciences are behind almost every part of our technology-driven lives. But learning about those topics is often not easy, which is where tech steps in to help illuminate some of science's fascinating secrets.

and more »

9NEWS.com

Europa mission begins with selection of science instruments
Astronomy Magazine
The payload of selected science instruments includes cameras and spectrometers to produce high-resolution images of Europa's surface and determine its composition. An ice-penetrating radar will determine the thickness of the moon's icy shell and search ...
NASA selects CU science instrument for Europa mission9NEWS.com
What should we take to Europa? NASA picks science instruments.Christian Science Monitor
NASA selects science instruments for proposed Europa missionNASASpaceflight.com
Clapway -Universe Today
all 207 news articles »

New York Times

Scientists Curbing the Ethical Use of Science
New York Times
rfdgenetics A researcher works at the University of California, Berkeley's Innovative Genomics Initiative, where a genome-editing technique that could be used to alter future generations was invented. Marsha Fenner/Innovative Genomics Initiative.


Popular Science

Spacecraft Returns Most Detailed Pictures Of Pluto Ever Seen
Popular Science
NASA's New Horizons spacecraft has been making its way toward the famous dwarf planet for the past nine years. Most of that time, the probe was in hibernation mode, but it recently “awoke” this past January prior to its flyby of the space rock ...

and more »

New York Times

Science Fiction and Fantasy
New York Times
For every interesting foray into hard science fiction, there's a formulaic comedy about the author whose character comes to life, or a brief, surreal thought experiment about what it must be like to be trapped inside a Victorian Christmas card. Some ...


Chicago Tribune

Weekend fest hopes to hook adults on science
Chicago Tribune
When she started the science council in 2006, there were virtually no science festivals in the United States, and only a couple of science cafes, Metzler said. Now science outreach for adults has "exploded" to more than 45 festivals and hundreds of ...

and more »

NY1

World Science Festival Brings Abstract Concepts to Life
NY1
The World Science Festival is underway around town, including Greenwich Village where a massive interactive sculpture from NASA is stopping people in their tracks because it sounds as good as it looks. NY1's Roger Clark filed this report. There are ...
NYC World Science Fair features NASA-designed orbit pavilionWashington Times
At World Science Festival, Students...Education World

all 20 news articles »

Popular Science

Black Solar Cells Reach Incredible New Efficiency Record
Popular Science
Renewable energy is the future. All over the world cities and countries are vowing to go quit fossil fuels and commit to getting their energy fix from 100 percent renewable sources. One of the most popular renewable options is solar—especially in ...


Science News

Fossils suggest another hominid species lived near Lucy
Science News
Here come the neighbors, Lucy. Scientists have discovered 3.5-million- to 3.3-million-year-old fossils possibly from a new species in the human evolutionary family. The species lived in what's now Ethiopia, near hominids best known for Lucy's partial ...
New human ancestor was Lucy's cousin and neighborScience /AAAS
Mysterious Humanlike Species May Have Lived Alongside 'Lucy'Live Science
'New species' of ancient human foundBBC News

all 227 news articles »
Google News

UAV Acoustic Apparatus for Insect Swarming Stimulus, part two

UAV Acoustic Apparatus for Insect Swarming Stimulus, part two; Using... Read More

Droughts and Salt Water Canals Random Thoughts

We need solutions to our drought crisis in this country.... Read More

Spray on Dirt for Camouflage

Super sticky spray on dirt or mud simulation coating or... Read More

Remote Control Bacteria; We Can Not Allow That.

Remote Control Bacteria. Why not, we have remote control everything.... Read More

Brain Waves Activating to the Tune of a Different Drummer?

Well, here is a most interesting thought. There are many... Read More

N400 Brain Wave to Assist in Learning and in Performance

In any important task you need to stay alert and... Read More

Ultra Thin Space Suits, just a concept

The space suits we saw on the first Moon visit... Read More

Preventing Death in a Bio Threat

In the event of Bio threat how to mobilize Hospitals... Read More

Embryonic Stem Cell

Stem cells are primitive undifferentiated cells that have the capability... Read More

Philosophical Discussion of Distribution Systems

To properly understand marketing one needs to understand the natural... Read More

Bio-Rhythm Disruption Frequency Identifier for Human Intentions

It appears we have found many identifiers for Bio-Metrics to... Read More

Einstein Half Dead

100 years ago Albert Einstein developed his Relativity Theory of... Read More

Ground Targets Via Space Laser Weapons

It is now possible to overwhelm our enemy from space... Read More

Electromagnetism, The Universe, And You

An electric current produces a magnetic field. This is the... Read More

Feb. 12 is Darwin Day -- Secular Americans Celebrate Bday of Evolution Champ

This Feb. 12 marks the 196th anniversary of Charles Darwin's... Read More

Mini UAV and MAV Power Plants

A set up of harnessed Lithium Polymer Cells can be... Read More

Medical Miracle or Mistake?

Fundamental elements of life and the aspects of cloning bring... Read More

Aerodynamics and Hydrodynamics of the Marine Life and Uses for AI, UAVs, Robotics, and the Future

Air has 750 times less density as the oceans, yet... Read More

Rodent Populations are Half within 3 miles of a Railroad Track

About a month ago, I was helping a friend collect... Read More

Electrical Industrys Protection - Destruction for Good

Destruction! Blow Up! Eliminate! These are not pleasant words!Unfortunately, when... Read More

MP Apprehension of High Strung or Drunken Soldiers

Recently scientists have discovered the hydrogen sulfide gas caused mice... Read More

Launching 400 UAVs from a Transport Plane

How to launch hundreds of UAVs for an autonomous mission... Read More

Ceramic Coatings Inside Plastic Water Bottles?

A new report claims Water in plastic bottles could pose... Read More

Heads Up Displays and Computer Human Interface

Heads Up Displays For High Tech Human Interface Need More... Read More

Methods of Improving Boiler Efficiency

With the rising cost of fuel prices, industries that use... Read More