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Want to Read more on Impact of CO2
Level,
Growth Chamber and CO2 Generator?
The
concentration of carbon dioxide in the atmosphere
has risen 30% since the onset of the Industrial
Revolution in the late 18th century. Change
has been a consistent feature of the earth's
climate. Periods of relatively cool temperatures
caused the ice ages. That warm period almost
exactly matches the period over which modern
agriculture has evolved.
For the first time in the history, climate
appears to be changing as a direct result
of human activity. People have released
chlorofluorocarbons (CFCs) into the atmosphere,
thereby degrading stratospheric ozone and
increasing biologically harmful ultraviolet
(UV) radiation that reaches the earth's
surface. Through mining and combustion of
fossil fuels, deforestation, maintenance
of livestock nerds, and even through crop
cultivation, people have released enormous
quantities of carbon dioxide, methane (CH4),
and other "greenhouse" gases into the atmosphere.
Samples from ice cores show that in past
the fluctuations in global temperatures
were strongly correlated with concentrations
of atmospheric CO2. Simulation models of
global atmospheric circulation predict that
greenhouse gases will cause a 2-8°C global
temperature rise before the end of the 21st
century.
International research organizations all
over the world and the United States Environmental
Protection Agency (USEPA) are cooperating
to determine the effects of a likely global
climate change on crop production. Under
such studies are: I) direct and indirect
effects of ultraviolet-B (UV-B) radiation
on crop, and ii) the direct and indirect
effects of increased CO2 and
temperature on different crop plants.
Ultraviolet-B
(UV-B) radiation damages leaf tissues in
crop seedlings. Leaves become stunted, stomata
collapse, and photosynthesis decreases.
Some crop varieties appear to be better
able than others to withstand the adverse
effects of UV radiation. Leaves of tolerant
varieties contain phenolic compounds, which
are natural chemicals that filter out harmful
UV-B radiation before it can damage sensitive
tissues. Research is now in progress to
predict possible regional losses in crop
productivity if UV-B radiation continues
to increase, and whether plant breeders
can prevent those yield losses by developing
new varieties that tolerate UV radiation.
In addition to its adverse direct effects
on crop plants, UV-B may change the susceptibility
and/or tolerance to disease. Although, there
is no evidence as of yet that susceptibility
to blast is affected by UV-B, it appears
that the tolerance for blast decreases.
In other words, disease frequency is not
increased by UV-B, but the effects of disease
on plant growth are enhanced by UV-B radiation.
GLOBAL
WARMING: Although, increasing
atmospheric CO2 stimulates plant
growth, the beneficial effects on crop growth
have been observed for levels only up to
500 ppm. Some plant species respond positively
to CO2 levels up to 1,000 ppm.
Experts predict that atmospheric CO2 will
surpass 650 ppm before the end of the 21st
century. Furthermore, the benefits of increased
CO2 would be lost if temperatures
also rise. That is because increased temperatures
shortens the period over which crop grows.
Research is being conducted to identify
means by which crop plants may better benefit
from increases in atmospheric CO2
while minimizing the adverse effects of
warmer temperatures.
Plant
growth and development and primarily governed
by environmental conditions of the soil
and climate of a country. The success and
failure of agricultural crop productivity
is generally related to the prevailing weather
conditions. Weather plays an important role
from germination of seeds to the maturity
of the crops. Interestingly, the most important
fact about climate is that it changes on
every scale of time and space, every year,
decade, century and in every region of the
world.
The green revolution has made tremendous
conditions to food production by prevailing
weather condition but does not move forward
as per expectation. The changes in weather
fluctuation have been largely responsible
for slowly down the production momentum
of the green revolution of early 1960. The
earlier high yielding varieties of cereal
crops have become sensitive to weather vagaries
and thus the yield of such varieties have
gone down substantially. The atmosphere
is becoming warmer day by day due to increase
in pollutants such as CO2, CH4,
CO, SO2, SO4, nitrous oxides and particulate
matters in the atmosphere. The most important
atmospheric pollutant is carbon dioxide
and it's content is increasing rapidly all
over the world due to burning of fossil
fuels, coal, fire wood, etc.
The
USA is the maximum producer of carbon dioxide.
It produces about 160 billion tons of CO2
annually, which is about 25 % of the total
CO2 produced in the world. Other
main producers of CO2 are China,
India, Australia, Canada, Ukraine, Mexico,
U.K., Brazil, France, Spain, Germany, etc.
The presence of CO2 in the atmosphere
causes the colossol warming of climate,
and thus the change is rainfall pattern,
a process on which crops are highly dependent.
Hill storms, flood, severe winds blow and
frosts are also expected under such conditions,
which ultimately affects the productivity
of the crops 1n a country.
Not many people think of it in this way,
but food, climate, and the rising levels
of atmospheric carbon dioxide are uniquely
interrelated. Food production is a critical
and an essential renewable resource. Without
food, the human race would not survive.
The production of this renewable resource,
upon which all life depends, is possible
only through photosynthesis, the most important
of biochemical processes. An essential raw
material, almost always in short supply,
is the low level of atmospheric carbon dioxide.
For example, an acre of corn crop, must
process over 40,000 tons of air to produce
the record yield of more than 130 bushels
per acre recorded in the U.S. for 1995.
Globally, some 25 crops stand between people
and starvation. The largest single food
group is the cereal grains, of which corn
is a leading member. They provide approximately
60 percent of the calories and 50 percent
of the protein consumed by the human race.
The legumes provide about 20 percent of
the world's protein. Then balance of calories,
protein and essential vitamins and minerals
is obtained from tuber and root crops and
various fruits, nuts and vegetables. Food
animals, deriving their food either directly
or indirectly from plants, provide 20 percent
of the protein with 5 percent coming from
fish.
The
most determinant factor in agricultural
(food) production is weather or the climate.
For agriculture, climate must be managed
both as a resource to be used wisely on
the one hand or a hazard to be dealt with
on the other. Food production is very much
a function of climate, which in itself is
unpredictable. In fact, the principal characteristic
of climate is variability. Predictive climate
changes derived from computer simulations
are far from accurate and may be deceptive
even with the most advanced modeling. Volcanoes,
cloud cover, regional characteristics and
changing of atmospheric components cannot,
if they ever will, be successfully factored
into an accurate climate model.
Of all the natural climate hazards, drought
is that which farmers fear most. The lack
of water is the single greatest impediment
to plant growth and global food production.
This is illustrated by the fact that today,
irrigated cropland-about 17 percent of the
world's total, produces one third of the
agricultural output
Concerning
changing levels of atmospheric carbon dioxide,
there are some well-known facts. First,
there is a documented increase. The isolated
test site at Mauna Loa in Hawaii shows more
than a 12 percent increase in the mean annual
concentration, from 316 ppm by volume of
dry air in 1959 to the 1996 level of 360
ppm. The current annual rate of increase
is about 0.5 percent or 1.6 ppm. Carbon
dioxide source-sink models predict that
the current level of atmospheric CO2
will be doubled by the latter part of 21st
century. Second, the increase is truly global.
The earth's atmosphere is very effective
in dispensing emissions from whatever the
source, be it natural or man-made. Third,
with the average level of CO2 rising, there
is an annual oscillation of the earth's
atmospheric CO2. The earth's atmospheric
CO2 level begins to fall in the spring and
continues through the summer months as it
appears to be sequestered by the vegetation
of the northern hemisphere. In the late
autumn, there is a resurgence of CO2 into
the atmosphere. The results in new heights
by mid-winter. With the amplitude increasing
by about 0.5 percent each year, it appears
the concentration or amount of the earth's
biomass is either increasing or is steady.
It is not decreasing. Thus there are two
ongoing global experiments inadvertently
being conducted by the world' people. The
outcomes of either we do not know.
First is the so-called global warming resulting
from increasing amounts of atmospheric CO2
and other radioactively active trace gases.
Second are the enrichment on improved photosynthetic
capacity, and its effects on plant growth
and development. This, in turn, increases
food production, forestry output, and biological
productivity with an improvement in water
use efficiency. Meanwhile, these two experiments
will likely continue well into the 21st
century with the final results not fully
realized. The topics of food security, the
magnitude of climate change (global warming),
and the beneficial biological effects of
rising levels of atmospheric carbon dioxide
are rent with both political and scientific
controversy. There are those including the
congress and those in the presidency of
the U.S. that are still advocating immediate
action with accompanying costs of billions
of dollars for reducing the world's output
of CO2. Global initiatives concerning such
were promoted at the Rio Earth Summit in
1992, and again in the recent Berlin Assembly
in March 1995. These are not warranted.
Global satellite readings of temperatures
over the earth show there has been no warming.
Thermometers taking temperatures in a real
world environment are confirming these results.
To
date, our knowledge of the climate effects
of the rising CO2 and other greenhouse gases
in the atmosphere is inadequate for initiating
any global attempt to change the climate.
If the climate does change, some warming
could be tolerated, and may even be beneficial
with no reductions in food production. A
warming trend would increase the lengths
of the growing seasons, encourage farmer
adaptations, and favor the introduction
of new technologies and cultural practices.
The results would be crops and food animals
more resistant to environmental stresses.
The prospects of climate change from increasing
levels of atmospheric carbon dioxide do
not frighten many agriculturists, farmers
or foresters. There are many disparities
among interests of farmers and other segments
of our society. A rainfall of two or more
inches in 24 hours may be newsworthy as
an extreme or hazardous climatic event for
politicians, environmentalists, and city
folks. It could be highly beneficial in
late summer to the producers of food, especially
in the U.S. Corn Belt when vapor-transpiration
greatly exceeds precipitation. There is
no evidence that climate variability or
hazardous events (floods, tornadoes, heat
waves, frost and even volcanoes) would be
more frequent as atmospheric carbon dioxide
increases. Marked inter-annual variations
have always been with us. The most recent
disaster for the grain belt of the U.S.
was the hot, dry summer of 1989. This
resulted in the first major scare tactics
of a global warming initiated by scientists,
with hearings before congress and released
to the press. The cold, wet summer of 1992
followed. Again, 1995 was a partial analog
of that experienced in the summer of 1989.
Food scarcity, climate change and variability,
and rising level of carbon dioxide are all
resources vital to the people of the earth.
Of these resources, the rising levels of
atmospheric carbon dioxide must not be viewed
as former senator and now Vice President
Albert Gore has declared in his best selling
book Earth in the Balance 1992: "the process
of filling the atmosphere with CO2 and other
pollutants-is a willful expansion of our
dysfunctional civilization into vulnerable
parts of the world."
Such pronouncements are too often accompanied
by projects of melting icecaps, coastal
flooding, mega hurricanes, drought, disease,
and famine. For the present, the direct
effects of an increasing atmospheric CO2
on food production and the outputs of range
lands and forests are much more important
than any effects thus far manifest for climate.
A recent review of over 1,000 individual
experiments with 475 plant crop varieties,
published in 342 peer-reviewed scientific
journals and authored by 454 scientists
in 29 countries, has shown an average growth
enhancement of 52 percent with a doubling
of the current level of atmospheric carbon
dioxide (Idso and Idso, 1994; Wittwer, 1995).
Yet some scientists, especially those with
ecological orientations take delight in
glamorizing, along with a widely sympathetic
press, in publicizing the few exceptions,
which, in turn, become widely quoted in
the scientific literature. The include tussock
arctic tundra (Oechel and Strain, 1985);
some grasslands where undesirable species
may, under restricted conditions, outgrow
the more desirable (Wedin and Tilman, 1996);
and in some ecosystems where competition
among species may create a lack of balance
(Bazzag and Fajer, 1992).
Globally,
it is estimated the overall crop productivity
has been already increased by 10 percent
because of CO2 and may account for much
of what has been attributed to the Green
Revolution. Meanwhile, changes in climate
in specific fields where crops actually
grow and are cultivated remain defiantly
uncertain. Conversely, the effects of an
enriched CO2 atmosphere on crop productivity
in large measure, are positive, and leave
little doubt as to the benefits for global
food security. With this note, it is a sad
commentary that most of the current and
modern textbooks on plant nutrition omit
inadvertently or otherwise, any mention
of the role of carbon dioxide as a fertilizer
or essential nutrient. This was true 35
years ago (Norman, 1962) and remains to
this day. Textbooks still ignore the fact
that different levels of CO2 may have pronounced
effects on plant growth and may interrelate
and compliment various levels of other nutrients
applied to crops in the rooting media. The
complimenting effects are also manifest
with respect to water requirements and positive
interrelations with temperature, light,
and other atmospheric constraints.
Contrastingly,
the rise level of atmospheric CO2 does not
make the U.S. the world's worst polluter.
It is the world's greatest benefactor. Unlike
other natural resources (land, water, energy)
essential for food production, which are
costly and progressively in shorter supply,
the rising level of atmospheric CO2 is a
universally free premium gaining in magnitude
with time on which we can all reckon for
the future. The effects of the increasing
atmospheric level of CO2 on photosynthetic
capacity for the enhancement of food production
and the output of rangelands and forests,
appear far more important than any detectible
change in climate. Elevated levels of atmospheric
CO2 also provide a cost-free environment
for the conservation of water, which is
rapidly becoming another of the world's
most limiting natural resource, the majority
of which is now used for crop irrigation.
Instrumentation
for monitoring of CO2 level/set point
The
non- dispersive infrared (NDIR) gas analyzer
used for measuring CO2. It (Insert) achieves
high accuracy and provides multiple function
and ease of operation through the use of
a microprocessor. It is available in 19-inch
rack, panel or tabletop mountings. Zero
and span calibrations are easily accomplished
by pressing the appropriate key on the front
panel. The NDIR system has single beam optical
system, which provides superior performance
to conventional double beam analyzers. It
is easy to maintain and offers excellent
long-term stability. The system is ideal
for continuous measurement of CO2 level.
MEASURABLE
GAS COMPONENTS:
Single
component, multiple range analyzer: CO2,
Range- 0 to 2500 PPM
MEASURING SYSTEM:
Nondispersive infrared absorption (NDIR)
method, singe light source-single beam
OUTPUTS: Analog 4 to 20mA DC, and 0 to 1mV
or 0 to 1V or 0 to 5V or 0 to 10VDC selectable
RS-232C
System
Features:
-
Microprocessor controlled
-
Single source, single beam optics
-
Direct readout in engineering units
-
Linear output · Low sensitivity to vibration
-
1 or 2 components, multiple ranges
-
Self diagnosis function
-
No optical alignment required
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RS-232C interface
Automation,
Control and Data Generation
- Open
Top Chamber ( OTCs) can be constructed
with MS/SS body with a covering of Polycarbonate
sheets.
-
Independent chamber are connected with
Cu piping. Independent CO2 ( through CO2
cylinders) and oxygen ( Air compressor)
supply are provided with controlled manner.
-
An independent line are drawn from each
chamber and connected to CO2 controller
to set and monitor of the desired CO2
level. A PLC-SDADA based platform is designed
to control and monitor continuous operation
of CO2 level.
-
Each chamber has the facility to monitor
temp & humidity (inside the chamber) with
an external control facility for temp
& humidity option.
-
Several solenoid valves & gas regulators
are used to deliver set level.
- PC
based recording / data generation system
works with PLC-SCADA platform to record
the data.
- CO2
level can be controlled and monitor from
the PC. The necessary relays are also
provided.
-
The graphical presentation of CO2 is also
possible.
-
Time event program can be set from the
CO2 controller to monitor CO2 level of
each chamber and can be analyzed through
CO2 analyzer in different time (set) interval.
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