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Production
of wheat under climate change
The
New Delhi-based Indian Agricultural Research Institute (IARI) has now
warned
that the country's annual wheat output could plunge by 4-5 million
tonnes with
every 1 degree Celsius rise in temperature. These projections cannot
and should
not be brushed aside as long term issues that have no immediacy. For,
the
adverse impact of temperature changes on wheat output has already been
in
evidence for the past few years and has contributed to the recent wheat
crisis,
transforming India
from a wheat exporter to an importer and forcing the government to
re-introduce
curbs on the wheat trade. [1]
Results of an experiment carried out by the Department of Agricultural
Meteorology, B A College of Agriculture, Anand
Agricultural
University,
says that global warming and greenhouse effect will have an impact on
the yield
of wheat and maize in the state. Wheat and maize yield will go down
manifolds
if the temperatures keep rising or falling.
The yield under temperature of four degree Celsius was only a little
above
2,800 kg per hectare and a little above 2,500 kg per hectare under 5
degree
Celsius. The base yield was fixed a little above 5,700 kg per hectare.
The wheat yield under reduced maximum temperature was best under minus
five
degree Celsius. Against the base yield fixed at little over 5,700 kg
per
hectare the wheat yield was almost 6,250 kg per hectare under minus
five degree
Celsius temperature.
This production decreased to 5,600 kg per hectare under minus four
degree
Celsius temperature. The yield took a further dip to a little below
5,500 kg
per hectare mark under minus three degree Celsius.
While, under minus two degree Celsius the yield was only 5,250 kg per
hectare
and under minus one degree Celsius it was 4,700 kg per hectare. So,
wheat will
suffer tremendously under the increasing temperatures in the
forthcoming years.
The decrease in cultivation of wheat may further worsen the situation
as more
and more farmers are turning towards cash crops like cotton. [2]
The estimated loss in wheat output is, however, based on the assumption
that
the availability of irrigation water would remain the same as it is
now. But
this seems unlikely in view of receding Himalayan glaciers and
increasing
nonagricultural use of water, the agenda note points out. [3]
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