Geoscience Reference
In-Depth Information
Central Russia, will give higher yields than spring cereals
because of longer growing seasons and reduced damage by
high evapotranspiration rates (Pitovranov et al., 1988).
The establishment of new zones of agricultural potential is
likely to bring about changes in crop location and crop varieties.
These changes will however be influenced by the regional pat-
tern of rainfall or variation in soils and competitiveness of
different crops (Parry et al., 1990). For instance, cereal crop
production in Europe will not be influenced as significantly
as elsewhere. Crop production will suffer most severely in the
inherently vulnerable regions of Africa, South America, Middle
East, Asia Pacific, South-East and Central Asia where changes
in temperature and precipitation will further stress the already
limited productive capacity of these regions. Cold and mar-
ginal regions of both the Northern and Southern Hemisphere
(Canada, Alaska, Iceland, Scandinavia, Russia, New Zealand,
Tasmania and others) will benefit from higher temperatures
and its associated optimum conditions, such as longer growing
seasons, higher growing degree units and more frost-free peri-
ods with higher yields (Smit et al., 1989). If the climate change
will occur as predicted, the agricultural production is likely to
increase in North America, northern Europe, Commonwealth
of Independent States, China and South America (Rosenzweig,
1985; Wilks, 1988; Wittwer, 1990). The crop yield of the Soviets
and other European countries will boost by 50% while China
and India will benefit with enhanced production of soya beans,
winter wheat, rice, corn and cotton with northern migration.
But there are also areas where productivity of some crops will
not change after an increase in CO
2
concentration; for example,
wheat production in major areas of the United States would
remain the same (Hansen et al., 1981).
The projected climate change will bring about a large num-
ber of changes in crop management that will modify the climate
change on agriculture. Some regions and crops are critically
more vulnerable than others (Chakravarty and Mallick, 2003).
Resources for crop production are usually most critical in agri-
culturally developing countries than in developed countries
(Oram, 1985). The climate change scenarios considered by vari-
ous models would relax the current constraints imposed by a
short and cool frost-free season, but without adjustive measures
drier conditions and accelerated crop development rates were
estimated to offset potential gains stemming from elevated CO
2
concentrations (Brklacich et al., 1996). Under such conditions,
higher crop yield would require greater amounts of fertiliser and
water (Wittwer, 1990). The yields of major crops in dry and arid
