the World with Smart Farming (continues
from page 1)
authors forecast not only the impacts if current trends
continue, but how alternative strategies can meet the future
food demand with less land clearing and environmental impacts.
current trends continue in agriculture, the poorest nations
will meet the need for food by clear-cutting more land to
put it under cultivation. The wealthiest nations will likely
follow pathways of improving fertility on existing lands
and boosting yields through advances in technology, as they
have done up to now.
examine here alternatives to meet the world's demand for
crops in 2050, without considering changes in dietary practices.
In group A nations, yields are up to three times higher
per hectare of land than in the poor nations of groups F
and G. Clearly, one solution is to transfer technologies
and practices that yield more food from the same land to
the poor nations. That reduces pressure to clear wild land,
with its many impacts on the environment.
___ More intense
application of nitrogen fertilizers can also improve future
yields without depending on better technologies. But by
maintaining fertilizer application at the same intensity
as now, or even less, yields would still increase 50% or
more by 2050 through continuing improvements in technology,
or better, transfers of technology to poorer nations.
the world chooses a policy of avoiding the clearing of new
land, yields can increase more than 50% through ambitious
transfers of farming technologies and practices. In that
scenario, it is possible to get the same yields even if
3 to 5 times less land were cleared, if less developed nations
adopt the practices that led to high yields in the developed
Climate impact. Clearing
land for agriculture, cultivating it, and making and using
fertilizer all release greenhouse gases, especially CO2.
Tilman and Clark assert that boosting the application of
nitrogen fertilizers in less developed nations will reduce,
not increase, the emission of such gases, contrary to what
we expect. This is because the pressure to clear new land
would be dramatically scaled back. They predict lower GHG
emissions from agriculture in 2050 than actually occurred
in 2005, if production of nitrogen fertilizers is maintained
at the current level. Avoiding deforestation would reduce
the GHG emissions by three times more than the GHG increases
that result from more intense fertilizer use.
The future demand for Calories can best be met
by ambitiously transferring techniques for boosting crop
yields from wealthy nations to the least developed nations,
rather than to continue current agricultural trends distinctive
to each group of nations. By adopting the techniques for
boosting soil fertility from the wealthy nations, developing
nations would not need to clear new lands for planting.
The developed world would not apply nitrogen fertilizers
ever more intensively on their own farmland, as they now
do, but rather deliver more fertilizers or more technology
and know-how to the nations that need it most. In some scenarios,
global emission of greenhouse gases from the production
of food could actually decrease.
food demand and the sustainable intensification of agriculture",
by David Tilman, C. Balzer, J. Hill, and B. Befort (2011).
Proceedings of Nat. Academy of Sciences, v. 108,
20260--20264, Dec. 13, 2011.
2. In the United States the
Calorie (with capital C), commonly used in nutrition, equals
1000 calories (with small c) used in science. A Calorie
is also called a kilocalorie. We follow the American usage
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