Feed the World with Smart Farming  (continues from page 1)

        The 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.

        If 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.

        We 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.

        If 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 nations.

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.

Conclusion. 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.

 CITATIONS                                                                            Top

1. "Global 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 here.

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