|Allen, Leon - Hartwell|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 2/1/2000
Publication Date: N/A
Interpretive Summary: Much literature has been published about the effects of CO2 and climate change on the oceans, the earth, and the ecosystems. However, information on agricultural crops has not been collected in one volume. ARS-USDA scientists at Gainesville, Florida analyzed and reviewed much of the known responses of the world's most important grain legume, soybean, to the impacts of elevated CO2, increased ozone, and other climate change factors (mainly temperature and rainfall). This chapter is a major contribution along with other chapters on other major agricultural cops. The two most salient points are that this crop will increase yield about 30 percent due to an increase of carbon dioxide, and that seed yields will decrease sharply with an increase of temperature (although vegetative biomass production can be maintained to much higher temperatures). Specialized agronomists and plant breeders are needed to select soybean crops to meet the challenge of crop production in future climatic conditions.
Technical Abstract: Soybean is the worlds most important grain legume, and it will be affected by rising CO2 and climate change as well as all other crops. Much of the known data were assembled in this analysis and review of responses to carbon dioxide (CO2), ozone, and climate change factors of temperature and water availability. First, a doubling of CO2 should cause a 30 percent increase in seed yields. Second, increasing temperatures will cause a sharp decline in grain yields, although vegetative biomass growth (of warm-season crops) can be maintained. Third, elevated ozone will cause a serious reduction in crop yield, but there is evidence that elevated CO2 can partially ameliorate the negative effects of ozone. There are also unresolved CO2 by ozone interactions. Finally, the threat of drought under high temperatures compounds the water deficit stress effects on soybean. The world needs specialized agronomists and plant breeders to assess and ameliorate climate change impacts on crops and design new cultivars for the future.