Concern that global warming will have a strong negative effect on crop
yields were widespread. Research published in Proceedings of the National
Academy of Sciences on historical maize yields across the U.S. Corn Belt
suggests that a continuation of the historical yield trend will depend on a
stable climate and continued farmer adjustments.



The research, conducted by Ethan Butler, postdoctoral associate in the
Department of Forest Resources in the College of Food, Agricultural and
Natural Resource Sciences at the University of Minnesota and his colleagues
from Harvard University and University of California, Irvine, analyzes how
both climate and management have influenced the increase in yields. Overall,
the research shows farmers have adapted to historical climate change. The
combination of changes in climate, primarily cooling of the hottest
temperatures, and farmer adjustments, including earlier planting and
planting longer maturing varieties, increased maize yield trends since 1981
by 28 percent.

The researchers used a statistical model to study how rainfed maize yields
reported by the U.S. Department of Agriculture (USDA) are affected by
temperature using three crop development phases: vegetative, early grain
filling, and late grain filling. They found that planting is occurring
earlier and that the late grain filling phase lasts longer. At the same
time, the hottest temperatures have cooled. The earlier planting and longer
grain filling are primarily associated with management decisions, while the
cooling of hot temperatures appears to be an unintended benefit of
widespread planting of high-yielding modern cultivars.

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-adjustments-offset-climate-change-impacts-corn