Past and potential future impacts of climate on crop production in the great lakes region

CERES-Maize, SOYGRO, and DAFOSYM simulation models were used to identify past and potential future climatic impacts in the Great Lakes region for corn, soybean, and alfalfa crops, respectively. Data in the study included 102 years of historical climatic data (1895-1996) from 13 stations across the region chosen for series length and homogeneity. Simulated historical crop yields were strongly linked to growing season precipitation and the availability of soil moisture. Most simulated yields exhibited a south to north gradient across the region. Simulated maize and soybean yields were found to increase since 1940 due at least in part to corresponding increases in growing season precipitation totals and frequency and decreases in potential evapotranspiration. Time series of alfalfa yields during the same period were steady or decreased slightly.

Potential future crop performance for the period 2001-2100 was modeled with simulated daily climatic data taken from Hadley Centre (HADCM2) and Canadian Climate Centre (CGCM1) transient general circulation models downscaled to individual station locations. Future simulations were run both with and without the effects of CO2 enrichment. Alfalfa and soybean yields in the future climate scenarios were greater than those of the historical scenarios while maize yields were similar to or less than historical yields. Simulated future yields of all three crops tended to exhibit lesser interannual variability than historical yields, especially with the addition of CO2 enrichment.