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Increase of CO 2 and Climate Change Effects on Iowa Soybean Yield, Simulated Using GLYCIM
Author(s) -
Haskett Jonathan D.,
Pachepsky Yakov A.,
Acock Basil
Publication year - 1997
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1997.00021962008900020004x
Subject(s) - environmental science , climate change , yield (engineering) , climatology , crop , climate model , general circulation model , atmospheric sciences , crop yield , agronomy , ecology , materials science , metallurgy , biology , geology
Increases in atmospheric CO 2 concentration are likely to have a significant impact on the climate and to affect the growth and development of crops. The effect of climate change on crops has to be assessed for large areas to provide information for global estimates and regional strategy development. In this study, computer simulations were done using the soybean [ Glycine max (L.) Merr.] crop model GLYCIM to assess the effects of these changes on soybean yields in the state of Iowa. The ability of the model to accurately predict the effect of changes in atmospheric CO 2 concentration was tested by comparing model results with a curve fit of CO 2 concentration yield response derived from measured data. To simulate the effects of climate change, we used projected monthly weather variables for ambient and increased CO 2 from three general circulation models (GCMs): Goddard Institute for Space Studies (GISS), Geophysical Fluid Dynamics Laboratory (GFDL), and United Kingdom Meteorological Office (UKMO). The monthly weather variables were converted to the daily weather to simulate soybean crop yields in nine crop reporting districts (CRDs) of Iowa, with and without increases in atmospheric CO 2 . When climate change was simulated with increasing levels of CO 2 (baseline 350, 450, 550, and 650 µL L −1 ), yields increased. Without increases in atmospheric CO 2 , yields remained essentially constant in the GFDL and GISS scenarios, while decreasing by 2 to 10% in the UKMO scenario. The variability in yields among nine CRDs increased for all scenarios as climate changed and levels of CO 2 increased. Overall, projected climate changes did not substantially alter simulated soybean yields. The increase in CO 2 concentration in the atmosphere was the primary determinant of yield response.