Influence of Precipitation on Maize Yield in the Eastern United States

Most General Circulation Models predict more infrequent but larger precipitation events in the eastern United States combined with a warmer climate. This could have a negative effect on maize production. To understand the sensitivity of maize production to future changes in precipitation, we analyzed growing season precipitation and average state maize yields in the eastern United States for the period 1963–2011. Growing season precipitation did not show a strong trend during this period. However, crop yields increased at 3.90% in the southern, 2.62% in the central, and 2.31% in the northern part of the eastern United States, which we attributed to technology and management. To separate technology and management effects from precipitation variability, we corrected maize yields for these yield trends. We then correlated maize yield corrected for advances in technology and management with total growing season precipitation and precipitation in the critical month of pollination, from the regional to state scale. Maize yield - precipitation relationships showed that moisture shortage rather than excess determined maize yield in the Eastern United States. The relationship between total growing season precipitation-maize yield was stronger in the southeastern than in the northeastern U.S., but the critical month precipitation-maize yield relationship was stronger in the northeastern than in the southeastern U.S. If climate model predictions are accurate and total growing season precipitation will not decrease in this region but variability will, it is likely that maize yields in the northeastern U.S. will be more significantly affected