Climatic influence on corn sowing date in the Midwestern United States

ABSTRACT This study investigated the climatic influence on the corn sowing date in the Midwestern United States by comparing the survey data of corn cultivation with meteorological records in nine states for the last 36 years (1979–2014). The results show that the year‐to‐year changes in the sowing date were significantly affected by springtime air temperature and precipitation in the nine states, although large state‐to‐state differences were found in the degree of sowing date–meteorology relationship. We determined that the 36‐year climatological warm period (CWP) with daily mean temperatures ≥10 °C plays an important role in the state‐to‐state differences. For the states with longer CWPs, the influence of air temperature (precipitation) was generally weaker (stronger). This observed counteractive relationship should be considered for crop modelling for more effective assessment of the impact of climate change on agriculture.