Quasi-biennial corn yield cycles in Iowa
R. W. Malone, D. W. Meek, J. L. Hatfield, M. E. Mann, R. J. Jaquis, and L. Ma
Agricultural and Forest Meteorology (15 June 2009)
DOI: 10.1016/j.agrformet.2009.01.009
Quasi-biennial cycles are often reported in climate studies. The interannual El Niño Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) are two phenomena containing quasi-periodicities of approximately 2.5 and 2.2 years. It is known that ENSO affects corn yield through weather patterns, NAO affects surface temperature and cloudiness, and surface temperature, rainfall, and radiation affect corn yield. However, a quasi-biennial pattern in corn yield and the combined effect of several climate signals on long-term U.S. corn yield are not known. Here we show statistically significant 2–3 year periods in long-term corn yield from one of the world's most important corn producing regions. High (low) yields are due in part to high (low) surface radiation and low (high) temperature early in the corn growing season coupled with sufficient (insufficient) rainfall later in the growing season. A statistical model we developed using three climate indices accounts for 54
keywords: QBO; NAO; ENSO; SOI; Nitrate leaching; Corn production; Climate; Multitaper spectral analysis