Agricultural Yield Impacts from ENSO through Observation and Modelling

This research aims to study the impact of ENSO on crop production (corn & soybeans) in the Midwest using the Integrated Science Assessment Model (ISAM), observed climate data and observed crop yield data for 20 specified sites across the region. This study is important to agricultural crop production because ENSO is known to induce anomalous atmospheric circulations which lead to variations in temperatures and precipitation year to year. These variations induce large uncertainty in agriculture practices (e.g. planting times, harvest times, irrigation amount and frequency) and are thus important to determine the overall yield for a growing season. As bioenergy and biopolymer production increases and competes with food crops, it is critical to further understand these climate processes as they relate to these productions. This study's method will first compare the observed climate data with the modeled climate data that is inputted to ISAM to ensure that they show the same trends. Next the impacts of ENSO on the observed climate data will be examined for each site through regression analysis. From the climate trends, the observed (and modeled) crop yields will be examined to find trends with respect to the climate. The preliminary research suggests that there is large spatial variability in the impact of ENSO on crop yield, which depends on spatial variability and the strength of the ENSO cycle. It has been seen that the climate of some years deviates from the expected ENSO impact. It is hypothesized that the Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO) may be the cause for these discrepancies as they have been shown to impact agricultural production. It is predicted that ISAM, a dynamic model, has the ability to capture the impact of ENSO in the crop yield.