Tilting the Odds in Maize Yields How Climate Information Can Help Manage Risks

It goes without saying that most crops are sensitive to variations in weather and climate. When the influence of the El Nino-Southern Oscillation on rainfall for several regions of the world was first discovered climate scientists assumed that this information would be of immediate use by farmers, the general agricultural community, and other communities. One of the reasons this has not happened as quickly and universally as expected is that many users are not able to relate the climate information to their practices. In this paper we illustrate an application of climate information as it relates to the risk of a poor crop yield. Specifically we show how the odds of a good, versus poor, maize yield are tilted by variation in the seasonal climate. In addition, we illustrate strategies that could allow farmers a way to manage the climate risk associated with these shifts. We illustrate maize-yield sensitivity to seasonal climate by simulating the influence of relatively small variations in dry spell duration on maize yields in Uruguay. We then show that the observed median dry spell durations in the maize-growing season of Uruguay during El Nino and La Nina episodes are in the range where maize yields are most sensitive to dry spell length. Variations in maize yields developed from the crop model are consistent with observed mean yields and with observed yields during El Nino and La Nina conditions. Finally, we discuss risk management strategies based on cultivar and planting dates.