AgWeb had an interesting article this week on predicting corn yields based on past years. One way to do this is to use analog years that are similar to this year and see what happened. In the article, they used 1972-73, 1982-83 and 1997-98. Using the analog method, they showed that in two of the three analog years, yields were very similar to long-term values, but one year, 1983, had very poor yields. It is not clear why this happened, but it would be interesting to try to dissect it.
Another method is to use statistics to look for patterns of yield. Agroclimate.org has produced some maps which relate yield of a variety of crops to the El Niño phase at https://agroclimate.org/tools/Regional-Yield-Maps/. The maps show that for corn in an El Niño year, yields are below average conditions. This year we are still in a strong El Niño, although it is starting to decay. The longer it stays in this phase, the more likely it is that corn yields will be worse than average. You can use the maps to look at other crops too and see if other crops might be a better choice. But you have to keep in mind that statistics only tells you the average conditions, and any particular year can vary.
