South America Calling

A big change in the weather pattern is coming for South America, one that may turn around the optimism from producers down there and change the course of the growing season weather.

So far, fronts have been frequent across Argentina and southern Brazil for the first two and half months of the growing season. Soil moisture has been very favorable for the winter wheat crop, which has been forecast to be well above normal and record high in Argentina. Early planted corn in Argentina, along with full-season corn and first-season soybeans in southern Brazil, have enjoyed some very favorable growing conditions thus far. Soil moisture is largely abundant and outside of some bouts of flooding and severe weather, optimism is high amongst producers there currently.

One more front is forecast to move through these regions this weekend into early next week, promising to produce one more round of widespread moderate-to-heavy precipitation. That could indeed come with some flooding and severe weather again, but overall, this maintains the prospects for good production early this season. However, that may be the last front to do so for a while.

While fronts are still forecast to move up through Argentina and into southern Brazil for the rest of November and into December, models have been insistent that the precipitation with them will underperform normal, resulting in gradual drying of soils in these regions as they go into the heart of their growing season.

Early season corn would be pollinating in December and a drying soil column would be hurtful to that process. Corn and soybeans farther north into Brazil could be affected in their reproductive and filling stages as well. The first-season soybean crop in southern Brazil would likely stand to have the largest impact during pod fill and could quickly turn what looked to be a good crop early in the year into a disappointing one. For those that double crop with corn or cotton, the safrinha crop, it would not leave the region in good shape, especially if this continues into the new year.

In contrast, the weather pattern may be more favorable for those in central and northern Brazil. So far this season, weather has been more chaotic than normal. Precipitation has largely come via fronts and less so from the regular monsoonal type of pop-up showers that characterizes the wet season in this part of the continent.

October was especially poor as DTN estimates that most areas saw 60-100 millimeters (about 2.4 to 4 inches) less rainfall than normal. Coming off of a very dry five months, this lack of rainfall has led to reports of wilting of germinating soybeans throughout the region and then end of planting has been slow. Other reports of replanting have come in as well. Soils are very dry and the rain that has been coming has not kept up with evaporation, leaving seeds to germinate and quickly die out in the dryness.

But this region may benefit from the changing weather pattern. The lack of strength in the fronts moving up from Argentina are going to cause them to stall in central and northern Brazil. Though they will still be interfering with the monsoonal pattern of showers, they are more likely to linger in the region, increasing the coverage and associated intensity of rainfall. Should this happen, producer concerns here would ease. However, this effectively has delayed the planting and development of soybeans in central Brazil. With an already tight window for double-cropping soybeans with corn or cotton, the second-season (safrinha) crop may be delayed as well, even after a quick start to planting this spring. Therefore, many concerns are still in play for the continent as a whole.

This change in the weather pattern toward drier conditions in Argentina and southern Brazil, and wetter conditions in central Brazil, is a direct result of the peaking La Nina event in the Pacific Ocean. Forecasts suggest that this event will be short-lived, with neutral conditions developing in January or February. Should that happen, this pattern could change for the tail end of the season. In other words, we may see some increased volatility in the prospects for corn and soybean production in South America as the months unfold.

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John Baranick can be reached at john.baranick@dtn.com

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