South America Calling

With the crop season in North America starting to wind down, attention will start to turn to South America's crops. This year, we're looking at them a little earlier than normal because the restrictions on planting soybeans in Brazil has been moved up to Sept. 1.

In the recent past, this was typical for mid-September. But it may not matter. Producers in Brazil usually wait for good soil conditions before starting to plant. Dry conditions for a vast majority of the continent are probably going to force producers into planting later. And a disruption in the southern polar vortex and a developing La Nina in the Pacific Ocean could raise more concerns going forward.

The disruption coming to the stratosphere above the South Pole will have a tendency to break the polar vortex into several pieces during the next few weeks, making for more widespread storm systems for Argentina, but also greater risks for bursts of cold air moving into the continent. You can read more about that here: https://business.weatherzone.com.au/….

The cold side of the El Nino Southern Oscillation, La Nina, is developing in the Pacific Ocean and could come rapidly during the next few weeks. Colder waters in the tropical Pacific tend to leave Argentina and southern Brazil drier and could push back the start of the wet season in central Brazil.

Below is a closer look at the three main growing regions in South America. But long story short, there are some major concerns for the coming crop year in all three.

CENTRAL BRAZIL -- LATE START TO WET SEASON RAINS?

Central Brazilian farmers get just enough rain to produce a double crop of soybeans followed by corn or cotton. The second-season (safrinha) crop, accounts for about three-quarters of the corn grown in Brazil, making this region very susceptible to disruptions to the wet season. The rains typically begin in late September, increase throughout October, start to wind down in April, and then end abruptly in early May.

In recent years, the wet season rains have shut down in April, about three weeks early, and have given corn producers a terrible end to their seasons. Hot weather during the winter has significantly dried out soils in the region, more so than usual. Therefore, getting the rains to come in on time will be very important.

Unfortunately for producers there, La Nina tends to delay the start of the wet season. It doesn't happen every year, but the probability is higher. A delay to the wet season rains push everything into a tighter window than they already have to deal with. Longer-range models are mixed. While the European ECMWF weekly model is calling for rains to start on time at the end of September, the American CFS brings those rains in about a week later. That may not sound like much, but with how dry it currently is there, it could tighten operations quite a bit. Fronts moving up from Argentina usually do not make it into central Brazil. They could, and there will be several that will try, but that probability is low regardless of the La Nina situation.

As long as the rains come in earnest and not sporadically in October, then the soybean crop is usually fine. It would be the window for getting corn planted that would truly be the concern. Producers harvest their soybeans in late January through mid-February and immediately plant their safrinha crop. They hope to get corn through pollination before the wet season rains shut off. If they do, the soil moisture built up over the wet season can sustain the corn crop through grain-fill. If not, there could be major issues.

Another risk, should the corn planting be significantly delayed, would be an increased frost risk for the safrinha crop in June. Usually, the crop is beyond the point of damage that late, but as we saw back in 2021, it could be a major threat if the crop is still vulnerable.

SOUTHERN BRAZIL, PARAGUAY, FAR NORTHERN ARGENTINA -- FAIR START, DRY FINISH?

This region is a hybrid. It has a long growing season, but it is difficult to double-crop soybeans with corn. Northern areas like Parana and Mato Grosso do Sul can do it. But the season is too short and the risks too large for northern Argentina. Instead, many areas will double crop a winter small grain like wheat or barley with a summer crop of corn or soybeans. Others will just produce a long, full-season corn crop. This leads to all sorts of variability on the timing of weather conditions and whether or not they will be favorable or unfavorable for the crop.

Southern Brazil, and particularly the state of Rio Grande do Sul, had historic flooding in early May. It wiped out some of the crop that needed to be harvested and significantly delayed winter wheat planting. That goes beyond the loss of property and infrastructure in the region that occurred as well. But it has left the region with overall decent soil moisture this year. Out of the three regions, this one had the most consistent rainfall, though it wasn't nearly as heavy outside of Rio Grande do Sul. Soil moisture is good there to start the year, which extends into southeastern Paraguay as well. But other spots just to the north and south have poor soil moisture going into planting. Frosts have been frequent in the late winter, more so than usual, and could have affected any winter crops, especially those that were planted later and were vulnerable to frost damage.

The disruption to the polar vortex is a major concern for the next few weeks. While several more storm systems are likely to go through during the next month and keep soil moisture high or even improve it in some locations, the risk of cold air moving in as well could lead to frost damage for the rest of the winter crop, or push producers to delay some planting if the forecast shows some risk. If producers forego the risk and plant early, they could see frost damage in September, which isn't unheard of, but is unusual for being this far north. It would be like south Texas or the Gulf Coast getting a frost in March.

Then there is La Nina. When that fully kicks in, the jet stream seems to bypass the region, with fewer storm systems to bring showers to the region. That typically comes into play in December or January, a critical time period when a lot of crops are either finishing their fill period or being planted if they are double cropped, or during pollination for some longer-season corn varieties. While that makes fieldwork easier, it comes with heat and stresses out developing plants. The effect usually lasts through the main part of the season, April or even May. Then what follows is a higher risk of strong cold fronts that can bring frosts in June. When they occur, they can be devastating like they were in 2021. What starts out like fair conditions with a risk of frost can turn into a hot and dry crisp. Models seem to be on board with that potential playing out this year.

CENTRAL AND SOUTHERN ARGENTINA: THE WORST OF THE BUNCH?

The plains of central and southern Argentina, colloquially called the Pampas region, is much like the American Central Plains. The weather is suitable for a long growing season and weather systems frequently move through to provide changes in temperature and waves of rain. With a source of moisture coming from the Atlantic, the rainfall is usually good enough to produce a good crop. However, the reliance on weather systems also leads to times of great drought when they do not occur.

The longer growing season allows producers here to spread out their risk. Some early corn planting occurs in September and October, usually skips November, and then picks back up again in December and January. Spreading out the risk allows producers to mitigate potential dry periods that often arise, especially in January. That is why producers usually skip over November; the corn would generally be pollinating in January. Soybeans are spread out as well, but they usually don't begin to be planted until November as they try to catch fall rains that come with a change in the season in March and April. That can sometimes be double cropped with winter wheat or barley as well.

The winter crops have taken a beating so far this year. Disruptions to the polar vortex in the last couple of months have meant very strong cold fronts moving through. Frosts are not uncommon during the winter, but hard freezes have been very frequent, cause damage to more advanced crops and slower development in the less-advanced crop. Temperatures have swung wildly as well, tricking crops into warmer conditions before bringing in the harsh cold.

Even with the frequent fronts, the rainfall here has been paltry. Outside of the state of Buenos Aires, and really the southeastern section of the state, rainfall has been more than disappointing. Soil moisture is very low across the majority of the country, and that is not a good place for producers to be when planting starts up next month.

The continued disruption of the polar vortex will mean these conditions will continue for a bit, though for how long is an unknown. Models continue to have waves of cold air moving through September at least. But they also do not produce a lot of rain. As La Nina starts to assert its dominance this spring, the country undergoes a lot of the same conditions as the section above, being hotter and drier during the heart and tail end of the growing season. It will come down to planting time and the conditions that follow. If crops go through a harsh stretch of hot and dry weather at the beginning of their life cycle, it could have a strong correlation to reduced yields, since the weather pattern the rest of the way is likely to be harsh. At the same time, just enough rain and just the right time might bring the crop out of the brink of catastrophe. But with limited soil moisture to begin the year, cold and dry conditions for the next month, and an outlook of hot and dry conditions for the primary growing season, the setup for this region is not good this year.

To find more international weather conditions and your local forecast from DTN, visit https://www.dtnpf.com/….

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

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