International grains prices have soared this year on the back of thin supplies and growing food demand while Argentine farm output - particularly in key agricultural province Buenos Aires - has come under pressure from months of heavy rains.
Even normal rainfall at this point poses a problem in Argentina, the world's top exporter of soyaoil and soyameal. "West, central and eastern Buenos Aires province are flooded. This is flat land that does not have enough slant toward the ocean to drain off. Logistics are in chaos because the floods are criss-crossing over the roads," said Anthony Deane, head of consultancy Weather Wise Argentina.
The National Weather Service said at least 10 millimeters (0.4 inch) of rain fell in the heart of Argentina's farm belt - Buenos Aires, Cordoba, Santa Fe and Entre Rios province - in the 24 hours through Monday morning. "It was not a lot of rain but any added moisture at this point sustains the flooding," Deane said.
Until the Sunday-Monday showers, the rate of soya and corn planting had picked up as the weather moderated after the Pampas was lashed by unusually harsh August-October storms. Toward the end of this week, Deane said he expects 100 to 150mm to fall over 60 percent of Argentina's grains belt, while the remaining 40 percent gets 40 to 50mm. Soggy topsoils make it impossible for farmers to drive their seeding machines - weighing about 30 tonnes each, fully outfitted - over their fields without sinking in the mud. The floods come at a bad time for consumer nations counting on South American grains supply. Low stocks have squeezed benchmark Chicago soya prices 22 percent higher this year while corn is up 17 percent and wheat 31 percent.