Weather erratic for Brazil soy as harvesting starts

BRASILIA (Reuters) - Heavy showers will sweep over central and northeastern soy regions in Brazil this week but little moisture will reach the critically dry south, forecaster Somar said on Tuesday, as some farmers fire up harvesters to start gathering the crop.

The world's No. 2 soy producer is now well into the wet summer season. But the La Nina weather anomaly has disrupted rainfall patterns in the south, keeping that region and neighboring Argentina's soy areas mostly dry in recent weeks.

The drought has already destroyed some of the corn planted in Parana state, the country's biggest corn state, and relief from dryness will be critical in the next week or two in No. 3 soy grower Rio Grande do Sul in the far south to prevent seed germination failing.

Dryness there and in world No. 3 producer Argentina, has given support to soybean futures in recent days, with no sign of imminent relief.

As of 10:31 a.m. CST (1631 GMT), the Chicago futures exchange's March contract , now the most active, traded up 24 cents at $12.31-3/4 per bushel. March corn was up 9-1/2 cents at $6.56 a bushel.

Brazil's top soy state, Mato Grosso has largely been spared the weather chaos facing other important states. In a weekly crop bulletin, Somar said its soy productivity looked "close to the maximum" as the first harvesting gets going there. The state is set to receive more rain in central and northern parts, but it will need mostly dry weather as harvesting quickens.

Further south in Parana, Brazil's No. 2 state for soy, the crop also looked in good shape, Somar said, though the current dry spell was likely to cut productivity. The drought has already caused widespread damage to Parana's corn crop.

In its extended forecast, Somar said rains would move a little to the south between January 7-11, bringing a total of 15-30 millimeters (0.6-1.2 inches) to the very dry states of Parana, Mato Grosso do Sul and Rio Grande do Sul. The heavy rain bound this week for states in the east of the country would also ease after a day or two.

- Reuters