Late season rains put the brakes on Argentine soy, corn losses

BUENOS AIRES, March 20 (Reuters) - Late season rains will halt further deterioration of drought-hit Argentine soybean yields, setting the stage for an estimated crop of at least 40 million tonnes after being trounced earlier in the season by extremely dry weather, experts said on Tuesday.

The 2017/18 crop year started with soy harvest estimates in the 55 million tonne range. But the drought has parched wide areas of Argentina's normally fertile Pampas grains belt since November and scorched some soy and corn fields beyond repair.

Showers over the weekend provided some relief, particularly in the bread-basket province of Buenos Aires. More precipitation is expected this weekend, with growers hoping the moisture will reach further north to key farm areas in Cordoba, Santa Fe and Entre Rios provinces.

Argentina is the world's No. 3 exporter of soy and corn. The drought put upward pressure on world food prices but Chicago Board of Trade soybean futures fell more than 2 percent on Monday after weekend showers were seen stabilizing crop losses.

"The rain helped a little, but the destiny of most soy plantations had already been written," said Eduardo Sierra, climate consultant to the Buenos Aires Grains Exchange. "It helped a handful of farmers whose soy and corn was at the right stage to be helped by moisture."

"The new moisture will maintain 40 million tonnes as a floor for the soy harvest, and maybe add 500,000 tonnes. Corn, with a bit of luck, could go from an estimated 34 million tonnes to 35 million tonnes," he said.

The exchange projects the soy harvest at 42 million tonnes, warning that further cuts are possible if rains do not reach the northern province of Chaco. The exchange forecasts the 2017/18 corn harvest at 34 million.

The Rosario grains exchange last week slashed its soy crop forecast to 40 million tonnes from a previous 46.5 million while cutting its corn estimate to 32 million tonnes from 35 million.

Wide areas of Buenos Aires got 3 to 4 centimeters (1.1 to 1.5 inches) of rain over the weekend. "We hope it will rain in Cordoba and Santa Fe over the days ahead," said Leandro Pierbattisti, an analyst with the country's grains warehousing industry chamber.

"For soybean yields, the movie has ended. A recovery in soybeans at the end of March is just impossible," he said.

But late-planted corn, which was sown in December, could still see some recovery. "I'm optimistic that there is room for corn yields to recover if it rains this coming weekend," Pierbattisti said.

Ground moisture also needed to set the stage for Southern Hemisphere autumn wheat and barley planting in May.

"We need a lot of rain over the next month but the forecasting models over the mid-term are not very promising," Pierbattisti said. (Reporting by Hugh Bronstein Editing by Alistair Bell)