Crop Watch - La Nina boosts dryness and heat threats to Argentine corn and soybeans

The strong start that Argentina’s corn and soybean crops have made to the 2025/26 growing season are being undermined by poor weather.

Hopes were that the ample rains received in the last months of 2025, which helped lift yields on Argentina’s recently-harvested wheat crop to a record high, would linger to protect corn and soybean crops too – should conditions turn unfavourable.

Meteorologists had warned of a deterioration in the growing weather given the onset of La Nina, which has a habit of bringing undue heat and dryness to Argentina, as opposed to the wet conditions often brought by El Nino.

However, there are signs that temperatures approaching 40 Celsius, and a lack of recent rains, are indeed damaging corn and soybeans in some areas – notably in parts of Córdoba and Buenos Aires, the two biggest producing provinces for both crops.

The Rosario grains exchange reports that “early-planted corn is expected to experience yield losses of up to 50% in south eastern Córdoba due to the lack of rain”, adding that “the yield potential of first-crop soybeans is threatened by the lack of water”.

The Buenos Aires grains exchange, noting “a lack of moisture in southern Córdoba and western Buenos Aires”, has reported sharp declines in national condition scores for both corn and soybean crops.

The proportion of the corn crop rated “good” or “excellent” has slumped to 52%, from 95% in mid-December.

The conditions questions expectations of a strong - potentially record - corn harvest, which stetches from late February to September, a factor which would enhance importers’ reliance on US supplies.

For soybeans, market expectations for output were already less upbeat, given a switch in area towards corn. A crop setback would risk returning Argentina to being a net importer of the oilseed for its huge crushing industry.

Forecasts for a further week of hot and dry weaher for most of the Argentine corn belt add to the unease.