BRECHAS DE RENDIMIENTO DEL MAÍZ EN ARGENTINA Y SU RELACIÓN CON EL FENOMENO EL NIÑO-OSCILACIÓN DEL SUR (ENSO)

ARAMBURU MERLOS, F.; MONZON, J.P.; GRASSINI, P.; ANDRADE, F.H.

Rosario

Congreso; X Congreso Nacional de Maíz; 2014

AIANBA

The objectives of this work were: i) to quantify maize water-limited yields (Yw), actual yields (Ya) and yield gaps (Yg) in Argentina; and ii) to identify the effects of the El Niño Southern Oscillation phenomenon (ENSO) on maize Yw, Ya and Yg. Using the CERES-Maize model, Yw were estimated at 15 buffer zones that cover ca. 50% of the Argentinean maize crop area, considering local management practices and soil variability. A weighted buffer zone actual farmer?s yield (Ya) was calculated based on the actual yield reported for the departments located within the buffer zone for the last seven cropping seasons. The yield gaps were calculated as the difference between Yw and Ya. Yield residuals associated to each phase in each buffer zone were assessed using non-parametric tests in order to analyze the effect of ENSO phases on Yw and Ya. Argentinean maize Yw was 11.6 t.ha-1, Ya was 6.8 t.ha-1, and the Yg was 4.8 t.ha-1 (42% of Yw). High spatial variability in these variables was observed, probably related to cropping history and environmental conditions of each zone. La Niña years were associated with lower Ya and Yw. On El Niño years, Ya were greater than in Neutral and La Niña years, but no significant differences were found in Yw between Neutral years and El Niño years. The different response of Yw and Ya to ENSO phases suggests that Yg are bigger on Neutral years and lower on La Niña years.