Global Maize Project in Argentina: Balcarce, Buenos Aires

A long-term field experiment was established at Balcarce, Buenos Aires, Argentina in the 2009-10 growing season. The crop rotation was maize-wheat/double cropped-soybean, with both crop phases occurring each year. Soil samples were collected during site establishment to characterize the initial conditions, especially the carbon content in the entire soil profile. Treatments included current farmer practice (FP) and Ecological Intensification (EI) practice. Treatments differed in cultivars, planting dates, pest and weed control, or nutrient management practices. Maize in the 2013/14 season grew under adequate climatic conditions, which resulted in improved grain yields compared to the previous 2012/13 season. Maize yields were 8.7 t/ha and 11.0 t/ha in FP and EI treatments, respectively - a significant difference of 26%. Wheat grew under normal conditions for the region and yields were 2.9 t/ha in FP and 5.8 t/ha in EI treatments - a significant difference of +101%. Double-cropped soybean was planted immediately after the wheat harvest in early January, but the crop was highly affected by a period of dry weather and high temperatures at early stages and grain yields were very low under both practices.

Considering the six crops of the first four years of this field experiment, EI resulted in higher yield and more efficient water use (kg grain/ha/mm) than FP. Nitrogen physiological use efficiency (kg grain per kg N uptake) was not reduced with EI despite the increase in N uptake, and water productivity (kg grain/total annual precipitation) was increased with EI.