The Global Maize project at Argentina
The Global Maize project includes two field locations at Argentina: Oro Verde (Entre Rios) in the northern Pampas, and Balcarce (Buenos Aires) at the southern Pampas. At both locations, a long-term field experiment has been established on the 2009-10 growing season. The crop rotation is maize-wheat/double cropped soybean, with both crop phases occurring each year. Treatments include farmer’s current practice (FP) and ecological intensification practice (EI). Treatments differed in either cultivar, planting date, pest and weed control, or nutrient management practices. Soil samples were obtained at the establishment of the experiment for initial characterization.
Ancillary field experiments are established at both locations to examine various factors of ecological intensification including: the interaction of N with maize plant population, N use efficiency for maize hybrids released in recent years, and an evaluation of cover crops as a source of carbon and N for a subsequent maize crop.
General objectives are i) to evaluate the effects of intensified management systems in system productivity and environmental impact under contrasting environments, and ii) to evaluate specific management practices to provide information in order to adjust the intensified management of grain production systems of the Pampas region. Specific objectives of this project are:
1. To evaluate the long- and short-term effects of intensified management practices (EI) compared to the current farmer’s practices (FP) at western Entre Rios and southeastern Buenos Aires regarding grain yields, nitrogen use efficiency, water productivity, soil C evolution, emissions of nitrous oxide (N2O) and carbon dioxide (CO2), concentration and amount of nitrates in drainage water, and profitability of the production system.
2. To develop a coordinated and public data base associated to the research sites.
3. To analyze the influence of EI and FP management in the relationships among water and N availability, and soil temperatures with N2O and CO2 emissions.
4. To determine nitrate transport outside of the crop rooting area in wheat/soybean-maize rotations under EI and FP management.
5. To develop specific field experiments to provide alternatives for the EI treatment, i.e. plant population*N*water availability interactions, cover crops to provide C and N to the system.
6. To validate predictability of crop simulation models to estimate the probability of occurrence of maize, wheat, and soybean yields in the long-term.
7. To utilize crop simulation models to i) analyze potential yields and yield gaps, ii) variability of potential yields, under dryland conditions, and attainable yields under both management strategies, iii) realize the risk analysis of maize, wheat, and soybean production under both strategies, and iv) generate a sensitivity analysis of the impact of different management practices on crop production.