Global Maize Project in Argentina: Oro Verde, Entre Ríos

A long-term field experiment was established at Oro Verde (Entre Ríos) 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 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 yields showed a low response to the EI treatment because of water stress during the V6-R3 stages, with 4.15 and 5.15 t/ha yields for the FP and EI treatments, respectively. Practically, this was a non-significant difference in yields between FP and EI treatments. Wheat yields, on the other hand, showed a significant difference between FP (2.48 t/ha) and EI (3.36 t/ha) treatments. Like in wheat, double cropped-soybean yields were also significantly higher in the EI (2.48 t/ha) treatment than in the FP (2.08 t/ha) treatment.

Considering the first three years and the three crops involved in the maize/wheat/double cropped soybean, the EI treatment significantly improved water use efficiency (determined as kg grain per mm of ET) over FP, but the treatments didn’t differ much in the capture of water (ratio of ET/total precipitation). The EI treatment also showed higher N use efficiency and less negative N balances, but lower partial factor productivity of N when compared with the FP treatment. IPNI-25