Global Maize Project in Argentina: Balcarce, Buenos Aires

A long-term field experiment was established at Balcarce, Buenos Aires, in the 2009/10 growing season. The crop rotation is maize-wheat/double cropped-soybean, with both crop phases occurring each year. Soil samples were collected during site establishment to characterize initial conditions, especially soil carbon content in the whole soil profile. Treatments include current farmer practice (FP) and Ecological Intensification practice (EI). Treatments differed by either cultivar, planting date, pest and weed control, or nutrient management practices.

Maize and wheat crops in the 2010/11 season developed under adequate climatic conditions, which favor the expression of an improved potential yield in the EI treatments. Maize yields were 12,647 kg/ha, and 14,726 kg/ha for the FP and EI treatments, respectively, a significant difference of 16% (p<0.002). Wheat yields were 3,141 kg/ha for FP and 4,745 kg/ha for EI, again with significant differences between treatments (p<0.007). Double cropped-soybean was planted immediately after the wheat harvest in January, and yields of 1,361 kg/ha and 1,165 kg/ha were obtained under the FP and EI treatments, respectively, without significant differences between treatments.

Considering the first 2 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 two treatments did not differ much in the capture of water (ratio of ET/total precipitation). The EI treatment also showed higher N use efficiency and N removal and less negative N balances, but lower partial factor productivity of N as compared to the FP treatment. IPNI-24