Global Maize Initiative, Colombia

The second year of the new location of Global Maize in Colombia (Meta Province) has continued with the comparison of two alternatives of Ecological Intensification (EI) in corn and three N fertilization rates, together with a set of crop rotations. Specifically, the treatments include: 1) Farmer practice (FP) of soybean followed with traditional corn, 2) FP corn in both years, 3) EI corn (first planting corn followed by soybean) with planting order switched in order to favor corn, 4, 5 and 6) rotations of soybean, sun hemp (Crotalaria), rice, EI corn, soybean, EI corn. These treatments are arranged so that any one year has all six crops in the field. The soils for the study are relatively poor, especially in terms of cation exchange capacity, but are not as extreme as many soils in the Meta region. For example, the study area does not have high exchangeable Al.

In the first half of 2014, when traditional FP corn and some EI corn was planted, we suffered from a strong storm that toppled part of the crop. Despite this damage, we were able to collect enough plants to complete our yield and nutrient uptake analyses, but the yields were still much less that in first planting 2013. Overall, EI is showing some yield advantages, especially with larger N application rates. In the second planting of 2013, the largest difference of EI corn was about 2.2 t grain/ha with the application of 308 kg N, and the smallest difference was 0.3 t grain/ha with application of 50 kg N, always in favor of EI corn. The first planting of 2014 was not normal because of the wind damage, and EI corn had lower yields than FP. In both management alternatives yield was only 50 to 60% of that obtained in the first planting in 2013.