Global Maize Initiative, Colombia


13 Mar 2012

2011 Annual Interpretive Summary

Global Maize Initiative, Colombia - 2011

In 2011, this study completed four consecutive crop cycles at Villa Escocia, and the fifth cycle was planted on October 27. The study had following specific objectives: 1) measure yield differences among different nitrogen management strategies and 2) compare the ecological intensification (EI) management against traditional maize technology.

In 2009-B, the first planted cycle, the average yield in the intensive management was 7.30 t/ha and the traditional management yield average was 5.49 t/ha. Only the treatment with intense management with N in all cycles showed a significantly higher yield (8 t/ha), but this was possibly an artifact as many other treatments suffered from plant lodging. Overall, this cycle indicated a high fertility soil, with small differences within N strategies tested with high or low planting densities.

Cycle 2010-B showed the lowest yield overall as a result of extreme rainfall, this was also the cycle in which the treatments with reduced N application (2/3 cycles) did not receive N. The average grain yield in 2010-B with intensive management was only 6.45 t/ha, while the traditional management average was 5.53 t/ha. The maximum yield was obtained with traditional management N applications in all cycles (8.77 t/ha), which was slightly higher than intensive management with N in all cycles (8.45 t/ha). It was noticeable by this time a carry-over effect with N management strategies, those treatments with no N or reduced applications (2/3 cycles) had significantly lower yields than N repeated in all cycles.

In the other two crop cycles (2010-A, and 2011-A), the treatments with N application and higher planting density had the highest yields followed by the treatments with N application and low planting density. The values of yield with no N applications declined progressively across the four consecutive crop cycles. IPNI-38