Dicyandiamide (DCD) effect on nitrous oxide emissions, nitrate leaching and pasture yield in Canterbury, New Zealand

A 3‐year study was carried out in Canterbury, New Zealand, to determine the effect of a nitrification inhibitor dicyandiamide (DCD) on N 2 O emissions, nitrate () leaching and pasture yield. In all 3 years, DCD was highly effective in reducing N 2 O emissions from urine‐nitrogen (N) applied in autumn (April and May), decreasing the N 2 O emission factor by 41%–82%. In addition, DCD consistently reduced ‐N leaching losses by 48%–69% from the animal urine applied in April. Pasture yield responses to DCD application varied from 0%–17%, probably due to other growth limiting factors and/or the methodology used in the pasture yield measurement. The reductions in leaching are of particular value at this point in time due to the increasingly strict regional council regulations that are being imposed on farmers to reduce N leaching losses.