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 N2O emissions, nitrate ( [GRAPHICS] ) leaching and pasture yield. In all 3 years, DCD was highly effective in reducing N2O emissions from urine-nitrogen (N) applied in autumn (April and May), decreasing the N2O emission factor by 41%-82%. In addition, DCD consistently reduced [GRAPHICS] -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 [GRAPHICS] 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.