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

Abstract

© 2014 The Royal Society of 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 (NO₃⁻) 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 NO₃⁻-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 NO₃⁻ 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.