Soil based approaches to reducing nitrogen losses

Abstract

Environmental concerns around N losses from intensive dairying threaten the long-term sustainability of these pasture production systems. New N-loss mitigation technology using the nitrification inhibitor DCD has been intensively researched at Lincoln University in recent years. This paper summarises data from these studies. Results show a mean reduction in nitrate leaching of 64 ± 3.6% from the application of DCD to cow urine patches. Comprehensive experimental data sets indicate a reduction in the nitrous oxide emission factor (EF3) of 68 ± 2.5% resulting from DCD application to soil. Pasture production increases in the South Island resulting from DCD application were 23 ± 1%. This extensive data set provides strong evidence that the nitrification inhibitor DCD is a consistent and effective tool to reduce soil nitrate-N leaching losses and nitrous oxide emissions, while at the same time improving pasture yields, in intensive grazed dairy pasture systems. Research investigating the effectiveness of DCD on a regional basis is ongoing.