Comparison of the ability of the nitrification inhibitors DCD and DMPP to reduce nitrification and N20 emissions from nitrogen fertilisers

摘要

Nitrification of applied nitrogen fertilisers leads to losses of nitrogen (N) as nitrate (N(V) or as the greenhouse gas nitrous oxide (N20). Nitrification inhibitors can be used to suppress the ammonia oxidizing bacteria involved in nitrification andhence reduce these losses. The ability of nitrification inhibitors to reduce nitrification is dependent upon both climatic and soil conditions, and different inhibitors respond differently. The ability of two nitrification inhibitors, 3,4-dimethylpyrazole phosphate (DMPP) (1.84 kg/t urea) and dicyandiamide (DCD) (10 kg/t urea) to reduce nitrification from applied fertiliser (100 kg N/ha) in a pasture soil, in small scale (150 g) incubation studies under a range of temperatures (5,15 and 25°C) was studied. Both products were applied as commercially prepared granular urea products. The comparable ability of the 2 inhibitors to reduce nitrification, as measured by NO3" formation, were similar across all treatments, with neither effective in the topsoil and both causing reduced N03" formation in the subsoil. N20 emissions were reduced by both inhibitors. DMPP was applied at a lower concentration than DCD and performed almost, and equally as well in many cases.