The aim of this study was to examine the effect of the nitrification inhibitor nitrapyrin on the fate and recovery of fertilizer nitrogen (N) and on N mineralization from soil organic sources. Intact soil cores were collected from a grassland field. Diammonium phosphate (DAP) and urea were applied as N sources. Cores were equilibrated at -5 kPa matric potential and incubated at 20 °C for 42 to 56 days. Changes in NH4+-N, accumulation of NO3--N, apparent recovery of applied N, and emission of N2O (acetylene was used to block N2O reductase) were examined during the study. A significant increase in NH4+-N released through mineralization was recorded when nitrapyrin was added to the control soil without N fertilizer application. In the soils to which N was added either as urea or DAP, 50-90 % of the applied N disappeared from the NH4+-N pool. Some of this N (8-16 %) accumulated as NO3--N, while a small proportion of N (1 %) escaped as N2O. Addition of nitrapyrin resulted in a decrease and delay of NH4+-N disappearance, accumulation of much lower soil NO3--N contents, a substantial reduction in N2O emissions, and a 30-40 % increase in the apparent recovery of added N. The study indicates that N recovery can be increased by using the nitrification inhibitor nitrapyrin in grassland soils at moisture condition close to field capacity.
|Number of pages||6|
|Journal||Journal of Plant Nutrition and Soil Science|
|Publication status||Published - 14 Aug 2003|
- nitrification inhibitor