论文题目: Determination of potential N2O-reductase activity in soil

论文编号:
作者: 作者：Shuping Qin (秦树平)， Haijing Yuan（袁海静），Chunsheng Hu（胡春胜，通讯作者），Oene Oenema，Yuming Zhang（张玉铭），（Xiaoxin Li）李晓欣
刊物名称:
卷期页码: In press, 影响因子：3.654,
发表年度: 2014
DOI: http://www.sciencedirect.com/science/article/pii/S0038071713004719
摘要: 　　Determination of N₂O-reductase activity in soil is important for understanding the microbial regulation of nitrous oxide (N₂O) concentrations in soil. Unfortunately, there are no easily applicable and accurate methods for determining N₂O-reductase activity, which frustrates the understanding of the mechanisms that control soil management effects on denitrification and N₂O emissions. The objectives of the study reported here were (i) to define the optimal experimental conditions for the determination of potential N₂O-reductase activity in soil, (ii) to compare the direct-N₂method with the acetylene inhibition technique, and (iii) to investigate the effects of long-term nitrogen (N) fertilization on the potential N₂O-reductase activity.

　　Various substrate concentrations, water/soil ratios, incubation times, temperatures and pH values were tested to find the optimal conditions for the potential N₂O-reductase activity in soils from two sites. Then, the potential N₂O-reductase activity was determined under optimal conditions (10g soil, 10ml buffer solution, pH 9, 40°C, 100ppmv N₂O) in soils from the long-term N fertilization experiment. There were significant differences between soils in potential N₂O-reductase activity, but the optimal experimental conditions were similar. The acetylene inhibition technique underestimated N₂O-reductase activity in soil relative to the direct-N₂method, especially in the treatment where fertilizer N was withheld for 15yrs. We recommend that the optimal experimental conditions for the determination of the potential N₂O-reductase activity are established also for other soils. More studies are needed to fully understand the interactive effects of long-term N fertilization on nosZ gene expression and N₂O-reductase activity in soils.