农业环境与发展Issue(4)：13-18,6.
内蒙古贝加尔针茅草原氮素去向的示踪研究
Fate of Labelled Nitrogen Applied to a Stipa Baicalensis Community of Meadow Steppe in Inner Mongolia Grassland,China
摘要
Abstract
An important grassland ecosystem management strategy is the application of nitrogen fertilizer,however, the fate of applied nitro-gen is highly correlated with risks and benefits associated with the fertilization of grasslands. The fate of nitrogen tracers applied to Inner Mongolia meadow steppe ecosystem has not been studied previously. We examined the fate of 15N labelled fertilizer in a Stipa baicalensis site at the sample area of the Laboratory of Ecological Agriculture, Agro-Environmental Protection Institute, Ministry of Agriculture. The results showed that after one growing season 28.36%~37.03%of the applied 15N was recovered in the plant pool.15N recovered by aboveground and belowground organs significantly increased with increasing nitrogen rates suggesting that nitrogen fertilizer significantly affected the recovery of 15N by plants. About 2.06%~3.28%of the applied 15N was recovered in the litter. About 35.86%~44.32%of the labelled nitrogen was re-tained in the soil pool, mostly in the 0~40 cm soil layer. 15N retained by the soil increased significantly with growth in the nitrogen application rate. The loss of 15N was about 19.68%~32.99%of the labeled nitrogen. Risk/benefit analysis showed that, under the climatic and soil condi-tions prevailing during this experiment, fertilizer application rates of 5 gN·m-2 and 15 gN·m-2 were associated with high risk/benefit ratios, whereas the 10 gN·m-2 fertilizer treatment achieved the lowest risk/benefit ratio among the nitrogen rate treatments. These results provide a reference for future grassland ecosystem management strategies.关键词
贝加尔针茅/草原/15N/氮素回收/氮素存留/氮素损失Key words
stipa baicalensis/meadow steppe/15N/nitrogen recovery/nitrogen retention/nitrogen loss分类
农业科学引用本文复制引用
乔江,赵建宁,李玉洁,于雯超,杨殿林..内蒙古贝加尔针茅草原氮素去向的示踪研究[J].农业环境与发展,2013,(4):13-18,6.基金项目
国家自然科学基金（31170435）；“十二五”国家科技支撑计划项目 （）
