CAJ | 학술논문

采用15N同位素示踪技术，开展了贝加尔针茅草原氮素去向的研究。结果表明：贝加尔针茅草原植物对标记氮素的回收率为28.36%~37.03%，施氮肥显著影响植物对15N的回收，随着施氮量的增加，植物地上和地下器官对15N的回收量均显著提高。凋落物的15N回收率为2.06%~3.28%。标记氮素的土壤存留率为35.86%~44.32%，大致分布在地表0~40 cm的土层范围内；各土层存留的15N量均随着施氮量的增加而显著升高。标记氮素的当季损失率为19.68%~32.99%。风险/收益比分析表明，在该试验条件下，添加10 gN·m-2的处理风险最低、收益最高，可为草原生态系统的氮素管理提供参考。
채용15N동위소시종기술，개전료패가이침모초원담소거향적연구。결과표명：패가이침모초원식물대표기담소적회수솔위28.36%~37.03%，시담비현저영향식물대15N적회수，수착시담량적증가，식물지상화지하기관대15N적회수량균현저제고。조락물적15N회수솔위2.06%~3.28%。표기담소적토양존류솔위35.86%~44.32%，대치분포재지표0~40 cm적토층범위내；각토층존류적15N량균수착시담량적증가이현저승고。표기담소적당계손실솔위19.68%~32.99%。풍험/수익비분석표명，재해시험조건하，첨가10 gN·m-2적처리풍험최저、수익최고，가위초원생태계통적담소관리제공삼고。
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.