氮肥对西双版纳地区稻田N2O排放通量的影响  

Impact of Nitrogen Fertilizer on N_2O Flux from a Paddy Soil in Xishuangbanna, Southwest China

作　　者：武文明[1] 杨光明[1] 沙丽清[1] 

机构地区：[1]中国科学院西双版纳热带植物园

出　　处：《农业环境科学学报》2008年第5期1876-1881,共6页Journal of Agro-Environment Science

基　　金：云南省自然科学基金(2004C0052M);中国科学院知识创新工程重大项目(KZCX1-SW-01)

摘　　要：采用静态暗箱-气相色谱法对云南西双版纳地区单季稻田N2O排放及氮肥、水热因子等对N2O排放的影响进行田间原位观测研究。试验设3个氮肥水平处理:NO(0kgN·hm-2)、N150(150kgN·hm-2)和N300(300kgN·hm-2)。结果表明,氮肥的施入显著促进了稻田N2O的排放,其平均排放通量分别为74.63μg·m-2·h-(1NO)、156.10μg·m-2·h-(1N150)和131.79μg·m-2·h-(1N300)。N150和N300处理N2O排放损失的氮量分别占施入肥料N的1.28%和0.45%。N300处理N2O排放通量同5cm土壤温度和地表温度存在显著相关关系(P<0.05),但N2O排放通量与稻田水深无显著的相关关系(P>0.05)。在长时间尺度内N2O的GWP将逐步超过CH4;而且随着施用氮肥量的提高,N2O的GWP逐步增加;未来氮肥的施用量会逐步提高,N2O对环境的影响会加剧,其对环境的影响不容忽视。The district Xishuangbanna is the most northerly situated tropical area in the world, with pronounced dry and wet seasons over the year. The soil, especially tropical agricultural soil is considered an important source of N2O emissions. More than a third of the N2O emissions are anthropogenic and generated from agricultural activities, and 80% of the emissions are related to application of nitrogen fertilizer. With the static opaque chamber and gas chromatography technique, N2O emission from a paddy soil and its main affecting factors were investigated in Xishuangbanna, SW China. In this study, three levels of nitrogen fertilizer application were designed as control （NO, 0 kg N·hm^-2）, N150 （150 kg N·hm^-2）and N300（300 kg N·hm^-2）. The results showed that application of nitrogen fertilizer can enhance N2O emissions in the early stage of rice plants. The N2O fluxes throughout the rice growth season differed among treatments at the 5% level, with the mean N2O fluxes of 74.63 μg·m^-2·h^-1,156.10 μg·m^-2·h^-1 and 131.79 μg·m^-2·h^-1, respectively, for NO, N150 and N300 treatments. There was a 1.28% and 0.45% of the added N as N2O-N lost to the atmosphere, respectively, for the N150 and N300 treatments. Throughout the growth season of rice plants, there was a positive linear relationship between soil temperature at 5 cm depth or soil surface temperature and the N2O flux from the N300 treatment. No significant relationship was observed between the N2O flux and water depth in the field. Based on the 20-, 100-, and 500-year horizons, the greenhouse effect of the N2O from addition of nitrogen fertilizer was higher than that of the control （P〈0.05）. In the long time scale, the global warming potentials of N2O emissions from paddy soils will exceed the contribution of CH4 emissions from the same sources, and it will be continuously increased with increasing amount of nitrogen fertilizers, which cannot be ignored in the future.

关 键 词：稻田 氮肥 N2O 全球增温潜势 

分 类 号：X511[环境科学与工程—环境工程]