不同氮磷肥施用对春玉米农田N_2O排放的影响  

Nitrous Oxide Emissions from Spring-maize Field Under the Application of Different Nitrogen and Phosphorus Fertilizers

作　　者：刘运通[1,2] 李玉娥[1,2] 万运帆[1,2] 高清竹[1,2] 秦晓波[1,2] 陈德立 

机构地区：[1]中国农业科学院农业环境与可持续发展研究所,北京100081 [2]农业部农业环境与气候变化重点开放实验室,北京100081 [3]Department of Resource Management and Geography, Melbourne School of Land and Environment, the University of Melbourne

出　　处：《农业环境科学学报》2011年第7期1468-1475,共8页Journal of Agro-Environment Science

基　　金：国家"973"项目(2010CB833504);国家"十一五"科技支撑计划(2008BAD95B13)

摘　　要：农田过量施肥会增加N2O排放,使农田土壤成为重要的温室气体排放源。为减少农田N2O排放,利用自动观测系统研究了春玉米农田中不同肥料对N2O排放的影响,并结合作物产量及N2O的排放量探索减少温室气体排放的施肥措施。采用田间试验方法设定了不施肥(CK)、尿素(U)、尿素加磷肥(NP)和硝酸磷肥(NOP)4个处理进行研究。结果表明,各处理下N2O排放总量分别为:CK0.21kgN·hm-2、U1.19kgN·hm-2、NP0.93kgN·hm-2、NOP0.69kgN·hm-2;N2O排放主要受施肥、灌溉,降雨和土壤温度的影响;在作物生长后期土壤含氮量小于7mgN·kg-1的情况下,观测到土壤吸收N2O的情况;各处理下排放因子均小于政府间气候变化委员会(IPCC)的缺省值1%,表明IPCC推荐的排放因子不适用于估算中国北方的春玉米农田N2O排放。施加磷肥有助于减少农田N2O排放并提高产量,硝态磷肥较尿素可以显著减少N2O排放。综合考虑产量和N2O排放,相对于施用尿素和尿素加磷肥处理,硝酸磷肥处理不仅可节约15%和30%的肥料投入,而且分别减少42%和26%的N2O排放,具有减排不减产的良好效果。Excessive fertilizer application to cropland results in high N2O emissions, cropland becomes an important source of greenhouse gas （GHG） emission. In order to reduce N2O emissions, this study investigated the effects of fertilizer types on N2O emissions in spring maize field in northern China, which was monitored continuously by automatic measurement system. The responses of grain yield, in addition to N2O emissions, were examined to explore feasible strategies to reduce N2O emission. Four fertilization management practices were selected, viz. （ 1 ）zero fertilizer as control treatment （CK）, （ 2 ）urea treatment （U）, （ 3 ）urea and phosphorus treatment （NP） and （4）nitric phosphate treatment （NOP）. The results indicated that the total N2O fluxes under each treatment were CK ： 0.21 kg N· hm^-2, U： 1.19 kg N· hm^-2, NP： 0.93 kg N·hm^-2, NOP ： 0.69 kg N· hm^-2 respectively. The N2O emissions were mainly influenced by fertilization, irrigation, precipitation and soil temperature. Soil N2O uptake was observed during the later growth stage of spring maize when the soil mineral N was lower than 7 mg N· kg^-1. The N2O emission factor（ EF ） of every fertilizer treatment was lower than 1% which was suggested by the Intergovernmental Panel on Climate Change （IPCC）. This meaned the default EF of IPCC should not be used for estimation of the regional N2O fluxes in spring maize field in northern China. Phosphorus fertilizer not only could reduce the N2O emissions but also increase maize grain yield, whereas nitric phosphate was significantly more effective than urea in reducing the N2O emissions. Evaluation based on crop yield and N2O emissions showed that NOP treatment was a better management practice in the sense that, when compared to U and NP treatments, it reduced not only N2O emission by 42% and 26% separately, but also farmers＇ expenditure on fertilizers by 15% and 30%, while maintaining crop yield.

关 键 词：春玉米 氮磷肥 N2O排放 

分 类 号：X511[环境科学与工程—环境工程]