不同施肥条件对稻田温室气体排放特征的影响

采用静态箱-气相色谱监测体系研究了上海郊区3种不同施肥条件下稻田系统温室气体(GHGs)排放特征及其全球增温潜能(GWP)。研究结果表明:施肥能显著增加稻田系统CO2的排放通量,但不同施肥条件对其影响差异不显著;施用有机肥能显著增加稻田系统CH4的排放通量,同时也能显著降低稻田N2O排放通量。整个水稻生育期,不施肥CK处理的GWP最低,为14 852 kg CO2·hm-2。相较于CK处理,施用尿素的CT处理、有机无机混施的MT处理和施用有机肥的OT处理分别增加了86.9%、111.5%和134.3%的稻田GWP,表明施肥会增加稻田土壤GHGs的GWP。

Impact of Different Fertilization Practices on Greenhouse Gas Emission from Paddy Field

Greenhouse gas(GHG) emissions from agricultural production systems contribute largely to global warming. A field experiment was conducted to examine GHG emissions under three different fertilization practices(CT-urea alone, MT-80% urea plus 20% manure and OT-manure alone) in Shanghai suburb, China. Carbon dioxide, methane and nitrous oxide were collected and measured by static chamber-gas chromatography system. Compared to the control(CK), fertilization significantly increased carbon dioxide emission from paddy field, but no differences were found between fertilization treatments. Organic manure significantly increased methane emission, but greatly decreased nitrous oxide emission from paddy field. During the whole rice season, CK had the lowest seasonal Global Warming Potential(GWP) with 14 852 kg CO₂·hm^-2. Urea alone and organic manure alone and their combinations increased seasonal GWP by 86.9%, 134.3% and 111.5%, respectively, as compared with CK. The observed data demonstrate that fertilization could increase GHG emission and GWP from paddy field.