长期不同施肥下太湖地区稻田净温室效应和温室气体排放强度的变化

Greenhouse Gas Emission and C Intensity for a Long-term Fertilization Rice Paddy in Tai Lake Region, China

利用田间观测和模型预测方法对太湖地区一个长期不同施肥处理的稻田生态系统进行了稻季温室气体排放观测和净温室气体排放强度分析。结果表明,不同施肥管理下,稻田土壤有机碳含量不同程度提高,有机无机肥料配施较单施化肥处理显著提高有机碳库储量,并且秸秆处理略高于猪粪处理。与不施肥处理相比,长期施用肥料显著提高了稻田生态系统CH4和CO2的排放量,有机肥料与化肥配施较单纯施用化学肥料下土壤碳(CO2和CH4)排放增加,但化肥配施秸秆与化肥配施猪粪下稻田生态系统CH4和CO2的排放没有显著差异。不同施肥处理下,稻田生态系统净温室效应表现为CFM≈CFS>CF>NF,但水稻生产的净温室气体排放强度并没有显著性差异。因此,在提高水稻产量的同时,有机无机配合施肥并没有提高净温室气体的排放强度。

Impact of agricultural management on global warming potential（GWP） and greenhouse gas intensity（GHGI） was studied by combining field measurement data and model prediction methods. The experiment was conducted in a long-term fertilization station initiated 1987, located in Tai lake region. The fertilization treatments included no fertilizer application（NF）, application of chemical nitrogen fertilizers only（CF）, combined application of chemical fertilizers and pig manure （CFM）, and straw return（CFS）. We found that long-term fertilization significantly enhanced soil carbon stock. Application of fertilizers intensively promoted CH4 and CO2 emissions compared with the control treatment. Relative to inorganic-only fertilization, combined fertilization significantly enhanced the carbon transfer from soils to the atmosphere, but no difference was detected between CFM and CFS. Compared with chemical nitrogen fertilizer only plots, combined organic and inorganic fertilizer remarkably increased the net annual GWP. However, there were no differences of GHGIs among three fertilization treatments.