By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the mode...By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the model with the observed data indicated that the model can simulate both the crop growth processes and emissions of CH4 and N2O accurately. Some nu-merical analyses were made to identify the impacts of different fertilizer application on assimilation of CO2 and emissions of CH4 and N2O, and the transformation principle of the composite global warming potential. Based on the results of the numerical analysis, the source-sink alternation of composite global warming potential in the paddy ecosystem was discovered, and some new con-ceptions of fertilizer index such as maximum-sink fertilizer, zero-emission fertilizer are put forward in this paper. The fertilizer scheme for Yangtze Delta was proposed to provide the important scien-tific basis for a sustainable agriculture in this region.展开更多
【目的】研究稻田生态系统中土壤钙、镁元素生物地球化学循环对长期大气CO2浓度升高的响应。【方法】利用中国稻田FACE(free air carbon-dioxide enrichment)试验平台,包括Ambient(对照,自由大气CO2浓度约为370μmol·mol-1)和FACE...【目的】研究稻田生态系统中土壤钙、镁元素生物地球化学循环对长期大气CO2浓度升高的响应。【方法】利用中国稻田FACE(free air carbon-dioxide enrichment)试验平台,包括Ambient(对照,自由大气CO2浓度约为370μmol·mol-1)和FACE(比对照大气CO2浓度高200μmol·mol-1)2个试验处理,在2004、2005和2007年稻季不同生育期原位采集5cm和15cm处土壤溶液并测定其中Ca、Mg浓度。【结果】在2004、2005和2007年,FACE处理5cm处土壤溶液Ca浓度分别是对照处理的125%、106%和72%,Mg浓度分别是对照处理的115%、104%和75%;FACE处理15cm处与5cm处土壤溶液Ca浓度的比值在2004、2005和2007年分别是对照处理的71%、114%和180%,Mg的比值分别是对照的74%、104%和159%;2007年FACE处理0-15cm耕层土壤溶液Ca、Mg浓度分别比对照处理低6.8%和4.6%。【结论】连续大气CO2浓度升高可改变土壤溶液中Ca、Mg元素在不同深度耕层的分布,提高15cm处与5cm处土壤溶液Ca、Mg浓度的比值,且这种影响存在一定的累积效应。稻田生态系统Ca、Mg循环对长期大气CO2浓度升高的响应值得深入研究。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.49899270).
文摘By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the model with the observed data indicated that the model can simulate both the crop growth processes and emissions of CH4 and N2O accurately. Some nu-merical analyses were made to identify the impacts of different fertilizer application on assimilation of CO2 and emissions of CH4 and N2O, and the transformation principle of the composite global warming potential. Based on the results of the numerical analysis, the source-sink alternation of composite global warming potential in the paddy ecosystem was discovered, and some new con-ceptions of fertilizer index such as maximum-sink fertilizer, zero-emission fertilizer are put forward in this paper. The fertilizer scheme for Yangtze Delta was proposed to provide the important scien-tific basis for a sustainable agriculture in this region.
文摘【目的】研究稻田生态系统中土壤钙、镁元素生物地球化学循环对长期大气CO2浓度升高的响应。【方法】利用中国稻田FACE(free air carbon-dioxide enrichment)试验平台,包括Ambient(对照,自由大气CO2浓度约为370μmol·mol-1)和FACE(比对照大气CO2浓度高200μmol·mol-1)2个试验处理,在2004、2005和2007年稻季不同生育期原位采集5cm和15cm处土壤溶液并测定其中Ca、Mg浓度。【结果】在2004、2005和2007年,FACE处理5cm处土壤溶液Ca浓度分别是对照处理的125%、106%和72%,Mg浓度分别是对照处理的115%、104%和75%;FACE处理15cm处与5cm处土壤溶液Ca浓度的比值在2004、2005和2007年分别是对照处理的71%、114%和180%,Mg的比值分别是对照的74%、104%和159%;2007年FACE处理0-15cm耕层土壤溶液Ca、Mg浓度分别比对照处理低6.8%和4.6%。【结论】连续大气CO2浓度升高可改变土壤溶液中Ca、Mg元素在不同深度耕层的分布,提高15cm处与5cm处土壤溶液Ca、Mg浓度的比值,且这种影响存在一定的累积效应。稻田生态系统Ca、Mg循环对长期大气CO2浓度升高的响应值得深入研究。
