School of Environment, State Key Joint Laboratory of Water Environment Simulation and Pollution Control, Beijing Normal University, Beijing, 100875, China.
Beijing Engineering Research Center for Watershed Environmental Restoration & Integrated Ecological Regulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
Environ Sci Pollut Res Int. 2018 Mar;25(9):9071-9084. doi: 10.1007/s11356-017-1092-x. Epub 2018 Jan 15.
The Miyun Reservoir plays a pivotal role in providing drinking water for the city of Beijing. In this research, ecological network analysis and scenario analysis were integrated to explore soil nitrogen cycling of chestnut and Chinese pine forests in the upper basin of the Miyun Reservoir, as well as to seek favorable fertilization modes to reduce agricultural non-point source pollution. Ecological network analysis results showed that (1) the turnover time was 0.04 to 0.37 year in the NH compartment and were 15.78 to 138.36 years in the organic N compartment; (2) the Finn cycling index and the ratio of indirect to direct flow were 0.73 and 11.92 for the chestnut forest model, respectively. Those of the Chinese pine forest model were 0.88 and 29.23, respectively; and (3) in the chestnut forest model, NO accounted for 96% of the total soil nitrogen loss, followed by plant N (2%), NH (1%), and organic N (1%). In the Chinese pine forest, NH accounted for 56% of the total soil nitrogen loss, followed by organic N (34%) and NO (10%). Fertilization mode was identified as the main factor affecting soil N export. To minimize NH and NO outputs while maintaining the current plant yield (i.e., 7.85e0 kg N/year), a fertilization mode of 162.50 kg N/year offered by manure should be adopted. Whereas, to achieve a maximum plant yield (i.e., 3.35e1 kg N/year) while reducing NH and NO outputs, a fertilization mode of 325.00 kg N/year offered by manure should be utilized. This research is of wide suitability to support agricultural non-point source pollution management at the watershed scale.
密云水库在为北京市提供饮用水方面发挥着关键作用。本研究综合运用生态网络分析和情景分析方法，探讨了密云水库上游板栗和油松人工林的土壤氮循环过程，并寻求了有利于减少农业面源污染的施肥模式。生态网络分析结果表明：（1）NH4+-N 库的周转率为 0.040.37 年，有机氮库的周转率为 15.78138.36 年；（2）板栗林模型的芬恩周转率和间接流与直接流的比值分别为 0.73 和 11.92，油松林模型的芬恩周转率和间接流与直接流的比值分别为 0.88 和 29.23；（3）板栗林模型中，NO3--N 占土壤氮素总流失量的 96%，其次是植物氮（2%）、NH4+-N（1%）和有机氮（1%）。在油松林模型中，NH4+-N 占土壤氮素总流失量的 56%，其次是有机氮（34%）和 NO3--N（10%）。施肥模式被确定为影响土壤氮素输出的主要因素。为了在保持当前植物产量（即 7.85e0 kg N/年）的同时，将 NH 和 NO 的输出最小化，应采用粪肥提供的 162.50 kg N/年的施肥模式。而要在减少 NH 和 NO 输出的同时达到最大的植物产量（即 3.35e1 kg N/年），则应采用粪肥提供的 325.00 kg N/年的施肥模式。本研究广泛适用于流域尺度的农业面源污染管理。
