广东省农业氮足迹分析

Analysis of the nitrogen footprint of agriculture in Guangdong

为对农业生产氮素利用和排放情况简单直观而又全面地评估,基于修正的N-Calculator模型的基础上,结合农业生产系统中的氮素流动过程,计算了广东省农业氮足迹.研究发现,该省农业氮足迹的主要来源是化肥施用和养殖业饲料,2010年,两者合计占约81%以上.近20年来,农业氮足迹总量上升了45%,按用地平均更增长了88%,增速最快的是来自非农业部门的大气沉降氮,年增速8.5%,农业能源氮足迹是另一增长较快的项目,增幅为107%.污染氮足迹已占到总足迹的31%,主要是因为土壤的氮素流失.另外,2010年,与农业活动相关的其他部门的农业隐含氮足迹为207209.79t,约为农业氮足迹的17%.

To simply, intuitively, and fully assess the nitrogen （N） footprint of agriculture in Guangdong Province, China, A modified N-calculator model was applied and an analysis of agricultural N flow processes was combined to calculate the use and emissions of N in agriculture. The main contributors to the N footprint were fertilizer and feed, together accounting for 81%of the N footprint in 2010. The size of the N footprint increased by 45%from 1990 to 2010, and by 88%during the same period if measured on an average land basis. The fastest growing contributor to the N footprint was atmospheric N deposition, which increased at an annual rate of 8.5%. Agricultural energy was another large contributor to the N footprint with a 107%increase from 1990 to 2010. Pollution accounted for more than 31%of the total N footprint, mainly because of the loss of soil N. Finally, the N footprint of other agriculture-related industries accounted for approximately 17%of the total agricultural N footprint （207209.79t）.