江苏省居民食物氮足迹研究

Study of the Food Nitrogen Footprints of Urban and Rural Residents in Jiangsu Province

我国城镇化进程的加快带动了城乡居民食物链中氮素的流动.食物氮足迹提出的目的在于量化食物生命周期中释放出的氮素及其对环境带来的影响.研究了江苏省2000—2015年氮素在农田、禽畜、家庭3个子系统中的流动所产生的食物氮足迹,探讨减少居民氮素排放对环境的影响.研究结果表明,江苏省城镇与农村人均食物氮足迹呈相反的变化趋势,但在2012年大致相等.城镇食物氮足迹从16.08 kgN/(人·年)波动上升至21.52 kgN/(人·年),平均为(19.93±1.45)kgN/(人·年).农村食物氮足迹从23.84 kgN/(人·年)波动下降至20.21 kgN/(人·年),平均为(22.33±1.34)kgN/(人·年).食物氮因子是导致食物氮足迹变化较大的主导因素,通过减少化肥施用量、宣传低氮消费、提高加工效率、提倡"光盘行动"等方法能够有效地减少食物氮足迹.

The acceleration of the urbanization process has led to the circulating of active nitrogen in the food chain of the urban and rural residents. The purpose of the food nitrogen footprint is to quantify the active nitrogen released in the food life cycle and identify the environmental effects imposed by the active nitrogen. Accordingly,this paper discusses how to shrink the environmental impacts made by the active nitrogen emissions in urban areas. To calculate the amount of the active nitrogen circulating in the food chain,the data during year 1990 to 2015 in Jiangsu province are analyzed. The results show that per capita food nitrogen footprint in urban and rural areas is the opposite trend. However,in 2012 they are equal. For urban areas,food nitrogen footprint rises from 16.08 kgN/(person · yr)to 21.52 kgN/(person · yr),with an average of(19.93±1.45)kgN/(person · yr). The food nitrogen footprint in rural areas decreases from 23.84 kgN/(person · yr) in 2000 to 20.21 kgN/(person · yr)in 2015,with an average of(22.33±1.34)kgN/(person · yr). The food nitrogen factor is dominant factor leading to large food nitrogen footprints. However,to shrink the food nitrogen footprint,we apply some methods,just as reducing the amount of fertilizer,promoting the ideals of low nitrogen consumption,improving the processing efficiency,initiating the campaign of“Clear Plate”etc.