Driving forces of nitrogen input into city-level food systems: Comparing a food-source with a food-sink prefecture-level city in China
Driving forces of nitrogen input into city-level food systems: Comparing a food-source with a food-sink prefecture-level city in China
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DOI：
10.1016/j.resconrec.2020.104850
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发表时间：
2020-09
影响因子：
13.2
通讯作者：
Wei Huang;Bing Gao;Jianyi Lin;Shenghui Cui;Qiumeng Zhong;Chu-Long Huang
中科院分区：
文献类型：
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作者：
Wei Huang;Bing Gao;Jianyi Lin;Shenghui Cui;Qiumeng Zhong;Chu-Long Huang
氮投入是反映城市粮食系统养分资源利用和污染潜力的重要指标，在全球养分循环及其管理研究中越来越受到重视。然而，对驱动因素及其对城市粮食系统氮输入的定量影响的了解有限。本研究采用对数平均分割指数（LMDI）方法，建立了中国两个不同城市粮食系统的分解模型。确定了人口、消费水平、供需比和粮食生产氮成本四个驱动因素，并对它们各自对两个城市粮食系统的影响进行了评价和比较。对于食物源城市（长春市），供需比是氮投入增长的最主要贡献者，人口对氮投入增长的正向影响较弱；而对于食物槽型城市（厦门），人口是一个较强的正向因素，但其拉升效应被供需比所抵消，最终导致氮投入下降。氮肥成本在很大程度上受农业生产结构的影响。在2003年之前，消费水平呈现出不断增强的正向效应，但在2003年之后，这种效应逐渐减弱。根据驱动因素，从“生产-贸易-消费”三个层面提出氮素投入的管理策略。该分解模型也适用于其他城市情况，有助于为城市一级粮食系统的可持续营养利用提供量身定制的见解。
Nitrogen input is an important index for indicating nutrient resource use and pollution potential of city-level food systems, which have received increasing attention in studies of global nutrient cycles and their management. However, limited understanding has been developed, of driving forces and their quantitative impacts on nitrogen input into city-level food systems. This study adopts the Logarithmic Mean Divisia Index (LMDI) method and develops a decomposition model for two distinct city-level food systems in China. Four driving factors—population, level of consumption, supply-demand ratio, and nitrogen cost of food production—are determined, and their respective impacts for the two city-level food systems are evaluated and compared. For the food-source city (Changchun), the supply-demand ratio is the most important contributor to the growth of nitrogen inputs, and population exerts a weak positive effect; whereas for the food-sink city (Xiamen), population is a strong positive factor, but its pulling-up effect is offset by the supply-demand ratio, ultimately contributing to the decline of nitrogen inputs. The nitrogen cost is largely affected by the structure of agricultural production. The level of consumption presented an increasing positive effect before 2003, but that effect gradually diminishes afterward, for both cases. In accordance with the driving factors, management strategies for nitrogen input are suggested from a three-pronged “production-trade-consumption” perspective. The decomposition model also applies to other city contexts and contributes to providing tailored insights into sustainable nutrient use in city-level food systems.