Assessing the Foodshed and Food Self-Sufficiency of the Pearl River Delta Megacity Region in China

Food self-sufficiency has long been regarded as essential for understanding and managing urban and regional food systems; however, few studies have examined the food self-sufficiency of megacity regions within a comprehensive framework that distinguishes different types of agricultural land (i.e., arable land, horticultural landscapes, and waters). To fill these gaps, we took the Pearl River Delta as a case study and quantified the foodsheds of different types of agricultural land by calculating the land footprint of food consumption. On this basis, food self-sufficiency is defined as the ratio of available and required agricultural area for regional food demand. The results indicated that the self-sufficiency level provided by the arable land in the Pearl River Delta is low and cannot realize self-sufficiency at the regional and urban levels. The horticultural landscapes can provide self-sufficiency at the regional level, whereas the regions with water cannot, as their foodsheds extend over the boundary of the Pearl River Delta. For arable land, establishing a localized regional food system requires expanding the foodshed size. These findings provide evidence that megacity regions may face increasing difficulties in achieving self-sufficiency in the near future. This research can improve policymakers' understanding of the sustainability and resilience of regional food systems in megacity regions.

Food processing industry changes across China regions: The case of flour, rice, oil, and other cereal derivative food

Faced with the pressure of slowing industrial growth and industrial transformation requirements, it is crucial to analyze the changes and the corresponding driving factors of the food processing industry in China. An analysis using traditional and spatial shift-share models was conducted to decompose the changes in the food processing industry in each region of China from 2009 to 2019 into five effects: national growth effect (NG), industrial mix effect (IM), competitive effect (CE), neighbor-nation competitive effect (NNC), and region-neighbor competitive effect (RNC). Among the five effects from 2009 to 2019, the NG contributed the most to the growth in most regions, indicating that the development of the food processing industry in China was greatly influenced by the industrial base and that China's food processing industry has entered a "growth bottleneck period." During the period 2009-2014 to period 2014-2019, compared to the IM and CE, the influence of spatial spillover effects was stronger and significantly enhanced. Moreover, the IM, CE, NNC, and RNC in most southern regions were stronger than those in most northern regions. Therefore, China's food processing industry needs and is transforming into high-quality development. It is necessary to innovate the mode of development of food processing industry and strengthen interregional exchanges and cooperation.

Satisfying meat demand while avoiding excess manure: Studying the trade-off in eastern regions of China with a nitrogen approach

Due to the rising incomes and rapid urbanization, China is facing a challenge in producing more meat while avoiding excess manure. These objectives might be in contrast: if excess manure is avoided, meat self-sufficiency might not be met; in contrast, meeting meat self-sufficiency might cause severe excess manure. Our study (1) characterizes the eastern regions of China according to the deficiency/excess of manure nitrogen and meat production, and investigates their relationships with natural resources and social economic indicators; (2) analyzes how the trade-off changes with increasing proportion of chemical nitrogen substituted with manure nitrogen (PCSM). Elaborating on data, we divided eastern regions of China into types according to satisfaction/unsatisfaction of meat demand and deficiency/excess of manure. We then re-calculated the number of regions in each type simulating the effect of increasing values of PCSM. In ~15% of the regions, meat self-sufficiency was met without manure excess, but in ~76% of the regions, manure excess occurred where meat self-sufficiency was met. In ~2% of the regions, meat self-sufficiency was not met and manure excess was absent; in ~7% of the regions, meat self-sufficiency was not met and excess manure was observed. The higher the regions' GDP (gross domestic product) per capita, the lower their ability to satisfy meat demand; the more arable land per capita in the regions, the higher their ability to satisfy meat demand and avoid excess manure. For the scenarios of increasing PCSM, our results show that some regions still cannot avoid excess manure with unchanged livestock quantity, although manure fertilizer completely replaced chemical fertilizer. Our study suggests that the regions of eastern China need to advocate a healthy diet and strengthen the management of food waste and livestock manures. The study is significant for policymakers to achieve sustainable agricultural production.