RESUMO
In this paper, using panel data of 28 cities in the middle reaches of the Yangtze River from 2003 to 2020 as the research sample, we built a dynamic spatial Durbin model based on the STIRPAT (stochastic impacts by regression on population, affluence, and technology) model and conducted an empirical study on the impact of the coordinated agglomeration of manufacturing and producer services on particulate matter (PM) 2.5 pollution. The results show a significant positive spatial spillover effect of PM2.5 pollution in the middle reaches of the Yangtze River. The coordinated agglomeration of manufacturing and producer services in the urban agglomerations there is conducive to reducing PM2.5 pollution. Similar to the inverted-U curve of the classic environmental Kuznets curve hypothesis, there is a significant inverted-U curve relationship between PM2.5 pollution and economic growth in urban agglomerations in the middle reaches of the Yangtze River. The proportion of coal consumption, the proportion of secondary industry, and the urbanization level are significantly and positively correlated with PM2.5 pollution in urban agglomerations in this area. Technological innovation, environmental regulation, and annual average humidity play an important role in addressing the PM2.5 pollution and spatial spillover effect. Industrial structure and technological innovation are the main ways for the coordinated agglomeration of manufacturing and producer services to affect PM2.5. The research conclusion can be of great practical significance to optimize the regional industrial layout, control PM2.5 pollution, and establish a sustainable development policy system in the middle reaches of the Yangtze River in China.
Assuntos
Poluição do Ar , Material Particulado , Material Particulado/análise , Poluição do Ar/análise , Rios , Poluição Ambiental , China , Cidades , Desenvolvimento EconômicoRESUMO
A 9-year field experiment was conducted on the Guanzhong Plain of Shaanxi Province to study the effects of subsoiling, rotary tillage, straw return, no-till seeding, and traditional tillage on the soil physical and chemical properties and the grain yield in a winter wheat-summer maize rotation system, and a comprehensive evaluation was made on the soil quality under these tillage patterns by the method of principal components analysis (PCA). Comparing with traditional tillage, all the conservation tillage patterns improved soil fertility quality and soil physical properties. Under conservative tillage, the activities of soil urease and alkaline phosphatase increased significantly, soil quality index increased by 19.8%-44.0%, and the grain yield of winter wheat and summer maize (expect that under no till seeding with straw covering) increased by 13%-28% and 3%-12%, respectively. Subsoiling every other year, straw-chopping combined with rotary tillage, and straw-mulching combined with subsoiling not only increased crop yield, but also improved soil quality. Based on the economic and ecological benefits, the practices of subsoiling and straw return should be promoted.