Plastic pollution in croplands threatens long-term food security.

Plastic pollution is a global concern given its prevalence in aquatic and terrestrial ecosystems. Studies have been conducted on the distribution and impact of plastic pollution in marine ecosystems, but little is known on terrestrial ecosystems. Plastic mulch has been widely used to increase crop yields worldwide, yet the impact of plastic residues in cropland soils to soil health and crop production in the long term remained unclear. In this paper, using a global meta-analysis, we found that the use of plastic mulch can indeed increase crop yields on average by 25%-42% in the immediate season due to the increase of soil temperature (+8%) and moisture (+17%). However, the unabated accumulation of film residues in the field negatively impacts its physicochemical properties linked to healthy soil and threatens food production in the long term. It has multiple negative impacts on plant growth including crop yield (at the mean rate of -3% for every additional 100 kg/ha of film residue), plant height (-2%) and root weight (-5%), and soil properties including soil water evaporation capacity (-2%), soil water infiltration rate (-8%), soil organic matter (-0.8%) and soil available phosphorus (-5%) based on meta-regression. Using a nationwide field survey of China, the largest user of plastic mulch worldwide, we found that plastic residue accumulation in cropland soils has reached 550,800 tonnes, with an estimated 6%-10% reduction in cotton yield in some polluted sites based on current level of plastic residue content. Immediate actions should be taken to ensure the recovery of plastic film mulch and limit further increase in film residue loading to maintain the sustainability of these croplands.

Influence of Publicity and Education and Environmental Values on the Green Consumption Behavior of Urban Residents in Tibet.

Faced with ecological environmental issues and a surge in the consumption of products in the Qinghai-Tibetan Plateau, it is necessary to explore the effective driving mechanism of green consumption behavior. This study investigated the impact of publicity and education on green consumption behavior and explored the mediating effects of environmental values and the moderating effects of price sensitivity. A cross-sectional survey was conducted with a sample of 500 questionnaires, which were randomly distributed by stratified random sampling to municipal government departments, public institutions, communities, streets, shops, and supermarket entrances in Lhasa, Shan Nan, and Xigaze in Tibet. Further, structural equation modeling was applied to derive data for statistical analyses. Publicity, education, and environmental values had a significant influence on green consumption behavior. Environmental values play a mediating role in the influence of publicity and education on green consumption behavior. Price sensitivity negatively moderates the relationship between publicity and education and environmental values; when considering the price of green consumption, the positive impact on environmental values is weakened by publicity and education. Furthermore, it moderates the mediating effect of environmental values. Publicity and education remain the primary intervention for promoting green consumption. Especially in areas with ethnic minorities, publicity and education in combination with the characteristics of ethnic areas should be used to promote the traditional Tibetan culture of respect for all life and to live in harmony with nature. Moreover, policies, regulations, and tax subsidies related to green consumption should be improved while reducing the negative impact of prices and other economic factors on the propensity to consume. These findings provide empirical evidence for the complex relationship between government intervention measures and urban residents' green consumption behavior.