An inverted U-shaped curve relating farmland vulnerability to biological disasters: Implications for sustainable intensification in China

The relationship between high-quality development and ecosystem health in China's urban agglomerations

China's rapid urbanization and economic development have significantly improved living standards and industrial capabilities. However, these advancements have also exerted pressure on the environment and ecosystem health (EH). Urban agglomerations (UAs)-clusters of interconnected cities-play a crucial role in driving high-quality development (HQD) and serve as hubs for economic growth, innovation, and social progress. Understanding the relationship between HQD and EH is essential for ensuring ecological security and promoting regional sustainable development. This study examines 17 UAs in China, each at different stages of development, and analyzes their HQD and EH levels from 2000 to 2021. The HQD index shows a steady upward trend over this period, increasing from 0.086 in 2000 to 0.236 in 2021, a cumulative rise of 174.42%. In contrast, EH levels remained relatively stable throughout this period, with moderate variations across different regions. On average, local-level UAs exhibited higher EH levels than national-level UAs, with regional-level UAs falling in between. A U-shaped relationship between HQD and EH was observed in most UAs. The coupling coordination degree between HQD and EH has gradually improved, with many areas achieving high or intermediate levels of coordination. Over time, the number of regions with serious or slight maladjustment in the coupling coordination has decreased. High-level coordination hotspots were primarily located in eastern and northern UAs, while cold spots were mainly found in the coastal areas of southeastern China. These findings provide valuable insights for policymakers to better balance economic development and environmental protection.

How do storm surge disaster losses affect economic development?: Perspectives from disaster prevention and mitigation capacity

Storm surge disasters have caused devastating losses to coastal areas, making disaster prevention and mitigation capacity (DPMC) critical in promoting high-quality and sustainable economic development. In this paper, the systematic construction of a comprehensive index of storm surge disaster losses (SSDLs) and DPMC in China is described respectively. Then, panel fixed effect and threshold models are established to explore the relationship between SSDLs and economic growth, in particular, the moderating effect of DPMC. Our results reveal that, from 2006 to 2019, SSDLs exhibit an inverted N-shaped trend, with losses gradually decreasing from south to north. DPMC has been increasing but has visible spatial differences. Notably, SSDLs have a significant negative impact on economic development in China's coastal areas, however, DPMC can play an effective role in mitigating and regulating these negative shocks. With the continuous improvement of China's disaster prevention and mitigation system, SSDLs can be largely offset. Heterogeneity analysis shows that DPMC is most effective in the sample with a high SSDL, low DPMC, and in the southern marine economic circle in China. Further, the robustness tests are ensured by replacing measurement method, replacing GDP per capita with night-time lighting data, and replacing econometric models. Importantly, our study highlights the crucial non-linear role of DPMC in reducing the losses caused by storm surge disasters and promoting sustainable economic development. These findings provide valuable insights for policymakers to improve capacity building and subjectivity, regional cooperation and ensure the economic resilience of coastal areas in the face of storm surge disasters.

The carbon emission reduction benefits of the transformation of the intensive use of cultivated land in China

The transformation of the intensive use of cultivated land has an important impact on agricultural carbon emissions (ACE). However, the existing research on the impact mechanisms of the transformation of intensive use of cultivated land on carbon emissions is not clear. In view of this, this study constructs the impact mechanism of the transformation of intensive use of cultivated land on carbon emissions from the perspective of production factors substitution based on the theory of induced technological change and the theory of marginal returns. Using the Cobb-Douglas production function, this study identifies the transformation patterns of intensive use of cultivated land in China from 1980 to 2021. Furthermore, this study simulates the carbon emission reduction benefits brought about by the transformation of the intensive use of cultivated land by considering the cost of agricultural production. The results show that, first, from 1980 to 2021, the price of agricultural labor increased by 224.10%, while the price of other agricultural production factors significantly decreased. China's intensive use of cultivated land methods has undergone four stages: agricultural labor-intensive (ALI), yield-enhancing factor-intensive (YEFI), labor-saving factor-intensive (LSFI), and innovation factor-intensive (IFI). In 2021, most of China's provinces were in the YEFI or ALI stages. Second, between 1993 and 2021, the transformation of China's intensive use of cultivated land brought about an 87.48% increase in carbon emissions, while the spatial clustering effect of carbon emissions weakened. Furthermore, the results show that, the transition of the use of cultivated land from ALI to YEFI and YEFI to LSFI will reduce carbon emissions by 7.89%, and input factors costs will increase by 23.85%. If all regions, except for those in the IFI stage, transition to the LSFI model, it will result in a 17.56% reduction in carbon emissions, with a corresponding increase of 33.40% of the input factors input costs. This research enriches the theoretical foundation of literature about the transformation of the intensive use of cultivated land. It also expands the research perspective on agricultural carbon emissions. This research also helps provide references for the direction of the transformation of the intensive use of cultivated land in China and the achievement of the dual carbon goals.

Effects of seaweed fertilizer application on crops' yield and quality in field conditions in China-A meta-analysis

Seaweed fertilizer, formulated primarily with seaweed extract as its main ingredient, has been extensively studied and found to significantly improve nutrient use efficiency, increase crop yield and quality, and enhance soil properties under field conditions. This growing body of evidence shows that seaweed fertilizer is a suitable option for sustainable agriculture in China. However, a comprehensive and quantitative analysis of the overall effects of seaweed fertilizer application in China is lacking. To address this gap, we conducted a meta-analysis of relevant studies on the effects of seaweed fertilizers under field conditions in China with MetaWin and SPSS software. Our analysis examined the effects of seaweed fertilizers on crop yield, quality, and growth under different preparation methods, application techniques, and regions. Our results showed that the application of seaweed fertilizer led to a significant average increase in crop yield of 15.17% compared with the control treatments. Root & tuber crops exhibited the most pronounced response, with a yield boost of 21.19%. Moreover, seaweed fertilizer application significantly improved crop quality, with elevations in the sugar-acid ratio (38.32%) vitamin C (18.07%), starch (19.65%), and protein (11.45%). In addition, plant growth parameters such as height, stem thickness, root weight, and leaf area showed significant enhancement with seaweed fertilizer use. The yield-increasing effect of seaweed fertilizers varied depending on their preparation and use method, climate, and soil of application location. Our study provides fundamental reference data for the efficient and scientific application of seaweed fertilizers in agricultural practices.

Regional intensity of biological disasters in farmland: quantitative assessment and spatiotemporal analysis

Biological disasters in farmland have become a serious threat to global sustainability. Quantitative studies on spatiotemporal change in regional intensity of biological disasters in farmland (RIBDF) are crucial for promoting sustainable intensification of farmland use and global food security. Many studies have revealed the impacts of natural environment on biological disasters in farmland. However, research on the impacts of farmers' activities on biological disasters remains very limited from the perspective of induced substitution in agricultural production. Based on the principle of induced substitution in agricultural production, a theoretical framework for the impacts of farmland use intensity (FUI), the occurrence intensity of biological disasters (OIBD), the natural loss intensity resulting from biological disasters (NLIBD), and the actual loss intensity controlled by human activities (ALIBD) on change in RIBDF was presented, and we therefore established an assessment model integrating these four key indices in this study. Taking Guangdong Province in China as the study area, this study analyzed the spatiotemporal changes in RIBDF from 1996 to 2017 and found that RIBDF increased overall with three change stages of slow growth, rapid growth, and decline at the provincial and regional levels. Moreover, the gravity center of RIBDF appeared to shift towards the coastal region in southwestern Guangdong at a speed of 18.20 km per year. The results reveal that the spatiotemporal change in RIBDF is determined by the key influencing factors including the substitution of chemical fertilizers for farmland and crop substitution. These findings suggest that it is necessary to expand the scale of farmland management and to encourage farmers to implement diversified cropping as well as chemical fertilizers reduction. The foremost contribution of this study is its exploration of an understanding of the linkage between farmland use activities characterized as induced substitution in agricultural production and biological disasters. Moreover, policy implications for sustainable intensification of farmland use were discussed based on these findings.

A New Framework of Green Transition of Cultivated Land-Use for the Coordination among the Water-Land-Food-Carbon Nexus in China

As a fundamental solution to the ecological problems of resources and environment, the Green Transition of Cultivated Land-use (GTCL) has become an inherent requirement for promoting ecological progress and implementing the food security strategy in the new era. This paper proposed a theoretical framework of GTCL and constructed a GTCL development index system based on four aspects: water, land, food and carbon; then, by applying a comprehensive evaluation model, a coupling coordination model and exploratory spatial data analysis, the development level of GTCL in China’s 31 provinces, municipalities and autonomous regions in 2000, 2005, 2010, 2015 and 2020 was evaluated and the spatial and temporal rates of change of “water, land, food and carbon” (WLFC) and their coupling coordination were finally analyzed to reveal the “water, land, food and carbon” effect of GTCL. Results showed that the systemic changes of WLFC and its coupling coordination degree of GTCL presented a spatial and temporal coincidence with a high degree of consistency; from 2000 to 2020, the overall GTCL rate in all Chinese provinces, municipalities and autonomous regions showed a “W”-shaped fluctuation uptrend. In the past five years, the development level of GTCL was higher in Northeast China, followed by Central China and North China, while South China was at a low level. In addition, WLFC showed a more obvious “W”-shaped fluctuation, with higher coupling coordination in Northeast China in good coordination and lower coordination in East China and Southwest China. Therefore, according to the results of the study, areas were divided into: benefit leading area, quality improvement area, connotation tapping potential area, ductile development area and ecological reserve area for the regulation of GTCL in all Chinese provinces, municipalities and autonomous regions.

Impacts of Agricultural Capitalization on Regional Paddy Field Change: A Production-Factor Substitution Perspective

Paddy fields are significant in ensuring food security and improving the agricultural ecological environment. In economic terms, paddy field use is affected by input costs and crop market price. There is insufficient understanding of factor input costs caused by agricultural production-factor substitution, driving paddy field change. This study uses a panel regression model to analyze the influence of agricultural production-factor substitution on paddy field use from 1990 to 2016. The case area is Hubei province, China. The results show that the overall growth trend in paddy fields is unequivocal in China's grain production areas. The improvement in agricultural production conditions, including irrigation and land quality, has a positive effect on the area proportion of paddy fields. With socioeconomic developments, the relationship between the substitution of nitrogen fertilizer for farmland and the area proportion of paddy field is inverted-U shaped, while the effect of the substitution of machinery for labor is U-shaped. The main conclusion is that the process of agricultural production-factor substitution, intended to maximize labor and land productivity, will increase the area proportion of paddy field. Public policies should focus on improving the level of agricultural mechanization and crop diversity to protect food security and sustainable agricultural intensification.