Food safety is a major concern for the Chinese public. This study collected 465 published papers on heavy metal pollution rates (the ratio of the samples exceeding the Grade II limits for Chinese ...soils, the Soil Environmental Quality Standard-1995) in farmland soil throughout China. The results showed that Cd had the highest pollution rate of 7.75%, followed by Hg, Cu, Ni and Zn, Pb and Cr had the lowest pollution rates at lower than 1%. The total pollution rate in Chinese farmland soil was 10.18%, mainly from Cd, Hg, Cu, and Ni. The human activities of mining and smelting, industry, irrigation by sewage, urban development, and fertilizer application released certain amounts of heavy metals into soil, which resulted in the farmland soil being polluted. Considering the spatial variations of grain production, about 13.86% of grain production was affected due to the heavy metal pollution in farmland soil. These results many provide valuable information for agricultural soil management and protection in China.
Southern China, which boasts high-yielding rice multi-crop systems, has long produced most of China’s rice. However, its ability to feed China has been weakened by changing rice cropping patterns in ...recent decades. In this study, we first examine production loss ascribed to rice multi-crop change in the south during 1998–2016 using agricultural statistics. Results show that the simultaneous removal of double-season rice (DSR) accounts for the majority of the reduction in rice output, and the region’s cropping shift from DSR to single-season rice (SSR) does not necessarily lead to production loss. Based on the calculation model of rice production, we then estimate rice loss caused by land-use changes across the south. Factor decomposition results show that the rice cropping share is the top rice loss factor, followed by the farmland area, whereas the farmland multiple cropping index (
MCI
) change makes little positive contribution. High variation in land-use changes and their effects on rice output are also found across the south. The most significant fall in rice production occurs in coastal southern China owing to the sharp decline in the rice cropping share and
MCI
. The middle reaches of the Yangtze River, in contrast, experience a cropping shift from DSR to SSR, but still gain expansion in rice area and rice output, where the rice cropping share and
MCI
present as positive factors. Finally, suggestions for enhancing food security through the reasonable utilization of paddy land resources in southern China are discussed.
The pollution and potential health risk due to lifetime exposure to heavy metals in urban soil of China were evaluated, based on the urban soil samples collected from published papers from 2005 to ...2014. The contamination levels were in the order of Cd > Hg > Cu > Zn > Pb >As > Ni > Cr, and Hg and Cd fell into the category of “moderately contaminated” to “heavily contaminated.” The non-carcinogenic risk for different populations varied greatly, among which children faced high risk, and then the adult female and adult male followed. The hazard index (non-carcinogenic risk) higher than 1.00 occurred in Shanghai, Gansu, Qinghai, Hunan, and Anhui, whereas most of those in northern and western China had low risks. For the carcinogenic risk, Anhui and Ningxia provinces had urban soils exceeding the safe reference (1 × 10 ⁻⁶–1 × 10 ⁻⁴). Qinghai and Gansu had high carcinogenic risks since their risk indexes were much closer to the reference, and the others were in low risk.
The outbreak of COVID-19 in 2020 caused extensive impact on household income and foods consumption. However, little attention has been paid to the immediate impact of income loss on animal-source ...foods consumption in the early stage of the COVID-19 pandemic. This paper aims to narrow this gap, and a total of 1301 valid samples of household food consumption surveys in Wuhan and Nanjing were obtained through specially designed online questionnaires. The surveys show that there were 69.6% (Wuhan) and 42.2% (Nanjing) of surveyed households whose animal-source foods consumption were affected, and there were 47.4% (Wuhan) and 18.9% (Nanjing) of surveyed households who suffered income loss. Furthermore, this paper makes an empirical study on the linkage between income loss and animal-source foods consumption. The results show that the pandemic affected household income, resulting in an immediate impact on animal-source foods consumption. This immediate impact may have been due to the combination of price increases, income loss and insufficient savings, which led to a "perfect storm" for animal-source foods consumption. Moreover, household income loss affected various animal-source foods consumption differently. For households suffering income losses, the odds of pork, beef and mutton, poultry, aquatic products, eggs and dairy products consumption being affected were increased by a factor of 1.894, 2.140, 2.773, 2.345, 1.802, 2.835, respectively, holding other variables constant. The results may be related to residents' consumption habits and food prices. During the COVID-19 pandemic, the reduction of animal-source foods consumption may have led to a state of tension concerning an increase in the development of nutrition intake and health, which may have led to increased food security risks.
In order to assess the implementation of China's National General Land Use Plan (1997–2010), this study combined conformance-based and performance-based criteria. The conformance analysis was carried ...out by contrasting outcomes with planning goals. Regarding the performance-based criteria, this study focuses on the role of decision-making elements in plan implementation, such as subsequent plans relevance to the plan being evaluated, policies developed to implement the plan being assessed, and, local government's strategic response to the implementation of subsequent plans. This study highlights the critical role of uncertainty, as well as the structure related to the plan implementation. The results show that the National General Land Use Plan (1997–2010) conformed and performed poorly, and failed to achieve its goals. This study also indicates that the failure of the plan implementation was a result of uncertainty, difficulty in coordination, policy bugs and redundant governance, and weak plan implementation monitoring.
•China's National General Plan has conformed and performed poorly, and has not been successful.•Conformance- and performance-based criteria are complements, rather than substitutes for each other.•Redundant governance hindered the success of the plan implementation.•Attention to uncertainty and implementation structure facilitates plan implementation analysis.•It is beneficial to distinguish between ‘being implemented’ and ‘being implemented successfully’.
Plastic greenhouses are an important hallmark of agricultural progress. To meet the growing demand for vegetable and food, the amount of plastic greenhouses has increased significantly over the past ...few decades. Remote sensing is considered as a promising data source for taking inventory and monitoring plastic greenhouses for managing modern agriculture. However, a systematic catalog of number and spatial distribution of plastic greenhouses is mostly inexistent. This is primarily due to the complex land surface characteristics and seasonal changes, which make automated classification based on EO data challenging. Current approaches generally suffer from the susceptibility of approaches toward thresholds and changes in the phenological stage. Besides, they often require an extensive training of models, however, often the necessary amount of training data is inexistent. To address these issues, we suggest an adaptable and universal plastic greenhouse mapping method based on very high spatial resolution optical satellite data (GaoFen-2 image) with a three-step procedure. A plastic greenhouse gathering area (100 km 2 ) is selected for the development of the initial method. We receive a very competitive mapping accuracy 97.34% and the likelihood of plastic greenhouses being mapped correctly reaches to 95.20%. Subsequently, we transfer it to a much larger area (2025 km 2 ) featuring a different phenological stage and different surrounding patterns. The stable mapping accuracy proves the validity of our approach.
It is well known that vegetation has cooling effect on urban land surface temperature (ULST). However, the influence of vegetation's structure, component, and spatial distribution on ULST has rarely ...been quantitatively studied. This paper, taking Landsat ETM+ data to retrieve ULST, and IKONOS data to obtain vegetation information, studied the relationship between ULST and vegetation patches. Results showed that in the urban environment, (1) ULSTs over tree and shrub, lawn, and weed patches were not much different, because of the edge effects of the vegetation patches and their fragmentized distribution pattern; (2) the relationship between ULST and area, perimeter, and shape index of vegetation patches exhibited positive, while LST and the ratio of perimeter/area presented negative linear relationship; (3) using land use polygons as units, area density had quadratic curve relationship to ULST, edge density and mean area density, had strongly negative relationship to ULST. These results indicated that not only the characteristics of vegetation patches, but also their spatial distribution had a great effect on ULST, which should be considered in urban ecological environment management.
The present study collected 464 peer-reviewed articles on chromium (Cr) concentrations throughout China from the published papers during 2005–2013, to evaluate the influence of Cr concentrations in ...arable soil on food production in China. The collected Cr concentrations in Chinese arable soil ranged from 0.05 to 3353.60 mg/kg, with a standard deviation of 140.82 mg/kg. The average Cr concentration was 78.94 mg/kg, significantly higher than its background concentration (57.30 mg/kg), indicating Cr has been introduced into soil by human activities. Generally, Cr concentrations varied greatly with some hotspots distributed throughout China. Based on the environment quality standard for soil in China (GB15618-1995), we evaluated the risk of Cr in arable soil on food production in China. Results showed that 0.13 % of arable land in China should be abandoned due to Cr pollution, and 1.26 % of arable land faced a high risk of Cr pollution. Furthermore, a greater percentage of paddy fields faced high risk from Cr pollution than dry lands.
•Response model of farmers’ behavior to land policy is constructed.•Three typical saline soil regions in China are selected for investigation.•Effect of land policies on farmers is significant and ...varied in different regions.•Varied suggestions of land policy optimization for different regions are proposed.
Soil salinization has become a global concern and poses a great threat to food production and sustainable land use. Land use policies are the main driver of saline soil farmland use in ecosystems. This paper proposes a theoretical framework for analyzing how saline soil farmland use is affected by land use practices of individual farm households. An empirical study, using an ordered probit model, was conducted based on questionnaire responses from farm households in 8 towns and 14 villages in eco-fragile areas in Shandong, Jilin and Xinjiang provinces. The results suggest that land tenure, state systems agricultural support, characteristics of a field parcel and characteristics of the farm households have different influences on farmer's land use in three regions. The adoption of organic fertilizer by individual households is constrained by the lack of stability and integrity in land tenure. Furthermore, the parcel of a field is generally small, sparsely distributed and often fragmented, which increases costs. Even subsidizing organic fertilizer does not necessarily help in its adoption. Given these challenges, this study makes recommendations for different regions that may promote the adoption of improved saline soil farmland cultivation methods by farmers.
Sustainable agricultural development has been the policy priority for countries with limited natural resources. New farmers’ emergence and growth have not only helped to address the labor crisis in ...agriculture to some extent, but they have also improved, integrated, and expanded the agricultural sectors. However, less attention has been paid to the performance of new farmers in adopting sustainable agricultural practices and the related spatial effects. Also, few studies have combined the composite adoption intensity of sustainable agricultural practices with the effects of various specific measures. Therefore, this study constructed the Tobit MLE spatial cross-section regression models to empirically study a sample of 174 farmers. We attempted to analyze the impact of the new farmers group on the diffusion of sustainable agricultural practices as well as farmers’ influence on various sorts of sustainable agricultural practices. The results show that new farmers greatly enhanced the adoption of sustainable agricultural practices, as evidenced by the fact that their adoption level was 69.9% greater than that of traditional farmers. However, they had statistically significant negative spillover effects on their neighboring farmers. For the composite adoption intensity of sustainable agricultural practices, there were also statistically significant negative spillover effects. Additionally, there were notable disparities among the factors influencing farmers’ decisions to adopt various types of sustainable agricultural practices and the spatial effects of those adoptions, particularly in the farm size, the number of plots, and the variety of marketing methods employed by farmers. Therefore, measures need to be proposed to address the barriers to the implementation and diffusion of various types of sustainable agricultural practices. This would increase farmers’ willingness to adopt sustainable agricultural practices and the effectiveness of their motivation to neighboring farmers.
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