The Challenges and Strategies of Food Security under Rapid Urbanization in China

Do clean energy technologies, ecotourism, health policy, and green education help in achieving sustainability in China?

Sustainable development has become the foremost requirement for sustainable economic conditions all around the globe, and this aspect demands new literature and regulators' emphasis. Hence, the present research investigates the impact of clean energy technologies, human development, health policies, green education, and ecotourism policy on sustainable development in China from 1991 to 2021. The researchers investigate the association among the variables using dynamic autoregressive distributed lag (DARDL). The outcomes revealed that clean energy technologies, human development, health policies, green education, and ecotourism policy have positive linkages with sustainable development in China. The article provides guidelines to the policymakers in developing policies related to attain sustainable development using effective clean energy technologies, human development, health policies, green education, and ecotourism policy.

Governing for food security during the COVID-19 pandemic in Wuhan and Nanjing, China

The global COVID-19 pandemic has elicited a range of public health governance responses. One common result has been an associated disruption of food supply chains and growing urban food insecurity. Policy responses to this situation have not yet received sufficient research attention. This paper therefore focuses on the urban food security implications of China's zero-COVID public health measures and the response of central, provincial and municipal government to the governance challenge of ensuring a stable and sufficient food supply to urban consumers. During the COVID-19 outbreak in early 2020 in China, zero-COVID lockdown measures aimed to contain and eliminate the spread of the virus. This paper examines the associated policy responses around urban food security in early 2020, with a particular focus on two cities: Wuhan (where SARS-CoV-2 was first identified) and Nanjing (a neighbouring city). The analysis is based on an inventory of policy-related documents providing a wide range of information about governance responses to the pandemic. Four major governance challenges are addressed: agricultural production, food transportation, stabilization of food prices, and new contactless methods in purchasing foods. Key recommendations for post-pandemic policy responses around urban food security include: ensuring consistency throughout all levels of government, strengthening existing food reserves to leverage emergency responses, addressing the root causes of pandemic-related food insecurity by focusing on access at the household level, and improving food utilization.

Effect of Sowing Date on the Growth Characteristics and Yield of Growth-Constrained Direct-Seeding Rice

To investigate changes in the yield and physiological characteristics of indica hybrid rice varieties sown on different dates, we evaluated appropriate hybrid rice varieties and their optimal sowing dates in the hilly areas of Sichuan. Three popular indica rice varieties were used as experimental materials, and five sowing dates were set uniformly locally [16 May (SD1), 23 May (SD2), 30 May (SD3), 6 June (SD4), and 13 June (SD5)] to investigate differences in the yield characteristics, growth period, and dry matter accumulation. The results showed that, over the two years, the sowing-to-heading period and overall growth period of the three varieties shortened as the sowing date was delayed, and the difference in yield between the SD1 and SD2 treatments was not significant, owing to higher material accumulation after flowering and higher assimilative material transport capacity. These varieties are both photosensitive and tolerant to low temperatures. Among the three varieties tested, the Huangyouyuehesimiao (V3) cultivar had the highest yield, with 10.75 t ha^-1 under the SD2 treatment. The impact of shifting the sowing date on yield components varied. Delaying the sowing date increased and then decreased the number of effective panicles, and the number of grains per panicle and the seed setting rate decreased by differing degrees. In summary, a high yield of indica hybrid rice can be maintained by sowing between 16 and 23 May each year in the study area. It indicated that indica hybrid rice in the hilly rice-producing region of Sichuan is highly adaptable to different sowing dates.

The Spatio-Temporal Evolution of Food Production and Self-Sufficiency in China from 1978 to 2020: From the Perspective of Calories

Ensuring national food security is an eternal topic. We unified six categories of food with calorie content including grain, oil, sugar, fruits and vegetables, animal husbandry, and aquatic products on the basis of provincial-level data, and we dynamically evaluated caloric production capacity and the supply-demand equilibrium under the increase in feed-grain consumption as well as the food losses and waste in China from 1978 to 2020 at four different levels. The results show that: (1) From the perspective of food production, the total national calorie production showed a linear growth trend, with a growth rate of 31.7 × 10¹² kcal/year, of which the proportion of grain crops has always exceeded 60%. Most provinces showed significant increasing trends in food calorific production, except for Beijing, Shanghai, and Zhejiang, which showed slightly decreasing trends. The distribution pattern of food calories and their growth rate were high in the east and low in the west. (2) From the perspective of the food supply-demand equilibrium, the national food calorie supply has been in surplus since 1992, but significant spatial heterogeneity is detected, with the Main Marketing Region changing from a tight balance to a short surplus, North China always remaining in calorie shortage, and 15 provinces still presenting supply and demand gaps up to 2020, necessitating the establishment of a more efficient and faster flow and trade system. (3) The national food caloric center has shifted 204.67 km to the northeast, and the population center has shifted to the southwest. The reverse migration of the centers of food supply and demand will further aggravate the pressure on water and soil resources and cause higher requirements for ensuring the circulation and trade system of food supply. The results are of great significance for the timely adjustment of agricultural development policies, making rational use of natural advantages and ensuring China's food security and sustainable agricultural development.

Managing Land Carrying Capacity: Key to Achieving Sustainable Production Systems for Food Security

Many previous studies have estimated the carrying capacity and feasible planetary boundaries for humankind. However, less attention has been given to how we will sustainably feed 9 billion people in 2050 and beyond. Here, we review the major natural resources that limit food production and discuss possible options, measures, and strategies to sustainably feed a human population of 9 billion in 2050 and beyond. Currently, food production greatly depends on external inputs, e.g., irrigation water and fertilizers, but these approaches are not sustainable. Due to the unbalanced distribution of global natural resources and large regional differences, urbanization expansion causes important areas to face more serious arable land resource shortages. Hence, sustainably feeding 9 billion people in 2050 and beyond remains an immense challenge for humankind, and this challenge requires novel planning and better decision-making tools. Importantly, the measures and strategies employed must be region-/country-specific because of the significant differences in the socioeconomic characteristics and natural environmental carrying capacity in different parts of the world. Considering the impact of unexpected extreme events (e.g., a global pandemic and war) in the future, the food trade and translocation of goods will also face challenges, and the strategies and decision-making processes employed must consider the possible influences at both regional and global scales.

COVID-19 Pandemic, Technological Progress and Food Security Based on a Dynamic CGE Model

The global spread of COVID-19 has complicated the international equilibrium of grain production and trade. China now faces external shocks in the international grain market and deep-seated problems associated with the structure of domestic supply. We used a dynamic, computable general equilibrium (CGE) model to analyse the effects on China’s food security and macroeconomics under the COVID-19 scenario and four technological progress paths in the agricultural sector. We showed that the COVID-19 pandemic is disrupting China’s food security in the short term, and critical quantitative variables such as grain production and grain consumption per capita have declined. Considering food security and macroeconomic development, labour-saving technological progress outperformed neutral technological progress, land-saving technological progress, and capital-saving technological progress in the short run. While land-saving technological progress contributes the most to the arable land area per capita of wheat and other grains in the long run.

The Impacts of Urbanization to Improve Agriculture Water Use Efficiency—An Empirical Analysis Based on Spatial Perspective of Panel Data of 30 Provinces of China

China has witnessed accelerated urbanization since the reforms and open policies which began in 1978. This eventually resulted in increased residential water requirements and worsening water shortages, particularly in the current century. In the context of resource and environmental constraints, improving agricultural water use efficiency (AWUE) is a crucial issue to ensure food security, improve the ecological environment, and meet the needs of sustainable agricultural development. Based on the panel data of 30 provinces in China from 1999 to 2018, the article uses the Super-SBM model to measure the AWUE. Moreover, the study uses the entropy method to establish the urbanization evaluation index system from the dimensions of population, land, economy, measures the comprehensive level of urbanization development, and further constructs a dynamic spatial econometric model. We use the unconditional maximum likelihood estimation method to evaluate the impact of urbanization development on AWUE and its heterogeneity. The findings reveal that the AWUE considering undesired outcomes has generally shown a steady improvement, but there is ample space for resource conservation and environmental protection, and there are noticeable differences among regions. The decomposition of spatial effects shows that urbanization development in each region has a short-term positive effect on AWUE in the region and neighboring regions, and a long-term effect exists only in the western region. The impact of urbanization in different dimensions has been found that both land urbanization and economic urbanization contribute to the improvement of AWUE, while population urbanization helps to improve AWUE by improving the awareness level of the farmers.

Multiscale analysis of factors affecting food security in China, 1980-2017

Food security is an important issue affecting people's lives and social stability. Clarifying levels of food security and the factors affecting it (social, economic, agricultural, climatic) can help improve regional food security. The spatiotemporal patterns and driving factors of food security vary at different scales. There is, however, a lack of research that considers the various factors affecting food security at multiple scales. This study, therefore, analyzed dynamic spatiotemporal changes in food security at small (city), medium (province), and large (country) scales; identified hot and cold areas of food security; and revealed the main factors affecting food security at different scales. A food security index (FSI) was built based on the coupling of grain yield, population, and GDP, and spatial analysis was used to evaluate dynamic spatiotemporal changes in China's food security from 1980 to 2017. Further, the relationship between food security and its driving factors was quantitatively analyzed using stepwise regression. The results showed greater heterogeneity in food security at the smaller scale than at the larger scale. The key factors affecting food security varied substantially at different scales: the added value of tertiary industry dominated the prefecture level, and gross agricultural output value was the main factor at the provincial and national levels. Multiple-scale research can reveal the status and primary factors of food security and provide a decision-making basis for improving regional food security.

The Impacts of Farmland Loss on Regional Food Self-Sufficiency in Yangtze River Delta Urban Agglomeration over Last Two Decades

Food security is essential for human survival and sustainable development. Due to rapid urbanization and industrialization, the farmland loss in Yangtze River Delta Urban Agglomeration (YRDUA) has threatened food security. Thus, this study intended to quantify the farmland loss and assess its impacts on food security in the YRDUA from 2000 to 2020 at three scales based on the Google Earth Engine platform. Our results show that the area of farmland in YRDUA is decreasing at a rather high speed in the past 20 years and the trend is getting worse. At the urban agglomeration scale, there was a farmland deficit of 0.44 million ha in 2000, followed by larger farmland deficits in 2010 and 2020. At the city scale, Shanghai had the largest scarcity of farmland. At the urban subgroup scale, Subgroup I in the west and Subgroup II in the north always maintained an oversupply of farmland, while Subgroup III in the east and Subgroup IV in the south faced serious food security problems. Our study suggests that farmland must be protected in YRDUA in order to ensure food self-sufficiency and promote regional sustainability.

Identifying the Determinants of Nongrain Farming in China and Its Implications for Agricultural Development

Promoted by rapid industrialization and urbanization, the structure and spatial pattern of farming in China has changed greatly, and nongrain farming (NGF) has become more common. However, excessive NGF in some areas is not conducive to sustainable agricultural development and threatens China’s food security. In this study, we briefly analyze the stage characteristics of NGF in China and investigate the spatial agglomeration of NGF and its influencing factors from the perspective of spatial econometrics. The results showed that the average annual growth rate of NGF in China from 1985 to 2019 was 0.64%, and there was a growing positive spatial correlation between NGF in each province. Spatial Durbin model (SDM) estimation showed that both the per capita disposable income of local rural residents and the local urbanization rate promoted the development of NGF, while local per capita farmland, road density, and the functional orientation of the main grain-producing areas had a negative impact on NGF. The per capita disposable income of rural households and urbanization rate in neighboring areas had a promoting effect on the development of NGF, while road density in neighboring areas was negatively correlated with NGF. Ultimately, some targeted measures are proposed to promote China’s agricultural development in the new era.

Spatial Differentiation of Cultivated Land Use Intensification in Village Settings: A Survey of Typical Chinese Villages

The intensified use of cultivated land is essential for optimizing crop planting practices and protecting food security. This study employed a telecoupling framework to evaluate the cultivated land use intensification rates in typical Chinese villages (village cultivated land use intensifications—VCLUIs). The pressure–state–response (PSR) model organizes the VCLUI indexes including the intensity press, output state, and structural response of cultivated land use. Empirical analysis conducted in Baiquan County, China, indicating that the cultivated land use intensification levels of the whole county were low. However, the intensifications of villages influenced by physical and geographic locations and socioeconomic development levels varied significantly. This paper also found that variations in the VCLUIs were mainly dependent on new labor-driven social subsystem differences. Thus, the expanding per capita farmland scales and increasing numbers of new agricultural business entities were critical in improving the VCLUI. Overall, the theoretical framework proposed in this study was demonstrated to be effective in analyzing interactions among the natural, social, and economic subsystems of the VCLUI. The findings obtained in this study potentially have important implications for future regional food security, natural stability, and agricultural land use sustainability.

Global Trends on Food Security Research: A Bibliometric Analysis

The issue of food security has been widely studied by the international community. To reveal the research situation as it pertains to food security objectively, this paper comprehensively utilizes bibliometrics techniques (i.e., Bibliometrix, VOSviewer, and CiteSpace) to explore the research status and development trends in the area of food security. The results show that: (1) food security research has shown an increasing trend during the past 30 years. The 2013–2019 period was shown to be an active period with a high yield of articles, which were published mainly in the developed regions of Europe and America. Particularly, the number of articles published in the United States was far ahead of other countries in the world. (2) Food security research involved agriculture, environmental science and ecology, food science and technology, and business economics. The research topic is an interdisciplinary subject with a good momentum of development and a large space remaining for research. (3) Climate change, poverty, gender, nutrition, and diet structure have been the focuses of food security research in recent years. Food security in China, India, and sub-Saharan Africa has attracted wide attention. (4) Food security research is becoming more and more mature. The research scope extended from food security to food security and water and land resource security. Research topics range from decentralized to systematic. (5) Food security research is likely to gain much attention in the future based on three pillars: food supply, food access, and food use. Sustainability and diversity of food supply, along with dietary restructuring and food conservation initiatives, are expected to be new trends in future research on land management.

Mapping Rice Paddy Based on Machine Learning with Sentinel-2 Multi-Temporal Data: Model Comparison and Transferability

Rice is an important agricultural crop in the Southwest Hilly Area, China, but there has been a lack of efficient and accurate monitoring methods in the region. Recently, convolutional neural networks (CNNs) have obtained considerable achievements in the remote sensing community. However, it has not been widely used in mapping a rice paddy, and most studies lack the comparison of classification effectiveness and efficiency between CNNs and other classic machine learning models and their transferability. This study aims to develop various machine learning classification models with remote sensing data for comparing the local accuracy of classifiers and evaluating the transferability of pretrained classifiers. Therefore, two types of experiments were designed: local classification experiments and model transferability experiments. These experiments were conducted using cloud-free Sentinel-2 multi-temporal data in Banan District and Zhongxian County, typical hilly areas of Southwestern China. A pure pixel extraction algorithm was designed based on land-use vector data and a Google Earth Online image. Four convolutional neural network (CNN) algorithms (one-dimensional (Conv-1D), two-dimensional (Conv-2D) and three-dimensional (Conv-3D_1 and Conv-3D_2) convolutional neural networks) were developed and compared with four widely used classifiers (random forest (RF), extreme gradient boosting (XGBoost), support vector machine (SVM) and multilayer perceptron (MLP)). Recall, precision, overall accuracy (OA) and F1 score were applied to evaluate classification accuracy. The results showed that Conv-2D performed best in local classification experiments with OA of 93.14% and F1 score of 0.8552 in Banan District, OA of 92.53% and F1 score of 0.8399 in Zhongxian County. CNN-based models except Conv-1D provided more desirable performance than non-CNN classifiers. Besides, among the non-CNN classifiers, XGBoost received the best result with OA of 89.73% and F1 score of 0.7742 in Banan District, SVM received the best result with OA of 88.57% and F1 score of 0.7538 in Zhongxian County. In model transferability experiments, almost all CNN classifiers had low transferability. RF and XGBoost models have achieved acceptable F1 scores for transfer (RF = 0.6673 and 0.6469, XGBoost = 0.7171 and 0.6709, respectively).

A Study on the Arable Land Demand for Food Security in China

Food security is the basis of social stability and development. Maintaining sufficient amounts of arable land is essential for China’s food security. In this paper, we consider the relationship between arable land demand to grain demand and production capacity. The changes in national population, grain production, and consumption from 2000 to 2015 are analyzed. Then, we forecast the respective possible changes in the future and accordingly forecast the arable land demand in different possible situations. The results show that the pressure to maintain sufficient amounts of arable land in 2030 may be greater than that in 2040.The higher pressure is due to larger population and lower production capacity. To ensure food security in China, we insist on maintaining 120 million ha of arable land, the “red line” for food security, and improve the arable land productivity to ensure domestic production and self-sufficiency. In addition, residents should be guided to cultivate sound food consumption habits in order to control per capita grain demand. Lastly, we should also make full use of international resources and markets to relieve the pressure on domestic resources and environments.

Analysis of Changes and Potential Characteristics of Cultivated Land Productivity based on MODIS EVI: A Case Study of Jiangsu Province, China

Cultivated land productivity is a basic guarantee of food security. This study extracted the multiple cropping index (MCI) and most active days (MAD, i.e., days when the EVI exceeded a threshold) based on crop growth EVI curves to analyse the changes and potential characteristics of cultivated land productivity in Jiangsu Province during 2001–2017. The results are as follows: (1) The MCI of 83.8% of cultivated land remained unchanged in Jiangsu, the cultivated land with changed MCI (16.2%) was mainly concentrated in the southern and eastern coastal areas of Jiangsu, and the main cropping systems were single and double seasons. (2) The changes in cultivated land productivity were significant and had an obvious spatial distribution. The areas where the productivity of single cropping system changed occupied 67.8% of the total cultivated land of single cropping system, and the decreased areas (46.5%) were concentrated in southern Jiangsu. (3) For double cropping systems, the percentages of the changed productivity areas accounting for cultivated land were 82.7% and 73.3%. The decreased areas were distributed in central Jiangsu. In addition, the productivity of the first crop showed an overall (72%) increasing trend and increased areas (40.8%) of the second crop were found in northern Jiangsu. (4) During 2001–2017, cultivated land productivity greatly improved in Jiangsu. In the areas where productivity increased, the proportions of cultivated land with productivity potential space greater than 20% in single and double cropping systems were greater than 60% and 90%, respectively. In the areas where productivity decreased, greater than 25% and 75% of cultivated land had potential space in greater than 80% of the single and double cropping systems, respectively. This result shows that productivity still has much room for development in Jiangsu. This study provides new insight for studying cultivated land productivity and provides references for guiding agricultural production.

Does Fallowing Cultivated Land Threaten Food Security? Empirical Evidence from Chinese Pilot Provinces

Facing worsening problems, including the decreasing amount, quality, and deterioration of land ecosystems, cultivated land needs protective measures. China has been conducting an experimental fallow policy to deter these problems in five pilot provinces since 2016. However, inadequate and inconclusive studies of the impacts of fallow policy on food security have motivated the authors to fill this knowledge gap and to provide evidence for policy-making. Using the modified cultivated land pressure model, this study explores the cultivated land pressure at three scales (nation, province, and prefecture) to determine the capacity of feeding people using cultivated land, and examines the impact of fallowing cultivated land. There are three main findings. First, the cultivated land pressure in China continually decreased during the period of 2000–2016, and would remain in a decreasing trend during 2017–2020 even if the measures implemented doubled the fallowing scale every year. Second, the spatial patterns of the cultivated land pressure between the provincial and prefectural scale show a similar overview, with some nuanced disparities. Finally, the five pilot provinces show various amplitudes of variation in cultivated land pressure, ranging from 0.017% to 9.027% under three fallow scale scenarios. Thus, the results of this research support the argument that fallow policy will not threaten food security at a national and provincial scale, based on the current fallow scale and enlargement pace. The deeper understanding of the impact of fallow policy provides a scientific reference for policymaking and calls for further studies focusing on a more comprehensive measurement of cultivated land pressure and optimization fallow scale.