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Food concerns national livelihood and food security is vital for national security. In the context of “dual circulation” (i.e., domestic and international economic circulation) in China, clarifying the basic situation and challenges of food security and exploring effective strategies for food development are crucial for ensuring stable national development. Using national macro statistics, we first analyzed the basic situation of food security in China and the challenges it faces in the context of “dual circulation”. Subsequently, we made a macro study on national food security and proposed the goals, strategic paths, major projects, and feasible countermeasures for ensuring national food security. Our study indicates that there exists a large gap between food supply and demand, a high degree of external dependence, and a large amount of imports of feed protein in China, as well as challenges including the difficulty in substituting feed protein domestically, rigidness of environmental restrictions on soil and water resources, low incentives for farmers to grow grains, and insufficient risk-resistant capabilities of the food security system. Moreover, we proposed a series of major projects, such as demonstration for upgrading grain production capacity, new protein resource substitution, green and lowcarbon planting and breeding circulation, development and utilization of international grain resources, and research and development demonstration of future foods. Several development strategies were further suggested, including the establishment of a food security guarantee system, moderate expansion of cultivated land areas, sustained increase in oil-bearing plant production, steady resumption of a multiple cropping system in South China, and sustained advancement of a rotational cropping system in North China.

Lack of accurate maps on the extent of global cropland, and particularly the spatial distribution of major crop types, hampers policy and strategic investment and could potentially impede efforts to improve food security in an environment characterized by continued market volatility and a changing climate. Here we discuss the pressing need for the provision of spatially explicit cropland datasets at a global scale and review the strengths and weaknesses of the various approaches used to develop such data. [ABSTRACT FROM AUTHOR]

Abstract: This paper presented an approach of combining together the biophysical, social and economic factors for spatially explicit assessment of potential risks of food insecurity. Two indicators, i.e., per capita food availability and per capita Gross Domestic Product (GDP), were used here to cover the four dimensions of food security, with the former representing the status of food availability and stability and the latter reflecting the situation of food accessibility and affordability. These two indicators were then linked to an integrated modeling framework in a loose coupling method. This proposed approach was applied to assess potential future risks of food insecurity at a global scale over a period of approximately 20 years, starting with the year 2000. The results show that both changes in per capita food availability and changes in per capita GDP during 2000–2020 vary across regions worldwide. Some regions such as China, most eastern European countries and most southern American countries where there is an increase in per capita food availability or an increase in the capacity to import food between 2000 and 2020 might be able to improve their food security situation. On the contrary, certain regions such as southern Asian countries and most African countries will likely remain hotspots of food insecurity in the future. In these regions, both the per capita food availability and the capacity of being able to import food will decrease between 2000 and 2020, thus more efforts are needed to combat hunger in terms of future actions. Although most developed countries will also experience both a decrease in per capita per capita food availability and a decrease in per capita GDP, these countries are likely to be food-secure due to their higher income and purchasing power, as well as the substantial adaptive capacity and proactive food management systems. [ABSTRACT FROM AUTHOR]

Soybean cultivation in China has significantly decreased due to the rising import of genetically modified soybeans from other countries. Understanding soybean’s extent and change information is of great value for national agricultural policy implications and global food security. Some previous studies have explored the quantitative relationships between crop area and spectral variables derived from remote sensing data. However, both those linear or non-linear relationships were expressed by global regression models, which ignored the spatial non-stationarity of crop spectral signature and may limit the prediction accuracy. This study presented a geographically weighted regression model (GWR) to estimate fractional soybean at 250 m spatial resolution in Heilongjiang Province, one of the most important food production regions in China, using time-series MODIS data and high-quality calibration information derived from Landsat data. A forward stepwise optimization strategy was embedded with the GWR model to select the optimal subset of independent variables for soybeans. Normalized Difference Vegetation Index (NDVI) of Julian day 233 to 257 when soybeans are filling seed was found to be the most important temporal period for sub-pixel soybean area estimation. Our MODIS-based soybean area compared well with Landsat-based results at pixel-level. Also, there was a good agreement between the MODIS-based result and census data at county level, with the coefficient of determination (R2) of 0.80 and the root mean square error (RMSE) was 340.21 km2. Additionally, F-test results showed GWR model had better model goodness-of-fit and higher prediction accuracy than the traditional ordinary least squares (OLS) model. These promising results suggest crop spectral variations both at temporal and spatial scales should be considered when exploring its relationship with pixel-level crop acreage. The optimized GWR model by combining an automated feature selection strategy has great potential for estimating sub-pixel crop area at regional scale based on remote sensing time-series data. [ABSTRACT FROM AUTHOR]

Challenges of ensuring food security under climate change require urgent and substantial increase in the focus of research, innovation, transformation of knowledge, and rapid adoption of available technologies. Here we simulate the effects of the adoption of higher-yielding varieties of rice, wheat and maize crops into the food production systems on China's food security index (FSI, or relative food surplus per capita) in 2050, using the CERES crop models, climate change and a range of socio- economic and agronomic scenarios which were developed following two contrasting development pathways in line with the IPCC A2 and B2 emission scenarios, respectively. The obtained results predict a slightly positive effect of climate change on the FSI, but the magnitude of this positive effect cannot compensate the negative effects of population growth, urbanization rate and the rising affluence on the future trends of the FSI. The outcomes of the adoption of higher-yielding varieties show that a systematic adoption of higher-yielding varieties can raise the average FSI values by a margin of 16 and 27 units under the A2 and B2 scenarios, respectively, during the 2030-2050 period, compared to the average predicted FSI values of -2 and 8 percentage points under A2 and B2 during the same period. This suggests that systematic adoption of higher-yield varieties is an effective measure for Chinese agriculture not only to ensure food security but also to build adaptive capacity to climate change in 2050. [ABSTRACT FROM AUTHOR]

Highlights • Effects of cropland area changes on cereal production are assessed across countries. • China has lost many primary lands but has increased cereal production markedly. • Brazil has expanded cropland area but has only limited cereal production increases. • Countries like China reduce hunger more significantly due to productivity improvement. • Sustainable production needs to balance area allocation and productivity improvement. Abstract Although cereal production is a linear function of cropland area in principle, the relationship between area change and production change is nonlinear at a larger geographical scale due to the spatially heterogeneous use of land. Based on globally gridded land cover maps between 2000 and 2010, this study presents a country-level comparison to understand how cropland area change contributes to cereal production variation across the world's major cereal producers. First, a map of potential cereal productivity is applied to represent the spatially varied biophysical capacity, and the cropland area change in primary and marginal locations are calculated separately for individual countries by adopting the country's average cereal productivity as a reference. Then the area-change-induced potential cereal production change is estimated and correlated with the actual production change at the country level. The results show that most countries increased cropland area in primary locations. A few countries decreased cropland area, and the area losses are mainly occurred in primary locations as well. Moreover, China and USA achieved a marked increase in actual production with an expected decrease in potential production. In contrast, Brazil, Argentina and Nigeria have a higher increase in potential production against a relatively lower increase in actual production. Combining these, a cluster analysis indicates that some countries better exploited cropland productivity (as represented by China), and some countries better allocated cropland area (as represented by Brazil). Although the former group has reduced hunger more significantly, sustainable cereal production requires balanced development in terms of both productivity-improvement and area-optimization, which simultaneously ensure production and minimize environmental effects. Consequently, the current comparative analysis provides a preliminary guideline for developing national-level strategies by comparing the performance of one country to that of others. [ABSTRACT FROM AUTHOR]

Total crop production is a function of the harvested area and the yield. Many studies have investigated opportunities to increase production by closing the yield gap and by expanding cropland area. However, the potential to increase the harvested area by increasing the cropping frequency on existing cropland has remained largely unexplored. Our study suggests that the attainable harvested area gap (HAG) in China ranges from 13.5 to 36.3 million ha, depending on the selected water allocation scenario, relative to the current harvested area of 160.0 million ha. Spatially, South China and the Lower Yangtze region have the largest potential to increase harvested area, as these regions allow triple-cropping, have sufficient water available, and have a good irrigation infrastructure. The results imply that management factors are equally important for exploring the potential against the resource endowment: water allocation has a large impact on both the size and the spatial pattern of the attainable HAG. This indicates the necessity of further examining the spatial-temporal dynamics of HAG at national and regional scales, and its potential contribution to food security and sustainable agricultural development. [ABSTRACT FROM AUTHOR]

Multiple cropping systems are particularly important in China to feed the 19% of the world’s population with only 8% of the arable land. Rising temperatures can dramatically affect multiple cropping systems and, as a consequence, food security in China. Here, we investigate the impacts of climate change on the northern limits and crop planting areas of multiple cropping systems in China, and estimate the impacts of the change in the crop planting areas of multiple cropping systems on the China’s crop production (maize, wheat, and rice). Based on both historical climate observations from the China Meteorological Administration and future climate A1B emission scenario (IPCC, 2007) data for China, we evaluate the effects of climate change on multiple cropping systems in China. Historical statistical crop yield and simulated crop yield by Agricultural Production Systems Simulator (APSIM model) in 2011–2100 were used to quantify the crop production (maize, wheat, and rice) in China. We found that the northern limits of multiple cropping systems have been shifted northward. The projected area of cultivated land for triple-cropping system may significantly expand during the 21st century. The northern shifts resulted in a 2.2% (∼8,000,000 t) increase in national production of three major crops (maize, wheat, and rice) during the period from 1981 to 2010, positively impacting China’s food security. Therefore, we conclude that the warming due to climate change may cause a positive impact on the crop production in China if concomitant changes adapted in multiple cropping systems take place. [ABSTRACT FROM AUTHOR]

Abstract: Food security is greatly affected by the consequences of global change, especially its impact on agriculture. Currently, global change and food system interaction is a hot issue across the scientific community. Scientists have tried to explain this interaction from different perspectives, and the issues related to this interaction can be classified as (1) crop yield and productivity in response to global change; (2) crop distribution and allocation in relation with global change; (3) general impacts on food security. However, most of the existing studies lack consistency and continuity. As food systems exist at the intersection of the coupled human and natural system, the interdisciplinary context of global change and food security requires an integrated and collaborative framework for better describing their importance and complexity. To do so, we decompose global change/food security studies into different levels in accordance with the previous mentioned issues, field, regional, and global, and categorize them into the life sciences, earth and environmental sciences, and social and sustainability sciences, respectively (yet not necessarily one to one correspondence). At the field level, long-term observations and controlled experiments in situ are important for exploring the mechanism of how global change will affect crop growth, and for considering possible adaptation methods that may maximize crop productivity. At the regional level, priority should be given to monitoring and simulating crop production (animal production and fishery are not included here) within large areas (a region or a continent). At the global level, food security studies should be based on scenario assessments to prioritize human adaptations under the changed environment, using integrated socioeconomic–biogeophysical measures. [Copyright &y& Elsevier]