Farmland abandonment is a global problem and considered one of the most important areas in land use change research. Farmland abandonment research currently focuses on understanding the factors that affect farmland abandonment and developing scientific models to simulate farmland abandonment. The study reviewed the natural and political factors driving farmland abandonment and summarized the main models for farmland abandonment simulation together with their advantages and disadvantages. We discuss the main ecological effects of farmland abandonment and propose farmland abandonment research directions. The study found that: (1) the influence of labor cost change and ageing labor force on farmland abandonment needs further investigation, (2) simulation models for farmland abandonment must include the decision-making mechanism of individual farmers and focus on macro large-scale abandonment prediction models, and (3) the influence of farmland abandonment on landscape culture must be investigated in detail.

Grain production patterns are the basis of a nation’s food security. Since China’s reform and opening-up began in 1978, China’s urbanization process, driven by rapid social and economic development, has accelerated steadily. During this time, the dietary structure of urban and rural Chinese has also changed significantly. Accordingly, grain production patterns have undergone major changes. First, traditional grain production patterns in the north and the south have changed, and the food production center has shifted toward the north. In 1980, the grain yield of southern provinces accounted for 60% of China’s total, while that of northern provinces accounted for 40%. In 2015, the grain yield of southern provinces accounted for 56% of the total, while that of northern provinces accounted for 44%. Second, grain production by regions of the country is “shrinking in the east but expanding in the central regions,” meaning that grain production in eastern coastal provinces has decreased significantly, while that in the central region has expanded. The proportions of the nation’s total grain production from the eastern, central and western regions were 38%, 36% and 26%, respectively, in 1980. These had changed to 27%, 46%, and 27%, respectively, in 2015. Third, the spatial centralization of grain production has increased. The total grain yield of 13 major grain-producing provinces and regions in the country accounted for 69.27% of nation’s total in 1980, and it had reached 76.18% in 2015, showing that the impact of major grain-producing areas on national food security has increased. The influence of rapid urbanization on grain production areas shows remarkable regional differences. As the level of urbanization has increased, build-up land occupies a large number of high-quality farmland, especially in east coastal provinces and thus the grain planting area decreased obviously. The effect of dietary structure changes on grain production patterns was evident in two ways. On the one hand, as dietary diversity has increased, total grain consumption has decreased. The reduction in the proportion of planting area for grain crops to total crop planting area dropped from 82% in 1980 to 68% in 2015, making this change in total grain consumption evident. On the other hand, the ratio of grain for human consumption declined as the ratio of grain consumed by animals increased. The reduction in the proportion of rice and wheat grown and an increase in the proportion of feed grain production (mostly maize) from 20% in the 1980s to 36% in 2015 makes this change in grain production and consumption evident. In the future, with the establishment of national functional areas for grain production, the spatial pattern of grain production will return, while the demand for feed grains will continue to increase but with the space for expansion limited.

Correlated increases in population and demand for food over recent decades have caused remarkable changes in cropland area globally. Utilizing the latest data product provided by the European Space Agency (ESA), this paper analyzes annual trends and spatiotemporal variations in cropland area and discusses cropland conversion, losses, and increases globally between 1992 and 2015 at a 300 m resolution. The results show that the global area of cropland increased rapidly between 1992 and 2004, more slowly between 2004 and 2012, and began to decrease gradually since 2012. First, an increasing trend in cropland area has been maintained solely in Africa; all other regions are characterized by decreasing trends in later periods despite different transition points and change rates. A reduction in cropland area frequently emerged earlier in high-income countries. Second, increase rates in cropland area have largely decreased in recent years while the overall rate of loss has remained almost the same. Hotspot areas of global cropland increases are mainly concentrated around the edge of the Amazon forest, Eurasian Steppe, and Sahara Desert. These hotspot areas of global cropland loss shifted from Europe to Asia while built-up areas have expanded at the expense of cropland.

The countries along the “Belt and Road” (B&R) should devote their efforts to top-level planning in the field of agriculture, so as to ensure the sustainable development of agriculture in the region. This will require a precise assessment of the sustainability of agriculture along the B&R. With a view to understanding the concept of sustainable agriculture along the B&R, combined with the interpretation of the agricultural objectives contained in the United Nation’s Sustainable Development Goals (SDGs), this study uses statistical regression analysis and trend prediction to predict the social and economic development trends in terms of economic growth and urbanization in the countries along the B&R up until 2030, and the corresponding impacts on agricultural resources and the environment. The results show that the future prospects for agricultural resources and the environment along the B&R are not promising, and meeting the future food security needs of the region will be difficult. Only by adopting innovative policies and implementing strategic planning can the goals of sustainable agricultural development and food security by 2030 be achieved in this region. Therefore, countries along the B&R should formulate agricultural development strategies from three aspects: building an agricultural cooperation platform, setting up special funds, and innovating the agricultural cooperation mode, so as to achieve the sustainable development of agriculture in the region.

The acceleration of urbanization has led to the occupation of more cropland, especially higher quality cropland, which could pose a huge threat to food security and have other implications for the inadequate cropland resource supply in China. Though the spatial status of Chinese cropland quality has been assessed, its temporal changes since 2000 to 2015 are still not clear. An accumulated probability distribution method was used to determine the criteria of cropland quality using the net primary production data product (MOD17) from Moderate Resolution Imaging Spectroradiometer (MODIS). Then the cropland quality of higher, median and lower production was spatially mapped and its changes due to occupation by urbanization were analyzed through the land use changes (LUCC) data primarily from Landsat TM images in the three periods of 2000-2005, 2005-2010, and 2010-2015. The results showed that of the total cropland reduction area the proportion taken by urbanization increased from 47.29% in the early stage to 77.46% in the recent period. The quality of Chinese cropland was dominated by low- and medium-yield fields, accounting for 40.81% and 48.74%, respectively, with high-yield fields accounting for only 10.44% of the total cropland in the country in 2000. The high-yield areas have been seriously threatened by the expansion of construction land fields, with the ratio of high-yield area to total area occupied by urbanization increasing from 9.71% in 2000-2005 to 15.63% in 2010-2015. Spatially, this phenomenon has been moving from eastern and southern China to central and western China, especially in Northwest China where the ratio has arrived at the highest proportion, with 52.97% of high-yield cropland in the total land taken by the expansion by 2015. This study not only provides a method to assess cropland quality but also reveals the threatening trend from the expansion of urbanization on high-quality cropland. More attention should be paid to the latter in land use planning and policies made to prevent threats to food security from declines in both cropland quantity and quality.

This paper examines the spatial characteristics of farmer/household behaviors in regional rice cropping systems (RCS), and the results provide necessary information for developing strategies that will maintain regional food security. Through field study and statistical analysis based on 402 households questionnaires finished in 2014-2015 in the Poyang Lake Region (PLR) of China, we arrived at two main conclusions. First, single- and double cropping rice were found across the study area, but showed a general distribution trend, with double cropping rice in the southeast part (especially in Jinxian county) and single cropping rice in the northwest (particularly in De’an county). Second, the household decisions concerning RCS varied in different parts of the PLR, but double cropping was the dominant type, with about 63.57% of the respondent households in the PLR cultivating double cropping rice. However, the multiple-cropping index of paddy rice was only 1.55. About 3% of interviewed households had altered their RCS during this period. Based on these findings, the local governments should guide farmers’ paddy field cultivation behaviors by increasing the comparative efficiency of rice production, promoting appropriate scale operations and land conversion, as well as optimizing rice growing conditions to improve the multiple cropping index and enhance food provision. Finally, land-use efficiency and more sustainable use of land resources should be improved.

In the context of global ecological overload, international trade has become one of the most important ways to make up for the ecological deficit. This study takes the “Belt and Road” Initiative as the study area to analyze the biocapacity and ecological footprint characteristics between China and other countries along the “Belt and Road” Initiative. Trade flow characteristics were explored from the perspective of biocapacity. The import and export of virtual land was used to assess the effect of trade on compensating for the resource gaps in crop and grazing land. The main results show that: 1) In 2005-2014, the majority of “Belt and Road” countries were experiencing increasing degrees of overload. In China, cropland takes up the largest proportion of biocapacity, while the ecological footprint is dominated by the carbon footprint. 2) The trade flow of agricultural and livestock products in the mainland of China shows a trend of increasing imports and decreasing exports, which increases dependence on specific regions. 3) In 2005-2014, China’s trade in cereals and oil crops along the “Belt and Road” Initiative were generally net imports, and the share of cereals traded along the “Belt and Road” Initiative is increasing gradually, but that of oil crops decreased rapidly. 4) The import trade has alleviated ecological deficit, as the selected products compensated for 1.03 times of the cropland deficit and 0.65 times of the grazing land deficit in China. This study is helpful to understand the relationship between the land use and trade deeply, and provide decision-making references for reducing ecological deficits, optimizing land resource allocation, and promoting win-win cooperation among China and other countries in the “Belt and Road” Initiative.

Based on the cost-income data of agricultural products and relevant statistical data, taking major grain crops and economic crops in the process of cultivated land use as study cases, we studied characteristics of the temporal variation of cultivated land use intensity and its composition in Shandong Province from 1980 to 2015, and then analyzed its main driving factors. The results showed that: (1) The total intensity of major crops in Shandong Province showed a rising trend from 919.73 Yuan ha^-1 in 1980 to 3285.06 Yuan ha^-1 in 2015, and the average annual intensity of economic crops was higher than that of grain crops. The labor cost and material cost of major crops both showed an increasing trend, but the material input was much higher than labor input for grain crops, while the labor input was much higher than material input for economic crops. (2) The labor intensity of major crops in Shandong Province showed a decreasing trend from 501.75 man-day ha^-1 in 1980 to 161.93 man-day ha^-1 in 2015. The labor intensity of grain crops was lower than that of economic crops and its decline rate was fast. On the contrary, the capital intensity showed an increasing trend from 518.33 Yuan ha^-1 in 1980 to 1159.95 Yuan ha^-1 in 2015. In the internal composition of capital intensity, the proportion of yield-increasing inputs such as seed, farmyard manure, fertilizer, pesticide and drainage and irrigation decreased gradually, while the proportion of labor-saving inputs such as agricultural machinery increased significantly. (3) The cultivated land use intensity in Shandong Province had significant negative correlations with the amount of agricultural labor and cultivated land area per capita. The primary direct driving factor was the net income per unit cost of major crops, but the time response lagged by 1-3 years. The main indirect driving factor was the reform of agricultural policy.

Karst areas in southwest China have experienced significant land cover and land use change (LUCC) due to utilization for human activity and a comprehensive rocky desertification control project (RDCP) since 2008. It is important to quantify the effect of LUCC on ecosystem productivity in this region for assessing the overall benefit of this ecological restoration project. In this study, we used using MODIS land cover and NPP products to investigate the relative contribution of LUCC to the change in net primary productivity (NPP) during 2008-2013 in Huanjiang County, one of first one hundred pilot counties to implement RDCP. Our results show that NPP increased in 95.53% of the county, and the average growth of NPP in non-rocky desertification area was higher than in rocky desertification or potential rocky desertification areas. LUCC has an important contribution (25.23%) to the NPP increase in the county, especially in the LUCC area (70.97%), which increased the average NPP by 3.9% and 10.5%, respectively. Across the six RDCP regions in the county, the average increase in NPP for the vegetation restoration measure of governed karst area is significantly greater than in the ungoverned karst area, and the positive change in NPP increased with the increasing implementation area of the vegetation restoration measure.

Land fragmentation is widely known to have an impact on farm performance. However, previous studies investigating this impact mainly focused on a single crop, and only limited data from China are available. This study considers multiple crops to identify the impact of land fragmentation (LF), as well as cropping system (CS), on farm productivity and the efficiency of grain producers in the North China Plain (NCP), using Cangxian County of Hebei Province as an example. Detailed household- and plot-level survey data are applied and four stochastic frontier and inefficiency models are developed. These models include different sets of key variables in either the production function or the inefficiency models, in order to investigate all possibilities of their influences on farm productivity and efficiency. The results show that LF plays a significant and detrimental role, affecting both productivity and efficiency. A positive effect is evident with respect to the CS variable, i.e., multiple cropping index (MCI), and the wheat-maize double CS, rather than the maize single CS, is usually associated with higher farm productivity and efficiency. In addition to LF and CS, four basic production input variables (labor, seed, pesticide and irrigation), also significantly affect farmers’ productivity, while the age of the household head and the ratio of the off-farm labor to total labor are significantly relevant to technical inefficiency. Policies geared toward the promotion of land transfer and the rational adjustment of cropping systems are recommended for boosting farm productivity and efficiency, and thus maintaining the food supply while mitigating the overexploitation of groundwater in the NCP.

Crop-livestock integration (CLI) is a significant practice for livestock grazing systems in alpine rangelands. It offers the potential to achieve sustainable crop and livestock production. However, the separate crop and livestock systems that exist today have led to issues of intensive agriculture, rangeland degradation and forage shortage in the Tibetan Plateau. Developing crop-livestock integration through sown pastures can be an effective way to lift pasture productivity and improve livestock production. Thus, to explore the potential for integrating crop and livestock production in alpine grazing systems, an assessment of potential forage and livestock production using multiple datasets was carried out in Burang County, China. Results showed the marginal land potentially available for sown pastures was about 560 ha, located mostly in the Burang township of the Karnali basin. Accumulated temperature was the dominant limiting factor for establishing sown pastures, therefore cold tolerance of forage species and growth period should be taken into consideration. Furthermore, the number of livestock decreased during the period 2012–2016; yet often, the number of livestock in rangeland landscape was greater than that in agro-pastoral landscape. The average number of livestock was about 110000 standard sheep units (SU) in the study area, but forage from sown pastures and crop residues could potentially feed about 11000 SU, accounting for 50% of the livestock population in the Karnali basin. We found that integrating crop and forage production could fill feed gaps for grazing systems, particularly in the agro-pastoral landscape of the Karnali basin. The results of this study provide scientific support to guide future forage production and to promote further crop and livestock integration in Burang County.

Improving the level of intensive cultivated land use is an important measure to ensure food security and promote the sustainable development of the regional society and economy. Based on data from the statistical yearbook of Maoming City and its counties and districts from 2005 to 2018 and the land use change database of Maoming City for 2018, this study constructed an evaluation index system for four aspects: cultivated land use intensity, cultivated land use degree, cultivated land output benefit and cultivated land sustainable use status. The level of intensive use of cultivated land in Maoming City from 2004 to 2017 was evaluated by AHP, the range method and the comprehensive evaluation model, and its temporal and spatial characteristics were evaluated. The results revealed three major points. (1) The intensive use of cultivated land in Maoming City in the past 14 years was good, and its level showed an overall upward trend, with the intensive use degree of cultivated land rising from 0.4045 in 2004 to 1.3148 in 2017. (2) The levels of intensive use of cultivated land in each county and district of Maoming City were generally on the rise, with no significant differences between them. However, according to the regional distribution, the intensive use level of cultivated land was highest in Maonan District, while it was relatively low in Dianbai County. The largest increase in the level of cultivated land intensive use was in Gaozhou, and the smallest was in Dianbai County. (3) According to the existing problems of cultivated land utilization in Maoming City, combined with the current international and domestic measures to effectively improve the level of intensive use of cultivated land, four suggestions are put forward: to improve the efficiency of cultivated land utilization and effectively protect basic farmland; to improve the overall urban planning and rationally adjust the layout of construction land; to raise farmers’ awareness of the intensive use of cultivated land; and to increase agricultural investment and improve agricultural infrastructure.

After operating for four years, the fallow project in the groundwater funnel area of the North China Plain has produced an initial water-saving effect. However, groundwater funnel remediation is a long-term process, and grain price changes over time may affect farmers’ willingness to participate in fallow. Based on the estimation by the Cobb-Douglas production function, the relationship between farmers’ satisfaction with fallow compensation and planting income is analyzed based on survey data collected from farming households in Hebei, a typical province located in the groundwater funnel area. Using this data, the impact of wheat price changes on farmers’ willingness to participate in fallow is simulated. The results indicate wheat price changes affect farmers' expected planting income and consequently their willingness to fallow; 88% of farmers would be unwilling to participate in fallow with a 0.1 yuan per 500 g increase in the wheat price, whereas 71.4% of farmers would be willing to participate in fallow with a 0.2 yuan per 500 g decrease in the price. Finally, some policy implications are proposed, such as the recommendation that the fallow compensation should be adjusted according to the wheat price multiplied by the average wheat yield of the three years before fallow in the North China Plain.