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.

Farmland protection is important for ensuring national food security and promoting sustainable socioeconomic development. China has a far lower amount of farmland area per capita than the global average. To improve farmland productivity, the Chinese government has implemented a basic farmland protection system (BFPS). A comprehensive and systematic analysis of the evolution mechanism of the BFPS, the failures of the BFPS and the key measures of the modern BFPS reform is lacking in the current literature. Based on a systematic review of the history of China’s BFPS, this study first summarizes the evolutionary mechanism of the BFPS, then analyzes the current conflicts faced by the BFPS on this basis, proposes several main breakthrough strategies for improving the BFPS and finally provides key ideas for further strengthening the development of the BFPS in the future. The results of this study show that China’s BFPS has gone through three development stages since 1963 and that there are differences in the main factors hindering the improvement in basic farmland productivity in the different stages. Correspondingly, the systems adopted to meet the demands for basic farmland protection are also different. The evolution of the BFPS is similar to a “scale” that constantly seeks balance between “system demand” and “system supply”. In the present stage, the main conflicts faced by China’s BFPS are between basic farmland quality and requirements for supplementary delimitation and production patterns; between basic farmland quantity, urban development and food security; and between basic farmland-use regulation and modern agriculture and the market economy. The Chinese government should further optimize the BFPS through improving the delimitation system, establishing a classified protection system and strengthening the basic farmland protection compensation system. To accelerate the establishment of a territorial spatial planning system in the future, the BFPS should also be fully integrated with the concept of an ecological civilization, be applied to resolve the contradiction between development and protection and be used to help improve the land-space-utilization control system, thus creating a unified development guide for national land.

Agricultural management, such as tillage and straw-returning, affect soil fertility and nutrient cycling in agroecosystems. With the increasing food demand and challenges imposed by climate change, these effects on soil fertility need to be closely monitored, so that short-term agricultural intensification should not threaten the long-term productivity of the land. Therefore, the main objective of this study was to examine the long-term effects of different management practices on soil aggregate stability and associated organic carbon (OC) and nitrogen (N) over a 33-year period in the croplands of the North China Plain. Bulk soils from the surface and subsurface layers were fractionated using the wet sieving approach. The results showed that the silt + clay (SC) fractions (<0.053 mm) were predominant, accounting for 32–56% of the mass at the 0–20 cm depth, and accounting for 41–55% of the mass at the 20–40 cm depth. Additionally, long-term (33 years) no-tillage management and straw-returning at different application rates increased the mass of large soil macroaggregates (LMA), the LMA- and macroaggregate-associated OC content, but decreased the SC-associated OC content. Mineral N and P fertilizers had a minor effect on the stabilization of soil aggregates. The treatment with straw significantly increased the mean weight diameter (MWD) and geometric mean diameter (GWD), compared with the treatment without straw. Our results indicate that carefully regulated management practices would enhance soil aggregate stability, associated OC and N content in the intensive agroecosystem.

The spatial zoning of cultivated land is a core aspect of territorial spatial planning and an important basis for implementing differentiated cultivated land protection policies. To provide theoretical guidance for the future direction of the protection and utilization of cultivated land in Shandong Province, this paper built a theoretical framework for the spatial zoning of cultivated land based on the trinity of quantity, quality, and ecology and formed an indicator system for the spatial zoning of cultivated land based on these three elements. Based on the analysis and grading results of spatial zoning indicators of cultivated land, hierarchical clustering analysis was performed on 133 county-level administrative units, and then the cultivated land resources of Shandong Province were divided into four types of zones: Key protection zones, comprehensive promotion zones, multifunctional utilization zones, and ecological utilization zones. Future development directions in relation to the protection and utilization of cultivated land in each type of zone were proposed. The results showed that the spatial zoning of cultivated land based on the trinity of quantity, quality, and ecology has important theoretical and practical significance for guiding the protection and utilization of cultivated land in Shandong Province and other regions.

Cultivated land is the basis of food security and an important component of the construction of ecological civilization. The sustainable use of cultivated land is an important issue in land resource management, and it is also an inevitable factor when addressing the contradiction between food demands and resource and environmental constraints. Cultivated land use is both a food production process and a water- and energy-intensive process. Therefore, sustainable use of cultivated land is important not only for cultivated land itself but also for the associated social, economic, and ecological impacts of water and energy input. Therefore, based on the water–land–energy–food nexus, this paper carries out a theoretical analysis of cultivated land use following the element–structure–function framework and builds an evaluation framework of the sustainable use of cultivated land. Finally, this paper selects appropriate evaluation indicators to evaluate the changes in element coordination and function trade-offs of cultivated land use in Quzhou County from 2000 to 2020; analyzes the key influencing factors in detail; and proposes future development directions. The results reflect the fact that the element coordination degree showed obvious continuous decline three times in a row, then a brief rise, and it finally stabilized at a high level, whereas the synergies between the functions decreased and then increased. This means that the sustainable use level of cultivated land in Quzhou County basically presents a good trend. At present, the obstacle that is restricting the efficient use of cultivated land and sustainable development is water, which should be improved by some measures in the future. The results of this evaluation have important theoretical and practical significance for identifying the characteristics of changes in cultivated land use and for guiding future sustainable use in Quzhou County and other regions.

Under the context of rapid urbanization, how to use construction land resources under the dual pressure of socioeconomic growth and cultivated land protection is critical to resource utilization and sustainable development. Thus, it is of great theoretical and practical significance to study the relationship between socioeconomic change and construction land expansion. Based on decoupling theory, this study constructed a two-dimensional model to analyze the population-construction land and economy (non-agricultural GDP)-construction land decoupling status and characteristics in Hebei Province at the county level. Then, a decoupling-based construction land-use zoning model was built to explore construction land saving and intensive utilization strategies in different construction land-use zones. The results show that (1) the construction land area, population and non-agricultural GDP in Hebei Province increased in the study period, but there were spatial differences in the hot areas of growth. (2) In the population-construction land dimension, the growth of the population and construction land in Hebei Province was generally in an uncoordinated state. According to the results of the calculation, the samples of counties whose relationships between population and construction land were uncoordinated accounted for 75.76% of all counties, and 68.94% of all counties demonstrated weak decoupling. (3) In the economy-construction land dimension, 89.39% of all counties in Hebei Province had coordinated relationships between economy and construction land change. The expansion negative decoupling was the main decoupling state in Hebei Province in this dimension. (4) On the basis of two-dimensional decoupling type results, the construction land-use in Hebei was divided into four zones: “Population–economy dual coordinated”, “population unilateral coordinated”, “economy unilateral coordinated” and “population–economy dual uncoordinated”. The results showed that the “economy unilateral coordinated” zone included 68.18% of all counties. According to the characteristics of different construction land-use zones, this study provided various regulatory and control countermeasures and suggestions to improve the efficiency of construction land-use and to promote sustainable development in Hebei Province.