Rui Zhao

Against the backdrop of increasing resource and environmental constraints, improving the land use efficiency of state-owned agricultural land is of great significance for promoting sustainable agricultural development. This study measures the land use efficiency of state-owned agricultural land across 29 provinces in China based on data from the China State Farms Statistical Yearbook (2019–2023). The super-efficiency slack-based measure model (Super-SBM), incorporating both desirable and undesirable outputs, is employed, and global and local spatial autocorrelation methods are further applied to analyze the spatiotemporal evolution of land use efficiency. The results indicate the following: (1) from 2019 to 2023, the overall land use efficiency of state-owned agricultural land in China remained below or slightly above the efficiency frontier, exhibiting a fluctuating trend characterized by an initial increase followed by a decline; (2) significant regional disparities exist, with high-efficiency areas mainly concentrated in Northeast China and the eastern coastal regions, while low-efficiency areas are primarily distributed in western regions and parts of central China; (3) spatial autocorrelation analysis reveals that land use efficiency shows an increasingly pronounced spatial clustering pattern at the provincial scale. After 2022, high–high and low–low clustering became more evident, although a certain degree of spatial heterogeneity still persists overall. These findings provide empirical evidence for understanding the spatial differentiation and evolutionary patterns of the land use efficiency of state-owned agricultural land and offer useful insights for optimizing land resource allocation and management.

Food security is a fundamental issue that has long been of great concern, and cultivated land resources are the core elements of food security. In recent years, the problem of “non-agriculturalization” and “non-grain” conversion of cultivated land has become prominent. The need for further strict control of cultivated land use has gained significant attention from the government and academia. Recently, it has been proposed in China that all forms of cultivated land occupation should be integrated into the management policy for balancing cultivated land occupation and reclamation. In this study, the concept of provincial-level land-type classification, along with agricultural land potential productivity evaluation, is adopted to determine the optimal scheme for balancing cultivated land occupation and reclamation. Thus, an analysis of the optimization scheme for implementing the cultivated land occupation and reclamation balance policy in Heilongjiang, along with a macro-level layout of this balance scheme, is carried out at the provincial level. The results show that the land-type classification system constructed from five dimensions—climatic conditions, geomorphic conditions, geological conditions, edaphic conditions, and hydrologic conditions—as well as the agricultural land potential productivity evaluation system constructed based on land types, can effectively identify the potential cultivated land utilization space in Heilongjiang Province. Based on the zoning of land suitable for farming, the cultivated land in unsuitable farming areas in Heilongjiang should be transferred out (403.01 km²) and, according to the principle of the balancing cultivated land occupation and reclamation policy, the non-cultivated land in highly and moderately suitable farming areas should be transferred in (249.80 km² and 163.39 km², respectively) to achieve balance. The results can provide reference for the implementation of the cultivated land occupation and reclamation policy at the provincial level, as well as for promoting the implementation of the strategy of “storing grain in the land”.

Agricultural land consolidation (ALC) is an effective tool to ensure national food security. The current ALC is a government‐led systematic behavior with regional characteristics, most ALC types are classified according to difficulty without considering the safety of soil systems, resulting in randomness in the site selection of projects. Given the soil complexity, ensuring soil security (SS) is a prerequisite for efficiently completing ALC. ALC that gives full play to the soil's functional advantages is an effective means of securing SS. The main goal of this study is to establish a new set of technical processes for classifying the types of ALC from the perspective of SS, including the agricultural SS evaluation system and the identification method of land‐improvable limiting factors. We used a generalized mean model to evaluate and analyze SS in multiple dimensions and identified 11 combinations of limiting factors in Wen County through the k‐means clustering method. The combination of the limiting factor clustering area with the SS spatial distribution patterns guided five ALC types. When compared using the spatial pattern comparison method, the new ALC guideline avoids the singularity of ALC types, selects the field patch as the evaluation and decision‐making unit, and improves the accuracy of land management measures. The results indicate that incorporating SS into ALC policy planning and decision‐making can provide complex and multifaceted knowledge of factors affecting SS, and potential solutions to make agricultural soils safer, enabling higher quality and sustainability of agricultural land use.

Given that farmland serves as a strategic resource to ensure national food security, blind emphasis on the improvement of food production capacity can lead to soil overutilization and impair other soil functions. Hence, the evaluation of soil health (SH) should comprehensively take soil productivity and ecological environmental effects into account. In this study, five functions from the perspective of functional soil management were summarized, including primary productivity, provision and cycling of nutrients, the provision of functional and intrinsic biodiversity, water purification and regulation, and carbon sequestration and regulation. For each soil function, in view of the natural and ameliorable conditions affecting SH, basic indicators were selected from the two aspects of inherent and dynamic properties, and restrictive indicators were chosen considering the external properties or environmental elements, with the minimum limiting factor method coupled with weighted linear model. The new evaluation system was tested and verified in Yixing City, China. The healthy and optimally functional soils were concentrated in the northeast and mid-west of Yixing City, whereas unhealthy soils were predominant in the south and around Taihu Lake. The main limitations to SH improvement included cation exchange capacity, nutrient elements, and soluble carbon. The SH evaluation method was verified using the crop performance validation method, and a positive correlation was noted between food production stability index and soil health index, indicating that the evaluation system is reasonable.

Given that cultivated land serves as a strategic resource to ensure national food security, blind emphasis on improvement of food production capacity can lead to soil overutilization and impair other soil functions. Therefore, we took Heilongjiang province as an example to conduct a multi-functional evaluation of soil at the provincial scale. A combination of soil, climate, topography, land use, and remote sensing data were used to evaluate the functions of primary productivity, provision and cycling of nutrients, provision of functional and intrinsic biodiversity, water purification and regulation, and carbon sequestration and regulation of cultivated land in 2018. We designed a soil function discriminant matrix, constructed the supply-demand ratio, and evaluated the current status of supply and demand of soil functions. Soil functions demonstrated a distribution pattern of high grade in the northeast and low grade in the southwest, mostly in second-level areas. The actual supply of primary productivity functions in 71.32% of the region cannot meet the current needs of the population. The dominant function of soil in 34.89% of the area is water purification and regulation, and most of the cultivated land belongs to the functional balance region. The results presented herein provide a theoretical basis for optimization of land patterns and improvement of cultivated land use management on a large scale, and is of great significance to the sustainable use of black soil resources and improvement of comprehensive benefits.

Under the task requirements of China’s 3rd national land survey on the grade determination of cultivated land, research on a reasonable and unified survey and evaluation system of cultivated land quality (CLQ) is of great importance. From the three dimensions of agricultural climate, production potential, and health status components of cultivated land, six factors are selected in this study to construct a set of simple, practicable, and operable county-level CLQ survey and evaluation system. These factors are climate conditions of cultivated land, soil characteristics, tillage conditions, the attributes of cultivated land type, environmental conditions, and biological activity. The developed survey and evaluation system meets the demands of national engineering for the inclusion and coordination of multiple departments based on the current evaluation system and evaluation methodology of all relevant land administrative departments. Wen County, Henan Province is used for field verification and evaluation. Results demonstrate that the average quality index of cultivated land in Wen County is 2196.33, ranging from 660.70 to 2802.96 with the largest area of the first-class and second-class land accounting for 20.98% and 52.61% of the county’s cultivated land, respectively; the third-class and fourth-class land, 12.63% and 13.78%. The obvious regional differentiation characteristics are presented along the boundary of Qingfengling with the quality of northern cultivated land higher than that in the south. The comparison with the results of the national utilization gradation in 2018 infers that they are in accordance with the distribution of CLQ, which bears a significant positive correlation trend with the measured grain output of the field. The constructed evaluation system serves as a rewarding attempt of a unified survey and evaluation of CLQ at the county scale to reflect the production capacity of local crops, realize the sharing of data platforms, save manpower and capital investment, improve the practical connection of supervision and management of cultivated land protection in different departments, and meet the requirements of current cultivated land protection and management.