Action mechanism and effectiveness evaluation of comprehensive land consolidation on promoting cropland stable utilization

Comprehensive land consolidation, as the latest tool for addressing the dilemma of cropland marginalization in China, is centered on ensuring the cropland stable utilization through spatial restructuring. However, it is still underdeveloped in terms of theoretical construction, monitoring methods, and effectiveness evaluation. This study analyzed the action mechanism by which comprehensive land consolidation promotes the cropland stable utilization based on the progressive dimensions of "pattern-utilization-capacity", and constructed an indicator system to evaluate the implementation effectiveness with conducting empirical research in Jiuguan Project, Huzhou City, Zhejiang Province, China. Utilizing the Google Earth Engine (GEE) platform and FRAGSTATS software, combined with remote sensing inversion models and the Cumulative Vegetation Index (CVI) model, the study conducted overall and zoned evaluations of cropland layout, land use efficiency, and grain production capacity, which resulted in the formation of Pattern Index (PI), Utilization Index (UI), Capacity Index (CI), and Cropland Stable Utilization Index (CSUI), as well as their trend indices, which were usd to reflect the effectiveness of comprehensive land consolidation. The results indicated that: 1) the trend index of CSUI was 17.45, indicating overall good consolidation effectiveness; 2) the trend indices of PI, UI, and CI were 17.27, 18.93, and 15.93, respectively, indicating cropland tended to be concentrated and contiguous, land use efficiency had significantly improved, and grain production capacity had been significantly enhanced; 3) there was a positive correlation between consolidation scale and effectiveness, with a correlation coefficient of 0.88 (α=0.01), and when the propotion of land occupied by the project reached 5.10%, the scale effect reached its maximum. Based on these findings, the following conclusions were drawn: Comprehensive land consolidation effectively promotes the cropland stable utilization through the pathway of "optimizing pattern-promoting utilization-enhancing capacity", which means by advancing the suitable restructuring of cropland layout, comprehensive land consolidation is able to create spatial conditions for moderate-scale agricultural operations, therefrom improves cropland utilization efficiency and grain production capacity, and as the scale of the project expands, pattern, capacity, and comprehensive dimensions achieve maximum scale effects in turn. Based on these conclusions, the following policy recommendations were proposed: 1) Grasp the core positioning of spatial governance in comprehensive land consolidation, and consolidate the leading function of grain production by reconstructing agricultural production space; 2) Leverage the key role of moderate scale operations in the cropland stable utilization, and create spatial conditions conducive to the scale operation; 3) Fully consider the impact of scale effect on the effectiveness of comprehensive land consolidation, and control the propotion of land occupied by the project to about 5% of the total area of consolidation region to maximize resource utilization efficiency. In summary, the proposed action mechanism in the study provided theoretical guidance for optimizing the pathway of related projects, and the constructed effectiveness evaluation system and methods provided a tool system with accessible data, easy-to-operate methods, and convenient promotion for relevant departments to conduct in-depth monitoring and evaluation, and the empirical conclusions could serve as a reference for related effectiveness evaluation results. All of the above have good prospects for promotion and application.