Objective The construction of ecological civilization in China provides spatial security for the protection and development of the national territory. In the current efforts in territorial spatial planning, it is a key focus and consensus to actively implement the principles of prioritizing ecological space protection and strictly adhering to the red line of arable land protection, comprehensively optimize the spatial management of land development and utilization, and form a coordinated development pattern of ecological space, agricultural space, and urban space. In the context of a new era of rational ecological planning paradigms, this research notes that the control measures for ecological space and agricultural space are fundamentally similar. The red line for ecological protection and that for basic farmland protection have become critical tools in curbing the disorderly expansion of urban spaces. However, the management of ecological and agricultural spaces is essentially two sides of the same coin. The logical consistency in the management and control of ecological space and that of agricultural space entails the collaboration of the both sides, ultimately achieving “conjugate” management and control. Therefore, appropriately resolving spatial conflicts and transforming them into flexible management spaces to achieve conjugate management and control is a key task for the next phase of collaborative management and control of ecological and agricultural spaces. This is also significant for deepening the understanding of the conjugation effects of the management and control of ecological and agricultural spaces. By identifying the characteristics of spatial conflicts in the Yangtze River Delta region of China, this research aims to reveal the logical relationships in and methods for the collaborative management and control of ecological and agricultural spaces in urban agglomerations. This will help realize the elastic constraint on urban spaces by ecological and agricultural spaces.

Methods This research focuses on the Yangtze River Delta Urban Agglomeration. Based on the evaluation of the importance of ecological protection, the suitability of agricultural production, and the suitability of urban construction in the Yangtze River Delta Urban Agglomeration, ArcGIS spatial overlay analysis is used to obtain the characteristics of spatial conflicts in the Yangtze River Delta Urban Agglomeration. First, a foundational database is constructed using diverse data sources, including geospatial and land use data, as well as basic planning and demographic and economic data, followed by preprocessing of various types of data. Second, the evaluation and scoring of various single factors are completed by referring to the specific processes of factor selection, factor grading, factor weighting, and result revision in the Technical Guidelines for the Evaluation of the Carrying Capacity of Resources and the Environment and the Suitability of Territorial Spatial Development. Then, spatial overlay analysis is conducted on each single-factor analysis map using relevant mathematical models, respectively obtaining the comprehensive evaluation results of ecological protection importance (9 single factors), agricultural production suitability (8 single factors), and urban construction suitability (13 single factors) in the Yangtze River Delta Urban Agglomeration. Finally, the evaluation results are graded and spatially merged and overlaid, with similar spatial overlay results being combined to obtain comprehensive spatial conflict identification results, based on which the distribution of different advantage zones and conflict types is summarized.

Results The spatial merging and overlaying of the three evaluation grading results produces 27 spatial combination types. According to the principle that “the higher the suitability grade of different evaluations, the higher the conflict level”, six types of advantage and conflict zones are summarized and organized: Ecological space advantage zone, agricultural space advantage zone, urban space advantage zone, low conflict zone, medium conflict zone, and high conflict zone, with four levels of control zones and implementation paths being further detailed. In terms of advantage zones, the agricultural space advantage zones are mainly distributed in the central east-west and northeastern belt areas of the Yangtze River Delta, with a total area of 41,805.40 km², accounting for 18.59% of the total area of local advantage and conflict zones, a relatively low overall proportion, reflecting the insufficient protection of basic farmland in China; the ecological space advantage zones are mainly concentrated in the southwestern area of the Yangtze River Delta Urban Agglomeration, with a total area of 32,265.66 km², accounting for 14.34%; the ecological space advantage zone is seldom seen in the central and northern areas of the Yangtze River Delta Urban Agglomeration; the urban construction space advantage zones are mainly concentrated in the central and northern areas with convenient transportation and well-developed infrastructure, occupying the largest area among all types of advantage zones, with a total area of 54,775.77 km², accounting for 24.38%. In terms of conflict zones, low conflict zones are scattered in the central and southern areas of the Yangtze River Delta Urban Agglomeration, being the largest type of conflict zone with a total area of 28,084.22 km², accounting for 12.49%; medium conflict zones are mainly distributed at the boundaries between ecological space, agricultural space, and urban space, threatening existing ecological protection areas, with a total area of 26,829.27 km², accounting for 11.97%; high conflict zones are mainly scattered around rivers, lakes, and mountain areas adjacent to urban space advantage zones, most vulnerable to human development activities. The total area of high conflict zones is 16,645.80 km², accounting for 7.39%, making it the smallest type of conflict zone.

Conclusion Based on the results of spatial conflict identification in the Yangtze River Delta region, this research innovatively proposes a reverse thinking approach of “identifying spatial conflicts − subdividing conflict functions − implementing graded control” and presents a framework for the implementation of collaborative management and control of regional ecological and agricultural spaces. This includes five main components: Mechanisms of spatial conflict causation, distribution patterns of spatial conflicts, subdivision of spatial conflict functions, extraction of subdivision results classification, and dynamic feedback of the management and control system. Additionally, this research further clarifies the application paths for collaborative management and control of different spatial conflict zones under “parallel conjugation” and “integrated conjugation” through a framework for collaborative management and control of regional ecological and agricultural spaces based on the conjugation effect. The research creatively proposes a zonal management and control approach of “rigid constraint and flexible integration”, which can, by delineating rigid management and control areas, ensure the baseline protection of regional ecological and agricultural spaces, help implement the top-level strategic goals of regional development for ecological pattern protection and food security assurance. For areas where spatial conflicts and functional overlaps arise from the utilization demands of various spaces within the region, flexible integration development zones are delineated to guide land functions and formulate differentiated control rules within the zones. This approach appropriately balances “protection” and “development” to serve the multiple demands of ecological protection, agricultural production, and urban development in the process of land development. This research effectively meets the requirements of integrative, systematic, differentiated, and dynamic control of spatial management in urban agglomerations, aiming to establish a consistent logic for the management and control of ecological, agricultural, and urban spaces.