Exploring cultivated land trade-off/synergy of production and ecological supply–demand mismatch for coordinated development: evidence from mega urban agglomeration

The balance between the production and ecological supply–demand of cultivated land is crucial for regional food and ecological security. However, most studies focus on either the production or ecological aspect, neglecting the trade-offs/synergies of multifunctional cultivated land supply–demand. This study utilized the Pearl River Delta (PRD) mega urban agglomeration in China as a case study. It employed the Enhanced Two-step Floating Catchment Area (E2SFCA) and Ecological Footprint (EF) methods to quantify the production and ecological supply–demand at municipal and grid levels. Spatial correlation analysis was applied to identify trade-offs/synergies, which provided a basis for delineating cultivated land protection areas. The findings indicated that: (1) Cultivated land in the PRD faced severe supply–demand imbalances in the production and ecological functions, with urbanized areas exhibiting high demands but insufficient supply. (2) Production and ecological supply–demand ratios were spatially distributed as “lower in central plains, higher in surrounding hills,” inversely correlated with urbanization and population density. (3) There were significant trade-offs/synergies relationship between production and ecological supply–demand, with synergies being dominant. (4) Four zoning categories—priority protection, strict regulation, production enhancement, and remediation/restoration—were proposed. Overall, the goal is to maintain a balanced supply and demand in the priority protection zones, address the imbalance in the strict regulate zones, enhance production functions in the production enhancement zones and ecological functions in the remediation and restoration zones. This study offers insights into spatially zonal protection strategies and sustainable cultivated land management for mega urban agglomerations.