Agricultural water savings and productivity responses to groundwater governance in the North China Plain

Groundwater depletion driven by irrigated agriculture poses a critical constraint on agricultural sustainability in the North China Plain. Using multi-source Earth observation data, causal inference, and a nested spatial design, this study assesses agricultural productivity responses and groundwater-relevant water use under groundwater governance in the North China Plain. We reconstruct a 10 m solar-induced chlorophyll fluorescence (SIF) dataset through Sentinel-1/2 data fusion to characterize field-scale photosynthetic activity, extract photosynthetic phenology, and apply a double machine learning framework to identify cropping-regime effects while controlling for high-dimensional confounding factors. The results show that although agricultural productivity exhibits an overall greening trend, productivity enhancement remains closely associated with persistent groundwater stress in groundwater-dependent areas. Groundwater governance can reduce consumptive blue water use through transitions from double-cropping to single-cropping systems, although these water savings are accompanied by substantial productivity costs, whereas long-term high-intensity agriculture imposes sustained structural pressure on groundwater resources. Integrated quantification further reveals a substantial productivity–water trade-off in the core irrigated area, where consumptive blue water savings are accompanied by comparable productivity losses. These findings highlight the potential for reducing groundwater pressure through structural and institutional adjustments rather than continued increases in irrigation inputs, providing empirical support for groundwater governance and agricultural water management in groundwater-dependent regions.