Hydrological Intensification Decouples Crop Production From Ecological Integrity: Identifying Biophysical Limits in an Arid Agro‐Ecosystem

ABSTRACT Hydrological intensification in desert oases decouples food production from aridity, yet how irrigation‐supported blue‐water consumption (BWC) reshapes nonlinear trade‐offs among ecosystem services remains uncertain. We examined crop production (CP), soil conservation (SC), and water purification (WP) in the Hetao Irrigation District from 2001 to 2023 using multisource earth observation, generalized additive models, pairwise interaction analysis, and path analysis. CP increased by 22.5% from 1.80 to 2.21 t ha −1 , while mean BWC rose from 37.7 to 130.2 mm. In contrast, SC varied strongly among years (0.80–3.33 t ha −1 ) and WP remained stable (0.78–0.80) but showed divergent spatial trends. CP increased almost monotonically with BWC, whereas SC declined sharply at low BWC and WP showed a hump‐shaped response, with the transition from positive to negative marginal sensitivity occurring at approximately 170–180 mm BWC. BWC reshaped the geometry and turning points of service relationships more strongly than climatic water balance, which mainly altered interaction magnitude. High BWC helped sustain CP during dry years but kept SC–WP coordination in a low‐synergy state and did not reproduce the broader CP–WP synergies observed under wet conditions. Path analysis further showed that stable croplands were characterized by a stronger BWC–CP linkage and landscape configuration constraints on regulating services, whereas expanding croplands were more strongly limited by temperature, sandy soils, and alkaline soil conditions. These results indicate that blue‐water‐dependent intensification can stabilize production but narrow the conditions for regulating service synergy, highlighting the need to reduce excessive blue‐water dependence in stable croplands and restrict expansion onto edaphically constrained margins.