Spatial-temporal patterns of wheat growth model parameter sensitivity and strategies for region-adaptive calibration and management

Sensitivity analysis (SA) of crop model parameters is essential for improving model understanding, application, and development. However, few studies have systematically examined the spatiotemporal variations of parameters simultaneously. In this study, we used soil and meteorological data from China's major wheat-producing regions as inputs and calibrated the annual WOrld FOod STudies (WOFOST) model simulation results from 2000 to 2009 against statistical wheat yield data. Based on this, the extended Fourier amplitude sensitivity test (EFAST) algorithm was employed to compute the first-order and total sensitivity indices of ten crop parameters related to leaf area index (LAI) and dry matter. A structural equation model (SEM) was constructed to quantify the contribution of parameters to growth indicators. The results show that the temporal dynamics of parameter sensitivity are attributed to the model’s simulation focus shifting with crop growth stages—from ''light interception and leaf construction'' to ''matter allocation and photosynthesis maintenance''. In contrast, the spatial variation of parameter sensitivity stems from regional differences driven by climate gradients, which manifest as photosynthesis prioritization in low latitudes and low-temperature adaptation in high latitudes. Additionally, the regional characteristics of dry matter sensitivity are more pronounced than those of LAI. By integrating EFAST sensitivity indices and SEM path coefficients, core parameters of spatiotemporally universal importance for wheat growth simulation can be identified. These parameters serve as high-priority targets for large-scale model calibration and act as key regulatory objects for regional agricultural management. This study provides a scientific basis for optimizing WOFOST parameterization schemes and formulating region-adaptive agricultural management strategies across different climatic zones and wheat production systems in China.