Implementing a Dynamic Root Distribution Scheme Responsive to Soil Environment Into Noah‐MP‐Crop: Improving Simulations of Soil Water, Crop Growth, and Energy Fluxes in Agro‐Ecosystems

Abstract Reliable simulation of land–atmosphere interactions in land surface models (LSMs) requires realistic root distribution modeling, yet conventional static root parameterizations often fail to capture seasonal root dynamics in cropland ecosystems. In this study, we developed a soil–environment–responsive dynamic root distribution scheme (SEᵣoot) within the Noah‐MP‐Crop framework that explicitly accounts for soil moisture (SM), temperature, aeration, bulk density, and soil texture. Evaluations against in situ observations in the North China Plain demonstrated that SEᵣoot substantially outperformed the default static (fixedᵣoot) and exponential dynamic (Expᵣoot) parameterizations. Site‐scale simulations exhibited improved accuracy in capturing SM dynamics, leaf area index (LAI), and latent heat flux (LHF), yielding R 2 values consistently above 0. 56. The simulated vertical root biomass distribution, with approximately 70% of root biomass concentrated in the upper 40 cm and declining with depth, closely matched field observations. Relative to the fixedᵣoot and Expᵣoot schemes, the site‐scale mean absolute errors were reduced by 10%–12% for SM and 4%–10% for LAI. Regional simulations further revealed that by capturing the dynamic feedback between root growth and local soil constraints, SEᵣoot better represented the spatial heterogeneity of SM and LAI, alongside modest LHF improvements. Overall, incorporating this soil‐responsive root parameterization improves the representation of SM dynamics, root allocation, crop growth, and land–atmosphere exchanges. These findings underscore the importance of explicitly representing root–soil interactions in agricultural LSMs, offering a robust pathway for coupling with climate models to capture crop–climate feedbacks and support sustainable management.