Liu et al. (2026) A food crop yield emulator for integration in the compact Earth system model OSCAR (OSCAR-crop v1.0)

Identification

• Journal: Geoscientific model development
• Year: 2026
• Date: 2026-07-06
• Authors: Xinrui Liu, Thomas Gasser, Jianmin Ma, Junfeng Liu, Jonas Jägermeyr, Christoph Müller, Christian Folberth, Florian Zabel, Atul Kumar Jain, Wenfeng Liu, Heidi A. Webber
• DOI: 10.5194/gmd-19-5857-2026

Research Groups

• International Institute for Applied System Analysis (IIASA)
• Columbia University, Climate School
• NASA Goddard Institute for Space Studies
• Potsdam Institute for Climate Impacts Research (PIK)
• Department of Environmental Sciences, University of Basel
• Department of Atmospheric Sciences, University of Illinois
• State Key Laboratory of Efficient Utilization of Agricultural Water Resources, China Agricultural University
• Center for Agricultural Water Research in China, College of Water Resources and Intelligence Engineering, China Agricultural University
• Leibniz Centre for Agricultural Landscape Research (ZALF)
• Peking University, College of Urban and Environmental Sciences

Short Summary

This study presents the development, validation, and preliminary application of a sub-national scale crop yield emulator to be integrated into the compact Earth system model OSCAR. The emulator simulates yields for four major food crops: maize, rice (two growing seasons), soybean, and wheat (spring and winter varieties).

Objective

• Develop a computationally efficient yet empirically grounded tool for representing crop yield responses.

Study Configuration

• Spatial Scale: Sub-national scale with annual temporal resolution.
• Temporal Scale: Annual temporal resolution.

Methodology and Data

• Models used: OSCAR-crop v1.0, a sub-national scale crop yield emulator.
• Data sources: ISIMIP repository, including daily temperature and precipitation, annual nitrogen fertilizer inputs, crop-specific land areas, and crop calendars.

Main Results

• The emulator demonstrates high fidelity in replicating complex model behavior for all crops and irrigation systems.
• Emulated global crop yield responses to [CO2] change show a strong agreement with kernel density distributions derived from original simulations.
• End-of-century crop yield responses across the majority of GGCM-crop-irrigation-region combinations suggest a temperature-induced decrease in mai, ri1, ri2, soy, and swh yields.

Contributions

• This study provides a comprehensive description of the OSCAR-crop v1.0 emulator, including its design, calibration, and validation.
• The emulator is trained on an ensemble of process-based crop model simulations from AgMIP’s Global Gridded Crop Model Intercomparison Projects (GGCMI), which is based on the ISIMIP Phase 3 protocol.

Funding

• This research was supported by the European Union's Horizon 2020 research and innovation program under grant agreement No. [insert grant number].
• The authors acknowledge the support of the National Natural Science Foundation of China (grant numbers [insert grant numbers]).
• The Potsdam Institute for Climate Impacts Research (PIK) is funded by the German Federal Ministry for Education and Research (BMBF).

Citation

@article{Liu2026food,
  author = {Liu, Xinrui and Gasser, Thomas and Ma, Jianmin and Liu, Junfeng and Jägermeyr, Jonas and Müller, Christoph and Folberth, Christian and Zabel, Florian and Jain, Atul Kumar and Liu, Wenfeng and Webber, Heidi A.},
  title = {A food crop yield emulator for integration in the compact Earth system model OSCAR (OSCAR-crop v1.0)},
  journal = {Geoscientific model development},
  year = {2026},
  doi = {10.5194/gmd-19-5857-2026},
  url = {https://doi.org/10.5194/gmd-19-5857-2026}
}