Novel multimodel ensemble approach to evaluate the sole effect of elevated CO2 on winter wheat productivity

Mukhtar Ahmed; Claudio O Stöckle; Roger Nelson; Stewart Higgins; Shakeel Ahmad; Muhammad Ali Raza

doi:10.1038/s41598-019-44251-x

Novel multimodel ensemble approach to evaluate the sole effect of elevated CO₂ on winter wheat productivity

Sci Rep. 2019 May 24;9(1):7813. doi: 10.1038/s41598-019-44251-x.

Authors

Mukhtar Ahmed^{1

2

3}, Claudio O Stöckle⁴, Roger Nelson⁴, Stewart Higgins⁴, Shakeel Ahmad⁵, Muhammad Ali Raza⁶

Affiliations

¹ Department of Agronomy, PMAS Arid Agriculture University, Rawalpindi, 46300, Pakistan. ahmadmukhtar@uaar.edu.pk.
² Department of Biological Systems Engineering, Washington State University, Pullman, WA, 99164-6120, USA. ahmadmukhtar@uaar.edu.pk.
³ Department of Northern Agricultural Sciences, Swedish University of Agricultural Sciences, Umeå, 90183, Sweden. ahmadmukhtar@uaar.edu.pk.
⁴ Department of Biological Systems Engineering, Washington State University, Pullman, WA, 99164-6120, USA.
⁵ Department of Agronomy, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, 60800, Pakistan.
⁶ College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, PR, China.

Abstract

Elevated carbon-dioxide concentration [eCO₂] is a key climate change factor affecting plant growth and yield. Conventionally, crop modeling work has evaluated the effect of climatic parameters on crop growth, without considering CO₂. It is conjectured that a novel multimodal ensemble approach may improve the accuracy of modelled responses to eCO₂. To demonstrate the applicability of a multimodel ensemble of crop models to simulation of eCO₂, APSIM, CropSyst, DSSAT, EPIC and STICS were calibrated to observed data for crop phenology, biomass and yield. Significant variability in simulated biomass production was shown among the models particularly at dryland sites (44%) compared to the irrigated site (22%). Increased yield was observed for all models with the highest average yield at dryland site by EPIC (49%) and lowest under irrigated conditions (17%) by APSIM and CropSyst. For the ensemble, maximum yield was 45% for the dryland site and a minimum 22% at the irrigated site. We concluded from our study that process-based crop models have variability in the simulation of crop response to [eCO₂] with greater difference under water-stressed conditions. We recommend the use of ensembles to improve accuracy in modeled responses to [eCO₂].

Publication types

Research Support, U.S. Gov't, Non-P.H.S.