Effects of Elevated CO2 on Wheat Yield: Non-Linear Response and Relation to Site Productivity

Agronomy

Håkan Pleijel¹  Zhaozhong Feng²  MalinC. Broberg³  Petra Högy⁴ 

[1] Technology, Nanjing 210044, China;;Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science &Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-40530 Göteborg, Sweden;Institute of Landscape and Plant Ecology, University of Hohenheim, Ökologiezentrum 2, August-von-Hartmann Str. 3, D-70599 Stuttgart, Germany;

关键词: carbon dioxide;    exposure system;    harvest index;    grain mass;    grain number;    grain yield;    meta-analysis;    response function;    site productivity;    specific grain mass;    Triticum aestivum;   

DOI  :  10.3390/agronomy9050243

来源: DOAJ

【 摘 要 】

Elevated carbon dioxide (eCO₂) is well known to stimulate plant photosynthesis and growth. Elevated carbon dioxide’s effects on crop yields are of particular interest due to concerns for future food security. We compiled experimental data where field-grown wheat (Triticum aestivum Linnaeus) was exposed to different CO₂ concentrations. Yield and yield components were analyzed by meta-analysis to estimate average effects, and response functions derived to assess effect size in relation to CO₂ concentration. Grain yield increased by 26% under eCO₂ (average ambient concentration of 372 ppm and elevated 605 ppm), mainly due to the increase in grain number. The response function for grain yield with CO₂ concentration strongly suggests a non-linear response, where yield stimulation levels off at ~600 ppm. This was supported by the meta-analysis, which did not indicate any significant difference in yield stimulation in wheat grown at 456–600 ppm compared to 601–750 ppm. Yield response to eCO₂ was independent of fumigation technique and rooting environment, but clearly related to site productivity, where relative CO₂ yield stimulation was stronger in low productive systems. The non-linear yield response, saturating at a relatively modest elevation of CO₂, was of large importance for crop modelling and assessments of future food production under rising CO₂.

【 授权许可】

Unknown