Temporal variability in the impacts of particulate matter on crop yields on the North China Plain

Wolffe, Michael C. and Wild, Oliver and Long, Stephen P. and Ashworth, Kirsti (2021) Temporal variability in the impacts of particulate matter on crop yields on the North China Plain. Science of the Total Environment, 776. ISSN 0048-9697

[img]
Text (AcceptedVersion)
AcceptedVersion.pdf - Accepted Version
Restricted to Repository staff only until 16 February 2022.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (2MB)

Abstract

The North China Plain (NCP) is a major agricultural region, producing 45% of China's maize. It is also vital to the Chinese economy, encompassing the Beijing-Tianjin-Hebei megacity region. Anthropogenic factors increasingly impact crop yields on the NCP, and globally. Particulate matter (PM) pollution is a significant problem in this region, where annual average PM concentrations over three times the Chinese national air quality standard were recorded for the Beijing-Tianjin-Hebei megacity region between 2013 and 18. PM absorbs light, reducing total shortwave radiation (SW), thereby limiting plant productivity. However, PM also scatters incoming SW, increasing the diffuse fraction, which has been shown to increase growth and biomass assimilation. The Joint UK Land Environment Simulator (JULES) crop model was used to assess the net impact of these competing changes in light on NCP maize yields. In contrast to some previous analyses, we find that PM-associated decreases in SW outweigh any positive impact on yield from an increasing proportion of diffuse radiation. Furthermore, carbon allocation to different portions of the growing cropchanges during the development cycle. We find significant differences between the effect on final yield of identical changes to diffuse fraction and total SW occurring during different development stages. The greatest simulated yield gains from increased SW and reduced diffuse fraction, consistent with reductions in PM, are observed during the early reproductive stage of development (July–August), when the simulated gain of yield is as much as 12.9% more than in other periods. To further assess the impact of PM-linked changes in SW and diffuse fraction on NCP crop yields, radiation profiles from different city regions were then applied across the NCP. The changes in SW associated with these city regions could increase maize yields across China by ~8 Mt. This would completely offset China's annual maize imports, increasing both national and global food security.

Item Type:
Journal Article
Journal or Publication Title:
Science of the Total Environment
Additional Information:
This is the author’s version of a work that was accepted for publication in Science of the Total Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Science of the Total Environment, 776, 2021 DOI: 10.1016/j.scitotenv.2021.145135
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2300/2311
Subjects:
ID Code:
152504
Deposited By:
Deposited On:
08 Mar 2021 13:20
Refereed?:
Yes
Published?:
Published
Last Modified:
16 Jun 2021 09:04