Volume 210, Issue 4 e12719
ORIGINAL ARTICLE

Diurnal and Seasonal Variations of Water Use Efficiency of Rice–Wheat Rotation Cropland in the Jianghuai River Basin of China

Xiaohan Zhao

Xiaohan Zhao

Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Jiangsu Key Laboratory of Agricultural Meteorology, College of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, China

Hydrological Center of Shandong Province, Jinan, China

Contribution: Validation, Data curation, Formal analysis, Visualization, Writing - original draft, Writing - review & editing, Methodology, Software, Conceptualization

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Fangmin Zhang

Corresponding Author

Fangmin Zhang

Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Jiangsu Key Laboratory of Agricultural Meteorology, College of Ecology and Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, China

Correspondence:

Fangmin Zhang ([email protected])

Contribution: Conceptualization, Methodology, Funding acquisition, Supervision, Resources, Project administration, Writing - review & editing

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Shengheng Weng

Shengheng Weng

Fujian Institute of Meteorological Sciences, China Meteorological Administration, Fuzhou, China

Contribution: Conceptualization, Methodology, ​Investigation, Data curation, Writing - original draft

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Chunfeng Duan

Chunfeng Duan

The Anhui Province Meteorological Science Research Institute/Atmospheric Science and Satellite Remote Sensing Key Lab Anhui Province, Hefei, China

Anhui Climate Center, Hefei, China

Contribution: Supervision, Resources

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Yanyu Lu

Yanyu Lu

The Anhui Province Meteorological Science Research Institute/Atmospheric Science and Satellite Remote Sensing Key Lab Anhui Province, Hefei, China

Anhui Climate Center, Hefei, China

Contribution: Supervision, Resources, Funding acquisition

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First published: 25 June 2024

Funding: This work was supported by Natural Science Foundation of China (U2342206), Anhui Provincial Key Research and Development Plan (2022m07020003) and National Key Research and Development Program of China (2023YFF0805402).

ABSTRACT

Rice–wheat rotation cropland is one of the most important agroecosystems in South China, the escalation of conflict between food demand augment and water supply shortage increased with climate change. Water use efficiency plays a more significant role in optimising water and carbon management. Thus, the diurnal and seasonal variations of water use efficiency were assessed by the 3-year eddy covariance observations in the Shouxian National Observatory, a typical rice–wheat rotation station. The results revealed a ‘U’-shaped diurnal pattern of water use efficiency for winter wheat (Triticum aestivum L.) and rice (Oryza sativa L.). Seasonal water use efficiency had two peaks with the highest in the winter wheat-growing season. The average water use efficiency for the rice–wheat rotation cropland was 2.85 g C kg−1 H2O over the whole year with 2.62 and 3.11 g C kg−1 H2O for winter wheat and rice, respectively. However, gross primary productivity and evapotranspiration of rice were higher than those of winter wheat. Temperature, photosynthetically active radiation were the principal impact factors of water use efficiency in the rice-growing season. Comparatively, soil water and vapour pressure deficit dominated the water use efficiency changes in the winter wheat-growing season. Our analyses can help understand the water use requirements for carbon assimilation on rice–wheat rotation cropland on the field scale.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

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