Estimation of Winter Wheat Evapotranspiration under Water Stress with Two Semiempirical Approaches

Zhang, Y; Yu, Q; Liu, C; Jiang, J; Zhang, X

Estimation of Winter Wheat Evapotranspiration under Water Stress with Two Semiempirical Approaches

Zhang, Y Yu, Q

Liu, C Jiang, J Zhang, X

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Publication Type:: Journal Article
Citation:: Agronomy Journal, 2004, 96 (1), pp. 159 - 168
Issue Date:: 2004-01-01

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Field	Value	Language
dc.contributor.author	Zhang, Y	en_US
dc.contributor.author	Yu, Q https://orcid.org/0000-0001-6950-1821	en_US
dc.contributor.author	Liu, C	en_US
dc.contributor.author	Jiang, J	en_US
dc.contributor.author	Zhang, X	en_US
dc.date.issued	2004-01-01	en_US
dc.identifier.citation	Agronomy Journal, 2004, 96 (1), pp. 159 - 168	en_US
dc.identifier.issn	0002-1962	en_US
dc.identifier.uri	http://hdl.handle.net/10453/8887
dc.description.abstract	Winter wheat (Triticum aestivum L.) is one of most important crops in the North China Plain. However, soil water deficit (SWD) often occurs due to lack of precipitation in its growing season. In this study, we introduce two semiempirical approaches, a recharge model and the crop coefficient (K c)-reference evapotranspiration (ET0) approach, to estimate wheat actual evapotranspiration (ETa) under no SWD and slight and severe SWD conditions. The recharge model allocated ET0 to reference evaporation and reference transpiration as a function of leaf area index. In the model, ETa is limited by soil water content, and crop water extraction for ETa is distributed through the soil profile as exponential functions of soil and root depth. The Kc-ET0 approach regarded ETa under the SWD condition as a logarithmic function of soil water availability. Under no SWD condition, the recharge model simulated 10-d ETa with a root mean square error (RMSE) of 5.58 mm and a bias of 0.95 mm compared with measurements from a large-scale weighing lysimeter. The two approaches both estimated seasonal evapotranspiration (ET) well compared with the adjusted ET (from the soil water balance and the recharge model-simulated deep drainage). The recharge model, which simulated the seasonal ET with the RMSE of 27.8 mm and the bias of -8.0 mm, was better than the Kc-ET0 approach (RMSE = 31.7 mm and bias = -33.1 mm). The seasonal pattern of soil water stress coefficient (Ks) showed that there were faster water losses at grain-filling stage than at other stages.	en_US
dc.relation.ispartof	Agronomy Journal	en_US
dc.subject.classification	Agronomy & Agriculture	en_US
dc.title	Estimation of Winter Wheat Evapotranspiration under Water Stress with Two Semiempirical Approaches	en_US
dc.type	Journal Article
utslib.citation.volume	1	en_US
utslib.citation.volume	96	en_US
utslib.for	0703 Crop and Pasture Production	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Life Sciences
utslib.copyright.status	closed_access
pubs.issue	1	en_US
pubs.publication-status	Published	en_US
pubs.volume	96	en_US

Abstract:

Winter wheat (Triticum aestivum L.) is one of most important crops in the North China Plain. However, soil water deficit (SWD) often occurs due to lack of precipitation in its growing season. In this study, we introduce two semiempirical approaches, a recharge model and the crop coefficient (K c)-reference evapotranspiration (ET0) approach, to estimate wheat actual evapotranspiration (ETa) under no SWD and slight and severe SWD conditions. The recharge model allocated ET0 to reference evaporation and reference transpiration as a function of leaf area index. In the model, ETa is limited by soil water content, and crop water extraction for ETa is distributed through the soil profile as exponential functions of soil and root depth. The Kc-ET0 approach regarded ETa under the SWD condition as a logarithmic function of soil water availability. Under no SWD condition, the recharge model simulated 10-d ETa with a root mean square error (RMSE) of 5.58 mm and a bias of 0.95 mm compared with measurements from a large-scale weighing lysimeter. The two approaches both estimated seasonal evapotranspiration (ET) well compared with the adjusted ET (from the soil water balance and the recharge model-simulated deep drainage). The recharge model, which simulated the seasonal ET with the RMSE of 27.8 mm and the bias of -8.0 mm, was better than the Kc-ET0 approach (RMSE = 31.7 mm and bias = -33.1 mm). The seasonal pattern of soil water stress coefficient (Ks) showed that there were faster water losses at grain-filling stage than at other stages.

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http://hdl.handle.net/10453/8887