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Seasonal
dynamics of surface energy fluxes over
a
center-pivot irrigated cropland in Saudi Arabia
R.
Madugundu1*, K.A. Al-Gaadi1,2, E. Tola1,
A.G. Kayad2, A.A. Hassaballa1 and V.C. Patil3
1Precision
Agriculture Research Chair, King Saud University, Riyadh-11451, Saudi Arabia
2Department of
Agricultural Engineering, College of Food and Agriculture Sciences, King Saud
Universtiy, Riyadh-11451, Saudi Arabia
3Electron Science
Research Institute, Edith Cowan University, Joondalup WA-6027, Australia
*Corresponding
Author E-mail: rmadugundu@ksu.edu.sa
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Key
words
Agroecosystem,
Eddy covariance,
Energy flux,
Evapotranspiration,
Hyper-arid climates
Publication Data
Paper received : 15.06.2016
Revised received : 17.10.16
Re-revised received :
23.02.2017
Accepted : 09.03.2017
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Abstract
Aim: This study focused
on the seasonal dynamics of energy fluxes over selected agro ecosystems
(alfalfa and corn crops) to understand the role of energy partitioning in
determining the mechanisms controlling the crop water requirement and
irrigation schedules.
Methodology:
Eddy
Covariance (EC) flux tower was installed on a center pivot irrigated field located
in the Eastern Region of Saudi Arabia. EC data of nearly three years (May
2013 to March 2016) was analysed for variations in agro-climatic conditions,
energy fluxes and their partition under both cropped (alfalfa and corn) and
non-cropped (fallow) scenarios.
Results:
Three-year
mean net radiation (Rn) varied from 106.8 to 816.54 Wm-2, while
the recorded sensible heat, soil heat (G) and latent heat fluxes were 291.6,
158 and 3.8 Wm-2, respectively. The latent heat was more during
the crop growing season (381.38 W m-2) compared to fallow (23.89 W
m-2); while, sensible heat showed an opposite trend compared to
latent heat. The sensible heat recorded during the growing season (38.42 W m-2)
was much lower than for the fallow season (281.35 W m-2). ????
Interpretation:
There
was contrasting variations in sensible heat and latent heat fluxes across
seasons and corresponding to the changing climate and surface conditions of
the field. In the case of silage corn, the proportions of partitioned energy
to sensible heat (12.4%) and latent heat (18%) were higher than alfalfa.
However, during the alfalfa post-harvest practices, the latent heat flux was
always less as the available energy was partitioned as sensible heat rather
than latent heat flux.
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Copyright
? 2017 Triveni Enterprises. All rights reserved. No part of the Journal can
be reproduced in any form without prior permission. Responsibility
regarding the authenticity of the data, and the acceptability of the conclusions
enforced or derived, rest completely with the author(s).
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