Evaluation of sap flow sensors to measure the transpiration rate of plants during sprinkler irrigation

Uddin, J. and Smith, R. J. and Hancock, N. H. and Foley, J. (2011) Evaluation of sap flow sensors to measure the transpiration rate of plants during sprinkler irrigation. In: SEAg 2011: Diverse Challenges, Innovative Solutions, 29-30 Sep 2011, Gold Coast, Australia.

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Abstract

Accurate measurement of transpiration is needed to quantify the different components of evaporation losses during sprinkler irrigation. Among the different methods for direct measurement of transpiration rate, measurement of sap flow on the basis of heat flow has been widely used. To evaluate the applicability of this method for use in field experiments involving sprinkler irrigation, stem flow measurements on small pot plants were compared with transpiration values estimated from successive mass measurements using pre-calibrated mini-lysimeters. Experiments were conducted in the glass house at USQ during the period August to October 2010. From this study it was found that during steady conditions, the sap flow sensors were able to measure the transpiration rate of plants in reasonable agreement (11% overestimation) with the lysimeter measurements. During canopy wetting (sprinkler irrigation) the decline in sap flow rate was less than and lagged the decline in transpiration rate due to the storage and buffering capacity of the stem. Sap flow sensors at different heights on the plant responded at different rates for the same reason. The study showed that the sap flow sensors do not give an accurate measurement of transpiration during canopy wetting and drying but will still aid interpretation of measurements of total evaporation during sprinkler irrigation.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: Publisher does not formally support archiving.
Depositing User: Mr Md Jasim Uddin
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - No Department
Date Deposited: 24 Jan 2012 05:28
Last Modified: 03 Jul 2013 01:00
Uncontrolled Keywords: sap flow; transpiration; eddy covariance; time lag; mini lysimeter
Fields of Research (FOR2008): 07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070199 Agriculture, Land and Farm Management not elsewhere classified
09 Engineering > 0906 Electrical and Electronic Engineering > 090605 Photodetectors, Optical Sensors and Solar Cells
07 Agricultural and Veterinary Sciences > 0799 Other Agricultural and Veterinary Sciences > 079901 Agricultural Hydrology (Drainage, Flooding, Irrigation, Quality, etc.)
Socio-Economic Objective (SEO2008): B Economic Development > 82 Plant Production and Plant Primary Products > 8299 Other Plant Production and Plant Primary Products > 829999 Plant Production and Plant Primary Products not elsewhere classified
URI: http://eprints.usq.edu.au/id/eprint/20554

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