A comparison of soil- and canopy temperature-based methods for the early detection of water stress in a simulated patch of pasture
✍ Scribed by Cecilia Stanghellini; Francesca Lorenzi
- Publisher
- Springer
- Year
- 1994
- Tongue
- English
- Weight
- 568 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0342-7188
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✦ Synopsis
This paper evaluates the sensitivity of two different methods of water stress detection in a simulated patch of pasture grown in a greenhouse. The performance of two indices, based respectively on canopy temperature and soil water content values -the latter gauged by means of a time domain reflectometry (TDR) system, was assessed against actual evapotranspiration, measured by a very accurate weighing system. Both methods were able to detect water shortage by the time transpiration was reduced to some 80 % of its potential value. The soil-based index, however, relied on the estimate of root water extraction rate, which may not be known. It is concluded that detection of water shortage by means of a canopy temperature-based stress index is to be preferred to measuring soil water deficits by time domain reflectometry, despite the accuracy of the TDR-based soil water content estimate.