Surface soil water dynamics in pastures in northern New South Wales. 1: Use of electrical resistance sensors

Title
Surface soil water dynamics in pastures in northern New South Wales. 1: Use of electrical resistance sensors
Publication Date
2004
Author(s)
Murphy, Sean
Lodge, G M
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/EA03026
UNE publication id
une:2749
Abstract
Stored soil water may influence both the generation of surface runoff and the rate of evapotranspiration from pastures, which may be significant in northern New South Wales. Continuous data is essential to fully understand these processes in field studies. Electrical resistance sensors were used to capture continuous data and they were calibrated directly for soil water content so as to provide quantitative data in real time. Calibration equations (logarithmic regression) were significantly different for a range of installation depths (2.5-20cm). To provide quantitative insight into soil water dynamics in studies of stored soil water, surface runoff, and evapotranspiration, real time data were collected at intervals ranging from 4 min to 24 h. Resistance sensors provided estimates of stored soil water (0-30 cm) that differed by up to 29% compared with estimates obtained from using a neutron moisture meter alone. In surface runoff studies, data collected at 4 min intervals showed that runoff was generated when soil water content was high. In studies of evapotranspiration, daily data were used to quantify different evapotranspiration rates (2.3-4.9mm/day) and progressive depth of drying for a range of treatments. We concluded that data collected in real time using resistance sensors may be used to make better estimates of SWC and so improve the interpretation of surface runoff generation and evapotranspiration data.
Link
Citation
Australian Journal of Experimental Agriculture, 44(3), p. 273-281
ISSN
1446-5574
0816-1089
1836-5787
1836-0939
Start page
273
End page
281

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