Soil and Water Management Research Site Logo
ARS Home About Us Helptop nav spacerContact Us En Espanoltop nav spacer
Printable VersionPrintable Version     E-mail this pageE-mail this page
Agricultural Research Service United States Department of Agriculture
Search
  Advanced Search
 
Programs and Projects
Subjects of Investigation
 

Research Project: SUSTAINING RURAL ECONOMIES THROUGH NEW WATER MANAGEMENT TECHNOLOGIES

Location: Soil and Water Management Research

Title: Field tests of a down-hole TDR profiling water content measurement system

Authors

Research conducted cooperatively with:
item

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 19, 2011
Publication Date: October 18, 2011
Citation: Casanova, J.J., Evett, S.R., Schwartz, R.C. 2011. Field tests of a down-hole TDR profiling water content measurement system [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. Paper No. 243-6.

Interpretive Summary: Measuring the amount of water in soil is important in managing crop irrigation. Current methods of soil water estimation are limited by accuracy, precision, ease of installation and cost. This paper presents the results of field tests, a new sensor design.

Technical Abstract: Accurate soil profile water content monitoring at multiple depths has previously been possible only using the neutron probe (NP), but with great effort and at unsatisfactory intervals. Despite the existence of several capacitance systems for profile water content measurements, accuracy and spatial representativeness has been precluded by fundamental problems related to conductivity and soil structure effects on the volume explored by the static electromagnetic (EM) field of these sensors, which causes unrealistic spatial variation in profile water contents. Time domain reflectometry (TDR) methods have the distinct advantage of employing a moving EM field that must pass through and be affected by both the drier and wetter soil structures in which the TDR electrodes are embedded. This gives rise to the expectation that a profiling water content system based on TDR methods will provide realistic spatial variations in profile water content and may be competitive with the NP for accuracy, while providing unattended, real-time, wireless data acquisition. Such a system is described and results of field tests are reported.

   

 
Project Team
Brauer, David - Dave
Tolk, Judy
Evett, Steven - Steve
Howell, Terry
Baumhardt, Roland - Louis
Schwartz, Robert
Colaizzi, Paul
Gowda, Prasanna
Van Pelt, Robert - Scott
Zobeck, Teddy - Ted
Lascano, Robert
 
Publications
   Publications
 
Related National Programs
  Climate Change, Soils, and Emissions (212)
  Water Availability and Water Management (211)
 
 
Last Modified: 05/25/2013
ARS Home | USDA.gov | Site Map | Policies and Links 
FOIA | Accessibility Statement | Privacy Policy | Nondiscrimination Statement | Information Quality | USA.gov | White House