Soil water content and potential measured by hollow time domain reflectometry probe

• Published in: Soil Science Society of America journal Vol. 58; no. 2
• Main Authors: Baumgartner, N, Parkin, G.W, Elrick, D.E
• Format: Journal Article
• Language: English
• Published: 01.03.1994
• Subjects: ANALISIS DEL SUELO; ANALYSE DE SOL; CONCEPTION; CONTENIDO DE AGUA EN EL SUELO; DISENO; INSTRUMENT DE MESURE; INSTRUMENTOS DE MEDICION; MEDICION; MESURE; POTENCIAL HIDRICO DEL SUELO; POTENTIEL HYDRIQUE DU SOL; PROCESOS DE TRANSPORTE EN EL SUELO; SOLUCIONES DEL SUELO; SOLUTE; SOLUTION DU SOL; SOLUTO; TECHNIQUE ANALYTIQUE; TECNICAS ANALITICAS; TENEUR EN EAU DU SOL; TRANSPORT DANS LE SOL
• ISSN: 0361-5995; 1435-0661
• DOI: 10.2136/sssaj1994.03615995005800020008x

A new soil probe used in conjunction with time domain reflectometry (TDR), tensiometry, and solution extraction devices and designed to allow simultaneous in situ measurement of soil-water content, matric potential, and solute concentration is proposed. Hollow stainless steel electrodes with a porous stainless steel tip serve as TDR wave guides in a standard two-parallel-probe configuration. The porous tip allows water inside the hollow rods to equilibrate with the soil water in an unsaturated or saturated system. A pressure transducer system is used to measure the soil matric potential around the porous tip. A vacuum pump can be used to withdraw soil solution through the permeable porous tip. A preliminary comparison between measurements of soil-water content obtained by a two-solid-wires TDR probe and the new probe gave encouraging results. Favorable agreement was obtained between measurements of the soil matric potential and depth to an artificial water table