Location: Soil and Water Management Research
Project Number: 3090-13000-015-039-A
Project Type: Cooperative Agreement
Start Date: Oct 1, 2016
End Date: Aug 31, 2019
Objective:
Improve NMR soil water content probe design to: 1) Improve the magnet design to decrease temperature drift; 2) tailor the response volume to <10 cm vertically but with relatively large radius, which will allow water content profiling measurements; and 3) Tailor NMR pulse sequencing to improve response to the hydrogen in plant-available soil water and accuracy.
Approach:
Cooperator will work with the commercial MTRA cooperator to guide the NMR probe design and integration of that with the NMR spectrometer. West Texas A&M University will operate the NMR sensor in the field at testing sites arranged by ARS at the Bushland laboratory and at Garden City, Kansas, and near Dalhart, Texas. Large soil columns may be used at ARS discretion if field work is inhibited by external factors. Field test protocols will involve wet and dry field calibration sites, direct volumetric sampling of soil for gravimetric determination of volumetric water content, plus TDR-based determination of soil apparent permittivity and bulk electrical conductivity, which will allow investigation of any soil dependent variations of the NMR signal. Development of wireless data transmission and integration into the ISSCADA system will follow procedures established by ARS.
