![](media/image1.png){width="0.8333333333333334in"
height="0.7083333333333334in"} **AMERICAN SOCIETY OF AGRONOMY**

**CROP SCIENCE SOCIETY OF AMERICA**

**SOIL SCIENCE SOCIETY OF AMERICA**

677 South Segoe Road ● Madison WI 53711 ● Fax (608) 273-2021

**ASA** (608) 273-8080 ● **CSSA** (608) 273-8086 ● **SSSA** (608)
273-8095

**NEWS RELEASE**

Contacts: Sara Uttech, ASA/CSSA/SSSA, 608-273-8090, ext. 323,
<suttech@agronomy.org>

Sander Huisman, Universities of Amsterdam & Giessen, 49-641-9937385,
<sander.huisman@agrar.uni-giessen.de>

Susan Hubbard, Lawrence Berkeley National Lab & University of
California, 510-486-5266, [sshubbard@lbl.gov]{.underline}

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##### **High-tech analysis of vineyard soil** 

In a special Soil Measurement & Methods section of Vadose Zone Journal,
scientists review the state-of-the-art tools for measuring the water
content in soil

**MADISON, WI, NOVEMBER 19, 2003 --** Growing grapes for wine is tightly
linked to soil moisture: too little, and the crop can be lost, but an
oversupply of water tends to favor leaf development at the expense of
fruit quality. It is often difficult to determine which portions of the
vineyards require more or less irrigation due to California wine
country's natural geologic variations that control the moisture in soil.
These natural variations, which appear over short distances, hamper the
ability to map soil moisture of an entire field using conventional
measurement techniques. Enter GPR, or ground penetrating radar.

In recent years, many researchers have made progress in the use of GPR
as an alternative for TDR, time domain reflectometers, for determining
field-scale variations of soil water content. These early TDR sensors
came about in the 1980s and utilized the influence of water on the
velocity of electromagnetic waves to obtain accurate measurements of
soil water content; however, assessment of an entire field remained a
tedious task because of the need to install a large number of TDR
sensors to adequately cover the field. To overcome these difficulties,
scientists have used GPR methods to map a field's varied soil moisture,
as in the case with the California vineyards.

GPR's high-resolution information can be used to improve vineyard
development and management, such as to develop vineyards within uniform
"blocks" of soil that have optimal properties, or to improve precision
irrigation approaches, says Susan Hubbard, long-time GPR researcher.

"Soil water content information obtained from GPR data can be extremely
useful for guiding many environmental, engineering, and agricultural
applications, such as in wine making. This is one example of a
successful GPR application, but many others can be imagined," she adds.

Hubbard recently joined a group of scientists to review the current
state-of-the-art methods for determining soil water content with GPR.
This review is one of the contributions to a special section in the
November issue of *Vadose Zone Journal*, published by the Soil Science
Society of America (SSSA). Over 20 papers are published in this special
section based on the symposium, "Soil Physical Measurements and Methods
Symposium," held during the 2002 SSSA Annual Meeting. Fittingly, this
symposium was dedicated to the research of C. Topp, one of the founding
fathers of TDR.

Sander Huisman, an author of the review says, "After recognizing the
dominating role of spatial variability at the field scale, it is now
time to deal with it. Clearly, the traditional methods cannot detect
these variabilities with sufficient resolution and, therefore, many
scientists and practitioners are currently searching for alternative
techniques. GPR is certainly one of the most promising methods currently
under scrutiny".

Of course, there is still a gap between the advances made in the
research community and the practical need for straightforward tools to
accurately measure water content at high resolution and over large
areas. The authors of the study, however, are confident that increased
experience and application of GPR will eventually lead to the acceptance
of GPR as one of the possible tools to measure field scale variation of
soil water content.

*Vadose Zone Journal,
[www.vadosezonejournal.org](http://www.vadosezonejournal.org/), is an
all-electronic, peer-reviewed, international publication published by
the Soil Science Society of America (SSSA), with the Geological Society
of America as cooperator. The mission of the Vadose Zone Journal is to
disseminate research and information of the vadose zone, the mostly
unsaturated zone between the soil surface and the permanent groundwater
table, including soil water flow and the fate and transport of chemicals
stemming from agricultural and industrial practices and waste disposal
operations.*

*The American Society of Agronomy (ASA)
[www.agronomy.org](http://www.agronomy.org/), the Crop Science Society
of America (CSSA) [www.crops.org](http://www.crops.org/) and the Soil
Science Society of America (SSSA) [www.soils.org](http://www.soils.org/)
are educational organizations helping their 11,000+ members advance the
disciplines and practices of agronomy, crop and soil sciences by
supporting professional growth and science policy initiatives, and by
providing quality, research-based publications and a variety of member
services.*

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