Agriculture Reference
In-Depth Information
Box 2.2 Electromagnetic Techniques for Soil Survey in Vineyards
The EM38 measures the bulk soil
EC
, which is affected by salinity, water content,
clay content, bulk density, and soil temperature. However, if the in-field variation
in one of these factors is large compared with the others, the EM38 can be
calibrated to measure that dominant factor. A basic instrument is shown in
figure B2.2.1A. It is normally placed in an insulated case to minimize temperature
(a)
(b)
Figure B2.2.1
(A) An
EM38 in vertical
orientation (White
2003). (B) An EM38 on a
nonconducting sled being
pulled through a vineyard.
(Courtesy of Dr. Robert
Bramley, CSIRO Ecosystem
Sciences, Adelaide, South
Australia.)
(continued)
