Proceedings - Balai Penelitian Tanah

133
Figure 1. Locations of assessment sites
McLeod et al.
In each site 1-3 permanent transects of about 100 m long each were
selected based on visual assessment of crop performance (Poor,
Medium and Good areas) at the initial survey in August 2005.
The apparent soil electrical conductivity (ECa) was measured at 5 m
intervals along each transect using the Geonic EM38 instrument. This
was conducted every three months between August 2005 and
January 2007. Both horizontal, EMh, (most sensitive to 0-45 cm
depths) and vertical, EMv, (most sensitive to 45-150 cm depths)
readings were taken at each measurement point. A higher EMh value
indicates salt accumulation in the top 30-45 cm of the soil profile,
while a higher EMv value indicates salt accumulation in the lower 45-
150 cm of the soil profile.
The site specific calibration to convert ECa data to soil electrical
conductivity at field saturation (ECe) was developed following Slavich
and Peterson (1993), and Slavich (2002).
RESULTS AND DISCUSSION
Soil salinity in the tsunami affected areas was highly variable between
the assessment sites (Figure 2). It had a wide range of values and
was generally higher at the soil surface (Table 1). Soil salinity reduced
over time due to leaching from natural rainfall or irrigation water.
However, some sites remained saline until January 2007.
International Workshop on Post Tsunami Soil Management, 1-2 July 2008 in Bogor, Indonesia