Proceedings - Balai Penelitian Tanah

55
Rachman et al.
Table 2. Characteristics of deposited mud measured in Aceh Besar,
January,2005
Soil properties
Lamcot
Sites
Keneuneu Lampineung Tanjung Mire
Thicknes (cm) 10-20 15-25 15-25 2-5 2-5
Sand (%) 53 26 12 47 6
Clay (%) 8 43 42 25 42
ECe (dS/m) 60.9 84.2 80.1 38.9 19.8
Salt (ppm) 31,280 46,268 44,116 20,140 9,804
pHH2O 7.4 7.8 7.7 7.7 8.1
Organic C (%) 2.9 4.1 2.3 1.0 2.8
P2O5(HCl) (g/kg) 520 550 930 300 1420
K2O(HCl) (g/kg) 300 1330 2560 730 2470
P2O5(Olsen) (ppm) 64 60 48 27 115
Ca (cmol(+)/kg) 24.7 20.1 18.6 8.6 18.9
Mg (cmol(+)/kg) 6.9 24.5 26.2 10.8 19.7
K (cmol(+)/kg) 0.5 2.2 2.9 0.8 2.4
Na (cmol(+)/kg) 13.6 59.7 56.9 18.9 13.8
Further survey was conducted on July 2005 to measure the thickness
of the mud remain on the ground 7 months after tsunami.
Approximately around 42,000 ha in Aceh Barat, Aceh Jaya, Aceh
Besar and Banda Aceh of land are still covered by tsunami mud. The
thickness varied from place to place with the largest areas covered by
mud was in Aceh Jaya followed by Aceh Besar and Banda Aceh
(Figure 2). The progress of the recovery process including
reestablishment of drainage channels has been a major contributor to
the reduction of tsunami mud remains on the agricultural land.
Changes in soil salinity
Less than one year after tsunami, most sites monitored in Bireuen (6
out of 7 sites) and Pidie (4 out of 7 sites) have returned to normal
condition (Table 3), other sites still suffered from either high electrical
conductivity or high sodium concentration. After 18 months more sites
(15 out of 20 sites) returned to normal levels of salinity. However,
there were some sites where salinity persisted for a longer period of
time, which may affect crop productivity. The recovery process of soil
from salinity appeared to be related to the thickness of mud deposited
after tsunami and restored farm activities. The areas inundated by
sea water for less than 3 days were left with a thin layer of tsunami
mud (