Unknown effects of 'surface/subsurface municipal garbage on interception,
subsequent wash-off, and movement. of agrochemicals through soils are concerns.
Calcium chloride movement as an analogous for a highly movable solute is monitored
in a sandy soil collected from the College of Agricuaure and Veterinary Medicine King
Farm at AI-Qassim province, Kinqdom of Saudi Arabia. The sandy soil was packed
uniformly in PVC columns. at. bulk density of 1.65 g/cm3. The height and diameter of
soil. column were 20.8 cm and 8.6·cm, respectively. The municipal garbage was applied
to the soil columns using five strategies: three levels of the municipal garbage at the top
of soil column (G.D" g, 49 9 and 60 g), and two levels was mixed in the upper 10-cm layer
(40 and 60 g) .. Calcium chloride solution 'Of 96.4 meq/l was applied at the top of each
soil column using a 1.5-cm constant water pressure head. An effluent of each column
was collected periodically. The effluents were analyzed for the EC which gives the
con_centration of calcium chloride in meq/1. The concentration distribution of ions in the
.effluent was described using. the. computer program of CXTFIT for the first three
' .. strategies of' garbagEl applications. the dispersion coefficient, D, and the mean pore
water velocity, p, were ~~lcUla~ed u~ing i'he comp~ter program. In' general, The
program described more' than 98% of the variations in the effluent concentrations of the
CaCI2. The variations in D and V were not significant at 5 % level for the first three
applications strategies. So, there is no effecUor the first three application strategies
on the movement of CaCb in the used soil. The pore volume at 50% effluent CaCI2
concentration was calculated for garbage application strategies. The CaCI2 was
moving more slowly when 60 g of the garbage was mixed in the upper 10-cm layer in
comparison to either application strategy. There were significant differences in the
pore volume between the fifth application (60 g mixed) and either application. But the
difference in the pore volume among the first four application strategies was not
significant. So, to delay the appearance of the movable solutes in effluent, it is
recommended to mix high organic residue in the upper soil layer.