Abstract:
A leaching column study was conducted at the Eastern University, Sri Lanka
to study the impact of locally available organic amendments with leaching
on pH in a saline soil. Farmyard manure (FYM), Gliricidia (G), partially
burnt paddy husk (PBPH) and tank silt (TS) were used as soil amendments
with leaching. All amendments were applied alone; FYM (T1), PBPH (T2),
G (T3) and TS (T4) and as a combination farmyard manure with other
amendments; FYM+PBPH (T1+ ½T2), FYM+G (T1+ ½T3), and FYM+TS
(T1+ ½T4) at the rate of recommendation (T1-22, T2-0.625, T3-3.5, T4-100
Tons/ha). These eight treatments including the control (simple leaching
without amendments) were replicated three times in a complete randomized
design. The amendments were added to sandy loam saline soil from paddy
land in Vaharai D.S. division, Batticaloa having an electrical conductivity
(EC) and soil pH 13.1dSm−1 and 7.8 respectively. Saline soils mixed with
treatments were filled into each leaching column (5.4 cm diameter and 30cm
height), and incubated at room temperature for three weeks. After
incubation, columns were filled with distilled water up to their saturation
point. Then once in two weeks 150 ml of distilled water was added to each
leaching column and the leachate was collected. Altogether four leaching
cycles were completed during the study period. pH was measured in each
leachate and in soil after the completion of leaching cycles. There was an
increase in pH from 1st to 4th stage of leaching. At the final stage of leaching,
the pH of leachate was significantly higher in control than other treatments.
This shows most of the base salts in organically amended soil were washed
at the time of the 3rd leaching while salts remains in control. Significantly
least amount of pH was observed in the soil amended with FYM. In the soil
analysis, significantly highest pH was recorded in control and significantly
least pH was recorded in the tank silt.
