pF Curves
The analysis of variance of 'F' ratio for soil moisture retention at different
suctions is shown in Table 8. Soil moisture retention characteristics were
significantly affected by treatments and the duration of cultivation. Soil
moisture retention at low suction ( > 0.003 MPa) declined with cultivation in
all treatments (Table 9a). Mean soil moisture retention for 0-5 cm depth at
0 and 0.003 MPa suctions was 49.6 and 24.3 percent in 1982, 35.6 and 20.0
percent in 1984 and 38.2 and 22.0 percent in 1985, respectively. Similar
trends were observed for 5-10 cm depth except that the magnitude of decline
was relatively small. This decline in soil moisture retention with the cultivation
duration was attributed to reduction in soil organic matter content
and decrease in the rate and amount of worm castings. By the end of the
third year of the cultivation cycle in January 1986, soil moisture retention
for 0-5 cm depth at zero suction was in the order of Leucaena-based system