Abstract:
Temporal and spatial variability off soil water content (SWC) in a catchment affects surface and sub-surface
runoff, modulates evapotramspiratiom and determines the degree of ground water recharge. The present
understanding of soil water dynamics in different land uses in Sri Lanka is poor. An experiment was
conducted to study the soil water dynamics in a grassland of mid country off Sri Lanka. Rainfall, runoff and
SWC were monitored for two years in an experimental plot of 525 m2. SWC was monitored up to
decomposing parent material using neutron moisture meter. Bata showed that the temporal variability off
SWC at 15 and 30 cm depths was very high. The variability of SWC in depths below 30 cm was low and
showed gradual change with time. The SWC in the profile remained below field capacity most of the time,
showing the capacity of the profile to absorb rain water. The runoff from the plot was negligible.
