1. Introduction
The paddy soils easily crack because they are often subject to wetting
and drying cycles due to mid-term drainage involving an intentional
drying, seasonalwater scarcity or poor management of water distribution
(Ma and Chen, 1999; Janssen et al., 2010). If the cracks develop extensively
under these drying conditions, theymay aggravate soil evaporation and
hinder root growth (Whiteley and Dexter, 1984). The crack patterns
(area, width or depth) could govern the rate and the velocity of water
and solute transport (Novák et al., 2000). Once upon flooding in paddy
field, they may serve as pathways for preferential flow and increase