Rice straw in corporation increased the puddlability as indicated by the decreased sinkage resistance after puddling and promoted the regeneration of soil structure during the rice growth period as indicated by the increased tensile strength and porosities after repeated drying. Shallow tillage increased the penetration resistance more than deep tillage due to shallower depth of the plough layer and may have negative effect on root growth when no sufficient rice strawwas incorporated.
Soil organic C influences the stability of porous system upon swelling and shrinkage and then the mechanical properties after puddling and during the rice growth period. The results suggested that sufficient rice straw should be incorporated to the plough layer to maintain SOC and then to improve soil puddlability and the recovery of pore structure with wetting and drying cycles.