The three-yearfield experiment demonstrated that more rice
straw incorporation decreased more the sinkage resistance after
puddling (Fig. 3a), while shallow tillage increased more the
penetration resistance than deep tillage (Fig. 3b). The maximum
sinkage resistance decreased from 100–150 kPa in C0 to 70 kP in
C1 and C2 and the effect more profound under ST. Shallow tillage
increased the penetration resistance more than deep tillage
possibly due to the shallower depth of the plough layer.Kirchhof
et al. (2000)reported that the sinkage resistance was below less
than 100 kPa in all the treatments with different tillage intensity,
but the rice yield or post-rice crop yield was reduced in some