The shrinkage capacity (COLE) after the 3rd drainage was not
significantly different among the rice straw incorporation treatments at100 kPa, but it was larger in C1 and C2 than C0 under ST
and larger under ST than DT in C1 and C2 under300 kPa (Fig. 5a).
The water retention curve showed larger difference in soil water
content at the lower range of soilwater suction(Fig. 5b). The pore size
distribution estimated from the water retention curve increased the
total porosity and all the fractions of >30, 30–1and C0) under DT
under ST except for 30–1mm under ST (Fig. 5c)