3.4. Tensile strength and total porosity after several drainages
The tensile strength of soil core was slightly different among
field treatments at the 1st drainage and the difference became
profound at the 2nd and 3rd drainage because of the decrease in
C0 and the increase in C2 under both ST and DT (Fig. 4a–c). At the
3rd drainage the tensile strength was larger in C2 than in C1 and
C0 under both DT and ST, and under ST than under DT in both
C1 and C2. The total porositywas smaller in C1 and C2 than in C0 at
the 1st drainage. The total porosity was C2C1 > C0 at the 3rd
drainage under both DT and ST because of the decrease in C0 and
increase in C2 under both DT and ST at the 3rd drainage than at the
1st drainage.