In soil bio-engineering, plant has been widely adopted as important material
in promoting sustainable ecological function in slope instability measures.
Plant canopy provides shelter and at subsurface level, root networking
attributes toward stability of soil against erosion and slope failure. To
investigate the potential of selected P. polystachion as biological
material in soil bio-engineering for improving the soil shear strength of
sandy soil planted with P. polystachion.
Methodology: The selected species was initially planted using
hyroseeding technique on studied plots which facilated with and without fiber
netting (made of paddy straw). A control plot was also prepared for reference
of this study. The plots were routinely watered twice a day for six months
before experimental program was scheduled for determining of root tensile and
soil shear strength tests.
The root tensile strength of P. polystachion exhibited a positive
significant relationship between root tensile force and root diameter. The
shear strength of soil was affected by the presence of root if compared to
that of soil without root (control). Biomass analysist also agree with the
soil water content, ws. High biomass contributed to the increase
in the values of soil shear strength parameter of cohesive, c and angle of
friction, q for root-permeated soil with P. polystachion.
Interpretation: This study has suggested that the
potential application of this selected species for slope vegetation in
improving the erosion control and slope stability in soil-bioengineering
Erosion, Pennisetum, Root tensile, Shear strength