• Corpus ID: 135021771

Soil-roots performance of Pennisetum setaceum ‘Rubrum’ on mechanical soil strength

@inproceedings{Abdullah2017SoilrootsPO,
  title={Soil-roots performance of Pennisetum setaceum ‘Rubrum’ on mechanical soil strength},
  author={Muhamad Firdaurs bin Abdullah},
  year={2017}
}

• M. Abdullah
• Published 2017
• Mathematics

The potential of Pennisetum setaceum ‘Rubrum’ root in soil reinforcement was
investigated. This African native perennial bunchgrass has been introduced in many
parts of the world as an ornamental plant and for soil stabilization. The traditional
civil engineering techniques such as concreting of welded wire walls for slope
stabilization may not be sustainable in the long term due to high initial capital cost. It
also looks harsh and unnatural to the road users. Alternatively, vegetation can be
used together with inert structure as a way of reducing the visual impact of civil
engineering works. Hence, the study is aimed towards the establishment of a flowery
plant that able to perform decent soil-root shear strength reinforcement. P. setaceum
‘Rubrum’ has been planted at the field plots at RECESS. A series of laboratory direct
shear tests was performed on rooted and non-rooted samples at 100, 200 and 300 mm
soil depth, every month throughout the seven months of study period. The roots
tensile strength was determined using an Instron Universal Testing Machine (Model
3369). Plant morphological data such as shoot biomass, root density and plant height
were also measured. The direct shear test results show that shear strength of rooted
sample of P. setaceum ‘Rubrum’ increases with time for all depths, with the highest
increment of 441 % over the control sample, that belong to one of rooted soil sample
of month 7 at 300 mm soil depth. The increment is due to high root tensile strength
(43.68 kPa ± 3 kPa) and root density (9.36 kg/m3). In term of average peak shear
stress, month 7 was highest at all depth. Its shear stress values were 307 ± 82 kPa
(100 mm), 181 ± 42 kPa (200 mm) and 179 ± 41 kPa (300 mm). Whereas, root
tensile strength decreased with increasing diameter of roots following the power
function with the highest average tensile strength of 50 ± 2 MPa (month 6). The
results of this paper improve the knowledge about biotechnical characteristics of root
systems of P. setaceum ‘Rubrum’ and indicate that this species could potentially
serve as soil reinforcement.