Abstract:
The present study assessed the impact of application of natural rubber tire waste
charcoal (NRTWC) on selected physical characteristics of tea cultivated soils which
belongs to Red Yellow Podzolic great soil group. Natural rubber tire waste charcoal
was applied as a soil amendment at different rates (0%, 1%, 1.6%, 2.2% and 2.8%
w/w). Physical attributes of soil; bulk density, particle density, porosity, texture and
aggregate stability were assessed at 10 and 20 weeks after application of NRTWC.
Natural rubber tire waste charcoal significantly improved physical characteristics
of soil by reducing soil bulk density, and increasing particle density, porosity and
aggregate stability. Natural rubber tire waste charcoal treated soils showed
significantly (p ≤ 0.05) lower bulk densities for the application rates of 2.2% and
2.8% (1.21 and 1.17 gcm-3 respectively) compared to the control (1.39 gcm-3) at 10
weeks after application. Significantly (p ≤ 0.05) lower particle density was observed
for the application rate of 2.8% (2.52 gcm-3) than the control at 20 weeks after
application. The increased porosity with time might be attributed to the increased
of soil organic matter content with the application of NRTWC. The highest porosity
change was observed at 1 % treatment (from 44.9% to 48.8%) and the lowest was
at 2.8% (from 49.4% to 56.3%). Despite no significant (p ≥ 0.05) difference was
reported in particle size distribution in soil treated with NRTWC, there was a
noticeable decreased in sand percentage and increased in either silt or clay
percentages at 20 weeks after application. Soil aggregate stability was found to be
significantly increased (p ≤ 0.05) in all treatments at 10 and 20 weeks after NRTWC
application compared to the control. However, further investigations are needed
before recommending the addition of NRTWC as an amendment to tea growing
soils
