Abstract:
In South East Asia, terraces were built several centuries ago in
order to ensure that food crops could be grown. In many parts of
the world, some forms of fallow such as grassland or woodland
have provided a rest period for the recovery of soil.
Sri Lanka is an agricultural country with tropical climatic
conditions. With the increase of the population most natural
forests were destroyed for agriculture. During the time of British
administration, plantation crops were introduced and tea is one
such monoculture plantation introduced to the wet zone of Sri
Lanka.
The pressure of anthropogenic activities on the soil has increased
significantly due to these plantations and soils were subject to
degradation. This situation could be clearly observed in many
monoculture plantations. Therefore it was decided to carry out the
present study to obtain the baseline data set to decide on extent of
degradation and to decide on the necessity for further studies. The
site selected for this study has both tea plantations and home
gardens and is situated at Wanduramba, Baddegama AGA division
in Galle district. Soil sampling was carried out according to ther
randomly stratified sampling technique to cover both dry and wet
seasons. The results were analyzed using a one way ANOV A table.
It is observed in the present study that the most important
physical and chemical parameters such as bulk density, pH,
organic carbon and cation exchange capacity of tea soils are
significantly different at 5% level compared to that of home
garden indicating that tea soils are already in degraded status.
Even though certain other soil quality parameters are not
significantly different, their differences show that human
interventions have caused a reasonable damage to soil under tea
plants.
The results obtained from the study further indicated that the
most of the soil quality parameters were negatively affected by
establishing monoculture plantation such as tea. However further
studies are needed to conform the validity and the consistency of
these results.
