Organic fertilizer is an alternative
fertilizer application both for immature state
and for tapping state, especially in poor
physical properties of soil. lmproper
characteristics of tropical soil such as rapid
decomposition of organic matter, low cation
exchangeable capacity and low pH can be
remedies by adding organic residue or
organic fertilizer other than annually
accumulated by leaf litter. Although many
investigations on the use of organic fertilizer
in rubber plantatibn of Thailand have been
done since 1976, the results can not be
concluded with certainty.