Abstract:
Palm oil (Elais guinensis) is the most consumed edible vegetable oil in the world. Commercial
scale Oil palm cultivations mostly depend on quality planting materials, correct management
practices. Due to the recent price hikeon chemical agricultural inputs in Sri Lanka, palm
cultivation faced different hardships to maintain their plantations. An experiment was carried
out at Talgaswella estate of Elpitiya Plantations PLC, in WL2aagro-ecological zone of Sri
Lanka to investigate the possibility to apply organic fertilizer for a marginal conventional oil
palm field for achieving a profitable yield with the integration of organic fertilizer. Ten years
aged oil palm field was selected for this experiment. Three treatments namely 100% organic,
100% inorganic and a combination of inorganic fertilizer with a portion of organic fertilizer
that provides the nutrients as same as the recommended inorganic fertilizer for oil palm were
tested rom September 2019 to September 2021. The experiment was carried out according to
RCBD with three replicates and each replicate consisted of six palms. Empty fruit bunches
(EFB) of oil palm, palm oil mill effluent (POME) and poultry litter (PL) were used for
preparation of organic fertilizer. Fresh fruit bunch yield and the leaf chlorophyll values were
recorded, and the data were analyzed with SAS statistical tool. The results revealed that the
treatment with 100% organic fertilizer showed significant increments in average fresh fruit
bunch weight (41kg) compared to that of the100% inorganic fertilizer (26 kg) and 50% to
50%inorganic-organic mixture (23 kg). The leaf chlorophyll values in the 17th frond of 100%
inorganic and 100% organic treatments were 75.57 and 75.91in SPAD units respectively while
it was 74.62 in the inorganic-organic mixture and there’s no significant different among the
treatments. Soil organic carbon percentage varied from 100% inorganic to 100% organic (1.99
and 2.05) respectively and it clearly showed the gradual increment of soil organic carbon
levels, which will directly affect to the fertilizer use efficiency. Therefore, the application of
organic fertilizer showed better yield (10030kg/ha/year) in oil palm compared to inorganic
fertilizer (9234kg/ha/year) in Talgaswela estate, Sri Lanka.
