The yield potential of oil palm planted on peatland has always been a controversial subject. Most past soil
research on oil palm yield on peat land was mainly based on the depth and drainability. Little attention
was given to the impact of peat characteristics on oil palm from a yield perspective. This study tests the
hypothesis that physical soil properties such as peat maturity, presence of wood, depth and nature of
underlying substratum affects oil palm yield. The initial study involved the evaluation of soil mapping
units on estates in Sibu, Sarawak, East Malaysia and from this exercise of four organic soil mapping units
which reflected the different characteristics of soils were selected. Data on peat depth, presence and
absence of decomposed and undecomposed wood, nature of underlying substratum and peat maturity
(fibric, sapric and hemic) were collected, analyzed and interpreted. Comparisons were also made on
mineral soil found at the same location. Yield data were analyzed from primary sources from oil palm
estates. Results show that differenttypes of peat have significant effect on oil palm yield ranging between
9.47 - 22.92mt/ha. Peat maturity has the most significant effect on yield. Sapric peat showed a yield range
of 19.48-22.92mt/ha as compared to hemic peat ranging between 9.47- 13.37mt/ha. Palms planted on
soils with sandy substratum showed significant 18 -142% higher yields compared to those over marine
clay as underlying material. No significant differences were observed in the yields due to the different
depths and presence/absence of wood as a single factor. However, a combined factor of peat maturity
and presence with nature of wood do have significant impact on yield.
The study further confirms that sandy spodosol like Bako series perform 30 - 40.44% lower yields
compared to peat soils such as Telong and Naman series.
The results are important aspeat areas withspecificphysical soilproperties andshowingpoor yields can
been left for conservation prior to development. Thus selective development based on semi detailed soil
surveys producing maps giving peat characteristics and its impactto oil palm yield is possible. However, a
more balanced view and future researchshould be emphasised to other issues suchas cost of development
of peatland compared to the price of crude palm oil in the world market, biodiversity, social issues, Green
House Gas (GHG) emissions and potentials of improving productivity on existing organic and mineral
soils need to be further explored. The study therefore challenges the existing believe that peat depth is
very significant in determining oil palm yield. The study also enhances the need for soil surveys for land
use decisions and wise use of peatlands. Further research is recommended to narrow the knowledge gaps
and uncertainties on peatland.