Rubber Soil Variability in Peninsular Malaysia as Affected by Its Parent Materials

The research objectives were to analyze soil variability induced by parent materials for rubber cultivation in Peninsular Malaysia. The research results can provide basic information on potential reserves of nutrients to improve soil productivity for rubber cultivation. Soil samples were collected from two locations (Granite soils and Basalt soils). The collected soil samples were completely analyzed in laboratory. The results showed that based on mineral resistance to weathering (sand and silt mineral sizes), mineral weathering of granite and basalt is divided into three categories, very slow weathered mineral (quartz and muscovite), slowly weathered mineral (K- feldspar, Na and Ca-feldspar and biotite), and easily weathered mineral (hornblende, augit, olivine, dolomite, calcite and gypsum). Losing mineral during weathering process from granite to clay is determined by containing mineral in rocks. Such minerals (CaO, Na2O, K2O, MgO and SiO2) loosed 100 %, 95.0 %, 83.5 %, 74.7 % and 52.5 % respectively, but Fe2O3 is disappeared only 14.4 %. Soil properties characters of granite soil is more acid, has very low to low chemical soil fertility and is dominated by sand fraction, furthermore basalt soil is acid, has low to moderate chemical soil fertility and is dominated by clay fraction. Granite and basalt soils are able to produce rubber latex 2700-3000 kg/ha in a year and 2200-2700 kg/ha in a year respectively. The production difference of both soils is around 300 kg/ha in a year. Key words: Soil variability, analyses, parent materials, rubber, Peninsular Malaysia