Influence of Soil Parent Materials and Soil-Related Factors on the Growth and Yield of Rubber Under Felcra Scheme, Sendayan

The influence of two terrain classes (i.e. 5 to 25% and 25 to 50% slopes) on soils developed from two parent materials (i.e. granite and sedimentary rocks) on the growth and yield of rubber (Hevea brasiliensis) after four years of tapping was evaluated by using the field data, viz. girth and yield of rubber from 1980 to 1983, obtained from the Federal Land consolidation and Rehabilitation Authority (FELCRA) Scheme at Sendayan, Negri Sembilan. RUbber grown on sedimentary rock derived soil on steep slopes (25 to 50% slope) after four years of tapping showed significantly bigger girth than those grown on same soil on undulating to rolling terrain (5 to 25% slope). The mean monthly and yearly dry weight of rubber after four years of tapping was significantly higher in areas planted on sedimentary rock derived soils located on steep terrain. The growth of rubber as influenced by the interaction of parent material and slope over time was not significant during the same period of tapping. However3 the overall yield of rubber was significantly higher on soils derived from sedimentary rocks on steep terrain than on soils derived from granite on similar terrain

Mineralogical and Chemical Properties of Some Acid Sulfate Soils in Malaysia and Their Effects on the Growth Performance of Oil Palm Seedlings (Elaeis Ruineensis, Jacq)

Acid sulfate soils are charllcterized by a very low pH and a high aluminium concentration resulting from the chemical and biological oxidation of pyrite upon drainage. These soils have low agricultural potential due to high acidity and poor physical conditions, which adversely affect crop growth. Successful reclamation and management of acid sulfate soils would require an in-depth understanding of the soil's chemical and mineralogical properties. In this study, acid sulfate soils at Pulau Lumut, Kelang were mapped, characterized morphologically and chemically,and classified. Soil solutions were extracted on samples from soil pit,limed and oxidized soils and a pot experiment at the matrix suction of 10 kPa and the activities of the major cations and anions were calculated by Geochem. XRD and TGA were carried out to deter mine the mineralogy of the various soil horizons. The morphological features of the minerals in the soils were studied by TEM and SEM. A controlled pot experiment was conducted to assess the performance of oil palm seedlings grown on acid sulfate soils under freely drained and waterlogged conditions