Physical and Chemical Properties and Nutritional Management of Major Soil Series of the Chu Tung Plan tation Center, Taiwan-Field survey

Restrictions on tree growth of the three major soil series in the Chu Tung area were studied. The results indicate that the thickness of the surface soil of the three soil series is too thin (10-12cm). The percentage of base saturation (1.4-17.4%) and the content of available phosphorus (0.6-16 mg/Kg) below a depth of 10 cm in the soil pedon are both low, possibly causing a nutritional imbalance for tree growth. The soil reaction ranged form extremely acidic (pH 3.9) to strongly acidic (pH5.5). High exchangeable acidity (28-40cmol (+) kg-1) an Al saturation percentage (95%) of the Hu Shan Series may restrict the growth of fine roots. The high stone content (80%) and low available water supply of the Ssu Ma Shian Series may also restrict root growth. Planting shallow-rooted trees is recommended for the Ssu Ma Shian Series, and liming, to raise pH values and reduce the toxicity of Al3+ and H+, should be carried out for the Hu Shan Series. Furthermore, fertilization of these three soil series is necessary to maintain the quality of the soil and normal growth rate of trees.