Soils suffer a considerable depletion of fertility as a result of monoculture of industrial and economic tree crop species. This is exemplified by Hevea brasiliensis (para rubber) tree in its growing cycle and yield of latex. On the basis of the premise that soil nutrients influence the growth and yield of para rubber and that the age of the para rubber tree has an impact on the fertility status of soils, a study was conducted in April to November, 2010 to evaluate soils developed over predominantly granite and phyllite deposits in the rain forest ecological zone of Ghana, West Africa. The area experiences a bi-modal rainfall pattern with about 1700 mm. The main rainy season is from April to July with a peak in June and a minor rainy season from September to November with a peak in October. Relative humidity is very high averaging between 75 % to 85 % in the rainy season and 70 % to 80 % in the dry season. The highest mean temperature of the district is 34 °C which is recorded between March and April, while the lowest mean temperature of 20 °C is experienced in August. The field had been cultivated to rubber since 1960. The topography is generally undulating, except certain portions within the plantation where gentle and few steep slopes occasionally occur. The field is approximately 260 hectares and was divided into upper, middle and lower slope segments using random sampling technique. A reconnaissance survey was conducted to randomly select soil catenae at both locations. Soil catenae of 7, 17, 40, 48 years of rubber cultivation on the granite and 13, 15, 36, 38, 52 years of rubber plantation on the phyllite were selected for the purpose of evaluating the influence of soil parent materials and ages of rubber plantation on the physical and the chemical properties of soils. These two parent materials served as the basis for blocking the field. Each catena was divided into three slope segments being the summit, the middle slope and the valley bottom. Twenty nine soil profiles were dug, described and classified as per the ... 전체 초록 보기