Growth of PB 260 Clone (Hevea Brasiliensis (Willd. Ex a. Juss.) Muell-Arg.) in Different Potting Media and Fertilization Scheme

Rubber is an important commodity for Indonesia. Currently, a problem encountered in the propagation of rubber planting materials is the availability of ideal soils with optimum nutrition as the planting medium. Peat can be used as a growing medium but it still has weaknesses such as high level of acidity and poor in nutrient content. This study was aimed to assess the performance of rubber budded stump grown on modified potting medium and applied with different forms and rates of fertilizers. The nursery experiment consisted of 17 treatments and arranged in a randomized complete block design. After rubber nursery stage, the performance of the rubber budded stump were also monitored in the field for 10 months. Results showed that mixture of peat and soil with the application of recommended rate of solid or liquid fertilizer produced rubber budded stump with bigger stem diameter and taller plants. The potting medium stimulated early root development which led to higher nutrient uptake. These budded stump also performed better in field, showed higher leaf nutrient concentration after 6 months and produced bigger stem diameter after 10 months

Land Suitability Evaluation of Abandoned Tin-mining Areas for Agricultural Development in Bangka Island, Indonesia

Kepulauan Bangka Belitung, Indonesia is one of the tin mineral-producer in the world. Agricultural crops could be a wise option for the reclamation since abandoned tin-mining lands have a high potency to be used as agricultural lands. This study was aimed to evaluate of the land/soil characteristics of abandoned tin-mining areas and to establish land suitability of the land area for agriculture used to formulate appropriate land development measures and amelioration strategies for utilization of mined areas for crop production. The land evaluation was conducted by comparing the land characteristics in every type of abandoned tin-mining areas with its crop requirements. The current suitability showed that in general food crops, vegetable crops, fruit crops, and industrial crops were consider as not suitable (N). Spice and medicinal crops [pepper (Piper nigrum L.) and citronella (Andropogoh nardus L. Rendle)] were consider as not suitable (N), while the Jatropha (Jatropha curcas L.) and Kemiri Sunan (Aleurites moluccana L. Willd) crops were considered as marginally suitable (S3) in abandoned tin-mining areas. The forest crops and forage crops were considered as marginally suitable (S3). The water availability, soil texture, and low soil fertility were considered as the limiting factors of all crops to get optimum production. For agricultural development, the soil physical and chemical properties of abandoned tin-mining land must be improved through integrated farming