Question

find the nutreints present in soil for growth of rubber and calculate their percentage.

Answer 1

RUBBER GROWING SOILS AND THEIR CHARACTERISTICS Lalani Samarappuli INTRODUCTION The rubber tree is grown on vast majority of acid soils of the humid tropics, but its performance and economic viability can be restricted severely where there is a limitation of a particular soil characteristic. Soil is an important edaphic component influencing the establishment, growth and yield of rubber. An understanding of the numerous soil factors affect) lg soil fertility is a prerequisite to proper management of soils for better performance of rubber. In essence, rubber can best be grown in areas where the soil is deep and readily drained with no compacted or impermeable horizons close to the surface with no toxic or extreme deficiency levels of nutrients. At the same time, the soil should be able to retain and supply sufficient nutrients and moisture for proper plant growth. Classification of rubber growing soils of Sri Lanka In order to facilitate the extrapolation of experience and experimental work between regions, attempts have been made to fit the rubber growing soils into international systems of nomenclature. Planting of rubber in Sri Lanka is mostly confined to two Great Soil Groups; Red Yellow Podzol (RYP) and Reddish Brown Latosol (RBL). The Red Yellow Podzolic soils are predominant in the rubber growing districts of Kalutara, Galle, Matara, Ratnapura, Avissawella and Monaragala. The Reddish Brown Latosolic soils occur mainly in the Kegalle, Mawanella, Kuninegala and Matale regions. Soil series In these rubber growing areas seven important soils units have been identified by the Rubber Research Institute (RRI), taking into consideration only the parent material from which the soiis were derived (Table 1 and Fig. 1). However, this soil classification does not directly reconciled with the Great Soil Groups. Nevertheless, it has practical advantages for research and extension purposes