IMPORTANCE OF IMPROVING BIOLOGICAL ACTIVITY OF TEA SOILS IN SOUTHERN PROVINCE OF SRI LANKA.

Abstract

Five separate field experiments were conducted at Hungama in the Hambantota district, SriLanka, to evaluate the growth performances of selected five tree species i.e.Tamarind(Tamarindus indica), Wood apple tFeronoa /imonia), Kottamba (Terminalia catappa),Kathurumurunga tSesbonia grandiflora) and Katuandara (Acasia leucoploeai, mainlyavailable in the salt-affected areas. Each tree species consisted of six treatments whichwere differentiated with three potting mixtures (i.e. top soil, sub soil and a mixture of topsoil - cattle manure) filled in planting holes and again with mulching and withoutmulching. The experimental design for at experiments were Randomized Complete BlockDesign (RCBD) with four replicates. Two months old plants raised in poly bags were usedin all the experiments. Plant height and dry matter yield of plants were determined asgrowth parameters, once in three months.

The experimental site was near the Hungama Lake and salinity of the soil is about 9.5mmhos!cm at topsoil and 8.3mmhos/cm at 30 cm depth. All the plants have shown goodgrowth performances in all treatments. Growth performances were not significantlyaffected by mulching for all plant species. Tamarind, Wood apple and Kottamba, whichwere grown in planting holes filled wi.l: subsoil, showed significantly higher growthperformances. But in Kathurumurunga, the better performances were observed in thetreatment, which used a potting mixture of cattle manure - top soil while in Katuandara,plants grew well in all the treatments irrespective of the treatment effect. Therefore all fivetree species, which were used for the experiment, may be recommended as salt tolerant treespecies.