Phytoextraction of Nutrients and Heavy Metals by two Monocot Plants in Thaulla Area of Small Reservoir in Anuradhapura, Sri Lanka

Abstract

Purpose : Small tanks/ reservoirs are one of the major components of dry zone landscape and they were the basis of prosperity in ancient Sri Lanka. There are identified ecosystem components associated with the tanks such as upper peripheral area (thaulla). It is useful to understand the role of hydrophytes in thaulla area scientifically. This field study aimed to investigate the phytoextraction ability of two monocot plants, Paspalidium punctatum and Cyperus rotundus naturally grown in thaulla area of Ulankulama tank located in Anuradhapura. Research Method : The accumulation of total N, P, K, Ca, Mg, Cd, Pb and As were assessed by getting both plant and soil samples from 20 sampling points in thaulla area. Total K, Ca, Mg, As, Cd, and Pb contents were measured using the Inductivity Couple Plasma Optical Emission Spectrophotometer (ICP-OES) procedure. N, P, K were assessed following standard analytical procedures. Findings : Results showed that As and Cd were not observed in detected amount in soils of root zone of the plants. However, As and Cd were present in shoots and roots in both plant species. Both species could be considered as hyperaccumulator for K, Ca and Mg as they have biological concentration factor higher than one. Originality / Value : Paspalidium punctatum and Cyperus rotundus could be considered as hyperaccumulator for K, Ca and Mg and bio accumulation of heavy metals in thaulla area.