Paper ID: 63
THE PHYTOEXTRACTION OF Cu AND Zn BY ELEPHANT GRASS (PENNISETUM PURPUREUM) FROM TROPICAL SOIL 21 YEARS AFTER AMENDMENT WITH INDUSTRIAL WASTE CONTAINING HEAVY METALS
1)*Abdul Kadir Salam, 2)M. Afif Hidayatullah, and 1)Supriatin, and 1)Sri Yusnaini
1)Faculty and 2) alumnus of the Department of Soil Science the University of Lampung Bandar Lampung, Indonesia;
Increased concentrations of heavy metals in soils are suggested to cause plant roots to work harder in obtaining nutrient elements for their growth and development. This research was aimed to study the root/shoot growth and heavy metal phytoextraction behaviors of elephant grass in soil about 21 years after amended with a Cu- and Zn-containing industrial waste. Soil samples were obtained from an experimental field factorially treated in 1998 with the heavy metal containing waste at 0, 15, and 60 Mg ha-1, lime at 0 and 5 Mg ha-1, and organic compost at 0 and 5 Mg ha-1. Soil samples were planted with elephant grass, 8 weeks after which the soil samples were analyzed for their DTPA-extracted Cu and Zn. Plant roots and shoots were harvested separately and weighed for their dry-masses and analyzed for Cu and Zn contents. The results demonstrate that the Root-To-Shoot Ratios increased and show good correlations with the increase in the soil DTPA-extracted Cu or Zn. The plant accumulation of Cu or Zn increased with the increase in the soil DTPA-extracted Cu or Zn resulted from waste treatments but decreased with lime treatment. Plant accumulation of Cu and Zn in roots and the whole plant roots and shoots as well as their translocation factors (in general > 1.00) were well correlated with their respective concentrations in soil (r2 > 0.90). These observations confirm that the root/shoot growth and heavy metal absorption by elephant grass are governed by the concentrations of heavy metals in soils and elephant grass is a Cu and Zn phytoextractor.