Impacts of Gold Mill Tailings Dumps on Agriculture Lands and its Ecological Restoration at Kolar Gold Fields, India

Abstract

Huge amount of mill tailings at Kolar Gold Fields are creating environmental problems. In this study, an at- tempt was made to assess the impacts of mill tailings on agriculture lands and to identify suitable species for its reclamation. For this, soils collected from different agriculture lands were mixed with tailings in different proportions and tomato (Ly- copersicon esculentum) was planted in soils and mixtures. For selection of suitable species, native species were planted only in tailings. Physico-chemical properties varied in soils, tailings and mixtures. pH and electrical conductivity of soils increased with an increase of tailings content. Nitrogen, phosphorous, potassium, magnesium in soil-tailings showed symptoms of deficiency in tomato plants except calcium and sulphur. Correlation among iron, manganese, zinc and copper indicated common source of their occurrence. These elements decreased with increase of pH and sand percentage, and increased with the increase of clay content. Iron, manganese, copper in tomato fruits were within the limit whereas zinc was observed toxic beyond 30% of mill tailings. Soil/tomato plant transfer coefficients distinguished the concentrations of micronutrients in tomato fruits and soil-tailings mixture. Growth status of native species revealed that Babool, Gulmohar, Neem and Euca- lyptus are suitable for dump reclamation.