Fertility Status of Soils Developed on anInactive Mine Tailings Deposition Area,in Papua

Abstract

Tailings are the residue of mined material after separation of metals such as copper, gold and silver elements. Separation of minerals involves crushing of the host material to fine particles and separation of the metals by flotation or other techniques. The total amount of tailings produced by PTFI from their Grasberg mine is about 230,000 tons/day. These tailings are deposited in a lowland area and are confined by two levees. There are two types of plant growth on inactive tailings according to land use (natural succession area or reclaimed agricultural area). This study of soil fertility on the mine tailing was required to contribute to information on the mangement of tailings. Representative sampling locations were chosen based on particle size distribution with soil (0 - ≤ 50 cm depth) being subjected to laboratory analysis. Total N soil is very low (< 0.02%), CEC ( 20 me/100g) low to medium, and organic-C ranges from 0.1 - 2%. pH is 7 - 8 resulting in the low availability of some nutrients, but values of extractable Cu may be high (≥ 300 mg/kg). Nutrient elements are more abundant in soils on fine textured tailings.