Fertility status of soils developed on an inactive mine tailings deposition area in Papua

摘要

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 tailings was required to contribute to information on the management of tailings. Representative sampling locations were chosen based on soil texture. Soil (0 - < 50 cm depth) was subjected to laboratory analysis. Total soil N is very low (< 0.02%), CEC low to medium (< 20 me/100g), 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.