Biogeochemical And Environmental Factors Affecting Phosphorus Availability On Mine Waste Rock Slopes

Abstract

Revegetation of mine waste rock is an important aspect of mine site reclamation but is often limited by factors such as poor nutrient status. One critical limiting nutrient is phosphorus, whose availability to plants is dependent upon multiple biogeochemical factors. The objective of this study is to evaluate associations between the availability of phosphorus and plant establishment during mine waste rock revegetation at the Carlota Copper Mine in Miami, Arizona. This study quantifies bioavailable phosphorus (AP) on hydroseeded and bare mine waste rock slopes. The parameters of pH, electrical conductivity (EC), DNA biomass, and the rhizosphere influence of shrubs and grasses are explored individually and with reference to AP. Undisturbed areas set the standard for natural phosphorus availability. Undisturbed areas had significantly higher levels of AP and DNA biomass and lower pH than the waste rock. Shrub rhizospheres contained significantly higher levels of AP, DNA Biomass and EC than grass rhizospheres. Significant correlations between AP and pH and between AP and DNA Biomass were found. Phosphorus availability on the waste rock slopes associates not only with plant establishment but several biogeochemical parameters as well, indicating the importance of a multi-faceted approach to addressing soil fertility during degraded land recovery.