E.J.M. Temminghoff

Modeling dynamic copper balances for a contaminated sandy soil following land use change from agriculture to forestry

Abstract Changing land use from arable farming to forestry results in increases in both soil organic matter content and soil solution H + concentrations. In this paper, effects of increased organic matter and decreased pH on copper speciation and consequent copper mobility are modeled for different land use change scenarios by applying the two species Freundlich equation to dynamic balances of copper in soil. The land use change scenarios show that copper accumulation in soil may appear harmless at first, but may adversely affect soil biology and groundwater quality later. Such effects depend on the history of copper input (agricultural use) and whether the litter is mixed through the topsoil (forestry). In a land use change scenario with a high copper input history, after 50 years Cu leaching is about four times higher if the litter remains on top of the topsoil than if it is mixed through the topsoil or with continuing high-input agriculture. The increase of the Cu 2+ activity is about 750:30:1 if the litter remains on top of the topsoil, if litter is mixed through the topsoil, and if high-input agriculture is continued, respectively.