Variability of vertical bromide redistribution within hummocky landscape

Abstract

Groundwater quality is a major issue for rural communities, and intensive agricultural practices have the potential to contaminate groundwater via leaching. By analysing the movement of a bromide tracer over three slope positions (top, middle and low) within two hummocky landscapes in central Alberta, the intensity of short-term leaching potential was measured, and the accuracy of a leaching potential index was assessed. Concentrations of bromide > 1 mg kg-1 were found at a 120-cm depth at each slope position, from both landscapes, after one snowmelt event and one growing season. However, the depth of a bromide concentration > 100 mg kg-1 varied significantly among slope positions after the snowmelt event, and after the growing season. The leaching potential index successfully distinguished between high leaching potential, and low and very low leaching potential. This index will become a useful tool to determine the variability of leaching within an agricultural landscape. Key words: Soil-landscape, leaching, tracer, soil moisture, soil profile index