The influence of simulated erosion on crop growth and the value of topsoil in soil productivity

Abstract

Wind erosion is a major soil degradation phenomenon on the Canadian prairies but its effects on soil productivity are not well quantified. In the spring of 1990, incremental depths of soil (0, 5, 10, 15 and 20 cm) were removed with an excavator, to simulate wind erosion at four sites (three dryland and one irrigated) in southern Alberta. Highly significant non-linear relationships were found between the depth of de-surfacing and subsequent spring wheat grain yields showing that simulated erosion drastically reduced soil productivity. Treatment effects at the irrigated site followed the same trend as the dryland site illustrating that topsoil loss cannot be compensated by adequate soil moisture. The 0-1 cm increment of topsoil was worth more (in terms of magnitude of yield loss when it was removed) on the irrigated site followed by the Black, Dark Brown, and Brown dryland soils.