Simulated soil erosion and crop productivity

Abstract

Several different soil types were employed to study the effects of simulated soil erosion on wheat and canola productivity. Varying amounts of topsoil were scraped from the surface of experimental fields and crops were grown using three levels of fertilizer applications. Topsoil removal treatments included 0 cm removed, (a basis for comparison) , 5, 10, and 20 cm of topsoil removed. Fertilizer application treatments consisted of no fertilizer applied, recommended rate of fertilizer applied and approximately double the recommended rate. Crops utilized for this study were Columbus wheat and Westar canola. It was found that yields generally decreased as the amount of topsoil removed increased. Data indicated yields to be severely depressed on all topsoil removal treatments where no fertilizer was applied. Soil texture played a role in determining the outcome of yields in that on the coarse textured soils, even twice the recommended rate of fertilizer was not able to bring the yields back to that of the control. The recommended rate of fertilizer application was able, on the other hand, to mitigate topsoil losses on the fine textured soils and in some cases yields exceeded the control at twice the recommended rate of fertilizer.