Evaluation of compost and straw mulching on soil-loss characteristics in erosion plots of potatoes in Prince Edward Island, Canada

The intensive use of Prince Edward Island (PEI) farmland for potato (Solanum tuberosum L.) production draws concern because of soil physical degradation under the intense tillage and other heavy traffic associated with the mechanisation of this crop, and the resulting vulnerability of sloping fields to hydraulic erosion. Growing public consciousness and pressure in favour of sustainable agriculture have engendered farmer interest in a possible place for commercial farm by-products in commercial cropping. Using existing natural erosion plots in PEI, the effects of compost amendment and straw mulching were assessed in terms of soil loss and soil physical condition on a fine sandy loam (Orthic Podzol). The treatment materials are local by-products of potato farming systems, and were used for an insight into the likelihood of sustainable commercial use. Compost had no effect on soil loss. Mulching reduced soil loss by almost 50%. Both treatments increased soil water content by 6-7%. Among the treatment effects on soil physical characteristics, soil penetration resistance below the root zone was reduced almost 20%; and, in the third year of the study, soil aggregate stability increased 7% with compost. Shear strength showed a strong (p less than or equal to0.05) regression relationship (R-2=0.835) with bulk density. (C) 2000 Elsevier Science B.V. All rights reserved.