Mulching potatoes: Aspects of mulch management systems and soil erosion

Abstract

Intensive potato production occupies much of the sloping arable land of Prince Edward Island, Canada, and is at the center of soil erosion concerns in this province. Corrective considerations have turned recent attention to mulching, but there is limited knowledge of its workability or effectiveness in potato systems. This study looks at the effect of mulching on soil loss from potatoes grown on standard erosion plots, and examines a relatively simple approach to assessing soil-surface splash detachment (splash erosion) under mulch-management systems with potatoes. Three sizes of splash cup (25, 50, and 100 mm in diameter) were used under simulated rainfall at 150 mm·h−1 for 10 minutes to measure splash erosion on potato plots under mulch-management systems which, respectively, left surface coverage of ∼ 5%, ∼ 15%, and ∼20%. The lowest straw coverage gave up to 56% more erosion than either of the two higher coverages. The 25-mm splash cup yielded 14% more sediment splash than the 100-mm splash cup on the basis of unit surface area of soil in the splash cup (unit area). Regression modeling of unit-area splash against straw cover showed an exponential decay in splash detachment with increasing straw cover. On the erosion plots, soil loss with mulching was half of what it was without mulching; and soil water retention was 5% greater with mulching.