Effectiveness of terraces/grassed waterway systems for soil and water conservation: A field evaluation

Abstract

ABSTRACT: Some of the most serious water erosion in Canada is associated with potato (Solanum tuberosum L.) production in the rolling topography of the upper Saint John River Valley in northwestern New Brunswick. Soil losses of 20 to 30 t/ha/yr are common, as are related damages caused by excessive runoff from potato fields. Variable grade diversions and grassed waterways are commonly used to minimize soil erosion. This study quantifies the benefits of these engineering structures to conserve both soil and water. Contour planting of potatoes associated with terracing will reduce runoff by as much as 150 mm of rainfall equivalent, and thereby increase available soil moisture for plant growth. Soil losses were reduced from 20 t/ha/yr to 1 t/ha/yr. Terracing also makes drainage basin hydological characteristics less prone to cause ditch and stream flooding.