The Effects of Drainage and Ploughing of Surface Water Gleys on Rooting and Windthrow of Sitka Spruce in Northern Ireland

Abstract

Rooting depth of Sitka spruce on surface water gleys is unlikely to be increased by intensive deep drainage, so trees must be encouraged to develop wide-spreading surface root-plates to maintain stability. Plough furrows, and even shallow turf ditches severely restrict root-plate development. Thus crops planted on ploughed sites are likely to suffer from windthrow much sooner and more seriously than those on turfplanted sites, where there are considerably fewer ditches. It is recommended that single mouldboard ploughing should be replaced either by double mouldboard ploughing or turf planting on gleys.