Is site preparation necessary for bur oak receiving post-planting weed control?

Abstract

Plowing and harrowing have been recommended before establishing hardwood plantations on abandoned farmland with herbaceous weed competitors. However, mechanical soil preparation is not always practical. The possibility of reducing site preparation efforts by using post-planting weed control treatments was tested. This study compares three different types of site preparation (plowing and harrowing; plowing, harrowing and simazine herbicide; a control), each plot of which were separated in two halves receiving either one of two post-planting weed control treatments (glyphosate herbicide or black plastic mulching) in 120 cm strips over the seedling rows of bur oak (Quercus macrocarpa Michx). After 5 years of weed control treatment, site preparation by plowing and harrowing did not produce superior growth results relative to the control. However, growth was superior when this mechanical site preparation was combined with simazine herbicide application. Oak seedling diameter and height were larger in the plastic mulch treatment than in the glyphosate treatment. Results support the feasibility of hardwood reforestation on sites where mechanical soil preparation is impractical, if post-planting weed control treatment are applied.