IS SITE PREPARATION NECESSARY FOR BUR OAK RECEIVING POSTPLANTING WEED-CONTROL

Plowing and harrowing have been recommended before establishing hardwo od plantations on abandoned farmland with herbaceous weed competitors. However, mechanical soil preparation is not always practical. The pos sibility of reducing site preparation efforts by using post-planting w eed 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 t reatments (glyphosate herbicide or black plastic mulching) in 120 cm s trips over the seedling rows of bur oak (Quercus macrocarpa Michx). Af ter 5 years of weed control treatment, site preparation by plowing and harrowing did not produce superior growth results relative to the con trol. However, growth was superior when this mechanical site preparati on was combined with simazine herbicide application. Oak seedling diam eter and height were larger in the plastic mulch treatment than in the glyphosate treatment. Results support the feasibility of hardwood ref orestation on sites where mechanical soil preparation is impractical, if post-planting weed control treatments are applied.