Effects of Mulch on Seedlings and Soil on a Closed Landfill

Landfills are ideal locations for short‐rotation forestry, tree‐based bioremediation, and wildlife habitat reconstruction. However, tree survival is reduced by harsh growing conditions and poor soil quality. This study was designed to determine survival of tree seedlings and test effects of different mulch types and depths on edaphic properties and herb emergence on a closed Ohio landfill. In spring 2002, five species of hardwood tree seedlings (Fraxinus pennsylvanica, Robinia pseudoacacia, Prunus serotina, Quercus macrocarpa, and Populus sp.) were planted in a clustered fashion on 35 plots. Each plot received a mulch treatment consisting of one type of mulch (hardwood, leaf, or mixed) at a specific depth (5 or 15 cm) or was designated as a nonmulched control. The status of each seedling and edaphic qualities (soil moisture, temperature, and nutrients) were recorded for two growing seasons. Aboveground herbaceous biomass was sampled at the end of each growing season. We found that survival and growth were species dependent. At the conclusion of the experiment, Fraxinus had the highest survival rate (70%) and Prunus the lowest (7%). The use of leaf mulch (15 cm deep) increased organic matter and various edaphic properties (cation exchange capacity, P, Mg) after the second growing season. Mulch treatments did not significantly affect aboveground herbaceous biomass when compared to nonmulched controls. These results suggest Fraxinus as a good candidate for landfill plantings. Additionally, leaves and yard waste are plentiful and could quickly enrich poor soils on a landfill if left to decompose aboveground.