Community Shade Tree Leaves: Beneficial Uses for Agriculture

Every autumn an abundance of leaves from various species of shade trees [e.g., oak (Quercus sp.), maple (Acer sp.)] are collected from urban landscapes. In 1988, shade tree leaves were banned from landfills and combustion facilities in New Jersey because it was an unsustainable practice. Composting and mulching leaves and using them as a resource was proposed. The purpose of this review is to summarize studies of mulching and amending soils with shade tree leaves and their potential to benefit agricultural production. Research sponsored by New Jersey Agricultural Experiment Station on soils and crops found that land application of shade tree leaves was beneficial for building soil organic matter content, protecting against erosion, and controlling weeds when used as a mulch. In general, crop yields and quality were improved with leaf mulch. Collected shade tree leaves on average have a relatively high carbon-to-nitrogen (N) ratio and the potential to cause a temporary deficiency of soil N availability. However, with good agronomic practices and well-timed N fertilization, crops perform well after shade tree leaves have been applied without increasing the recommended N fertilizer application rate.