Rapid urbanization has led to increased need in cities for greenspace and the ecosystem services they provide. Compacted and degraded soils from land management create inhospitable soil conditions for trees, contributing to higher mortality rates for trees in cities. Developing soil management practices to improve soil quality and tree planting success is crucial for successful land reclamation and reforestation, especially in cities. This study compares the effects of soil amendments from organic waste on soil quality and tree survival in a compacted soil at a previously-developed site in Beltsville, Maryland. The area was divided into four quadrants based on levels of soil compaction, and each treatment was randomly assigned to five or six 2 square-meter subplots per block. Treatments included tilled-in yard waste compost and biosolids, as well as tilled and untilled control plots. Bareroot Quercus Alba seedlings (30-45 cm tall) were transplanted into the center of each subplot in early Summer, and survival was monitored over the growing season. Soil was analyzed post growing-season for physical, chemical, and biological indicators of soil quality. Spring 2020 data collection will include post-treatment soil physical, chemical and biological data as well as spring tree survival data.
Results/Conclusions
Pre-treatment soil organic matter content was higher for plots where seedlings showed aboveground signs of survival one month after planting than in plots where trees showed no aboveground signs of survival (N=40, p<0.05). Pre-treatment soil organic matter content was also higher for plots where scratch tests showed that seedlings’ mainstems were still alive one month after planting than in those where seedlings’ mainstems were dead (N=40, p<0.05). However, three months after planting, there were no significant differences in pre-treatment soil organic matter between plots with living versus dead mainstems, nor between plots with versus without aboveground signs of survival. This suggests that soil organic matter conditions even before the addition of amendments may play a meaningful role in tree response to initial transplant shock. Comparisons of aboveground signs of tree survival showed no significant difference between treatments, indicating that effects of tillage and amendment additions on tree survival are not yet significant. This study will increase scientific understanding of the effects of amendment use on soil quality, tree survival, and potential ecosystem service provision, better informing soil management practices in urban land management, urban forestry, green infrastructure and more.