Effects of recycled materials added to the substrate on nursery trees

Transplant can be a shock for plants, especially when they are moved from the nursery, where the environmental conditions are very favourable, to urbanised areas, where resources and maintenance are scarce. Moreover, some characteristics of urban soils, such alkaline pH and compaction, make it difficult for trees to adapt. Recycled organic material (compost) added as mulch to tree plantings is effective in contrasting compaction in urban soils (Scharenbroch and Watson 2014). Designed soil materials can promote successful urban tree planting, allowing better root growth and plant development (grabosky et al. 2001). The industry of recycled paper produces tons of waste, which in some cases can be a source of pollutants (Tandy et al. 2008). The deinking sludge we choose is a clean material consisting mainly of cellulose, that can be potentially used as a component in plant growth substarte. This material ha a good water retention and porosity and it has been successfully employed as a growing media component (Vannucchi et al. 2017). In the present study the deinking sludge converted into pellets has been added to the growing media of nursery trees, with the aim of increasing the water storage in the substrate and, at the same time, of contrasting soil compaction. In order to get the permission to use the waste in the experiment, an application was submitted to the local planning authorities primarly inteded to manage industrial waste.