Problem: Biochar, a waste product from the burning of biomass, has tremendous potential as a soil amendment for urban tree care. Biochar has been used intentionally or unintentionally for many years throughout the world for restoration of infertile soils. Urban soils may be deficient in carbon, available nutrients, and biological activity. Because biochar has a high affinity for nutrients and long persistence, it may be a superior organic amendment for urban soil restoration. Urban trees generate a great amount of woody waste that could potentially be turned to biochar for soil improvement. To date, no studies have examined biochar’s impacts on urban trees and soil.
Goals: This research aims to take a comprehensive look at biochar for urban tree care. Because biochar is a new urban soil amendment, application procedures are currently not available. The research will also identify appropriate application rates and procedures for urban tree management with biochar. The research will consider economic and social aspects of biochar as an urban tree care amendment compared to other current practices.
Methods: Multiple projects are underway comparing biochars to other amendments in a greenhouse, tree nursery, and urban landscape settings. Biochar application technologies include: top-dressing, drilling, and air-cultivation techniques. Various biochars, application rates and mixes are being assessed. Soil sampling and tree health and growth assessments are performed annually on these projects.
Personnel: This research is led by Dr. Bryant Scharenbroch and Dr. Kelby Fite (Bartlett Tree Research). Michelle Catania is a Research Assistant on the biochar research.
Funding: This research is funded in part by a grant from The Tree Research and Education Endowment.
Scharenbroch, B.C., E. Meza, M. Catania, and K. Fite. 2013. Biochar and biosolids increase tree growth and improve soil quality for urban landscapes. Journal of Environmental Quality. doi:10.2134/jeq2013.04.0124.