Rehabilitation of urban soils: A critical first step for long-term soil productivity and canopy cover in urban forests

2006 | Susan D. Day and Roger Harris, Virginia Tech

In this project we will evaluate several soil rehabilitation protocols, including subsoiling, topsoil replacement, and organic matter incorporation, on scraped, heavily compacted sites to determine their effects on soil physical properties and tree establishment and growth. Current practices in land development—specifically rapid urbanization of rural landscapes, infill development within cities and towns, and modern construction techniques that destroy soil structure—create a situation where many new trees are planted into soil that has been scraped and compacted. This results in poor tree establishment, slow growth, and a host of associated plant healthcare problems. Results from this study will allow professionals to make appropriate recommendations for soil improvement methods on a job site or at a new development.

Objectives include:

  • Evaluate the effects of several soil rehabilitation techniques for highly disturbed soils on soil properties and tree growth.
  • Obtain initial documentation of the relationship between easily measurable soil characteristics (such as bulk density, organic matter content, and pH) to tree growth in urban landscape conditions. Propose a more generalized scheme of soil productivity classes that can be evaluated in further research and that can make use of currently available literature from the Long-term Soil Productivity studies carried out in traditional forestry research.

 

Study Results

The intensive soil rehabilitation procedure “profile rebuilding” effectively reduces soil compaction and accelerates tree growth. It shows great promise for increasing canopy growth in many types of urban and landscape settings.

Year: 2006

Funding Duration: 3-5 years

Grant Program: Hyland R. Johns

Grant Title: Rehabilitation of urban soils: A critical first step for long-term soil productivity and canopy cover in urban forests

Researcher: Dr. Susan Day

Abstracts, Papers, Posters from Grant:

  • Day, S.D. 2016 Soil Profile Rebuilding: An Alternative to Soil Replacement. City Trees. Sept/Oct 2016: 30–34.
  • Layman, Rachel M., Day, Susan D., Mitchell, David K., Chen, Yujuan, Harris, J. Roger, Daniels, W.L. (2016). Below ground matters: Urban soil rehabilitation increases tree canopy and speeds establishment. Urban Forestry & Urban Greening 16 (2016): 25–35.
  • Layman, R.M., Day, S.D., J.R. Harris, W.L. Daniels, P.E. Wiseman, and S.B. Dickinson. Rehabilitating damaged urban soils to optimize tree establishment and growth and improve soil function. Arboriculture Research & Education Academy. International Society of Arboriculture’s 85th Annual Conference. Providence, RI July, 2009. (poster)
  • Day, S.D., J. R. Harris, P.E. Wiseman, Tang Dai, J. Bartens, and E. G. McPherson. 2008. Tree root systems in urban settings: Growth and development—part of the International Society of Arboriculture’s Literature Review Series. In Arboriculture for the Third Millenium. Ed. F. Ferrini. European Congress of Arboriculture. June 16-18, 2008, Turin, Italy. (in press)
  • Layman, Rachel M., Susan D. Day, and J. Roger Harris. 2008. Rehabilitation for Severely Compacted Urban Soils to Optimize Tree Establishment and Growth and Improve Soil Function. Landscape Below Ground III, October 7-10, Lisle, IL (Abstract)—Note the full proceedings report will appear in the LBGIII book currently in press.
  • Layman, R.M.* and S.D. Day, 2008. Conference Poster: Soil Rehabilitation Experimental Site. Society of Environmental Journalists Conference, October 15, 2008, Roanoke, VA. (poster)
  • Soil Rehabilitation Experiment Site at Kentland Farm, Virginia Tech. Center for Sustainable Urban Landscapes, Virginia Tech 2008. (Poster)

Presentations:

  • Layman, R.M., J.R. Harris, S.D. Day, W.L. Daniels, and P.E. Wiseman. Rehabilitation for severely compacted urban soils to optimize tree establishment and growth. 2nd International Conference on Landscape and Urban Horticulture, International Society for Horticultural Science. Bologna, Italy. June 12, 2009.
  • Layman, R., S. D. Day, and J. R. Harris. Urban soil rehabilitation: Rehabilitation for severely compacted urban soils to optimize tree establishment and growth and improve soil function. Landscape Below Ground III, Lisle, IL, October 8, 2008.
  • “New Paths for Roots in Urban Landscapes” Idaho Horticulture Expo, Idaho Nursery & Landscape Association, Boise, ID. January 21-23, 2009.

Additionally, this research was highlighted in the following presentations:

  • Urban Trees—Urban Soils: A research overview focused on sustainable landscapes. Department of Horticulture, Virginia Tech. March 16, 2009.
  • Sustainable Urban Landscapes: Urban Horticulture as a Tool for Environmental Sustainability. University of Idaho Department Plant, Soil, and Entomological Sciences. July 1, 2008.
  • Sustainable Urban Landscapes: Teaching Undergraduates. University of Idaho Department Plant, Soil, and Entomological Sciences. July 2, 2008.
  • Forestería Urbana: Nuevas Direcciones en Educación e Investigación Universitaria para lograr una Ciudad Ecológica. (Urban Forestry: New Directions in University Research and Education to Achieve Ecological Cities.) Urban Forestry Conference, Facultad de Ciencias Agroalimentarias, Universidad de Costa Rica, San José, Costa Rica. May 8, 2008. (Presented in Spanish)

For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.