Pine bark is the primary component in container nursery substrates, comprising 60% to 80% by volume of most substrate blends. Pine bark is a commodity used by other industries including fuel generation, fiber (Lu et al., 2006), charcoal, landscape mulch, and as a source for extracting biochemicals. Pine bark is primarily generated as a byproduct in the forest products industries, in which trees are debarked for the purpose of obtaining clean wood. The price for PB at any given time is dependent on supply/demand dynamics in the forest products industries as well as transportation and processing costs, which are tied directly to fuel costs.
A compelling body of research has emerged on the use of whole pine trees as an alternative component to replace PB as the base substrate (Boyer et al., 2008; Fain et al., 2008, Jackson et al., 2010; Wright and Browder, 2005). The nursery and greenhouse industries can bypass the forest products industry by harvesting whole trees using independent contractors, thus avoiding dependency on the economic volatility of the forest products industry. This research is also appealing to northern U.S. states that could use local pine tree stands instead of the current practice of importing PB from wood mills located primarily in southern U.S. states. The goal of this research was to evaluate the horticultural feasibility of using PW to replace all or part of the PB fraction currently used in container nursery production in Ohio. Specifically, the first objective was to determine the influence of substituting PB at commercial nursery operations with commercially harvested and processed PW on substrate physical properties.
Altland, J.E., Owen, J.S. Jr & Fonteno, W. 2010 Developing moisture characteristic curves and their descriptive functions at low-tensions for soilless substrates J. Amer. Soc. Hort. Sci. 135 563 567
Boyer, C.R., Fain, G.B., Gilliam, C.H., Gallagher, T.V., Torbert, H.A. & Sibley, J.L. 2008 Clean chip residual as a substrate for perennial nursery crop production J. Environ. Hort. 26 239 246
Breedlove, D., Ivy, L. & Bilderback, T. 1999 Comparing potting substrates for growing ‘Hershey Red’ azaleas. Proc. Southern Nurs. Assoc. Res. Conf. 44:71–75
Fain, G.B., Gilliam, C.H., Sibley, J.L. & Boyer, C.R. 2008 WholeTree substrates derived from three species of pine in production of annual vinca HortTechnology 18 13 17
Fonteno, W.C. & Bilderback, T.E. 1993 Impact of hydrogel on physical properties of coarse-structured horticultural substrates J. Amer. Soc. Hort. Sci. 118 217 222
Gabriel, M., Altland, J.E. & Owen, J. 2009 The effect of peat moss and pumice on the physical and hydraulic properties of douglas-fir bark based soilless substrate HortScience 44 874 878
Jackson, B.E., Wright, R.D. & Barnes, M.C. 2010 Methods of constructing a pine tree substrate from various wood particle sizes, organic amendments, and sand for desired physical properties and plant growth HortScience 45 103 112
Lea-Cox, J.D. & Smith, I.E. 1997 The interaction of air-filled porosity and irrigation regime on the growth of three woody perennial (citrus) species in pine bark substrates. Proc. Southern Nurs. Assoc. Res. Conf. 42:169–174
Lowder, A.W., Kraus, H.T., Warren, S.L. & Prehn, A. 2006 Nursery production of Helleborus sp.: Substrate irrigation. Proc. Southern Nurs. Assoc. Res. Conf. 51:36–39
Lu, W., Sibley, J.L., Gilliam, C.H., Bannon, J.S. & Zhang, Y. 2006 Estimation of U.S. bark generation and implications for horticultural industries J. Environ. Hort. 24 29 34
Milks, R.R., Fonteno, W.C. & Larson, R.A. 1989 Hydrology of horticultural substrates: I. Mathematical models for moisture characteristics of horticultural container media J. Amer. Soc. Hort. Sci. 114 48 52
Pokorny, F.A., Gibson, P.G. & Dunavent, M.G. 1986 Prediction of bulk density of pine bark and/or sand potting media from laboratory analyses of individual components J. Amer. Soc. Hort. Sci. 111 8 11
Puustjarvi, V. & Robertson, R.A. 1975 Physical and chemical properties, p. 23–38. In: Robinson, D.W. and J.G.D. Lamb (eds.). Peat in horticulture. Academic Press, London, UK
Yeager, T.H., Gilliam, C.H., Bilderback, T.E., Fare, D.C., Niemiera, A.X. & Tilt, K.M. 2007 Best management practices: Guide for producing nursery crops. Southern Nursery Assoc., Atlanta, GA