Submitted to: Journal of Environmental Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2011
Publication Date: 9/1/2011
Publication URL: http://handle.nal.usda.gov/10113/53945
Citation: Altland, J.E., Locke, J.C. 2011. Use of ground miscanthus straw in container nursery substrates. Journal of Environmental Horticulture. 29:114-118.
Interpretive Summary: Pine bark is the primary potting component used in container nursery production. Shifts in the forest products industry and economy have resulted in a drastic decline in pine bark availability and increase in pine bark price. This research evaluates the potential for using a biomass crop, giant miscanthus (Miscanthus ×giganteus), as an alternative to pine bark in nursery potting substrates. We found that up to 60% of the substrate can be composed of miscanthus straw without loss of plant quality. Miscanthus straw does affect the physical and chemical properties of the substrate, but effects are relatively minor. Use of miscanthus straw in nursery substrates will alleviate over-reliance on pine bark, lower overall production costs for nursery crops, and provide greater control for nursery producers in managing their production resources.
Technical Abstract: Pine bark (PB) is the primary component in nursery substrates in the U.S. Availability of pine bark is decreasing and price is increasing. The objective of this research was to determine if miscanthus straw (MS) can replace all or part of the pine bark fraction in nursery container substrates. Five substrates were created that contained 15% sphagnum peatmoss, 5% municipal solid waste compost, and the remaining 80% consisted of one of the five following PB and MS ratios: 0:80, 20:60, 40:40, 60:20, and 80:0. Additions of ground MS affected physical properties of substrates by increasing air space, and decreasing container capacity and bulk density. Additions of MS did not affect chlorophyll content, and had negligible effects on foliar nutrient levels. Increasing levels of MS caused a decrease in plant shoot dry weight, although growth reduction was most pronounced with 80% MS. Ground MS has potential to be a suitable substrate for nursery growers, however, some changes to management practices will be necessary.