Integration of arbuscular mycorrhiza inoculation in hydroseeding technology: effects on plant growth and inter-species competition

Hydroseeding is a technique increasingly used to establish vegetation on large degraded areas, such as large-scale road construction sites and quarries. Native grasses and legume species are used on rehabilitation and restoration projects as a first step in the recovery of such places, prior to the establishment of native forbs and shrubs that occurs at a slower pace. The effect of mycorrhizal inoculation on the development of nine species of grasses and legumes that can be potentially used in restoration processes in the Mediterranean area was studied, in microcosm experiments under greenhouse conditions. The effect of adding arbuscular mycorrhizal (AM) inoculum to a hydroseeding mixture was also investigated in greenhouse and in field conditions. In the hydroseeding experiments the mycorrhizal inoculum was added to the seed slurry in a jet agitated hydroseeding machine and sprayed to the soil surface with a pressurised spray in a one-step application. The study shows that Glomus intraradices Schenk & Smith BEG72 is able to establish the symbiosis when applied at sowing while Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe BEG116 is not. It also confirms that legumes are more highly mycotrophic than grasses. The results of the hydroseeding experiments demonstrate the establishment of the symbiosis using this technology, both in the greenhouse and in the field. Mycorrhizal inoculation improved above ground plant growth and increased the legumes/grasses ratio. Copyright © 2007 John Wiley & Sons, Ltd.