Enhancement of Plant Establishment on Dredged Material Sites with Mycorrhizal Fungi and Clay Amendments
Abstract
The effect of vesicular-arbuscular mycorrhizae (VAM) and clay amendments on the growth in sandy substrates of selected plant species was investigated in greenhouse experiments and a field trial. VAM were applied as commercially available preparations of the fungi Glomus deserticola, G. etunicatum, and G. intraradices. The clays attapulgite, bentonite, kaolinite, and montmorillonite from various commercial sources were used as sediment amendments at rates from 5 to 15 percent (equivalent to 19 to 57 tons/acre). Apparent host specificity, and the effects of inoculum density, fertilizer, clay type, clay particle size, and calcining of clays were evaluated in greenhouse experiments. In general, the 12 plant species tested (11 grasses and 1 herb) exhibited enhanced shoot and/or root growth when inoculated with any of the three VAM species. Only 4 of the 48 plant-VAM combinations did not result in higher plant yields than in uninoculated controls. The combination of VAM with clay amendments and mulch provides a practical, low-maintenance revegetation scheme for sandy dredged materials. It is recommended that sandy substrates be amended with ca. 25 tons montorillonite or bentonite clay per acre, that VAM inoculation be applied while seeding, and that mulching take place after planting. This regimen successfully revegetated sandy dredged materials without further attention during a severe drought and should readily succeed under more moderate conditions. Keywords: Clay amendments; Dredged material sites; Mycorrhizal fungi; Plant establishment. (kt)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1989
- Accession Number
- ADA214292
Entities
People
- James K. Mitchell