Sewage Sludge and Mycorrhizal Effects on Secar Bluebunch Wheatgrass in Mine Spoil

Abstract

Establishing vegetation on mine spoil often requires amendments to supply nutrients and microorganisms to re‐establish attributes associated with developed soil. Arbuscular‐mycorrhizal fungi (AMF) and composted sewage sludge (CSS) were evaluated as possible minespoil amendments to create a topsoil substitute for revegetation of the Midnite Mine, Stevens County, Washington. Most original topsoil was buried and existing spoil is low in nutrients and organic matter and not capable of supporting desired vegetation. Secar bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) A. Love × Elymus lanceolatus ssp. lanceolatus (Scribn. & J.G. Sm.) Gould] was grown in nonsterile spoil amended with 0.0, 6.2, 12.4, 24.5, and 49.0 g dry CSS per liter of spoil‐sand mix for 16 wk in a glasshouse experiment. Arbuscular‐mycorrhizal fungi treatments were spores of Glomus mosseae [(Nicol. & Gerd.) Gerdemann & Trappe] collected from native bluebunch wheatgrass plants, non‐native spores of Glomus intraradices (Schenck & Smith) and Entrophaspora sp. (Ames & Schneider), or no added spores. In addition, Secar was grown in nonsterile, stockpiled topsoil with both AMF treatments to compare to AMF present in the topsoil. Each CSS rate increase produced increased above‐ground and belowground plant growth. Secar growth was enhanced by native AMF in CSS‐amended spoil. Composted sewage sludge appeared to reduce AMF colonization; however, hyphae levels in plants with native AMF were unaffected. Plant growth was not affected by AMF treatments in stockpiled topsoil but AMF colonization was greater in plants with the topsoil alone. Benefits from CSS and selection of an effective AMF culture are evident.

Stabilisation of metals in mine spoil with amendments and growth of red fescue in symbiosis with mycorrhizal fungi

“…In these cultures the increased absolute (a% = 35) and relative (A% = 17) arbusculum richness indicated good functioning of the symbiosis (Table 4). The observed high rate of mycorrhizal infection of red fescue in our sewage sludge compost amended mine spoil is in contrast with results of Thorne et al (1998), who found reduced arbuscular mycorrhizal fungi colonization of Secar bluebunch wheatgrass grown in sewage sludge compost amended mine spoil.…”

The role of organic amendments in soil reclamation: A review

“…Arbuscular mycorrhizal fungi are able to exploit nutrients released by mineralization of organic matter. However, when applied in high concentrations, organic amendments such as manure, sewage sludge or compost can be harmful to arbuscular mycorrhizal fungi (Thorne et al 1998). Given this disparity, Gryndler et al (2008) assessed application of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria to spoil bank clays to increase plant growth and compensate for reduced organic amendments.…”

Arbuscular mycorrhizas contribute to phytostabilization of uranium in uranium mining tailings

“…However, the establishment of a plant cover is only part of the reclamation process; creation of a self-sustaining ecosystem after revegetation practices is of equal importance (Pichtel et al, 1994). Amendment of mine spoils with sewage sludge and arbuscular mycorrhizal (AM) fungi will help to create a functional soil (Sabey et al, 1990;Thorne et al, 1998).…”