Improving growth and adaptation of Carpolepis laurifolia, an endemic plant species used on ecological restoration of mined areas in New Caledonia. Field experiment on the combined effects of arbuscular mycorrhizal fungi (AMF) and organic amendment

TitreImproving growth and adaptation of Carpolepis laurifolia, an endemic plant species used on ecological restoration of mined areas in New Caledonia. Field experiment on the combined effects of arbuscular mycorrhizal fungi (AMF) and organic amendment
Publication TypeJournal Article
Year of Publication2014
AuthorsAmir, H, Laurent, A, Cavaloc, Y, Pagand, P, Gunkel-Grillon, P, Le Mestre, M, Medevielle, V
JournalConference paper: Second International Conference of the Society for Ecological restoration Australasia (SERA), Noumea, New Caledonia
Date Published11/2014
Type of ArticleConference paper
Abstract

A field experiment was conducted in a mining company area, in Goro south of New Caledonia. It was assessed on degraded topsoil, spread before the experiment. Four different treatments were tested: (1) control (C. laurifolia plants, in non-amended topsoil); (2) plants inoculated with AMF, in non-amended topsoil; (3) non-inoculated plants, in topsoil amended with sewage sludge; (4) plants inoculated with AMF, in topsoil amended with sewage sludge. Four parcels of land of 25 m² were used for each treatment and were combined on a randomized complete block. On each parcel 25 plants, grown 16 months on a nursery, inoculated or not with AMF, were planted. The experiment was followed for 20 months. AMF inoculation induced a total biomass 4.2 times higher than the control. A similar improvement was noted for sewage sludge amended topsoil. The combined effects of AMF and organic amendment induced a gain of 740 % of biomass, indicating additive effects of the two tested treatments. Mycorrhizal colonisation (F) of inoculated plants reached 72 % in non-amended soil and mycorrhizal density (M) was 12.8 %. Sewage sludge amendment increased significantly mycorrhizal colonization (F: 85 %; M: 16.8%). AMF population diversity in plant roots was improved in inoculated parcels, and reduced in sewage sludge amended parcels. Plant mineral nutrition was improved by AMF inoculation. The Ca/Mg ratio was also increased by these two treatments. The combination of AMF inoculation and sewage sludge amendment could then improve the success of ecological restoration of mined areas.