title: Wood ash application increases pH but does not harm the soil mesofauna.
abstract: Application of bioash from biofuel combustion to soil supports nutrient recycling, but may have unwanted and detrimental ecotoxicological side-effects, as the ash is a complex mixture of compounds that could affect soil invertebrates directly or through changes in their food or habitat conditions. To examine this, we performed laboratory toxicity studies of the effects of wood-ash added to an agricultural soil and the organic horizon of a coniferous plantation soil with the detrivore soil collembolans Folsomia candida and Onychiurus yodai, the gamasid predaceous mite Hypoaspis aculeifer, and the enchytraeid worm Enchytraeus crypticus. We used ash concentrations spanning 0-75 g kg-1soil. As ash increases pH we compared bioash effects with effects of calcium hydroxide, Ca(OH)2, the main liming component of ash. Only high ash concentrations above 15 g kg-1agricultural soil or 17 t ha-1had significant effects on the collembolans. The wood ash neither affected H. aculeifer nor E. crypticus. The estimated osmolalities of Ca(OH)2and the wood ash were similar at the LC50concentration level. We conclude that short-term chronic effects of wood ash differ among different soil types, and osmotic stress is the likely cause of effects while high pH and heavy metals is of minor importance.
authors.affiliation: Soil Fauna Ecology and Ecotoxicology, Department of Bioscience, Vejlsøvej 25, 8600 Silkeborg, Denmark.
authors.forename: Jiayi
authors.initials: J
authors.lastname: Qin
authors.affiliation: Biology, Terrestrial Ecology, University Park 15, 2100 Copenhagen, Denmark.
authors.forename: Mads Frederik
authors.initials: MF
authors.lastname: Hovmand
authors.affiliation: Biology, Terrestrial Ecology, University Park 15, 2100 Copenhagen, Denmark.
authors.forename: Flemming
authors.initials: F
authors.lastname: Ekelund
authors.affiliation: Biology, Terrestrial Ecology, University Park 15, 2100 Copenhagen, Denmark.
authors.forename: Regin
authors.initials: R
authors.lastname: Rønn
authors.affiliation: Biology, Terrestrial Ecology, University Park 15, 2100 Copenhagen, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Christensen
authors.affiliation: ALTERRA, Wageningen UR, P.O. Box 47, 6700 AA, Wageningen, The Netherlands.
authors.forename: Gerard Arjen de
authors.initials: GA
authors.lastname: Groot
authors.affiliation: Biology, Terrestrial Ecology, University Park 15, 2100 Copenhagen, Denmark.
authors.forename: Louise Hindborg
authors.initials: LH
authors.lastname: Mortensen
authors.affiliation: Department of Geosciences and Natural Resource Management (IGN), University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark.
authors.forename: Simon
authors.initials: S
authors.lastname: Skov
authors.affiliation: Soil Fauna Ecology and Ecotoxicology, Department of Bioscience, Vejlsøvej 25, 8600 Silkeborg, Denmark. Electronic address: phk@bios.au.dk.
authors.forename: Paul Henning
authors.initials: PH
authors.lastname: Krogh
mesh_terms: D000383:Agriculture; D000818:Animals; D001181:Arthropods / Q000187:drug effects* / Q000502:physiology; D060729:Coal Ash / Q000737:chemistry* / Q000633:toxicity; D017753:Ecosystem; D054750:Ecotoxicology; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000737:chemistry / Q000633:toxicity; D009835:Oligochaeta / Q000187:drug effects* / Q000502:physiology; D012098:Reproduction / Q000187:drug effects; D012987:Soil / Q000737:chemistry* / Q000592:standards; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity; D014934:Wood / Q000737:chemistry*
chemical_list: D060729:Coal Ash; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants
keywords: Enchytraeus crypticus; Folsomia candida; Hypoaspis aculeifer; Onychiurus yodai; Osmolality; Reproduction; Soil pH; Wood ash