Fate of phosphorus in soils receiving municipal sludge and solid waste incinerator ash when managed using vermicomposting technology

Laboratory soil columns were used to determine the effects of vermicomposting municipal sludge and municipal solid waste (MSW) incinerator bottom ash on soil phosphorus (P) forms and movements. Soil columns receiving vermicomposting treatment received the following earthworms: Eisenia fetida (N = 200); Lumbricus terrestris (N = 10); Allolobophora calignosa (N = 10).;Sixty percent of the total P applied from sludge applications was recovered in the top (0-15 cm) soil layer, with 50% in the Fe- and Al-bound P form. The vermicomposting of sludge (by earthworms) accelerated sludge decomposition, incorporated sludge into the soil, and created extensive tunneling that increased Fe- and Al-bound P and loosely-bound P levels in the middle soil layers. In soil columns receiving sludge but no vermicomposting treatment, sludge rapidly accumulated at the surface and caused ponding of applied sludge. MSW ash applications significantly increased Ca-bound P in the surface soils. (Abstract shortened with permission of author.)...