title: Biochar amendment before or after composting affects compost quality and N losses, but not P plant uptake.
abstract: We investigated the use of biochar (10% on a dry weight basis) to improve the composting process and/or the compost quality by adding it to either the feedstock mixture or the mature compost. The addition of biochar to the feedstocks was essayed in a full scale trial using a mixture of green waste and the organic fraction of municipal solid waste. Addition of biochar to mature compost was performed in a medium scale experiment. The use of biochar, even in small amounts, changed the composting process and the properties of the end products. However these effects depended on the time of application. We observed a faster decomposition in the bio-oxidative phase and lower greenhouse gas emissions when biochar was added at the beginning of the composting process, and a reduction in readily available P when biochar was applied during compost storage. Biochar as a means to increase the C content of the compost was only effective during compost storage. The P fertilizer replacement value of the compost with and without biochar was tested in a plant trial with annual ryegrass. While there was a clear effect on readily available P concentrations in the compost, adding biochar to the feedstock or the compost did not affect the P fertilizer replacement value.
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Plant Sciences Unit, Caritasstraat 21, Melle, Belgium. Electronic address: bart.vandecasteele@ilvo.vlaanderen.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Vandecasteele
authors.affiliation: Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria, CRA-RPS, Via Trieste 23, 34170 Gorizia, Italy.
authors.forename: Tania
authors.initials: T
authors.lastname: Sinicco
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Plant Sciences Unit, Caritasstraat 21, Melle, Belgium.
authors.forename: Tommy
authors.initials: T
authors.lastname: D'Hose
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Plant Sciences Unit, Caritasstraat 21, Melle, Belgium.
authors.forename: Thijs
authors.initials: T
authors.lastname: Vanden Nest
authors.affiliation: Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria, CRA-RPS, Via Trieste 23, 34170 Gorizia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Mondini
mesh_terms: D002606:Charcoal; D005308:Fertilizers; D006801:Humans; D008129:Lolium / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D012987:Soil
chemical_list: D005308:Fertilizers; D012987:Soil; C540010:biochar; D002606:Charcoal; D010758:Phosphorus; D009584:Nitrogen
keywords: Methane; N losses; Nitrous oxide; Organic matter decomposition; Organic residues; P availability