title: Efficiency of near-infrared reflectance spectroscopy to assess and predict the stage of transformation of organic matter in the composting process.
abstract: Changes in composts of sewage sludges and green wastes were analysed by near infrared reflectance spectroscopy (NIRS) and chemical analysis with 426 samples representative of six stages of composting: 8, 20, 35, 75, 135 and 180 days. Maturity of compost was assessed through changes in C:N ratio. Results of spectroscopic properties (200 wavelengths) were studied with several multivariate analyses. First, a descriptive approach revealed compost changes with time of maturation. Then, a constrained ordination (RDA with permutation tests) demonstrated a significant effect of three factors of sampling: stage of composting, depth and position in windrows. Precise calibration models between spectral data, the C, N, C:N values and composting time were build using partial least square regression (r(2)>0.95). Together, these results show the efficiency of NIRS to predict chemical changes and the stage of transformation of organic matter during the composting process.
authors.affiliation: Université Paul Cézanne Aix-Marseille III, Institut Méditerranéen d'Ecologie et de Paléoécologie, Marseille, France. remy.albrecht@univ-cezanne.fr
authors.forename: Remy
authors.initials: R
authors.lastname: Albrecht
authors.forename: Richard
authors.initials: R
authors.lastname: Joffre
authors.forename: Raphaël
authors.initials: R
authors.lastname: Gros
authors.forename: Jean
authors.initials: J
authors.lastname: Le Petit
authors.forename: Gérard
authors.initials: G
authors.lastname: Terrom
authors.forename: Claude
authors.initials: C
authors.lastname: Périssol
mesh_terms: D002244:Carbon / Q000032:analysis; D007700:Kinetics; D009584:Nitrogen / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D013055:Spectrophotometry, Infrared / Q000379:methods; D013997:Time Factors
chemical_list: D009930:Organic Chemicals; D012987:Soil; D002244:Carbon; D009584:Nitrogen