Fig 5. Changes in concentrations of total organic carbon (a), nitrogen (b), phosphorus (c) and potassium (d) during experiment set 1 of BSF frass composting.
Key: 5Gypsum, 10Gypsum, 15Gypsum = substrate amended with 5, 10 and 15% gypsum, respectively, 5Biochar, 10Biochar, 15Biochar and 20Biochar = substrate amended with 5, 10, 15 and 20% biochar, respectively, control = unamended substrate.