Analytical methods
Samples from the manures were analysed at 105
oC dry weight basis for: total solids (TS) content
(drying at 105 oC for 24 h); volatile solids (VS)
content (ashing of TS at 550 oC for 5 h in a muffle
furnace); total nitrogen (TN) content (regular-
Kjeldahl method; (Bremner, 1996)); pH (1:10 w/v
sample:water extract, using a pH meter, Model
8000). The total carbon (TC) content was
estimated from the ash content according to the
formula (Mercer and Rose, 1968):
TC (%) [100 Ash (%)] /1.8