Agriculture Reference
In-Depth Information
Table 5.2
Maturity parameters established for composts of different sources
Parameter
Value
Reference
Colour (degree of darkness)
Dark brown or black colour
Sugahara et al. (
1979
)
Temperature
More or less constant after
turning of material
Stickelberger (
1975
)
pH
Close to neutral value
Gray et al. (
1971
); Finstein
and Miller (
1985
)
EC
Stable at the end
Avnimelech et al. (
1996
), Wu
et al. (
2000
)
C/N
Poincelot (
1974
); Cardenas
and Wang (
1980
); Golueke
(
1981
)
< 20
Juste (
1980
); Roig et al. (
1988
)
< 15
< 12
Iglesias Jiménez and Pérez
García (
1992
); Bernal et al.
(
1998
)
Water soluble C/N ratio
5-6
Chanyasak and Kubota (
1981
)
Cw/TOC
Hue and Liu (
1995
)
< 0.70
NH
4
content
< 0.04 %
Zucconi and de Bertoldi
(
1987
)
NH
4
/NO
3
Bernal et al. (
1998
)
< 0.16
CEC
Harada and Inoko (
1980
)
> 60 meq/100 g
CEC/TOC
Roig et al.
1988
> 1.70
HA/FA
Saviozzi et al. (
1988
); Iglesias
Jiménez and Pérez García
(
1992
)
> 1.9
HI
> 30
Raj and Antil (
2011
), Bernal
et al. (
1998
)
GI
Zucconi et al. (
1981
)
> 50 %
> 80 %
Tiquia et al.
1996
; Sellami
et al.
2008
> 110 %
Ko et al. (
2008
)
CO
2
production rate
Hue and Liu (
1995
)
< 120 mg CO
2
/kg/h
Microbial diversity bacterial,
fungal and actinomycetes
counts)
Decrease in bacterial and
fungal counts, and increase
in actinomycetes counts and
stable at the end of composting
Petkova and Kostov (
1996
);
Antil and Raj (
2012
)
Micro-organism counts (total
coliform, faecal coliforms and
faecal enterococci)
< 500 MPN/g
Vuorinen and Saharinen
(
1997
); Dahshan et al. (
2013
)
Enzyme activities cellulase,
xylanase and protease)
Maximum between 30 and 60
days of composting
Goyal et al. (
2005
)
5.3.1.1
Colour and Odour
During composting of organic wastes, a gradual darkening or melanisation of the
material takes place. The final product, after a sufficiently long period of matu-
ration, is dark brown or almost black colour (Iglesias Jiménez and Pérez García
1992
). Sugahara et al. (
1979
) proposed a simple technique to determine the maturity
of compost by measuring the degree of darkness of composting material. It is also
