Decomposition of Organic Materials into High Value Compost for Sustainable Crop Productivity - Composting for Sustainable Agriculture - page 255

Table 12.3 Important regulations required for C:N ratio maintenance in composting process
Factor Regulation and importance

Carbon Microbial cells use carbon source as sole source of energy for

building cellular block(s)/unit(s)

Nitrogen Necessary for microbial growth and function as these are crucial

component of cellular metabolites

Ideal C:N ratio 30:1

C:N ratio < 30:1 Nitrogen content supplied excess and lost ammonia as resultant

odorous compost

Insufficient nitrogen. Slow growth of microorganisms. Compost
remain degradative and slow processed

C:N ratio > 30:1

Table 12.4 C:N ratio
of selected raw compost
materials including organic
materials

Organic materials C:N ratio

Hairy vetch/alfalfa 10:1-15:1

Rye (seedling) 12:1-15:1

Sweet clove 14:1-16:1

Food waste 14:1-16:1

Grass clippings 18:1-20:1

Rye (flowering) 20:1-21:1

Fruit waste 38:1-36:1

Dry leaves 50:1-56:1

Corn stalks 60:1-72:1

Straw 250:1-500:1

Sawdust 2:1-3:1

Liquid manure 10:1

Chicken dung 12:1

Grass cutting 13:1-23:1

Cow/pig/horse dung 20:1-25:1

Feather, hair 30:1

Paper and cardboard 250:1-500:1

compost maturity (Goyal et al. 2005 ). The initial carbon to nitrogen (C/N) ratio
is prime factor influences compost quality (Michel et al. 1996 ). Important regula-
tions are important to maintain the best integrity and product quality of compost
(Table 12.3 ). In general, C/N ratio within the range of 25-30 is considered ideal
for composting (Kumar et al. 2010 ). Composting at lower initial C/N ratio can thus
increase the amount of manure treated, but can also increase the loss of nitrogen
as ammonia gas. C:N ratio can be affected with aeration rate and moisture content
during composting (Table 12.4 ). It is interesting to note that gaseous emission from
composting can be effects the C:N ratio. Lower C:N ratio caused higher NH 3 and
CH 4 emissions. The intial moisture contents influence gaseous emission signifi-
cantly. Hence, high moisture content lead the low C:N ratio (Jiang et al. 2011 ).
In the early stages of composting total N decrease due to loss of N in the form of
ammonia which in turn depends upon the type of material and its C:N ratio (Goyal
et al. 2005 ). The composting material with low C:N ratio results in more N losses
than high C:N ratio varies within the range of 13.9:15.1-15.9:16.2.