Table 1.
Chemical characteristics of the three manures.
Fig 1.
Changes of temperature, pH, ammonium nitrogen [NH4+-N], nitrate nitrogen [NO3--N], and NH4+-N / NO3--N ratio during composting.
Fig 2.
Changes of GI in the swine, cattle and chicken manure composts during composting.
Fig 3.
The spectra of 13C CP/TOSS [thin lines] and CP/TOSS after dipolar dephasing [thick lines] of swine, cattle and chicken manures and composts [only data of selected days shown].
Fig 4.
Relative proportions of functional groups [%] in swine, cattle and chicken manure composts obtained by the CP/TOSS and their changes with time.
Fig 5.
Alkyl C/ O-alkyl C ratios of manures and composts during composting.
Alkyl C/ O-alkyl C = alkyl C [0-44ppm] / O-alkyl C [44–113 ppm] based on CP/TOSS spectra.
Fig 6.
Aromaticity of manures and composts during composting.
Aromaticity = aromatic C [113–162 ppm] / total C [0–220 ppm] based on CP/TOSS spectra.
Table 2.
Days required for three manures to reach the threshold values of some maturity indices proposed in the literature as well as threshold values and references.