Humification parameters

Ciavatta, C., Govi, M., Bonoretti, G., and Gess, C. (1996). Identification of peat and leonardite using humification parameters and isoelectric focusing (IEF) A first approach. Fertil. Res. 44,225-230. 

Govi, M., Ciavatta, C., and Gessa, C. (1994). Evaluation of the stability of the organic matter in slurries, sludges and composts using humification parameters and isoelectric focusing. In Humic Substances in the Global Environment and Implications on Human Health, Senesi, N., and Miano,T. M., eds., Amsterdam, 1311-1316. 

Canali, S., A. Trinchera, A. Benedetti and F. Pinzari (1998), Study of compost maturity by means of humification parameters and isoelectric focusing technique, proceedings of the 16 World Congress of Soil Science, S miposium 40, Montpellier, France, 20-26 August (CD-ROM). 

Figure 16.42 illustrates the spectra of a whole soil sample and of the same calcinated soil. As seen, the soil fluorescent emission is basically due to organic matter (OM) (Milori et al., 2006). As the soil samples are illuminated with near-ultraviolet or blue light, mainly the more complex structures are excited, and the area under the normalized curve (divided by C content) provides a parameter proportional to the humification degree of SOM. 

The second approach consists of the study of both humic and fulvic fractions evolution. This way seems to be more operational. The evolution of the humic nature of the organic matter during composting or after mixture with soil can be estimated by one of the following methods C/N ratio [14-16], humification index [17-19] or biodegradability index [11,14]. Another parameter, based on the use of two wavelengths (465 and 665 nm), can also be used for the characterisation of the evolution of humic-like substances [20,21]. 

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