Identification of primary substrates in organo-mineral fertilizers by means of isoelectric focusing

Organo-mineral fertilizers (OMF) are used to improve the efficiency with wh ich plants absorb the nutrients contained in mineral fertilizers, thanks to the properties of the fertilizer's organic component. The quality of the o rganic component, and hence its origin, is of primary importance for its ef ficient use in agriculture as a fertilizer. It is thus necessary to identif y analytical techniques which are able to distinguish the primary substrate s in a mixture, as well as their humification levels. In this study, isoele ctric focusing was used to recognize the four primary substrates fi om diff erent organo-mineral fertilizers containing peat, leather meal, poultry man ure, or dried pig slurry. The experiments gave positive results. Peat could be distinguished from leather meal, although poultry manure was not distin guishable from dried pig slurry.