Evolution of humic fractions in calcimagnesic soils and brown isohumic soils amended with compost and manure

The composting process of organic wastes consists of the bioconversion of biologically unstable wastes to stabilized products for application to soils. This study was carried out on different soils (brown isohumic soils in Sfax region in southern Tunisia and calcimagnesic soils in Korba region in northern Tunisia). The mineralization process of organic matter is more important in isohumic soils, showing less tenors of fine fractions than in calcimagnesic soils. The study of different humic fractions in amended soils shows that humic acid tenors and the polymerization rates are linked to soil nature. Calcimagnesic soils ensure a more important humification than isohumic soils.