El impacto de la ganadería y la agricultura en los ecosistemas terrestres.-Use of molecular separative techniques (UF and IEF) to study humic-enzyme complexes in different agricultural soil managements

Abstract

ABSTRACT In this paper, membrane ultrafiltration (UF) and isoelectric focusing (IEF) techniques were used to fractionate and purify a humic-bound β-glucosidase complex in two soil types, both under organic (biological) and mineral (conventional) management. This complex could be more effective and consistent indicator of management induced changes to soil quality than conventional parameters. The study showed that the β-glucosidase-humic complex focussed in the pH range 4.5-4.2 and resulted higher in the organic than in mineral fertilization systems. This result clearly indicated a better preservation of stable humic-carbon and biochemical energy in soils treated with the organic fertiliser. In conclusion, UF and IEF techniques may be successfully adopted for the study, at molecular scale, of the impact of different management practices (organic and mineral management) on soil quality. The study was carried out in the framework of the European project “Indicators and threshold for desertification, soil quality and remediation” (INDEX- STREP n. 505450, 2004-06).