IEF technique to study the b-glucosidase humic complexes in organic and mineral amended soils

In this work, fields with different slopes (0, 2 and 6%) located in an erodible area due to topographic and climatic conditions and improper management, were submitted to rehabilitation practices that included almond tree cultivation under organic or mineral fertilization. Conventional parameters usually related to soil fertility and quality (total organic carbon, total nitrogen, water soluble carbon, humic carbon, etc.) along with unconventional parameters (b-glucosidase-humic complexes, soil enzyme activity) were measured with the aim of evaluating the capability of the rehabilitation practices to improve soil quality and/or prevent soil degradation. The application of both organic and mineral fertilizers and the presence of almond trees resulted effective in increasing general soil chemical properties and in particular biochemical properties related to the humic-bound b-glucosidase enzyme (HEG). The analytical isoelectric focussing technique (IEF), was able to isolate and characterise extracellular humicenzyme complexes discriminating among different slopes and treatments. The organic and mineral fertilisers and plants were more efficient in increasing amount and activity of humic-enzyme complexes in 0 and 2% slopes, while 6% slope showed a significative increase only with organic amendment. The active humicb- glucosidase enzyme complexes isolated and purified through analytical IEF, even though they represent only a small part of soil humic substances are relevant indicators for assessing amount and role of humic carbon stored in degraded soils, following regeneration practices