The potential of use the recyclable organic materials for soil fertilization

The decrease productivity of soils that occurs following an agricultural overproduction is manifested by insufficient of nutrients, nitrogen and phosphorus, by salinity increasing, humus deficiency, soil aggregation changing moisture content modified, etc, finally through undesirable phenomena of erosion. The uses of sewage sludge for fertilizing purposes of degraded soils remain a method of managing this recyclable waste. Sewage sludge anaerobically stabilized brings into soil an important input of nutrients (C, N, P), micronutrients and an significant settlement of compatible microorganisms with soil biocenosis. The potential hazards of sewage sludge due to pathogenic agents load is reduced by anaerobic stabilization. The potential of physicochemical contaminants is controlled by national legislation. Using a quantity of 40 t·ha-1 sewage sludge anaerobically stabilized for fertilization of cultivated soils with maize led to an increase of grain production of 12% over the amount harvested from a control field and with 5% of the amount collected from a fertilized field with 40 t·ha-1 manure. In the aerial parts of the harvested plants from fertilized fields with the sewage sludge haven’t accumulated toxic metals (Cd, Ni, Cr, Pb) in the detectable range, and the amount of Zn was according to the nutritional requirements.