Abstract

The fertilization of crops with swine wastewater is a common practice and attractive for the reduction of natural resources and environmental pollution control. The feasibility of such use is due to the large volume of waste generated and the amount of nutrients that are easily mineralized when applied in soil. However, copper and zinc, added in high concentrations in swine rations, can accumulate on soil-water-plant system after successive applications. Thus, this study aimed at evaluating the effects of doses of swine wastewater associated with mineral fertilization in the levels of copper and zinc in an intensive no-tillage system (maize, black oats and soybeans) for four years. The experiments were carried out in area with twenty-four lysimeters of drainage, in typical oxisol. Swine wastewater treated in stabilization ponds and biodigester was applied in doses of 0, 100, 200 and 300 m³ ha^-1 associated with presence and absence of mineral fertilization, resulting in eight treatments with three repetitions each. Increases of 15.60% copper and 188% zinc in soil were found after four years of swine wastewater application. In the presence of mineral fertilization, zinc was 57% higher than in its absence. Copper and zinc levels detected were within the recommended range of mineral nutrition for maize, black oats and soybeans.

Key words: Fertilization, heavy metals, leaching, pig slurry, water reuse.