| dc.description.abstract | The use of liquid pig slurry (DLS) has been highlighted as an alternative for fertilization in crops, but there are risks related to the inappropriate use of these wastes, such as the possible contamination of water bodies by phosphorus or nitrate in addition to other elements through Of the runoff process. The objective of this work was to analyze the environmental impacts caused by the successive application of DLS through surface runoff and to analyze the concentrations of nitrate, ammonium, phosphorus, potassium, copper and zinc of the drained water and compare them with the Normative Instruction IAP 105/006 and CONAMA Resolution 357. The study was conducted in a Red Latosol Distroferric, under no-tillage system and crop rotations. The experimental design was randomized blocks with four replicates, divided into plots of 50 m2 (10m x 5m). For this test, doses of DLS were applied before soybean planting. The DLS distribution was calculated according to the phosphorus requirement and the treatments were: control (T0); Fertilization with 60 kg of P ha-1 through mineral formula 0-20-20 (TM); Application of 60 kg of P ha-1 in the form of DLS (T100) equivalent to 40 m3ha-1; Application of 120 kg of P ha-1 in the form of DLS (T200) equivalent to 80 m3 ha-1. To generate the surface
runoff, a rainfall simulator was used in which the flow samples were collected in 50 x 50 cm2 miniparcels from a rain of intensity of 70 mm h -1. Rain was simulated 30 days after application of DLS with three replicates for each treatment. The solution was collected in glass containers and sent to the laboratory for chemical analysis. The samples were separated into soluble and particulate NPK, Cu and Zn. For the nitrate and ammonium
concentrations, the colorimetric method was used and for the others, direct reading was used in ICP-EOS. Confronting the values obtained with Normative Instruction IAP 105 (2006), the results are below the indices allowed in all treatments. When comparing the results with CONAMA Resolution 357 (2005) Class 1, the values for P (0.11, 0.50, 0.63, 0.99 mg L-1 for treatments T0, TM, T100 and T200, respectively ), Cu (0.013, 0.017, 0.012 mg L-1 for the treatments T0, TM and T200, respectively) and NH4 (6.9, 4.7, 4.61, 5.12 mg L-1 for treatments T0 , TM, T100 and T200, respectively) are above the established limit, which may mean that DLS has a potential polluter when applied in high doses. | |
