In this study, the effect of intensive swine liquid manure (SLM) application was evaluated through the overland flow method, on chemical characteristics of a Yellow-red Podzolic soil (Ultisol) cultivated with four forage species: Amazonian kikuyu grass (Brachiaria humidicola (Rendle) Schweick), signal grass (Brachiaria decumbens Stapf), coastcross bermudagrass (Cynodon dactylon (L.) Pers.) and Tifton 85 bermudagrass (Cynodon spp.) were evaluated. SLM was applied in plots of 4m² and with 5% slope, during four months, at an average equivalent to 800 kg ha-1d-1 of biochemical oxygen demand (BOD5). Soil samples were collected at 0-0,20 m depth, in the beginning and at the end of the experiment. The result showed the increase of the P, K, Na and Zn concentrations while the Mg and Cu concentrations decreased and Ca continued unaltered. The acidity, sum of bases and CEC increased in the soil that received SLM, while the saturation of bases decreased. Due to the nourishiment accumulation, it is recommended to monitor the soil chemical characteristcs and underground water on the profile for evaluation of the enviromental contamination risks.
swine liquid manure; overland flow; forage grasses; sewage disposal in the soil
