CHEMICAL PROPERTIES OF SOIL FERTIRRIGATED WITH DAIRY AND SLAUGHTERHOUSE WASTEWATER

ABSTRACT The aim of this study was to evaluate the soil chemical properties submitted to fertigation with slaughterhouse (SW) and dairies (DW) wastewater. The experiment was conducted in the Environmental Engineering Center and Sanitary of UFLA/MG in PVC columns filled with Dark Red Latosol (Oxisol) and randomly distributed. The treatments applied with nitrogen based load (300 kg ha years-1 of N) consisted of four doses of SW and DW (100, 200, 300 and 400% of the recommendation) and AQT0 control at random. The soil was collected at a depth of 0.30 m and, subsequently, characterized in terms of physical, chemical and physicochemical. The application of treatment of the largest irrigation of DW provided, after 120 days of monitoring, N concentration of 1.85 g kg-1. However, the treatment with AQT0 obtained N concentration of 0.81 g kg-1, in the soil. We observed that the largest irrigation of SW provided increases of 2.62 and 5.49 g kg-1, respectively, in the P and K concentrations of the soil. There was quadratic increase in the N concentration in the 0.30 m soil depth of the columns with the increase in the applied irrigations of SW and DW, being obtained maximum values of 1.85 and 1.02 g kg-1 that were obtained in the relative irrigation of the application dose of 600 kg ha-1 of N.摘要 本研究旨在评估经屠宰场废水（slaughterhouse wastewater, SW）与乳品厂废水（dairies wastewater, DW）灌溉施肥后的土壤化学性质。实验于UFLA/MG环境工程与卫生中心开展，采用填充有暗红色砖红壤（Dark Red Latosol，氧化土Oxisol）的PVC柱进行随机布置。本实验以氮负荷为基准设置处理组，施氮水平为300 kg·ha⁻¹·yr⁻¹，包含4个梯度的SW与DW施用剂量（分别为推荐用量的100%、200%、300%和400%），以及随机设置的AQT0对照组。于0.30 m土层采集土壤样品，随后对其物理、化学及理化性质进行表征。经120天监测后，施用最高剂量DW灌溉的处理组土壤氮浓度可达1.85 g·kg⁻¹，而AQT0对照组的土壤氮浓度仅为0.81 g·kg⁻¹。本研究观察到，施用最高剂量SW灌溉可使土壤磷（P）、钾（K）浓度分别提升2.62 g·kg⁻¹与5.49 g·kg⁻¹。随SW与DW灌溉剂量的提升，0.30 m土层的土壤氮浓度呈二次曲线变化趋势，当施氮剂量为600 kg·ha⁻¹时，分别获得1.85 g·kg⁻¹与1.02 g·kg⁻¹的氮浓度最大值。