Chemical alterations in soils fertirrigated with wastewater from swine facilities

The increasing size of swine farms poses an environmental risk to water bodies, considering that manure is generally applied to croplands without appropriate agronomic criteria. Objective: the present work aimed to evaluate various chemical changes occurring in soils fertirrigated with filtrated wastewater from swine facilities (FWS). Methods: 21 drainage lysimeters filled with Dystrophic Red-Yellow Latossoil were cultivated with tomato plants in protected environments, and fertirrigated with several doses of FWS, with and without fertilizer addition. Treatments were: T1: control (provided the recommended irrigation and fertilization needs for tomato plants). Treatments T2, T3, and T4, provided 100, 150, and 200% of recommended nitrogen (N), respectively, by adding filtered swine wastewater. Treatments T5, T6, and T7 provided equivalent N percentages with fertilizer addition. The experiment was conducted in a completely randomized design (seven treatments and three replications). Results: compared with initial conditions, an increase in the concentration of available phosphorus was observed, mainly in the superficial layers. The FWS addition resulted in increments in N concentration in the superficial layers, while chemical fertilizer application resulted in larger displacements in the soil profile. Conclusion: chemical fertilization was more effective than FWS for ionizing the soil solution.