Effect of biofertilization with cattle urine on the chemical properties of an Oxisol from the Amazon savanna

ABSTRACT Soil correctives and mineral fertilizers are important for a sustainable production; however, they are ineffective in the long run, showing the need to apply alternative products. This research aimed to analyze the effect of cattle urine concentrations on the chemical properties of an Oxisol from the Amazon savanna. The experimental design was completely randomized, in a split-plot scheme over time, with five replications. Six cow urine concentrations (0, 10, 20, 40, 80 and 100 %) were randomized in the plots, and five soil collection times for evaluation (0, 7, 14, 21 and 28 days after application) were designated as subplots. At each collection time, the soil chemical properties were determined. The applied cow urine increases the soil pH up to the neutral range. The application of increasing concentrations of cattle urine positively influences the potassium content, sum of bases, base saturation and cation exchange capacity of the soil. The levels of organic matter decrease linearly over the evaluation periods, independently of the applied cattle urine concentrations. Among the studied concentrations, that of 80 % is the most recommended to improve the soil chemical attributes.