MOBILITY OF P, Cu AND Zn IN SOIL COLUMNS UNDER NO-TILL AND ORGANIC AND MINERAL FERTILIZATION

The retention of mineral elements applied to the soil surface is crucial to maintain water quality. The objective of this study was to evaluate the effect of liquid swine manure and mineral fertilizer on leaching of P, Cu and Zn through undisturbed soil columns (height 25 cm, diameter 20.3 cm) of an Oxisol under no tillage. A water volume (10.020 cm(3)) corresponding to three times soil total pore volume (3,340 cm(3)) was continuously applied to the columns, and the sampling and analysis of the elements subdivided into five fractions. The first soil pore volume (3,340 cm(3)) was split into three equal portions of 1,113 cm(3), and at the last two the volume of 3,340 cm(3) was applied at once to the soil columns. The soil mineral elements level was determined in the layers 0-2.5, 2.5-10 and 10-20 cm. In relation to the applied liquid swine manure, 99.6, 98.8 and 100 % of P, Cu, and Zn was retained, respectively. Phosphorus retention of the applied mineral fertilizer was 89.7 %. Regardless of the fertilizer type, the soil P, Cu and Zn levels were highest in the 0-2.5 cm layer. These results indicate the low leaching potential of these elements and the importance of soil and water conservation practices to ensure runoff retention and infiltration.