Evaluation of the application of vinasse in sandy soil of the Rio Claro Formation

Abstract

The use of vinasse in the fertilization of sugarcane, although it is an accepted practice, must be accomplished in a controlled manner, being regulated in the State of São Paulo by the Companhia Ambiental do Estado de São Paulo (CETESB) through Technical Standard P 4.231/2015. In this context, to evaluate the contaminant potential of vinasse when applied at the dosage calculated by the mentioned standard and higher dosages, constant load percolation tests were carried out in columns with samples of sandy soil from the Rio Claro Formation. These samples were previously infiltrated with doses of 0 m3/ha (control), 55 m3/ha (equivalent to the maximum dose allowed), 80 m3/ha, 400 and 800 m3/ha. The application of these doses allowed the evaluation of its effects on the hydraulic parameters of the studied soil and the possible generation of different degrees of contamination in the percolated effluent. The results indicated that the application of 55 and 80 m3/ha doses did not bring any significant changes in the saturated hydraulic conductivity but there was an increase in the retention capacity of the soil, which is a positive factor regarding soil fertility and environmental aspects. However, with the application of higher doses (400 and 800 m3/ha), in addition to reduction of hydraulic conductivity, a progressive fall in the soil retention capacity was observed, which implies losses due to leaching and, consequently, can compromise the quality of groundwater.

Keywords

• Cana-de-Açúcar. Norma Técnica P 4.231/2015. Ensaios de Coluna. Contaminação de Solo e Água Subterrânea. Hidrogeologia de Contaminantes.