Efeito residual de quatro aplica??es anuais de lodo de esgoto e vinha?a na qualidade tecnológica da cana-de-a?úcar

摘要

The main objective of this research was to evaluate the residual effect of different residues applied during four years in distinct application modes and rates, on the technological quality of the 5th ratoon of sugar cane (cultivar SP 81-3250). The treatments were from combination of two residues (sewage sludge, vinasse, sewage sludge + vinasse) applied according two different ways (close to the sugar cane line and spread in the whole area), in two rates (100 and 200%) besides a control treatment. The experimental design was randomized blocks with thirteen treatments and three replications, resulting 39 experimental plots. The following parameters were analyzed: percentage of soluble solids in juice (Brix % JC), apparent percentage of sucrose in juice (Pol % JC), percentage of fiber in sugar cane (Fiber % Cane), purity (%), apparent percentage of sucrose in sugar cane (Pol % Cane), percentage of reducing sugar in sugar cane (RS % Cane), percentage of total reducing sugar in sugar cane (TRS % Cane), recoverable total sugar content in sugar cane (RTRS). The evaluated factors (type of residues, application way and rates) did not cause alterations on the technological parameters and sugar cane commercial value.