Produção de substratos para mudas a partir de resíduos compostados do setor sucroalcooleiro

Abstract

Many are the products of processing of sugarcane, but the ones that stand out are the sugar and ethanol. However, besides these products also generate important by-products such as bagasse from sugarcane, the filter cake and boiler ash, which if designed improperly can cause environmental impacts. The use of organic waste as raw materials for substrates of seedling production has provided increases in production and quality of the final product. However, for the use of such waste turn feasible, it’s necessary that they entail in increasing productivity and be available in the growing region. Thus, studies of the parameters involved the composting process on a small scale and the interference of such wastes in the quality of seedlings, are needed. Thus, the objectives of this study are to evaluate the composting process on a small scale waste of this sector, as well as the use of the resulting compounds in the substrate composition for the production of lettuce and arugula seedlings. For the evaluation of the composting process was used completely randomized design (CRD) with 4 treatments and 3 repetitions. The treatments were: T0 - 100% filter cake (TF), T1 -100% bagasse sugarcane (BC), T2 - 50% filter cake and 50% bagasse sugarcane, and T3 - 70% filter cake and 30% bagasse sugarcane. For the production of substrates from organic compounds produced in the first stage, the design was CRD in factorial scheme 2x9 (two waste decomposition times - 0 and 90 days x nine substrates compositions) with 30 repetitions, where each seedling was a repetition. The treatments were: S1 - 100% T0, S2 - 50% T0 and 50% boiler ash, S3 - 100% T1, S4 - 50% T1 and 50% boiler ash, S5 - 100% T2, S6 - 50% T2 and 50% boiler ash, S7 - 100% T3, S8 - 50% and 50% T3 boiler ash, S9 - commercial magnifying glass substrate mark (composition: pine bark / eucalyptus and ash). Were evaluated for the composting process temperature parameters within the cell, the electrical conductivity of the solution (EC), pH of the material and cell volume, and to evaluate the maturity of the compost was analyzed together stabilized values of temperature and EC, and the C / N at the end of the process. When considered mature, compounds were classified according to the parameters established by legislation (IN25 / 2009). For the production of substrates were evaluated for each treatment, the percentage of germination, and 30 days after sowing the number of true leaves (NF), seedling height (HP), fresh weight of shoot (MFPA) and dry weight of shoot (MSPA). At the end of each experimental phase the data were submitted to analysis of variance and means were compared by the Scott-Knott test at 5% significance by Sisvar statistical program. From this study it is concluded that the process on a small scale for organic compounds possessed in its formulation filter cake is possible; these same compounds reached maturity at 90 days. But the compound that was formulated only with sugarcane bagasse was not mature at this time interval. That to determine the maturation, the parameters of temperature stabilization, EC and C/N ratio were satisfactory; according to the legislation, compounds were classified as belonging to the class A and were in accordance with the law, except to T1. Thus, it is possible the formulation of substrates for seedling production from waste sugar and alcohol sector, filter cake and bagasse sugarcane; and finally the substrate that produced better quality seedlings, besides the commercial substrate, was formulated with pure filter cake and composted.