Corrective Action and Fertilizer From the Ashes of Sugarcane Agroindustries.

The ashes from burning bagasse for co-generation of energy are important residues in the sugar industry, in terms of quantity, physical and chemical characteristics, and production flow. However, in many aspects there is no clear definition of disposal of these ashes, and undoubtedly the most interesting and sustainable alternative would be the re-incorporation of these materials in the production system. The ashes may be used in soils of low fertility, improving their physical and chemical characteristics. The objective of this study was to evaluate the lime and fertilizer potential of sugarcane bagasse ash in the region of Maringá, Paraná State, Brazil. Samples were collected from the ashes of two alcohol and sugar mills: one production in both sandy soil and sandy loam soil, and another with production in clay soils. The ashes were chemically characterized. Subsequently soil samples of low natural fertility (Vi <30%) were incubated with its ashes for different values of estimated base saturation (V40%, V60%, V80% and V100%), in a randomized block design with four replications during 53 days. In the sequence, corn was planted. The ash decreased soil acidity, increased phosphorus available and the exchangeable bases in the both soils, especially potassium. The use of base saturation as criteria for the application of ash on soil results in the application of high doses. They determine values of the percentage saturation of potassium higher than 10% in all the treatments in which ashes have been added in sandy soils. However, no deleterious effect on growth of corn was registered. The ashes have positively influenced the growth of plants as assessed by dry weight and height of corn plants. The results indicate the feasibility of using the ashes as a source of plant nutrients, especially phosphorus and potassium, in low fertility soil.