THE INFLUENCE OF THE ETHANOL INDUSTRY VINASSE USED AS AN AGRICULTURAL FERTILIZER ON POTASSIUM SOIL SALINIZATION

The process of salinization of soils is typical of arid and semi-arid regions and usually resultingon the association of the predominant geological formation in the landscape, poor distributionof rainfall, poor drainage and... [ view full abstract ]

The process of salinization of soils is typical of arid and semi-arid regions and usually resultingon the association of the predominant geological formation in the landscape, poor distributionof rainfall, poor drainage and inadequate agricultural exploitation. Within the context ofagricultural exploration we can emphasize the planting of sugarcane, which generates largequantities of vinasse and waste generated in large quantities and with high polluting power.However, anaerobic biodigestion is an alternative that allows degradation of the organicmatter present in vinasse reconciled with the preservation of high levels of nitrogen andpotassium in the final residue, which makes it an attractive fertilizer. The presence of nutrientssuch as potassium, nitrogen, phosphorus and calcium makes it a more widespread alternativefor vinasse to be applied in the sugar cane crop itself as fertilizer. However, this practice canlead to problems such as increased soil salinity and groundwater contamination resulting fromthe bioleaching of compounds present in vinasse (CORAZZA, 2006). The present work had theobjective of analyzing soil salinization due to the application of vinasse in soil columns wherewheat was grown. The analyzes show the variations of potassium concentrations at differentdepths with and without vinasse application. It was possible to verify that the concentration ofK in the soil was higher in the columns treated with vinasse compared to those that receivedcommon fertilizer used in agriculture. The results showed that potassium can move in the soildepth and reach higher concentration levels. Potassium can also reach sub-surface water. Itwas observed that the mobility of K in the soil from the addition of different forms of vinassetreated by alkaline process depends on the amount of alkaline material added to this waste.The vinasse that received 25% of alkaline material was the one that presented less mobility ofK in the soil.Thus, it was concluded that vinasse can contribute to soil salinization in depth.