Íria Oliveira Franco
Abstract:
Sugar cane, as an industrial production, was introduced in Goiás southwest in 1946 with the establishment of Santa Helena plant; Later, in the 1980s, the Goálcool plant was implemented in Serranópolis city, resulting from the National Alcohol Program (PROÁLCOOL), expanding the use of ethanol in vehicles. Due to the recent demand for ethanol as a fuel and others associated with the favorable international environment, the sugar and alcohol sector is expanding. Since 2007, in Goiás southwest, the number of new sugar and alcohol plants has been increasing rapidly, which concerns the scientific community for the possible impacts that may occur. Based on the assumption, established by the Sugarcane Agroecological Zoning, that the expansion of sugarcane in southwest Goiás occurs over sandy soils, occupied by old degraded pastures or in the process of degradation, this work aims to: Identify and locate the sugar and alcohol plants located in the southwest of Goiás; Verify the classes of soils occupied with sugar cane in the region, based on satellite images; Simulate sugarcane productivity in the main soil classes of southwest Goiás; To compare the expected and observed sugarcane yields in the analyzed plants, in their respective soil classes; To infer about the sugarcane expansion in the southwest of Goiás, according to the soil classes and the yields obtained by the plants, building a scenario of possible land use and occupation by this sector. As a result, it was found that of the eighteen municipalities of the southwest, by the year 2011, eleven of them had sugarcane processing facilities. The mapping in southwest Goiás of the sugarcane areas of 2011 revealed that the area cultivated with sugarcane is 263,549 ha, which corresponds to 36% of the area cultivated with sugarcane in the state. Regarding soil classes, the most representative in sugarcane cultivated areas in 2011 in the southwest of Goiás are the Latosols with 206,993.94 ha, of which 73.9% are Dystroferric Red Latosols and 26% are Aluminoferic Red Latosols. The class of the Quartzarenic Neossols presents an area with 29,900 ha of sugarcane, which corresponds to 11.34% of the sugarcane areas of southwest Goiás in 2011, according to Embrapa's soil classification (2006). Of the areas occupied with sugarcane in 2011, 55% occurred over areas where, in 2006, there was agriculture, 28% pasture and 17% cerrado. The simulations in the DSSAT/CANEGRO model confirmed the preference of the plants to cultivate sugarcane in the most fertile soils, since the sugarcane yields obtained by the plants as well as those expected in the simulations indicate that the Oxisols are more productive than Quartzarenic Neossols. For example, the Decal plant, with its sugarcane cultivated in Oxisols, had a yield of 3,103 kg of sucrose per hectare more than the Serranópolis Energetic Plant, where the predominant class of sugarcane soils is the Quartzarenic Neosol. In the simulations, the results of the DSSAT/CANEGRO model indicate that the Quartzarenic Oxisols produce about 1,200 kg/ha less sucrose than that found in the Red-Yellow Oxisol.
