They actually burn it to avoid harm to the workers and use its ash to fertilize their land. However, mechanization has reduced the need to burn fields and pollution has gradually been decreased.
It has similar issues, such as using fertilizers and water usage. At the same time, one of the main issues is deforestation in the Amazon and field burning before harvest.
Still, it probably still makes sense to use it. For example, its energy balance(ethanol/energy for its production) is ~8-10 whereas in the US is ~1-2.
