Sugarcane field with controlled burn at sunset in countryside

Controlled burn in a sugarcane field in the São Paulo countryside at sunset, a regulated agricultural practice that prepares the cane for harvest.

About this subject

Controlled burning of sugarcane fields is a traditional agricultural technique in Brazil, especially in the state of São Paulo, the country's largest sugarcane producer. Fire is applied in a planned manner to remove straw and dry leaves, making manual or mechanical cutting easier. Although mechanized harvesting without burning has grown in recent years, controlled burning is still used in areas with steep terrain or where mechanization is unfeasible. In the São Paulo countryside, such as the regions of Ribeirão Preto and Piracicaba, burns occur in the late afternoon when relative humidity is higher and winds are weaker, reducing the risk of uncontrolled spread.

The practice is regulated by state and federal laws, requiring prior authorization from environmental agencies like CETESB in São Paulo. Burns can only be carried out under specific weather conditions, with monitoring of wind direction and speed, plus a minimum distance from urban areas and highways. The sunset hour is preferred because cooler temperatures and higher humidity help control the flames, which consume quickly, leaving the field ready for harvest in the following hours.

Sugarcane is the basis for Brazilian ethanol, one of the world's leading biofuels. São Paulo state accounts for about 60% of national sugarcane production, with emphasis on mills that process both sugar and ethanol. Despite environmental controversy, controlled burning is considered less impactful than accidental fires and, when well managed, does not significantly harm the soil, as carbonized organic matter returns as nutrients. However, the trend is toward gradual reduction, with incentives for mechanized harvesting and programs like the Agro-Environmental Protocol of the sugar-energy sector.

Interestingly, the landscape of sugarcane fields on fire at sunset is a striking scene in the São Paulo countryside, photographed by many as a symbol of the strength of Brazilian agribusiness. The image evokes a cycle that combines tradition and technology, where fire, an ancient agricultural ally, still plays a relevant role in renewable energy production.

Frequently Asked Questions

Why is controlled burning done in sugarcane fields?

Controlled burning removes straw and dry leaves from the cane, making manual or mechanical cutting easier. It also reduces the volume of material to be processed and drives away venomous animals, increasing worker safety.

Is controlled burning allowed by law?

Yes, but it requires prior authorization from environmental agencies such as CETESB. The legislation sets rules like distance from urban areas, suitable weather conditions, and permitted times, usually late afternoon.

What is the environmental impact of controlled burning?

The burning releases CO2 and particulates, but is considered low-impact when controlled. Ashes return nutrients to the soil. However, the trend is to replace it with mechanized harvesting to reduce emissions.