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July 29, 2016

Dry Weather results in Increase in Fires in Central Brazil

This winter season in southern Brazil has been characterized by numerous outbreaks of polar air and freezing temperatures. The below normal temperatures have impacted the safrinha corn, the winter wheat, coffee, and fruit crops. In contrast, the weather in central Brazil has been just the opposite with temperatures in the mid 80's or higher, low relative humidity, and no rainfall. This is typically the dry season in central Brazil, but this year the dry season started earlier than normal and it has been dryer than normal.

These hot and dry conditions are a perfect setup for fires. According to the Brazilian National Space Research Institute (INEP), which used satellite technology to monitor the number of fires across Brazil, the state of Mato Grosso is leading in the number of fires recorded this dry season. During the first 27 days of July, there were 2,120 fires in the state and thus far in 2016, the number of fires in the state has reached 8,894 or 44% more than the same period last year.

The area of the state with the most fires has been the northern and eastern region where the rainfall was the least during the summer rainy season. This is also the area where the soybean and corn crops were most impacted by hot and dry weather this past growing season.

In all of Brazil, INEP has registered 30,000 fires thus far in 2016 or almost 50% more than last year. INEP detects these fires as hot spots on their satellite photos. The increase in fires is being attributed to the exceptionally dry weather all across central Brazil.

Most of these fires are in dry pastures and they are either accidental or set on purpose to burn off dry vegetation allowing new green shoots to emerge for the cattle. During the dry season, the pastures in Brazil turn completely brown and the tall grasses with their dry stems make it very difficult for the cattle to reach any potential new growth. If the pastures are burned off, there is a flush of new growth that can help to sustain the cattle during a period when they typically lose weight.

While most of the fires are in pastures, there have also been a number of fires in corn fields in central Brazil. Unfortunately, fires in corn fields are a common occurrence this time of the year. Some of the fires are in mature corn fields while others are in the dry stubble left after harvesting. Probably, most of the fires in corn fields were the result of pastures being burned nearby and the fire moved into neighboring corn fields.

These fires in corn fields can have a long lasting impact on the soil fertility by eliminating valuable organic matter. The cerrado soils of central Brazil are naturally very low in organic matter and farmers try hard to increase the organic matter in order to improve the fertility of the soil. Higher levels of organic matter offer numerous benefits such as: increased water infiltration, increased microbial activity, reduced erosion, and the capacity to hold onto nutrients. After a serious fire in a mature corn field, it could take several years to rebuild the fertility in the field.

No more rainfall is expected in Mato Grosso and central Brazil until mid-September when the first summer rains return. Farmers in the region will be allowed to start planting their 2016/17 soybean crop starting September 15th with the expiration of the current soybean-free period.