Scientists studying satellite image data from the fires in the Amazon rain forest said that most of the fires are burning on agricultural land where the forest had already been cleared

By K.K. Rebecca Lai, Denise Lu and Blacki Migliozzi of The NY Times. Excerpts:

"Most of the fires were likely set by farmers preparing the land for next year’s planting, a common agricultural practice, said the scientists from the University of Maryland."

"The majority of the agricultural land currently in use in Brazil’s Amazon region was created through years of deforestation. 

“Most of this is land use that have replaced rain forest,” said Matthew Hansen, who is a co-leader of the Global Land Analysis and Discovery laboratory at the University of Maryland. 

“Brazil has turned certain states like Mato Grosso into Iowa,” said Mr. Hanson, referring to the Brazilian state on the southern edge of the Amazon region. “You’ve got rain forest, and then there’s just an ocean of soybean.”"

"The increase in fires every August to October coincides with the season when farmers begin planting soybean and corn."