A fifth of EU soy imports from Brazil may come from land illegally deforested, according to a study that offers a detailed inventory of farms in the supply chain.

One major soy industry group representing traders said it shuns purchases from farms identified by Brazil as problematic. That research, published in the journal Science, also opens the door for both international companies and Brazilian law enforcement to pinpoint specific farms violating rules against Amazon deforestation, according to study coauthor Raoni Rajao, who specializes in environmental management at the Federal University of Minas Gerais. Previous research had traced sales only to municipalities where illegal deforestation took place. “Brazil has the means to develop a great government-led monitoring system that is able to clean supply chains of deforestation,” Rajao said. “Before the technical means weren’t there, and now we have developed those means.” More monitoring is especially important, the study says, as the country seeks to feed the world. Brazil, which now produces a similar volume of soy as the United States, is on track to become by far the world’s biggest soybean exporter by 2029, according to a report by the OECD and the United Nations’ Food and Agriculture Organization. In their study, Rajao and other researchers looked at deforestation in Brazil’s Amazon and in the bordering Cerrado savannah since 2008.