Why do you doubt that? China's population is so large, even their ample farming capacity isn't enough to support it on its own. To whom do you think they turn to fill the deficit if not South America?
china imports around 10% of its food needed. the specifics get complex depending on how you measure and what you measure - but it is not at all credible that 36% of china's food is from south america. and in the recent past they were far less integrated with global trade
https://tradingeconomics.com/china/food-imports-percent-of-m...
Other answers have provided more than enough detail on this.
Probably she meant (China's food imports from "this region") / (China's total food imports)
Where "this region" means Brazil, not just the disputed province.
Common sense tells you they grow more than 64% of their own food. And any imports would mainly come from other Asian countries or North America, not across the Panama Canal and 6,000 miles of ocean,
Do you want to place a bet on this?
https://www.cepea.esalq.usp.br/en/brazilian-agribusiness-new...