President Trump has picked an assistant U.S. Trade Representative to serve as the agency’s chief agricultural negotiator. Julie Callahan, AUSTR for agricultural affairs and commodity policy, was announced as the nominee for the deputy USTR slot on Thursday. Callahan has been with the agency since 2016, serving first as senior director for agricultural affairs, then deputy AUSTR. She was promoted to AUSTR in 2020. “In this role, she oversees work to promote the interests of U.S. farmers, ranchers and food...