ST. PAUL, Minn. — The president of the Minnesota Farmers Union, Gary Wertish, says farmers are feeling a financial strain nobody has ever seen. “We’ve been through the 1980s farm crisis, but this is potentially setting up to be a lot worse,” he said. The global trade war created by President Trump has wiped out U.S. soybean exports to China. Instead, the Chinese are buying from Argentina and Brazil. U.S. farmers are selling at depressed prices — $10.23 a bushel compared to $12.74 a year ago. Every bushel now sells at a loss, which is unsustainable. To be sure, some U.S. farmers are putting harvests into storage, but that’s risky. Who knows what’s ahead. How big has the China loss been? China had been the largest U.S. soybean customer — 12 billion a year. No more.