The escalating trade war is imposing new burdens on Minnesota’s vast and economically important agricultural sector. Farmers have already endured almost five years of marginal profits as they produced record volumes in summer after summer of good weather. Now, the trade war appears likely to tip them from small profits to sizable losses. Many are reluctantly preparing to take what they consider a distasteful step: turning to the government for help. Last Tuesday, the U.S. Department of Agriculture started accepting farmer applications for $4.7 billion in emergency aid aimed at helping them through this year. But the market is already signaling danger for 2019. Bankers who provide capital to farmers won’t stand for losses and, instead, will likely force many farmers to sit on the sidelines. As many as 20 percent of farmers in the Upper Midwest won’t be able to get credit to finance spring planting, barring a miracle turnaround in prices, said Al Kluis, a commodity broker in Wayzata. Farmers have lost big foreign markets like China and Mexico, which placed taxes on their products after Trump imposed tariffs on steel imports and pushed to recraft other trade deals. As a short-term response, the Trump administration responded by creating the aid program.