Justin Knopf finished harvesting soybeans as November’s first snowflakes started falling on his fields in Gypsum, Kan. Then he did what thousands of farmers throughout the grain belt are doing: He got an application for some of the $12 billion in federal emergency relief intended to blunt the economic fallout from President Trump’s trade policy brinkmanship.

China, the biggest buyer of American soybeans, all but stopped purchases after the White House imposed tariffs this summer and set a retaliatory spiral in motion. The pronouncements and maneuvers in world capitals have reverberated through the kitchens and living rooms of farmers, who were targets in part because they are big exporters and core supporters of Mr. Trump.

“Some say enough already — it’s a big gamble and the timing is horrible for us to be messing with trade,” Mr. Knopf said. “Other farmers are incredibly excited about what the administration is doing on trade and truly believe they’ll come up with a better deal for us long term. I’m probably somewhere in the middle. I’m cautiously hopeful.”