Personal income for farmers fell by the most in three years in the first quarter, as losses to U.S. agriculture mount from President Donald Trump's trade wars.

The Commerce Department on Monday cited the steep decline in farm proprietors' income as a key factor weighing on the nation's overall personal income growth in March, even though agricultural producers represent only about 2 percent of total employed Americans.

The report provided fresh evidence of the growing financial strain on U.S. farmers hit by the trade war, low commodity prices and a series of natural disasters, including spring floods in the Midwest. With rural voters a key part of Trump's electoral coalition, it also underscores the political pressure to conclude the China trade war as U.S. negotiators begin another round of talks in Beijing this week.