The bailout is the second round of financial support for farmers, who received $12 billion in subsidies last year to help cushion the fallout from trade disputes. While Canada and Mexico lifted their retaliatory tariffs this year after Mr. Trump stopped taxing their metals, tariffs on the European Union continue and the bloc still has levies on American products like whiskey, orange juice and peanut butter. China has been among the biggest buyers of American agricultural products, snapping up goods like pork, cranberries, cotton, sorghum and soybeans.

The program, which uses money from a depression-era fund, allows farmers earning less than $900,000 a year to receive payments if they produce one of the agricultural products that has faced retaliation from China.

The first aid package drew criticism that it favored some products over others and attracted backlash after a study that found city residents who own shares in farms and relatives of farmers have been capitalizing on the bailout. Farmers also complained that the money was slow to be paid out and did little to cover their full losses.

This time around, payments will be determined based on a farm’s size and location, with rates of $15 to $150 an acre. The size will depend on the effect of retaliatory tariffs in a particular county. No applicant can receive more than $500,000 worth of aid.

Farmers are a key constituency for Mr. Trump, and he has been taking aggressive measures to blunt the financial pain they have experienced as a result of retaliation from tariffs that he has imposed on China, Europe, Mexico and Canada in the last two years. Total farm income across the country fell 16 percent in 2018, according to the Agriculture Department, as retaliatory tariffs took a significant toll on exports. Pork and soybeans were among the hardest hit products, as China started importing them from other markets.